HANDLES¶

Before you can use libguestfs calls, you have to create a handle. Then you must add at least one disk image to the handle, followed by launching the handle, then performing whatever operations you want, and finally closing the handle. By convention we use the single letter "g" for the name of the handle variable, although of course you can use any name you want.

The general structure of all libguestfs-using programs looks like this:

 guestfs_h *g = guestfs_create ();
 
 /* Call guestfs_add_drive additional times if there are
  * multiple disk images.
  */
 guestfs_add_drive (g, "guest.img");
 
 /* Most manipulation calls won't work until you've launched
  * the handle 'g'.  You have to do this _after_ adding drives
  * and _before_ other commands.
  */
 guestfs_launch (g);
 
 /* Either: examine what partitions, LVs etc are available: */
 char **partitions = guestfs_list_partitions (g);
 char **logvols = guestfs_lvs (g);
 
 /* Or: ask libguestfs to find filesystems for you: */
 char **filesystems = guestfs_list_filesystems (g);
 
 /* Or: use inspection (see INSPECTION section below). */
 
 /* To access a filesystem in the image, you must mount it. */
 guestfs_mount (g, "/dev/sda1", "/");
 
 /* Now you can perform filesystem actions on the guest
  * disk image.
  */
 guestfs_touch (g, "/hello");
 
 /* Synchronize the disk.  This is the opposite of guestfs_launch. */
 guestfs_shutdown (g);
 
 /* Close and free the handle 'g'. */
 guestfs_close (g);

The code above doesn't include any error checking. In real code you should check return values carefully for errors. In general all functions that return integers return "-1" on error, and all functions that return pointers return "NULL" on error. See section "ERROR HANDLING" below for how to handle errors, and consult the documentation for each function call below to see precisely how they return error indications. See guestfs-examples(3) for fully worked examples.

DISK IMAGES¶

The image filename ("guest.img" in the example above) could be a disk image from a virtual machine, a dd(1) copy of a physical hard disk, an actual block device, or simply an empty file of zeroes that you have created through posix_fallocate(3). Libguestfs lets you do useful things to all of these.

The call you should use in modern code for adding drives is "guestfs_add_drive_opts". To add a disk image, allowing writes, and specifying that the format is raw, do:

 guestfs_add_drive_opts (g, filename,
                         GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
                         -1);

You can add a disk read-only using:

 guestfs_add_drive_opts (g, filename,
                         GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
                         GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
                         -1);

or by calling the older function "guestfs_add_drive_ro". If you use the readonly flag, libguestfs won't modify the file. (See also "DISK IMAGE FORMATS" below).

Be extremely cautious if the disk image is in use, eg. if it is being used by a virtual machine. Adding it read-write will almost certainly cause disk corruption, but adding it read-only is safe.

You should usually add at least one disk image, and you may add multiple disk images. If adding multiple disk images, they usually have to be "related", ie. from the same guest. In the API, the disk images are usually referred to as "/dev/sda" (for the first one you added), "/dev/sdb" (for the second one you added), etc.

Once "guestfs_launch" has been called you cannot add any more images. You can call "guestfs_list_devices" to get a list of the device names, in the order that you added them. See also "BLOCK DEVICE NAMING" below.

There are slightly different rules when hotplugging disks (in libguestfs ≥ 1.20). See "HOTPLUGGING" below.

MOUNTING¶

Before you can read or write files, create directories and so on in a disk image that contains filesystems, you have to mount those filesystems using "guestfs_mount" or "guestfs_mount_ro". If you already know that a disk image contains (for example) one partition with a filesystem on that partition, then you can mount it directly:

 guestfs_mount (g, "/dev/sda1", "/");

where "/dev/sda1" means literally the first partition (1) of the first disk image that we added ("/dev/sda"). If the disk contains Linux LVM2 logical volumes you could refer to those instead (eg. "/dev/VG/LV"). Note that these are libguestfs virtual devices, and are nothing to do with host devices.

If you are given a disk image and you don't know what it contains then you have to find out. Libguestfs can do that too: use "guestfs_list_partitions" and "guestfs_lvs" to list possible partitions and LVs, and either try mounting each to see what is mountable, or else examine them with "guestfs_vfs_type" or "guestfs_file". To list just filesystems, use "guestfs_list_filesystems".

Libguestfs also has a set of APIs for inspection of unknown disk images (see "INSPECTION" below). You might also want to look at higher level programs built on top of libguestfs, in particular virt-inspector(1).

To mount a filesystem read-only, use "guestfs_mount_ro". There are several other variations of the "guestfs_mount_*" call.

FILESYSTEM ACCESS AND MODIFICATION¶

The majority of the libguestfs API consists of fairly low-level calls for accessing and modifying the files, directories, symlinks etc on mounted filesystems. There are over a hundred such calls which you can find listed in detail below in this man page, and we don't even pretend to cover them all in this overview.

Specify filenames as full paths, starting with "/" and including the mount point.

For example, if you mounted a filesystem at "/" and you want to read the file called "etc/passwd" then you could do:

 char *data = guestfs_cat (g, "/etc/passwd");

This would return "data" as a newly allocated buffer containing the full content of that file (with some conditions: see also "DOWNLOADING" below), or "NULL" if there was an error.

As another example, to create a top-level directory on that filesystem called "var" you would do:

 guestfs_mkdir (g, "/var");

To create a symlink you could do:

 guestfs_ln_s (g, "/etc/init.d/portmap",
               "/etc/rc3.d/S30portmap");

Libguestfs will reject attempts to use relative paths and there is no concept of a current working directory.

Libguestfs can return errors in many situations: for example if the filesystem isn't writable, or if a file or directory that you requested doesn't exist. If you are using the C API (documented here) you have to check for those error conditions after each call. (Other language bindings turn these errors into exceptions).

File writes are affected by the per-handle umask, set by calling "guestfs_umask" and defaulting to 022. See "UMASK".

Since RHEL 6.4, it is possible to mount the libguestfs filesystem on a local directory, subject to some restrictions. See "MOUNT LOCAL" below.

PARTITIONING¶

Libguestfs contains API calls to read, create and modify partition tables on disk images.

In the common case where you want to create a single partition covering the whole disk, you should use the "guestfs_part_disk" call:

 const char *parttype = "mbr";
 if (disk_is_larger_than_2TB)
   parttype = "gpt";
 guestfs_part_disk (g, "/dev/sda", parttype);

Obviously this effectively wipes anything that was on that disk image before.

LVM2¶

Libguestfs provides access to a large part of the LVM2 API, such as "guestfs_lvcreate" and "guestfs_vgremove". It won't make much sense unless you familiarize yourself with the concepts of physical volumes, volume groups and logical volumes.

This author strongly recommends reading the LVM HOWTO, online at http://tldp.org/HOWTO/LVM-HOWTO/.

DOWNLOADING¶

Use "guestfs_cat" to download small, text only files. This call cannot handle files containing any ASCII NUL ("\0") characters. However the API is very simple to use.

"guestfs_read_file" can be used to read files which contain arbitrary 8 bit data, since it returns a (pointer, size) pair.

"guestfs_download" can be used to download any file, with no limits on content or size.

To download multiple files, see "guestfs_tar_out" and "guestfs_tgz_out".

UPLOADING¶

To write a small file with fixed content, use "guestfs_write". To create a file of all zeroes, use "guestfs_truncate_size" (sparse) or "guestfs_fallocate64" (with all disk blocks allocated). There are a variety of other functions for creating test files, for example "guestfs_fill" and "guestfs_fill_pattern".

To upload a single file, use "guestfs_upload". This call has no limits on file content or size.

To upload multiple files, see "guestfs_tar_in" and "guestfs_tgz_in".

However the fastest way to upload large numbers of arbitrary files is to turn them into a squashfs or CD ISO (see mksquashfs(8) and mkisofs(8)), then attach this using "guestfs_add_drive_ro". If you add the drive in a predictable way (eg. adding it last after all other drives) then you can get the device name from "guestfs_list_devices" and mount it directly using "guestfs_mount_ro". Note that squashfs images are sometimes non-portable between kernel versions, and they don't support labels or UUIDs. If you want to pre-build an image or you need to mount it using a label or UUID, use an ISO image instead.

COPYING¶

There are various different commands for copying between files and devices and in and out of the guest filesystem. These are summarised in the table below.

file to file

Use "guestfs_cp" to copy a single file, or "guestfs_cp_a" to copy directories recursively.

To copy part of a file (offset and size) use "guestfs_copy_file_to_file".

file to device

device to file

device to device

Use "guestfs_copy_file_to_device", "guestfs_copy_device_to_file", or "guestfs_copy_device_to_device".

Example: duplicate the contents of an LV:

 guestfs_copy_device_to_device (g,
         "/dev/VG/Original", "/dev/VG/Copy",
         /* -1 marks the end of the list of optional parameters */
         -1);
    

The destination ("/dev/VG/Copy") must be at least as large as the source ("/dev/VG/Original"). To copy less than the whole source device, use the optional "size" parameter:

 guestfs_copy_device_to_device (g,
         "/dev/VG/Original", "/dev/VG/Copy",
         GUESTFS_COPY_DEVICE_TO_DEVICE_SIZE, 10000,
         -1);
    

file on the host to file or device

Use "guestfs_upload". See "UPLOADING" above.

file or device to file on the host

Use "guestfs_download". See "DOWNLOADING" above.

UPLOADING AND DOWNLOADING TO PIPES AND FILE DESCRIPTORS¶

Calls like "guestfs_upload", "guestfs_download", "guestfs_tar_in", "guestfs_tar_out" etc appear to only take filenames as arguments, so it appears you can only upload and download to files. However many Un*x-like hosts let you use the special device files "/dev/stdin", "/dev/stdout", "/dev/stderr" and "/dev/fd/N" to read and write from stdin, stdout, stderr, and arbitrary file descriptor N.

For example, virt-cat(1) writes its output to stdout by doing:

 guestfs_download (g, filename, "/dev/stdout");

and you can write tar output to a file descriptor "fd" by doing:

 char devfd[64];
 snprintf (devfd, sizeof devfd, "/dev/fd/%d", fd);
 guestfs_tar_out (g, "/", devfd);

LISTING FILES¶

"guestfs_ll" is just designed for humans to read (mainly when using the guestfish(1)-equivalent command "ll").

"guestfs_ls" is a quick way to get a list of files in a directory from programs, as a flat list of strings.

"guestfs_readdir" is a programmatic way to get a list of files in a directory, plus additional information about each one. It is more equivalent to using the readdir(3) call on a local filesystem.

"guestfs_find" and "guestfs_find0" can be used to recursively list files.

RUNNING COMMANDS¶

Although libguestfs is primarily an API for manipulating files inside guest images, we also provide some limited facilities for running commands inside guests.

There are many limitations to this:

• The kernel version that the command runs under will be different from what it expects.
• If the command needs to communicate with daemons, then most likely they won't be running.
• The command will be running in limited memory.
• The network may not be available unless you enable it (see "guestfs_set_network").
• Only supports Linux guests (not Windows, BSD, etc).
• Architecture limitations (eg. won't work for a PPC guest on an X86 host).
• For SELinux guests, you may need to enable SELinux and load policy first. See "SELINUX" in this manpage.
• Security: It is not safe to run commands from untrusted, possibly malicious guests. These commands may attempt to exploit your program by sending unexpected output. They could also try to exploit the Linux kernel or qemu provided by the libguestfs appliance. They could use the network provided by the libguestfs appliance to bypass ordinary network partitions and firewalls. They could use the elevated privileges or different SELinux context of your program to their advantage.

  A secure alternative is to use libguestfs to install a "firstboot" script (a script which runs when the guest next boots normally), and to have this script run the commands you want in the normal context of the running guest, network security and so on. For information about other security issues, see "SECURITY".

The two main API calls to run commands are "guestfs_command" and "guestfs_sh" (there are also variations).

The difference is that "guestfs_sh" runs commands using the shell, so any shell globs, redirections, etc will work.

CONFIGURATION FILES¶

To read and write configuration files in Linux guest filesystems, we strongly recommend using Augeas. For example, Augeas understands how to read and write, say, a Linux shadow password file or X.org configuration file, and so avoids you having to write that code.

The main Augeas calls are bound through the "guestfs_aug_*" APIs. We don't document Augeas itself here because there is excellent documentation on the http://augeas.net/ website.

If you don't want to use Augeas (you fool!) then try calling "guestfs_read_lines" to get the file as a list of lines which you can iterate over.

SELINUX¶

We support SELinux guests. To ensure that labeling happens correctly in SELinux guests, you need to enable SELinux and load the guest's policy:

1.

Before launching, do:

 guestfs_set_selinux (g, 1);
    

2.

After mounting the guest's filesystem(s), load the policy. This is best done by running the load_policy(8) command in the guest itself:

 guestfs_sh (g, "/usr/sbin/load_policy");
    

(Older versions of "load_policy" require you to specify the name of the policy file).

3.

Optionally, set the security context for the API. The correct security context to use can only be known by inspecting the guest. As an example:

 guestfs_setcon (g, "unconfined_u:unconfined_r:unconfined_t:s0");
    

This will work for running commands and editing existing files.

When new files are created, you may need to label them explicitly, for example by running the external command "restorecon pathname".

UMASK¶

Certain calls are affected by the current file mode creation mask (the "umask"). In particular ones which create files or directories, such as "guestfs_touch", "guestfs_mknod" or "guestfs_mkdir". This affects either the default mode that the file is created with or modifies the mode that you supply.

The default umask is 022, so files are created with modes such as 0644 and directories with 0755.

There are two ways to avoid being affected by umask. Either set umask to 0 (call "guestfs_umask (g, 0)" early after launching). Or call "guestfs_chmod" after creating each file or directory.

For more information about umask, see umask(2).

ENCRYPTED DISKS¶

Libguestfs allows you to access Linux guests which have been encrypted using whole disk encryption that conforms to the Linux Unified Key Setup (LUKS) standard. This includes nearly all whole disk encryption systems used by modern Linux guests.

Use "guestfs_vfs_type" to identify LUKS-encrypted block devices (it returns the string "crypto_LUKS").

Then open these devices by calling "guestfs_luks_open". Obviously you will require the passphrase!

Opening a LUKS device creates a new device mapper device called "/dev/mapper/mapname" (where "mapname" is the string you supply to "guestfs_luks_open"). Reads and writes to this mapper device are decrypted from and encrypted to the underlying block device respectively.

LVM volume groups on the device can be made visible by calling "guestfs_vgscan" followed by "guestfs_vg_activate_all". The logical volume(s) can now be mounted in the usual way.

Use the reverse process to close a LUKS device. Unmount any logical volumes on it, deactivate the volume groups by caling "guestfs_vg_activate (g, 0, ["/dev/VG"])". Then close the mapper device by calling "guestfs_luks_close" on the "/dev/mapper/mapname" device (not the underlying encrypted block device).

MOUNT LOCAL¶

In RHEL ≥ 6.4, it is possible to mount the libguestfs filesystem on a local directory and access it using ordinary POSIX calls and programs.

Availability of this is subject to a number of restrictions: it requires FUSE (the Filesystem in USErspace), and libfuse must also have been available when libguestfs was compiled. FUSE may require that a kernel module is loaded, and it may be necessary to add the current user to a special "fuse" group. See the documentation for your distribution and http://fuse.sf.net for further information.

The call to mount the libguestfs filesystem on a local directory is "guestfs_mount_local" (q.v.) followed by "guestfs_mount_local_run". The latter does not return until you unmount the filesystem. The reason is that the call enters the FUSE main loop and processes kernel requests, turning them into libguestfs calls. An alternative design would have been to create a background thread to do this, but libguestfs doesn't require pthreads. This way is also more flexible: for example the user can create another thread for "guestfs_mount_local_run".

"guestfs_mount_local" needs a certain amount of time to set up the mountpoint. The mountpoint is not ready to use until the call returns. At this point, accesses to the filesystem will block until the main loop is entered (ie. "guestfs_mount_local_run"). So if you need to start another process to access the filesystem, put the fork between "guestfs_mount_local" and "guestfs_mount_local_run".

MOUNT LOCAL COMPATIBILITY

Since local mounting was only added in RHEL 6.4, you should consider writing code so that it doesn't depend on this feature, and can fall back to using libguestfs file system calls.

If libguestfs was compiled without support for "guestfs_mount_local" then calling it will return an error with errno set to "ENOTSUP" (see "guestfs_last_errno").

MOUNT LOCAL PERFORMANCE

Libguestfs on top of FUSE performs quite poorly. For best performance do not use it. Use ordinary libguestfs filesystem calls, upload, download etc. instead.

HOTPLUGGING¶

In libguestfs ≥ 1.20, you may add drives and remove after calling "guestfs_launch". There are some restrictions, see below. This is called hotplugging.

Only a subset of the attach-method backends support hotplugging (currently only the libvirt attach-method has support). It also requires that you use libvirt ≥ 0.10.3 and qemu ≥ 1.2.

To hot-add a disk, simply call "guestfs_add_drive_opts" after "guestfs_launch". It is mandatory to specify the "label" parameter so that the newly added disk has a predictable name. For example:

 if (guestfs_launch (g) == -1)
   error ("launch failed");
 
 if (guestfs_add_drive_opts (g, filename,
                             GUESTFS_ADD_DRIVE_OPTS_LABEL, "newdisk",
                             -1) == -1)
   error ("hot-add of disk failed");
 
 if (guestfs_part_disk ("/dev/disk/guestfs/newdisk", "mbr") == -1)
   error ("partitioning of hot-added disk failed");

To hot-remove a disk, call "guestfs_remove_drive". You can call this before or after "guestfs_launch". You can only remove disks that were previously added with a label.

Backends that support hotplugging do not require that you add ≥ 1 disk before calling launch. When hotplugging is supported you don't need to add any disks.

INSPECTION¶

Libguestfs has APIs for inspecting an unknown disk image to find out if it contains operating systems, an install CD or a live CD. (These APIs used to be in a separate Perl-only library called Sys::Guestfs::Lib(3) but since version 1.5.3 the most frequently used part of this library has been rewritten in C and moved into the core code).

Add all disks belonging to the unknown virtual machine and call "guestfs_launch" in the usual way.

Then call "guestfs_inspect_os". This function uses other libguestfs calls and certain heuristics, and returns a list of operating systems that were found. An empty list means none were found. A single element is the root filesystem of the operating system. For dual- or multi-boot guests, multiple roots can be returned, each one corresponding to a separate operating system. (Multi-boot virtual machines are extremely rare in the world of virtualization, but since this scenario can happen, we have built libguestfs to deal with it.)

For each root, you can then call various "guestfs_inspect_get_*" functions to get additional details about that operating system. For example, call "guestfs_inspect_get_type" to return the string "windows" or "linux" for Windows and Linux-based operating systems respectively.

Un*x-like and Linux-based operating systems usually consist of several filesystems which are mounted at boot time (for example, a separate boot partition mounted on "/boot"). The inspection rules are able to detect how filesystems correspond to mount points. Call "guestfs_inspect_get_mountpoints" to get this mapping. It might return a hash table like this example:

 /boot => /dev/sda1
 /     => /dev/vg_guest/lv_root
 /usr  => /dev/vg_guest/lv_usr

The caller can then make calls to "guestfs_mount" to mount the filesystems as suggested.

Be careful to mount filesystems in the right order (eg. "/" before "/usr"). Sorting the keys of the hash by length, shortest first, should work.

Inspection currently only works for some common operating systems. Contributors are welcome to send patches for other operating systems that we currently cannot detect.

Encrypted disks must be opened before inspection. See "ENCRYPTED DISKS" for more details. The "guestfs_inspect_os" function just ignores any encrypted devices.

A note on the implementation: The call "guestfs_inspect_os" performs inspection and caches the results in the guest handle. Subsequent calls to "guestfs_inspect_get_*" return this cached information, but do not re-read the disks. If you change the content of the guest disks, you can redo inspection by calling "guestfs_inspect_os" again. ("guestfs_inspect_list_applications2" works a little differently from the other calls and does read the disks. See documentation for that function for details).

INSPECTING INSTALL DISKS

Libguestfs (since 1.9.4) can detect some install disks, install CDs, live CDs and more.

Call "guestfs_inspect_get_format" to return the format of the operating system, which currently can be "installed" (a regular operating system) or "installer" (some sort of install disk).

Further information is available about the operating system that can be installed using the regular inspection APIs like "guestfs_inspect_get_product_name", "guestfs_inspect_get_major_version" etc.

Some additional information specific to installer disks is also available from the "guestfs_inspect_is_live", "guestfs_inspect_is_netinst" and "guestfs_inspect_is_multipart" calls.

SPECIAL CONSIDERATIONS FOR WINDOWS GUESTS¶

Libguestfs can mount NTFS partitions. It does this using the http://www.ntfs-3g.org/ driver.

DRIVE LETTERS AND PATHS

DOS and Windows still use drive letters, and the filesystems are always treated as case insensitive by Windows itself, and therefore you might find a Windows configuration file referring to a path like "c:\windows\system32". When the filesystem is mounted in libguestfs, that directory might be referred to as "/WINDOWS/System32".

Drive letter mappings can be found using inspection (see "INSPECTION" and "guestfs_inspect_get_drive_mappings")

Dealing with separator characters (backslash vs forward slash) is outside the scope of libguestfs, but usually a simple character replacement will work.

To resolve the case insensitivity of paths, call "guestfs_case_sensitive_path".

LONG FILENAMES ON NTFS

NTFS supports filenames up to 255 characters long. "Character" means a 2 byte UTF-16 codepoint which can encode the most common Unicode codepoints.

Most Linux filesystems support filenames up to 255 bytes. This means you may get an error:

 File name too long

when you copy a file from NTFS to a Linux filesystem if the name, when reencoded as UTF-8, would exceed 255 bytes in length.

This will most often happen when using non-ASCII names that are longer than ~127 characters (eg. Greek, Cyrillic) or longer than ~85 characters (Asian languages).

A workaround is not to try to store such long filenames on Linux native filesystems. Since the tar(1) format can store unlimited length filenames, keep the files in a tarball.

ACCESSING THE WINDOWS REGISTRY

Libguestfs also provides some help for decoding Windows Registry "hive" files, through a separate C library called hivex(3).

Before libguestfs 1.19.35 you had to download the hive file, operate on it locally using hivex, and upload it again. Since this version, we have included the major hivex APIs directly in the libguestfs API (see "guestfs_hivex_open"). This means that if you have opened a Windows guest, you can read and write the registry directly.

See also virt-win-reg(1).

SYMLINKS ON NTFS-3G FILESYSTEMS

Ntfs-3g tries to rewrite "Junction Points" and NTFS "symbolic links" to provide something which looks like a Linux symlink. The way it tries to do the rewriting is described here:

http://www.tuxera.com/community/ntfs-3g-advanced/junction-points-and-symbolic-links/

The essential problem is that ntfs-3g simply does not have enough information to do a correct job. NTFS links can contain drive letters and references to external device GUIDs that ntfs-3g has no way of resolving. It is almost certainly the case that libguestfs callers should ignore what ntfs-3g does (ie. don't use "guestfs_readlink" on NTFS volumes).

Instead if you encounter a symbolic link on an ntfs-3g filesystem, use "guestfs_lgetxattr" to read the "system.ntfs_reparse_data" extended attribute, and read the raw reparse data from that (you can find the format documented in various places around the web).

EXTENDED ATTRIBUTES ON NTFS-3G FILESYSTEMS

There are other useful extended attributes that can be read from ntfs-3g filesystems (using "guestfs_getxattr"). See:

http://www.tuxera.com/community/ntfs-3g-advanced/extended-attributes/

WINDOWS HIBERNATION AND WINDOWS 8 FAST STARTUP

Windows guests which have been hibernated (instead of fully shut down) cannot be mounted. This is a limitation of ntfs-3g. You will see an error like this:

 The disk contains an unclean file system (0, 0).
 Metadata kept in Windows cache, refused to mount.
 Failed to mount '/dev/sda2': Operation not permitted
 The NTFS partition is in an unsafe state. Please resume
 and shutdown Windows fully (no hibernation or fast
 restarting), or mount the volume read-only with the
 'ro' mount option.

In Windows 8, the shutdown button does not shut down the guest at all. Instead it usually hibernates the guest. This is known as "fast startup".

Some suggested workarounds are:

• Mount read-only (eg. "guestfs_mount_ro").
• On Windows 8, turn off fast startup. It is in the Control Panel → Power Options → Choose what the power buttons do → Change settings that are currently unavailable → Turn on fast startup.
• On Windows 7 and earlier, shut the guest off properly instead of hibernating it.

RESIZE2FS ERRORS¶

The "guestfs_resize2fs", "guestfs_resize2fs_size" and "guestfs_resize2fs_M" calls are used to resize ext2/3/4 filesystems.

The underlying program (resize2fs(8)) requires that the filesystem is clean and recently fsck'd before you can resize it. Also, if the resize operation fails for some reason, then you had to call fsck the filesystem again to fix it.

In libguestfs "lt" 1.17.14, you usually had to call "guestfs_e2fsck_f" before the resize. However, in "ge" 1.17.14, e2fsck(8) is called automatically before the resize, so you no longer need to do this.

The resize2fs(8) program can still fail, in which case it prints an error message similar to:

 Please run 'e2fsck -fy <device>' to fix the filesystem
 after the aborted resize operation.

You can do this by calling "guestfs_e2fsck" with the "forceall" option. However in the context of disk images, it is usually better to avoid this situation, eg. by rolling back to an earlier snapshot, or by copying and resizing and on failure going back to the original.

USING LIBGUESTFS WITH OTHER PROGRAMMING LANGUAGES¶

Although we don't want to discourage you from using the C API, we will mention here that the same API is also available in other languages.

The API is broadly identical in all supported languages. This means that the C call "guestfs_add_drive_ro(g,file)" is "$g->add_drive_ro($file)" in Perl, "g.add_drive_ro(file)" in Python, and "g#add_drive_ro file" in OCaml. In other words, a straightforward, predictable isomorphism between each language.

Error messages are automatically transformed into exceptions if the language supports it.

We don't try to "object orientify" parts of the API in OO languages, although contributors are welcome to write higher level APIs above what we provide in their favourite languages if they wish.

C++

You can use the guestfs.h header file from C++ programs. The C++ API is identical to the C API. C++ classes and exceptions are not used.

C#

The C# bindings are highly experimental. Please read the warnings at the top of "csharp/Libguestfs.cs".

Erlang

See guestfs-erlang(3).

GObject

Experimental GObject bindings (with GObject Introspection support) are available. See the "gobject" directory in the source.

Haskell

This is the only language binding that is working but incomplete. Only calls which return simple integers have been bound in Haskell, and we are looking for help to complete this binding.

Java

Full documentation is contained in the Javadoc which is distributed with libguestfs. For examples, see guestfs-java(3).

Lua

See guestfs-lua(3).

OCaml

See guestfs-ocaml(3).

Perl

See guestfs-perl(3) and Sys::Guestfs(3).

PHP

For documentation see "README-PHP" supplied with libguestfs sources or in the php-libguestfs package for your distribution.

The PHP binding only works correctly on 64 bit machines.

Python

See guestfs-python(3).

Ruby

See guestfs-ruby(3).

For JRuby, use the Java bindings.

shell scripts

See guestfish(1).

LIBGUESTFS GOTCHAS¶

http://en.wikipedia.org/wiki/Gotcha_(programming): "A feature of a system [...] that works in the way it is documented but is counterintuitive and almost invites mistakes."

Since we developed libguestfs and the associated tools, there are several things we would have designed differently, but are now stuck with for backwards compatibility or other reasons. If there is ever a libguestfs 2.0 release, you can expect these to change. Beware of them.

Read-only should be the default.

In guestfish(3), --ro should be the default, and you should have to specify --rw if you want to make changes to the image.

This would reduce the potential to corrupt live VM images.

Note that many filesystems change the disk when you just mount and unmount, even if you didn't perform any writes. You need to use "guestfs_add_drive_ro" to guarantee that the disk is not changed.

guestfish command line is hard to use.

"guestfish disk.img" doesn't do what people expect (open "disk.img" for examination). It tries to run a guestfish command "disk.img" which doesn't exist, so it fails. In earlier versions of guestfish the error message was also unintuitive, but we have corrected this since. Like the Bourne shell, we should have used "guestfish -c command" to run commands.

guestfish megabyte modifiers don't work right on all commands

In recent guestfish you can use "1M" to mean 1 megabyte (and similarly for other modifiers). What guestfish actually does is to multiply the number part by the modifier part and pass the result to the C API. However this doesn't work for a few APIs which aren't expecting bytes, but are already expecting some other unit (eg. megabytes).

The most common is "guestfs_lvcreate". The guestfish command:

 lvcreate LV VG 100M
    

does not do what you might expect. Instead because "guestfs_lvcreate" is already expecting megabytes, this tries to create a 100 terabyte (100 megabytes * megabytes) logical volume. The error message you get from this is also a little obscure.

This could be fixed in the generator by specially marking parameters and return values which take bytes or other units.

Ambiguity between devices and paths

There is a subtle ambiguity in the API between a device name (eg. "/dev/sdb2") and a similar pathname. A file might just happen to be called "sdb2" in the directory "/dev" (consider some non-Unix VM image).

In the current API we usually resolve this ambiguity by having two separate calls, for example "guestfs_checksum" and "guestfs_checksum_device". Some API calls are ambiguous and (incorrectly) resolve the problem by detecting if the path supplied begins with "/dev/".

To avoid both the ambiguity and the need to duplicate some calls, we could make paths/devices into structured names. One way to do this would be to use a notation like grub ("hd(0,0)"), although nobody really likes this aspect of grub. Another way would be to use a structured type, equivalent to this OCaml type:

 type path = Path of string | Device of int | Partition of int * int
    

which would allow you to pass arguments like:

 Path "/foo/bar"
 Device 1            (* /dev/sdb, or perhaps /dev/sda *)
 Partition (1, 2)    (* /dev/sdb2 (or is it /dev/sda2 or /dev/sdb3?) *)
 Path "/dev/sdb2"    (* not a device *)
    

As you can see there are still problems to resolve even with this representation. Also consider how it might work in guestfish.

KEYS AND PASSPHRASES¶

Certain libguestfs calls take a parameter that contains sensitive key material, passed in as a C string.

In the future we would hope to change the libguestfs implementation so that keys are mlock(2)-ed into physical RAM, and thus can never end up in swap. However this is not done at the moment, because of the complexity of such an implementation.

Therefore you should be aware that any key parameter you pass to libguestfs might end up being written out to the swap partition. If this is a concern, scrub the swap partition or don't use libguestfs on encrypted devices.

MULTIPLE HANDLES AND MULTIPLE THREADS¶

All high-level libguestfs actions are synchronous. If you want to use libguestfs asynchronously then you must create a thread.

Only use the handle from a single thread. Either use the handle exclusively from one thread, or provide your own mutex so that two threads cannot issue calls on the same handle at the same time. Even apparently innocent functions like "guestfs_get_trace" are not safe to be called from multiple threads without a mutex.

See the graphical program guestfs-browser for one possible architecture for multithreaded programs using libvirt and libguestfs.

PATH¶

Libguestfs needs a supermin appliance, which it finds by looking along an internal path.

By default it looks for these in the directory "$libdir/guestfs" (eg. "/usr/local/lib/guestfs" or "/usr/lib64/guestfs").

Use "guestfs_set_path" or set the environment variable "LIBGUESTFS_PATH" to change the directories that libguestfs will search in. The value is a colon-separated list of paths. The current directory is not searched unless the path contains an empty element or ".". For example "LIBGUESTFS_PATH=:/usr/lib/guestfs" would search the current directory and then "/usr/lib/guestfs".

QEMU WRAPPERS¶

If you want to compile your own qemu, run qemu from a non-standard location, or pass extra arguments to qemu, then you can write a shell-script wrapper around qemu.

There is one important rule to remember: you must "exec qemu" as the last command in the shell script (so that qemu replaces the shell and becomes the direct child of the libguestfs-using program). If you don't do this, then the qemu process won't be cleaned up correctly.

Here is an example of a wrapper, where I have built my own copy of qemu from source:

 #!/bin/sh -
 qemudir=/home/rjones/d/qemu
 exec $qemudir/x86_64-softmmu/qemu-system-x86_64 -L $qemudir/pc-bios "$@"

Save this script as "/tmp/qemu.wrapper" (or wherever), "chmod +x", and then use it by setting the LIBGUESTFS_QEMU environment variable. For example:

 LIBGUESTFS_QEMU=/tmp/qemu.wrapper guestfish

Note that libguestfs also calls qemu with the -help and -version options in order to determine features.

Wrappers can also be used to edit the options passed to qemu. In the following example, the "-machine ..." option ("-machine" and the following argument) are removed from the command line and replaced with "-machine pc,accel=tcg". The while loop iterates over the options until it finds the right one to remove, putting the remaining options into the "args" array.

 #!/bin/bash -
 
 i=0
 while [ $# -gt 0 ]; do
     case "$1" in
     -machine)
         shift 2;;
     *)
         args[i]="$1"
         (( i++ ))
         shift ;;
     esac
 done
 
 exec qemu-kvm -machine pc,accel=tcg "${args[@]}"

ATTACH METHOD¶

The attach method controls how libguestfs creates and/or connects to the back-end daemon, eg. by starting qemu directly, or by using libvirt to manage an appliance, or connecting to an already running daemon.

You can set the attach method by calling "guestfs_set_attach_method", or by setting the environment variable "LIBGUESTFS_ATTACH_METHOD".

Possible attach methods are described below:

"appliance"

Run qemu directly to launch an appliance.

This is the ordinary method and normally the default, but see the note below.

"libvirt"

"libvirt:URI"

Use libvirt to launch and manage the appliance.

The optional URI is the libvirt connection URI to use (see http://libvirt.org/uri.html). The typical libvirt attach method with a URI would be "libvirt:qemu:///session"

The libvirt attach method supports more features, including hotplugging (see "HOTPLUGGING") and sVirt.

"unix:path"

Connect to the Unix domain socket path.

This method lets you connect to an existing daemon or (using virtio-serial) to a live guest. For more information, see "ATTACHING TO RUNNING DAEMONS".

"appliance" is usually the default attach method. However since libguestfs ≥ 1.19.24, libguestfs can be built with a different default by doing:

 ./configure --with-default-attach-method=...

To find out if libguestfs was compiled with a different default attach method, do:

 unset LIBGUESTFS_ATTACH_METHOD
 guestfish get-attach-method

ATTACHING TO RUNNING DAEMONS¶

Note (1): This is highly experimental and has a tendency to eat babies. Use with caution.

Note (2): This section explains how to attach to a running daemon from a low level perspective. For most users, simply using virt tools such as guestfish(1) with the --live option will "just work".

Using guestfs_set_attach_method

By calling "guestfs_set_attach_method" you can change how the library connects to the "guestfsd" daemon in "guestfs_launch" (read "ARCHITECTURE" for some background).

The normal attach method is "appliance", where a small appliance is created containing the daemon, and then the library connects to this. "libvirt" or "libvirt:URI" are alternatives that use libvirt to start the appliance.

Setting attach method to "unix:path" (where path is the path of a Unix domain socket) causes "guestfs_launch" to connect to an existing daemon over the Unix domain socket.

The normal use for this is to connect to a running virtual machine that contains a "guestfsd" daemon, and send commands so you can read and write files inside the live virtual machine.

Using guestfs_add_domain with live flag

"guestfs_add_domain" provides some help for getting the correct attach method. If you pass the "live" option to this function, then (if the virtual machine is running) it will examine the libvirt XML looking for a virtio-serial channel to connect to:

 <domain>
   ...
   <devices>
     ...
     <channel type='unix'>
       <source mode='bind' path='/path/to/socket'/>
       <target type='virtio' name='org.libguestfs.channel.0'/>
     </channel>
     ...
   </devices>
 </domain>

"guestfs_add_domain" extracts "/path/to/socket" and sets the attach method to "unix:/path/to/socket".

Some of the libguestfs tools (including guestfish) support a --live option which is passed through to "guestfs_add_domain" thus allowing you to attach to and modify live virtual machines.

The virtual machine needs to have been set up beforehand so that it has the virtio-serial channel and so that guestfsd is running inside it.

ABI GUARANTEE¶

We guarantee the libguestfs ABI (binary interface), for public, high-level actions as outlined in this section. Although we will deprecate some actions, for example if they get replaced by newer calls, we will keep the old actions forever. This allows you the developer to program in confidence against the libguestfs API.

BLOCK DEVICE NAMING¶

In the kernel there is now quite a profusion of schemata for naming block devices (in this context, by block device I mean a physical or virtual hard drive). The original Linux IDE driver used names starting with "/dev/hd*". SCSI devices have historically used a different naming scheme, "/dev/sd*". When the Linux kernel libata driver became a popular replacement for the old IDE driver (particularly for SATA devices) those devices also used the "/dev/sd*" scheme. Additionally we now have virtual machines with paravirtualized drivers. This has created several different naming systems, such as "/dev/vd*" for virtio disks and "/dev/xvd*" for Xen PV disks.

As discussed above, libguestfs uses a qemu appliance running an embedded Linux kernel to access block devices. We can run a variety of appliances based on a variety of Linux kernels.

This causes a problem for libguestfs because many API calls use device or partition names. Working scripts and the recipe (example) scripts that we make available over the internet could fail if the naming scheme changes.

Therefore libguestfs defines "/dev/sd*" as the standard naming scheme. Internally "/dev/sd*" names are translated, if necessary, to other names as required. For example, under RHEL 5 which uses the "/dev/hd*" scheme, any device parameter "/dev/sda2" is translated to "/dev/hda2" transparently.

Note that this only applies to parameters. The "guestfs_list_devices", "guestfs_list_partitions" and similar calls return the true names of the devices and partitions as known to the appliance, but see "guestfs_canonical_device_name".

DISK LABELS

In libguestfs ≥ 1.20, you can give a label to a disk when you add it, using the optional "label" parameter to "guestfs_add_drive_opts". (Note that disk labels are different from and not related to filesystem labels).

Not all versions of libguestfs support setting a disk label, and when it is supported, it is limited to 20 ASCII characters "[a-zA-Z]".

When you add a disk with a label, it can either be addressed using "/dev/sd*", or using "/dev/disk/guestfs/label". Partitions on the disk can be addressed using "/dev/disk/guestfs/labelpartnum".

Listing devices ("guestfs_list_devices") and partitions ("guestfs_list_partitions") returns the raw block device name. However you can use "guestfs_list_disk_labels" to map disk labels to raw block device and partition names.

ALGORITHM FOR BLOCK DEVICE NAME TRANSLATION

Usually this translation is transparent. However in some (very rare) cases you may need to know the exact algorithm. Such cases include where you use "guestfs_config" to add a mixture of virtio and IDE devices to the qemu-based appliance, so have a mixture of "/dev/sd*" and "/dev/vd*" devices.

The algorithm is applied only to parameters which are known to be either device or partition names. Return values from functions such as "guestfs_list_devices" are never changed.

• Is the string a parameter which is a device or partition name?
• Does the string begin with "/dev/sd"?
• Does the named device exist? If so, we use that device. However if not then we continue with this algorithm.
• Replace initial "/dev/sd" string with "/dev/hd".

  For example, change "/dev/sda2" to "/dev/hda2".

  If that named device exists, use it. If not, continue.

• Replace initial "/dev/sd" string with "/dev/vd".

  If that named device exists, use it. If not, return an error.

PORTABILITY CONCERNS WITH BLOCK DEVICE NAMING

Although the standard naming scheme and automatic translation is useful for simple programs and guestfish scripts, for larger programs it is best not to rely on this mechanism.

Where possible for maximum future portability programs using libguestfs should use these future-proof techniques:

• Use "guestfs_list_devices" or "guestfs_list_partitions" to list actual device names, and then use those names directly.

  Since those device names exist by definition, they will never be translated.

• Use higher level ways to identify filesystems, such as LVM names, UUIDs and filesystem labels.

NULL DISKS¶

When adding a disk using, eg., "guestfs_add_drive", you can set the filename to "/dev/null". This string is treated specially by libguestfs, causing it to add a "null disk".

A null disk has the following properties:

• A null disk will appear as a normal device, eg. in calls to "guestfs_list_devices".
• You may add "/dev/null" multiple times.
• You should not try to access a null disk in any way. For example, you shouldn't try to read it or mount it.

Null disks are used for three main purposes:

1.

Performance testing of libguestfs (see guestfs-performance(1)).

2.

The internal test suite.

3.

If you want to use libguestfs APIs that don't refer to disks, since libguestfs requires that at least one disk is added, you should add a null disk.

For example, to test if a feature is available, use code like this:

 guestfs_h *g;
 char **groups = [ "btrfs", NULL ];
 
 g = guestfs_create ();
 guestfs_add_drive (g, "/dev/null");
 guestfs_launch (g);
 if (guestfs_available (g, groups) == 0) {
   // group(s) are available
 } else {
   // group(s) are not available
 }
 guestfs_close (g);
    

DISK IMAGE FORMATS¶

Virtual disks come in a variety of formats. Some common formats are listed below.

Note that libguestfs itself is not responsible for handling the disk format: this is done using qemu(1). If support for a particular format is missing or broken, this has to be fixed in qemu.

COMMON VIRTUAL DISK IMAGE FORMATS

raw

Raw format is simply a dump of the sequential bytes of the virtual hard disk. There is no header, container, compression or processing of any sort.

Since raw format requires no translation to read or write, it is both fast and very well supported by qemu and all other hypervisors. You can consider it to be a universal format that any hypervisor can access.

Raw format files are not compressed and so take up the full space of the original disk image even when they are empty. A variation (on Linux/Unix at least) is to not store ranges of all-zero bytes by storing the file as a sparse file. This "variant format" is sometimes called raw sparse. Many utilities, including virt-sparsify(1), can make raw disk images sparse.

qcow2

Qcow2 is the native disk image format used by qemu. Internally it uses a two-level directory structure so that only blocks containing data are stored in the file. It also has many other features such as compression, snapshots and backing files.

There are at least two distinct variants of this format, although qemu (and hence libguestfs) handles both transparently to the user.

vmdk

VMDK is VMware's native disk image format. There are many variations. Modern qemu (hence libguestfs) supports most variations, but you should be aware that older versions of qemu had some very bad data-corrupting bugs in this area.

Note that VMware ESX exposes files with the name "guest-flat.vmdk". These are not VMDK. They are raw format files which happen to have a ".vmdk" extension.

vdi

VDI is VirtualBox's native disk image format. Qemu (hence libguestfs) has generally good support for this.

vpc

vhd

VPC (old) and VHD (modern) are the native disk image format of Microsoft (and previously, Connectix) Virtual PC and Hyper-V.

Obsolete formats

The following formats are obsolete and should not be used: qcow (aka qcow1), cow, bochs.

DETECTING THE FORMAT OF A DISK IMAGE

Firstly note there is a security issue with auto-detecting the format of a disk image. It may or may not apply in your use case. Read "CVE-2010-3851" below.

Libguestfs offers an API to get the format of a disk image ("guestfs_disk_format", and it is safest to use this.

Don't be tempted to try parsing the text / human-readable output of "qemu-img" since it cannot be parsed reliably and securely. Also do not use the "file" command since the output of that changes over time.

SECURITY OF MOUNTING FILESYSTEMS¶

You should never mount an untrusted guest filesystem directly on your host kernel (eg. using loopback or kpartx).

When you mount a filesystem, mistakes in the kernel filesystem (VFS) can be escalated into exploits by attackers creating a malicious filesystem. These exploits are very severe for two reasons. Firstly there are very many filesystem drivers in the kernel, and many of them are infrequently used and not much developer attention has been paid to the code. Linux userspace helps potential crackers by detecting the filesystem type and automatically choosing the right VFS driver, even if that filesystem type is unexpected. Secondly, a kernel-level exploit is like a local root exploit (worse in some ways), giving immediate and total access to the system right down to the hardware level.

These exploits can be present in the kernel for a very long time (https://lwn.net/Articles/538898/).

Libguestfs provides a layered approach to protecting you from exploits:

   untrusted filesystem
 --------------------------------------
   appliance kernel
 --------------------------------------
   qemu process running as non-root
 --------------------------------------
   sVirt [if using libvirt + SELinux]
 --------------------------------------
   host kernel

We run a Linux kernel inside a qemu virtual machine, usually running as a non-root user. The attacker would need to write a filesystem which first exploited the kernel, and then exploited either qemu virtualization (eg. a faulty qemu driver) or the libguestfs protocol, and finally to be as serious as the host kernel exploit it would need to escalate its privileges to root. Additionally if you use the libvirt back end and SELinux, sVirt is used to confine the qemu process. This multi-step escalation, performed by a static piece of data, is thought to be extremely hard to do, although we never say 'never' about security issues.

Callers can also reduce the attack surface by forcing the filesystem type when mounting (use "guestfs_mount_vfs").

GENERAL SECURITY CONSIDERATIONS¶

Be careful with any files or data that you download from a guest (by "download" we mean not just the "guestfs_download" command but any command that reads files, filenames, directories or anything else from a disk image). An attacker could manipulate the data to fool your program into doing the wrong thing. Consider cases such as:

• the data (file etc) not being present
• being present but empty
• being much larger than normal
• containing arbitrary 8 bit data
• being in an unexpected character encoding
• containing homoglyphs.

PROTOCOL SECURITY¶

The protocol is designed to be secure, being based on RFC 4506 (XDR) with a defined upper message size. However a program that uses libguestfs must also take care - for example you can write a program that downloads a binary from a disk image and executes it locally, and no amount of protocol security will save you from the consequences.

INSPECTION SECURITY¶

Parts of the inspection API (see "INSPECTION") return untrusted strings directly from the guest, and these could contain any 8 bit data. Callers should be careful to escape these before printing them to a structured file (for example, use HTML escaping if creating a web page).

Guest configuration may be altered in unusual ways by the administrator of the virtual machine, and may not reflect reality (particularly for untrusted or actively malicious guests). For example we parse the hostname from configuration files like "/etc/sysconfig/network" that we find in the guest, but the guest administrator can easily manipulate these files to provide the wrong hostname.

The inspection API parses guest configuration using two external libraries: Augeas (Linux configuration) and hivex (Windows Registry). Both are designed to be robust in the face of malicious data, although denial of service attacks are still possible, for example with oversized configuration files.

RUNNING UNTRUSTED GUEST COMMANDS¶

Be very cautious about running commands from the guest. By running a command in the guest, you are giving CPU time to a binary that you do not control, under the same user account as the library, albeit wrapped in qemu virtualization. More information and alternatives can be found in the section "RUNNING COMMANDS".

CVE-2010-3851¶

https://bugzilla.redhat.com/642934

This security bug concerns the automatic disk format detection that qemu does on disk images.

A raw disk image is just the raw bytes, there is no header. Other disk images like qcow2 contain a special header. Qemu deals with this by looking for one of the known headers, and if none is found then assuming the disk image must be raw.

This allows a guest which has been given a raw disk image to write some other header. At next boot (or when the disk image is accessed by libguestfs) qemu would do autodetection and think the disk image format was, say, qcow2 based on the header written by the guest.

This in itself would not be a problem, but qcow2 offers many features, one of which is to allow a disk image to refer to another image (called the "backing disk"). It does this by placing the path to the backing disk into the qcow2 header. This path is not validated and could point to any host file (eg. "/etc/passwd"). The backing disk is then exposed through "holes" in the qcow2 disk image, which of course is completely under the control of the attacker.

In libguestfs this is rather hard to exploit except under two circumstances:

1.

You have enabled the network or have opened the disk in write mode.

2.

You are also running untrusted code from the guest (see "RUNNING COMMANDS").

The way to avoid this is to specify the expected disk format when adding disks (the optional "format" option to "guestfs_add_drive_opts"). You should always do this if the disk is raw format, and it's a good idea for other cases too. (See also "DISK IMAGE FORMATS").

For disks added from libvirt using calls like "guestfs_add_domain", the format is fetched from libvirt and passed through.

For libguestfs tools, use the --format command line parameter as appropriate.

CVE-2011-4127¶

https://bugzilla.redhat.com/752375

This is a bug in the kernel which allowed guests to overwrite parts of the host's drives which they should not normally have access to.

It is sufficient to update libguestfs to any version ≥ 1.16 which contains a change that mitigates the problem.

CVE-2012-2690¶

https://bugzilla.redhat.com/831117

Old versions of both virt-edit and the guestfish "edit" command created a new file containing the changes but did not set the permissions, etc of the new file to match the old one. The result of this was that if you edited a security sensitive file such as "/etc/shadow" then it would be left world-readable after the edit.

It is sufficient to update libguestfs to any version ≥ 1.16.

CVE-2013-2124¶

https://bugzilla.redhat.com/968306

This security bug was a flaw in inspection where an untrusted guest using a specially crafted file in the guest OS could cause a double-free in the C library (denial of service).

It is sufficient to update libguestfs to a version that is not vulnerable: libguestfs ≥ 1.20.8, ≥ 1.22.2 or ≥ 1.23.2.

CVE-2013-4419¶

https://bugzilla.redhat.com/1016960

When using the guestfish(1) --remote or guestfish --listen options, guestfish would create a socket in a known location ("/tmp/.guestfish-$UID/socket-$PID").

The location has to be a known one in order for both ends to communicate. However no checking was done that the containing directory ("/tmp/.guestfish-$UID") is owned by the user. Thus another user could create this directory and potentially hijack sockets owned by another user's guestfish client or server.

It is sufficient to update libguestfs to a version that is not vulnerable: libguestfs ≥ 1.20.12, ≥ 1.22.7 or ≥ 1.24.

guestfs_h *¶

"guestfs_h" is the opaque type representing a connection handle. Create a handle by calling "guestfs_create" or "guestfs_create_flags". Call "guestfs_close" to free the handle and release all resources used.

For information on using multiple handles and threads, see the section "MULTIPLE HANDLES AND MULTIPLE THREADS" above.

guestfs_create¶

 guestfs_h *guestfs_create (void);

Create a connection handle.

On success this returns a non-NULL pointer to a handle. On error it returns NULL.

You have to "configure" the handle after creating it. This includes calling "guestfs_add_drive_opts" (or one of the equivalent calls) on the handle at least once.

After configuring the handle, you have to call "guestfs_launch".

You may also want to configure error handling for the handle. See the "ERROR HANDLING" section below.

guestfs_create_flags¶

 guestfs_h *guestfs_create_flags (unsigned flags [, ...]);

Create a connection handle, supplying extra flags and extra arguments to control how the handle is created.

On success this returns a non-NULL pointer to a handle. On error it returns NULL.

"guestfs_create" is equivalent to calling guestfs_create_flags(0).

The following flags may be logically ORed together. (Currently no extra arguments are used).

"GUESTFS_CREATE_NO_ENVIRONMENT"

Don't parse any environment variables (such as "LIBGUESTFS_DEBUG" etc).

You can call "guestfs_parse_environment" or "guestfs_parse_environment_list" afterwards to parse environment variables. Alternately, don't call these functions if you want the handle to be unaffected by environment variables. See the example below.

The default (if this flag is not given) is to implicitly call "guestfs_parse_environment".

"GUESTFS_CREATE_NO_CLOSE_ON_EXIT"

Don't try to close the handle in an atexit(3) handler if the program exits without explicitly closing the handle.

The default (if this flag is not given) is to install such an atexit handler.

USING "GUESTFS_CREATE_NO_ENVIRONMENT"

You might use "GUESTFS_CREATE_NO_ENVIRONMENT" and an explicit call to "guestfs_parse_environment" like this:

 guestfs_h *g;
 int r;
 
 g = guestfs_create_flags (GUESTFS_CREATE_NO_ENVIRONMENT);
 if (!g) {
   perror ("guestfs_create_flags");
   exit (EXIT_FAILURE);
 }
 r = guestfs_parse_environment (g);
 if (r == -1)
   exit (EXIT_FAILURE);

Or to create a handle which is unaffected by environment variables, omit the call to "guestfs_parse_environment" from the above code.

The above code has another advantage which is that any errors from parsing the environment are passed through the error handler, whereas "guestfs_create" prints errors on stderr and ignores them.

guestfs_close¶

 void guestfs_close (guestfs_h *g);

This closes the connection handle and frees up all resources used. If a close callback was set on the handle, then it is called.

The correct way to close the handle is:

 if (guestfs_shutdown (g) == -1) {
   /* handle write errors here */
 }
 guestfs_close (g);

"guestfs_shutdown" is only needed if all of the following are true:

1.

one or more disks were added in read-write mode, and

2.

guestfs_launch was called, and

3.

you made some changes, and

4.

you have a way to handle write errors (eg. by exiting with an error code or reporting something to the user).

guestfs_last_error¶

 const char *guestfs_last_error (guestfs_h *g);

This returns the last error message that happened on "g". If there has not been an error since the handle was created, then this returns "NULL".

Note the returned string does not have a newline character at the end. Most error messages are single lines. Some are split over multiple lines and contain "\n" characters within the string but not at the end.

The lifetime of the returned string is until the next error occurs on the same handle, or "guestfs_close" is called. If you need to keep it longer, copy it.

guestfs_last_errno¶

 int guestfs_last_errno (guestfs_h *g);

This returns the last error number (errno) that happened on "g".

If successful, an errno integer not equal to zero is returned.

In many cases the special errno "ENOTSUP" is returned if you tried to call a function or use a feature which is not supported.

If no error number is available, this returns 0. This call can return 0 in three situations:

1.

There has not been any error on the handle.

2.

There has been an error but the errno was meaningless. This corresponds to the case where the error did not come from a failed system call, but for some other reason.

3.

There was an error from a failed system call, but for some reason the errno was not captured and returned. This usually indicates a bug in libguestfs.

Libguestfs tries to convert the errno from inside the applicance into a corresponding errno for the caller (not entirely trivial: the appliance might be running a completely different operating system from the library and error numbers are not standardized across Un*xen). If this could not be done, then the error is translated to "EINVAL". In practice this should only happen in very rare circumstances.

guestfs_set_error_handler¶

 typedef void (*guestfs_error_handler_cb) (guestfs_h *g,
                                           void *opaque,
                                           const char *msg);
 void guestfs_set_error_handler (guestfs_h *g,
                                 guestfs_error_handler_cb cb,
                                 void *opaque);

The callback "cb" will be called if there is an error. The parameters passed to the callback are an opaque data pointer and the error message string.

"errno" is not passed to the callback. To get that the callback must call "guestfs_last_errno".

Note that the message string "msg" is freed as soon as the callback function returns, so if you want to stash it somewhere you must make your own copy.

The default handler prints messages on "stderr".

If you set "cb" to "NULL" then no handler is called.

guestfs_get_error_handler¶

 guestfs_error_handler_cb guestfs_get_error_handler (guestfs_h *g,
                                                     void **opaque_rtn);

Returns the current error handler callback.

guestfs_push_error_handler¶

 void guestfs_push_error_handler (guestfs_h *g,
                                  guestfs_error_handler_cb cb,
                                  void *opaque);

This is the same as "guestfs_set_error_handler", except that the old error handler is stashed away in a stack inside the handle. You can restore the previous error handler by calling "guestfs_pop_error_handler".

Use the following code to temporarily disable errors around a function:

 guestfs_push_error_handler (g, NULL, NULL);
 guestfs_mkdir (g, "/foo"); /* We don't care if this fails. */
 guestfs_pop_error_handler (g);

guestfs_pop_error_handler¶

 void guestfs_pop_error_handler (guestfs_h *g);

Restore the previous error handler (see "guestfs_push_error_handler").

If you pop the stack too many times, then the default error handler is restored.

guestfs_set_out_of_memory_handler¶

 typedef void (*guestfs_abort_cb) (void);
 void guestfs_set_out_of_memory_handler (guestfs_h *g,
                                         guestfs_abort_cb);

The callback "cb" will be called if there is an out of memory situation. Note this callback must not return.

The default is to call abort(3).

You cannot set "cb" to "NULL". You can't ignore out of memory situations.

guestfs_get_out_of_memory_handler¶

 guestfs_abort_fn guestfs_get_out_of_memory_handler (guestfs_h *g);

This returns the current out of memory handler.

guestfs_acl_delete_def_file¶

 int
 guestfs_acl_delete_def_file (guestfs_h *g,
                              const char *dir);

This function deletes the default POSIX Access Control List (ACL) attached to directory "dir".

This function returns 0 on success or -1 on error.

(Added in 1.19.63)

guestfs_acl_get_file¶

 char *
 guestfs_acl_get_file (guestfs_h *g,
                       const char *path,
                       const char *acltype);

This function returns the POSIX Access Control List (ACL) attached to "path". The ACL is returned in "long text form" (see acl(5)).

The "acltype" parameter may be:

"access"

Return the ordinary (access) ACL for any file, directory or other filesystem object.

"default"

Return the default ACL. Normally this only makes sense if "path" is a directory.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.63)

guestfs_acl_set_file¶

 int
 guestfs_acl_set_file (guestfs_h *g,
                       const char *path,
                       const char *acltype,
                       const char *acl);

This function sets the POSIX Access Control List (ACL) attached to "path".

The "acltype" parameter may be:

"access"

Set the ordinary (access) ACL for any file, directory or other filesystem object.

"default"

Set the default ACL. Normally this only makes sense if "path" is a directory.

The "acl" parameter is the new ACL in either "long text form" or "short text form" (see acl(5)). The new ACL completely replaces any previous ACL on the file. The ACL must contain the full Unix permissions (eg. "u::rwx,g::rx,o::rx").

If you are specifying individual users or groups, then the mask field is also required (eg. "m::rwx"), followed by the "u:ID:..." and/or "g:ID:..." field(s). A full ACL string might therefore look like this:

 u::rwx,g::rwx,o::rwx,m::rwx,u:500:rwx,g:500:rwx
 \ Unix permissions / \mask/ \      ACL        /

You should use numeric UIDs and GIDs. To map usernames and groupnames to the correct numeric ID in the context of the guest, use the Augeas functions (see "guestfs_aug_init").

This function returns 0 on success or -1 on error.

(Added in 1.19.63)

guestfs_add_cdrom¶

 int
 guestfs_add_cdrom (guestfs_h *g,
                    const char *filename);

This function is deprecated. In new code, use the "guestfs_add_drive" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This function adds a virtual CD-ROM disk image to the guest.

Do not use this function! ISO files are just ordinary read-only disk images. Use "guestfs_add_drive_ro" instead.

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_add_domain¶

 int
 guestfs_add_domain (guestfs_h *g,
                     const char *dom,
                     ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_ADD_DOMAIN_LIBVIRTURI, const char *libvirturi,
 GUESTFS_ADD_DOMAIN_READONLY, int readonly,
 GUESTFS_ADD_DOMAIN_IFACE, const char *iface,
 GUESTFS_ADD_DOMAIN_LIVE, int live,
 GUESTFS_ADD_DOMAIN_ALLOWUUID, int allowuuid,
 GUESTFS_ADD_DOMAIN_READONLYDISK, const char *readonlydisk,

This function adds the disk(s) attached to the named libvirt domain "dom". It works by connecting to libvirt, requesting the domain and domain XML from libvirt, parsing it for disks, and calling "guestfs_add_drive_opts" on each one.

The number of disks added is returned. This operation is atomic: if an error is returned, then no disks are added.

This function does some minimal checks to make sure the libvirt domain is not running (unless "readonly" is true). In a future version we will try to acquire the libvirt lock on each disk.

Disks must be accessible locally. This often means that adding disks from a remote libvirt connection (see http://libvirt.org/remote.html) will fail unless those disks are accessible via the same device path locally too.

The optional "libvirturi" parameter sets the libvirt URI (see http://libvirt.org/uri.html). If this is not set then we connect to the default libvirt URI (or one set through an environment variable, see the libvirt documentation for full details).

The optional "live" flag controls whether this call will try to connect to a running virtual machine "guestfsd" process if it sees a suitable <channel> element in the libvirt XML definition. The default (if the flag is omitted) is never to try. See "ATTACHING TO RUNNING DAEMONS" in guestfs(3) for more information.

If the "allowuuid" flag is true (default is false) then a UUID may be passed instead of the domain name. The "dom" string is treated as a UUID first and looked up, and if that lookup fails then we treat "dom" as a name as usual.

The optional "readonlydisk" parameter controls what we do for disks which are marked <readonly/> in the libvirt XML. Possible values are:

readonlydisk = "error"

If "readonly" is false:

The whole call is aborted with an error if any disk with the <readonly/> flag is found.

If "readonly" is true:

Disks with the <readonly/> flag are added read-only.

readonlydisk = "read"

If "readonly" is false:

Disks with the <readonly/> flag are added read-only. Other disks are added read/write.

If "readonly" is true:

Disks with the <readonly/> flag are added read-only.

readonlydisk = "write" (default)

If "readonly" is false:

Disks with the <readonly/> flag are added read/write.

If "readonly" is true:

Disks with the <readonly/> flag are added read-only.

readonlydisk = "ignore"

If "readonly" is true or false:

Disks with the <readonly/> flag are skipped.

The other optional parameters are passed directly through to "guestfs_add_drive_opts".

On error this function returns -1.

(Added in 1.7.4)

guestfs_add_domain_va¶

 int
 guestfs_add_domain_va (guestfs_h *g,
                        const char *dom,
                        va_list args);

This is the "va_list variant" of "guestfs_add_domain".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_add_domain_argv¶

 int
 guestfs_add_domain_argv (guestfs_h *g,
                          const char *dom,
                          const struct guestfs_add_domain_argv *optargs);

This is the "argv variant" of "guestfs_add_domain".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_add_drive¶

 int
 guestfs_add_drive (guestfs_h *g,
                    const char *filename);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_add_drive_opts" with no optional arguments.

(Added in 0.3)

guestfs_add_drive_opts¶

 int
 guestfs_add_drive_opts (guestfs_h *g,
                         const char *filename,
                         ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_ADD_DRIVE_OPTS_READONLY, int readonly,
 GUESTFS_ADD_DRIVE_OPTS_FORMAT, const char *format,
 GUESTFS_ADD_DRIVE_OPTS_IFACE, const char *iface,
 GUESTFS_ADD_DRIVE_OPTS_NAME, const char *name,
 GUESTFS_ADD_DRIVE_OPTS_LABEL, const char *label,
 GUESTFS_ADD_DRIVE_OPTS_CACHEMODE, const char *cachemode,

This function adds a disk image called "filename" to the handle. "filename" may be a regular host file or a host device.

When this function is called before "guestfs_launch" (the usual case) then the first time you call this function, the disk appears in the API as "/dev/sda", the second time as "/dev/sdb", and so on.

In libguestfs ≥ 1.20 you can also call this function after launch (with some restrictions). This is called "hotplugging". When hotplugging, you must specify a "label" so that the new disk gets a predictable name. For more information see "HOTPLUGGING" in guestfs(3).

You don't necessarily need to be root when using libguestfs. However you obviously do need sufficient permissions to access the filename for whatever operations you want to perform (ie. read access if you just want to read the image or write access if you want to modify the image).

This call checks that "filename" exists.

"filename" may be the special string "/dev/null". See "NULL DISKS" in guestfs(3).

The optional arguments are:

"readonly"

If true then the image is treated as read-only. Writes are still allowed, but they are stored in a temporary snapshot overlay which is discarded at the end. The disk that you add is not modified.

"format"

This forces the image format. If you omit this (or use "guestfs_add_drive" or "guestfs_add_drive_ro") then the format is automatically detected. Possible formats include "raw" and "qcow2".

Automatic detection of the format opens you up to a potential security hole when dealing with untrusted raw-format images. See CVE-2010-3851 and RHBZ#642934. Specifying the format closes this security hole.

"iface"

This rarely-used option lets you emulate the behaviour of the deprecated "guestfs_add_drive_with_if" call (q.v.)

"name"

The name the drive had in the original guest, e.g. "/dev/sdb". This is used as a hint to the guest inspection process if it is available.

"label"

Give the disk a label. The label should be a unique, short string using only ASCII characters "[a-zA-Z]". As well as its usual name in the API (such as "/dev/sda"), the drive will also be named "/dev/disk/guestfs/label".

See "DISK LABELS" in guestfs(3).

"cachemode"

Choose whether or not libguestfs will obey sync operations (safe but slow) or not (unsafe but fast). The possible values for this string are:

This function returns 0 on success or -1 on error.

(Added in 1.5.23)

guestfs_add_drive_opts_va¶

 int
 guestfs_add_drive_opts_va (guestfs_h *g,
                            const char *filename,
                            va_list args);

This is the "va_list variant" of "guestfs_add_drive_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_add_drive_opts_argv¶

 int
 guestfs_add_drive_opts_argv (guestfs_h *g,
                              const char *filename,
                              const struct guestfs_add_drive_opts_argv *optargs);

This is the "argv variant" of "guestfs_add_drive_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_add_drive_ro¶

 int
 guestfs_add_drive_ro (guestfs_h *g,
                       const char *filename);

This function is the equivalent of calling "guestfs_add_drive_opts" with the optional parameter "GUESTFS_ADD_DRIVE_OPTS_READONLY" set to 1, so the disk is added read-only, with the format being detected automatically.

This function returns 0 on success or -1 on error.

(Added in 1.0.38)

guestfs_add_drive_ro_with_if¶

 int
 guestfs_add_drive_ro_with_if (guestfs_h *g,
                               const char *filename,
                               const char *iface);

This function is deprecated. In new code, use the "guestfs_add_drive" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This is the same as "guestfs_add_drive_ro" but it allows you to specify the QEMU interface emulation to use at run time.

This function returns 0 on success or -1 on error.

(Added in 1.0.84)

guestfs_add_drive_with_if¶

 int
 guestfs_add_drive_with_if (guestfs_h *g,
                            const char *filename,
                            const char *iface);

This function is deprecated. In new code, use the "guestfs_add_drive" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This is the same as "guestfs_add_drive" but it allows you to specify the QEMU interface emulation to use at run time.

This function returns 0 on success or -1 on error.

(Added in 1.0.84)

guestfs_aug_clear¶

 int
 guestfs_aug_clear (guestfs_h *g,
                    const char *augpath);

Set the value associated with "path" to "NULL". This is the same as the augtool(1) "clear" command.

This function returns 0 on success or -1 on error.

(Added in 1.3.4)

guestfs_aug_close¶

 int
 guestfs_aug_close (guestfs_h *g);

Close the current Augeas handle and free up any resources used by it. After calling this, you have to call "guestfs_aug_init" again before you can use any other Augeas functions.

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_aug_defnode¶

 struct guestfs_int_bool *
 guestfs_aug_defnode (guestfs_h *g,
                      const char *name,
                      const char *expr,
                      const char *val);

Defines a variable "name" whose value is the result of evaluating "expr".

If "expr" evaluates to an empty nodeset, a node is created, equivalent to calling "guestfs_aug_set" "expr", "value". "name" will be the nodeset containing that single node.

On success this returns a pair containing the number of nodes in the nodeset, and a boolean flag if a node was created.

This function returns a "struct guestfs_int_bool *", or NULL if there was an error. The caller must call "guestfs_free_int_bool" after use.

(Added in 0.7)

guestfs_aug_defvar¶

 int
 guestfs_aug_defvar (guestfs_h *g,
                     const char *name,
                     const char *expr);

Defines an Augeas variable "name" whose value is the result of evaluating "expr". If "expr" is NULL, then "name" is undefined.

On success this returns the number of nodes in "expr", or 0 if "expr" evaluates to something which is not a nodeset.

On error this function returns -1.

(Added in 0.7)

guestfs_aug_get¶

 char *
 guestfs_aug_get (guestfs_h *g,
                  const char *augpath);

Look up the value associated with "path". If "path" matches exactly one node, the "value" is returned.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 0.7)

guestfs_aug_init¶

 int
 guestfs_aug_init (guestfs_h *g,
                   const char *root,
                   int flags);

Create a new Augeas handle for editing configuration files. If there was any previous Augeas handle associated with this guestfs session, then it is closed.

You must call this before using any other "guestfs_aug_*" commands.

"root" is the filesystem root. "root" must not be NULL, use "/" instead.

The flags are the same as the flags defined in <augeas.h>, the logical or of the following integers:

"AUG_SAVE_BACKUP" = 1

Keep the original file with a ".augsave" extension.

"AUG_SAVE_NEWFILE" = 2

Save changes into a file with extension ".augnew", and do not overwrite original. Overrides "AUG_SAVE_BACKUP".

"AUG_TYPE_CHECK" = 4

Typecheck lenses.

This option is only useful when debugging Augeas lenses. Use of this option may require additional memory for the libguestfs appliance. You may need to set the "LIBGUESTFS_MEMSIZE" environment variable or call "guestfs_set_memsize".

"AUG_NO_STDINC" = 8

Do not use standard load path for modules.

"AUG_SAVE_NOOP" = 16

Make save a no-op, just record what would have been changed.

"AUG_NO_LOAD" = 32

Do not load the tree in "guestfs_aug_init".

To close the handle, you can call "guestfs_aug_close".

To find out more about Augeas, see http://augeas.net/.

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_aug_insert¶

 int
 guestfs_aug_insert (guestfs_h *g,
                     const char *augpath,
                     const char *label,
                     int before);

Create a new sibling "label" for "path", inserting it into the tree before or after "path" (depending on the boolean flag "before").

"path" must match exactly one existing node in the tree, and "label" must be a label, ie. not contain "/", "*" or end with a bracketed index "[N]".

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_aug_load¶

 int
 guestfs_aug_load (guestfs_h *g);

Load files into the tree.

See "aug_load" in the Augeas documentation for the full gory details.

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_aug_ls¶

 char **
 guestfs_aug_ls (guestfs_h *g,
                 const char *augpath);

This is just a shortcut for listing "guestfs_aug_match" "path/*" and sorting the resulting nodes into alphabetical order.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.8)

guestfs_aug_match¶

 char **
 guestfs_aug_match (guestfs_h *g,
                    const char *augpath);

Returns a list of paths which match the path expression "path". The returned paths are sufficiently qualified so that they match exactly one node in the current tree.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.7)

guestfs_aug_mv¶

 int
 guestfs_aug_mv (guestfs_h *g,
                 const char *src,
                 const char *dest);

Move the node "src" to "dest". "src" must match exactly one node. "dest" is overwritten if it exists.

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_aug_rm¶

 int
 guestfs_aug_rm (guestfs_h *g,
                 const char *augpath);

Remove "path" and all of its children.

On success this returns the number of entries which were removed.

On error this function returns -1.

(Added in 0.7)

guestfs_aug_save¶

 int
 guestfs_aug_save (guestfs_h *g);

This writes all pending changes to disk.

The flags which were passed to "guestfs_aug_init" affect exactly how files are saved.

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_aug_set¶

 int
 guestfs_aug_set (guestfs_h *g,
                  const char *augpath,
                  const char *val);

Set the value associated with "path" to "val".

In the Augeas API, it is possible to clear a node by setting the value to NULL. Due to an oversight in the libguestfs API you cannot do that with this call. Instead you must use the "guestfs_aug_clear" call.

This function returns 0 on success or -1 on error.

(Added in 0.7)

guestfs_available¶

 int
 guestfs_available (guestfs_h *g,
                    char *const *groups);

This command is used to check the availability of some groups of functionality in the appliance, which not all builds of the libguestfs appliance will be able to provide.

The libguestfs groups, and the functions that those groups correspond to, are listed in "AVAILABILITY" in guestfs(3). You can also fetch this list at runtime by calling "guestfs_available_all_groups".

The argument "groups" is a list of group names, eg: "["inotify", "augeas"]" would check for the availability of the Linux inotify functions and Augeas (configuration file editing) functions.

The command returns no error if all requested groups are available.

It fails with an error if one or more of the requested groups is unavailable in the appliance.

If an unknown group name is included in the list of groups then an error is always returned.

Notes:

• You must call "guestfs_launch" before calling this function.

  The reason is because we don't know what groups are supported by the appliance/daemon until it is running and can be queried.

• If a group of functions is available, this does not necessarily mean that they will work. You still have to check for errors when calling individual API functions even if they are available.
• It is usually the job of distro packagers to build complete functionality into the libguestfs appliance. Upstream libguestfs, if built from source with all requirements satisfied, will support everything.
• This call was added in version 1.0.80. In previous versions of libguestfs all you could do would be to speculatively execute a command to find out if the daemon implemented it. See also "guestfs_version".

See also "guestfs_filesystem_available".

This function returns 0 on success or -1 on error.

(Added in 1.0.80)

guestfs_available_all_groups¶

 char **
 guestfs_available_all_groups (guestfs_h *g);

This command returns a list of all optional groups that this daemon knows about. Note this returns both supported and unsupported groups. To find out which ones the daemon can actually support you have to call "guestfs_available" on each member of the returned list.

See also "guestfs_available" and "AVAILABILITY" in guestfs(3).

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.3.15)

guestfs_base64_in¶

 int
 guestfs_base64_in (guestfs_h *g,
                    const char *base64file,
                    const char *filename);

This command uploads base64-encoded data from "base64file" to "filename".

This function returns 0 on success or -1 on error.

(Added in 1.3.5)

guestfs_base64_out¶

 int
 guestfs_base64_out (guestfs_h *g,
                     const char *filename,
                     const char *base64file);

This command downloads the contents of "filename", writing it out to local file "base64file" encoded as base64.

This function returns 0 on success or -1 on error.

(Added in 1.3.5)

guestfs_blkid¶

 char **
 guestfs_blkid (guestfs_h *g,
                const char *device);

This command returns block device attributes for "device". The following fields are usually present in the returned hash. Other fields may also be present.

"UUID"

The uuid of this device.

"LABEL"

The label of this device.

"VERSION"

The version of blkid command.

"TYPE"

The filesystem type or RAID of this device.

"USAGE"

The usage of this device, for example "filesystem" or "raid".

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.15.9)

guestfs_blockdev_flushbufs¶

 int
 guestfs_blockdev_flushbufs (guestfs_h *g,
                             const char *device);

This tells the kernel to flush internal buffers associated with "device".

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

(Added in 0.9.3)

guestfs_blockdev_getbsz¶

 int
 guestfs_blockdev_getbsz (guestfs_h *g,
                          const char *device);

This returns the block size of a device.

Note: this is different from both size in blocks and filesystem block size. Also this setting is not really used by anything. You should probably not use it for anything. Filesystems have their own idea about what block size to choose.

This uses the blockdev(8) command.

On error this function returns -1.

(Added in 0.9.3)

guestfs_blockdev_getro¶

 int
 guestfs_blockdev_getro (guestfs_h *g,
                         const char *device);

Returns a boolean indicating if the block device is read-only (true if read-only, false if not).

This uses the blockdev(8) command.

This function returns a C truth value on success or -1 on error.

(Added in 0.9.3)

guestfs_blockdev_getsize64¶

 int64_t
 guestfs_blockdev_getsize64 (guestfs_h *g,
                             const char *device);

This returns the size of the device in bytes.

See also "guestfs_blockdev_getsz".

This uses the blockdev(8) command.

On error this function returns -1.

(Added in 0.9.3)

guestfs_blockdev_getss¶

 int
 guestfs_blockdev_getss (guestfs_h *g,
                         const char *device);

This returns the size of sectors on a block device. Usually 512, but can be larger for modern devices.

(Note, this is not the size in sectors, use "guestfs_blockdev_getsz" for that).

This uses the blockdev(8) command.

On error this function returns -1.

(Added in 0.9.3)

guestfs_blockdev_getsz¶

 int64_t
 guestfs_blockdev_getsz (guestfs_h *g,
                         const char *device);

This returns the size of the device in units of 512-byte sectors (even if the sectorsize isn't 512 bytes ... weird).

See also "guestfs_blockdev_getss" for the real sector size of the device, and "guestfs_blockdev_getsize64" for the more useful size in bytes.

This uses the blockdev(8) command.

On error this function returns -1.

(Added in 0.9.3)

guestfs_blockdev_rereadpt¶

 int
 guestfs_blockdev_rereadpt (guestfs_h *g,
                            const char *device);

Reread the partition table on "device".

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

(Added in 0.9.3)

guestfs_blockdev_setbsz¶

 int
 guestfs_blockdev_setbsz (guestfs_h *g,
                          const char *device,
                          int blocksize);

This function is deprecated. In new code, use the "guestfs_mkfs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This call does nothing and has never done anything because of a bug in blockdev. Do not use it.

If you need to set the filesystem block size, use the "blocksize" option of "guestfs_mkfs".

This function returns 0 on success or -1 on error.

(Added in 0.9.3)

guestfs_blockdev_setro¶

 int
 guestfs_blockdev_setro (guestfs_h *g,
                         const char *device);

Sets the block device named "device" to read-only.

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

(Added in 0.9.3)

guestfs_blockdev_setrw¶

 int
 guestfs_blockdev_setrw (guestfs_h *g,
                         const char *device);

Sets the block device named "device" to read-write.

This uses the blockdev(8) command.

This function returns 0 on success or -1 on error.

(Added in 0.9.3)

guestfs_btrfs_device_add¶

 int
 guestfs_btrfs_device_add (guestfs_h *g,
                           char *const *devices,
                           const char *fs);

Add the list of device(s) in "devices" to the btrfs filesystem mounted at "fs". If "devices" is an empty list, this does nothing.

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_device_delete¶

 int
 guestfs_btrfs_device_delete (guestfs_h *g,
                              char *const *devices,
                              const char *fs);

Remove the "devices" from the btrfs filesystem mounted at "fs". If "devices" is an empty list, this does nothing.

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_filesystem_balance¶

 int
 guestfs_btrfs_filesystem_balance (guestfs_h *g,
                                   const char *fs);

Balance the chunks in the btrfs filesystem mounted at "fs" across the underlying devices.

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_filesystem_resize¶

 int
 guestfs_btrfs_filesystem_resize (guestfs_h *g,
                                  const char *mountpoint,
                                  ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_BTRFS_FILESYSTEM_RESIZE_SIZE, int64_t size,

This command resizes a btrfs filesystem.

Note that unlike other resize calls, the filesystem has to be mounted and the parameter is the mountpoint not the device (this is a requirement of btrfs itself).

The optional parameters are:

"size"

The new size (in bytes) of the filesystem. If omitted, the filesystem is resized to the maximum size.

See also btrfs(8).

This function returns 0 on success or -1 on error.

(Added in 1.11.17)

guestfs_btrfs_filesystem_resize_va¶

 int
 guestfs_btrfs_filesystem_resize_va (guestfs_h *g,
                                     const char *mountpoint,
                                     va_list args);

This is the "va_list variant" of "guestfs_btrfs_filesystem_resize".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_btrfs_filesystem_resize_argv¶

 int
 guestfs_btrfs_filesystem_resize_argv (guestfs_h *g,
                                       const char *mountpoint,
                                       const struct guestfs_btrfs_filesystem_resize_argv *optargs);

This is the "argv variant" of "guestfs_btrfs_filesystem_resize".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_btrfs_filesystem_sync¶

 int
 guestfs_btrfs_filesystem_sync (guestfs_h *g,
                                const char *fs);

Force sync on the btrfs filesystem mounted at "fs".

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_fsck¶

 int
 guestfs_btrfs_fsck (guestfs_h *g,
                     const char *device,
                     ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_BTRFS_FSCK_SUPERBLOCK, int64_t superblock,
 GUESTFS_BTRFS_FSCK_REPAIR, int repair,

Used to check a btrfs filesystem, "device" is the device file where the filesystem is stored.

This function returns 0 on success or -1 on error.

(Added in 1.17.43)

guestfs_btrfs_fsck_va¶

 int
 guestfs_btrfs_fsck_va (guestfs_h *g,
                        const char *device,
                        va_list args);

This is the "va_list variant" of "guestfs_btrfs_fsck".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_btrfs_fsck_argv¶

 int
 guestfs_btrfs_fsck_argv (guestfs_h *g,
                          const char *device,
                          const struct guestfs_btrfs_fsck_argv *optargs);

This is the "argv variant" of "guestfs_btrfs_fsck".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_btrfs_set_seeding¶

 int
 guestfs_btrfs_set_seeding (guestfs_h *g,
                            const char *device,
                            int seeding);

Enable or disable the seeding feature of a device that contains a btrfs filesystem.

This function returns 0 on success or -1 on error.

(Added in 1.17.43)

guestfs_btrfs_subvolume_create¶

 int
 guestfs_btrfs_subvolume_create (guestfs_h *g,
                                 const char *dest);

Create a btrfs subvolume. The "dest" argument is the destination directory and the name of the snapshot, in the form "/path/to/dest/name".

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_subvolume_delete¶

 int
 guestfs_btrfs_subvolume_delete (guestfs_h *g,
                                 const char *subvolume);

Delete the named btrfs subvolume.

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_subvolume_list¶

 struct guestfs_btrfssubvolume_list *
 guestfs_btrfs_subvolume_list (guestfs_h *g,
                               const char *fs);

List the btrfs snapshots and subvolumes of the btrfs filesystem which is mounted at "fs".

This function returns a "struct guestfs_btrfssubvolume_list *", or NULL if there was an error. The caller must call "guestfs_free_btrfssubvolume_list" after use.

(Added in 1.17.35)

guestfs_btrfs_subvolume_set_default¶

 int
 guestfs_btrfs_subvolume_set_default (guestfs_h *g,
                                      int64_t id,
                                      const char *fs);

Set the subvolume of the btrfs filesystem "fs" which will be mounted by default. See "guestfs_btrfs_subvolume_list" to get a list of subvolumes.

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_btrfs_subvolume_snapshot¶

 int
 guestfs_btrfs_subvolume_snapshot (guestfs_h *g,
                                   const char *source,
                                   const char *dest);

Create a writable snapshot of the btrfs subvolume "source". The "dest" argument is the destination directory and the name of the snapshot, in the form "/path/to/dest/name".

This function returns 0 on success or -1 on error.

(Added in 1.17.35)

guestfs_canonical_device_name¶

 char *
 guestfs_canonical_device_name (guestfs_h *g,
                                const char *device);

This utility function is useful when displaying device names to the user. It takes a number of irregular device names and returns them in a consistent format:

"/dev/hdX"

"/dev/vdX"

These are returned as "/dev/sdX". Note this works for device names and partition names. This is approximately the reverse of the algorithm described in "BLOCK DEVICE NAMING" in guestfs(3).

"/dev/mapper/VG-LV"

"/dev/dm-N"

Converted to "/dev/VG/LV" form using "guestfs_lvm_canonical_lvm_name".

Other strings are returned unmodified.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.7)

guestfs_cap_get_file¶

 char *
 guestfs_cap_get_file (guestfs_h *g,
                       const char *path);

This function returns the Linux capabilities attached to "path". The capabilities set is returned in text form (see cap_to_text(3)).

If no capabilities are attached to a file, an empty string is returned.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.63)

guestfs_cap_set_file¶

 int
 guestfs_cap_set_file (guestfs_h *g,
                       const char *path,
                       const char *cap);

This function sets the Linux capabilities attached to "path". The capabilities set "cap" should be passed in text form (see cap_from_text(3)).

This function returns 0 on success or -1 on error.

(Added in 1.19.63)

guestfs_case_sensitive_path¶

 char *
 guestfs_case_sensitive_path (guestfs_h *g,
                              const char *path);

This can be used to resolve case insensitive paths on a filesystem which is case sensitive. The use case is to resolve paths which you have read from Windows configuration files or the Windows Registry, to the true path.

The command handles a peculiarity of the Linux ntfs-3g filesystem driver (and probably others), which is that although the underlying filesystem is case-insensitive, the driver exports the filesystem to Linux as case-sensitive.

One consequence of this is that special directories such as "c:\windows" may appear as "/WINDOWS" or "/windows" (or other things) depending on the precise details of how they were created. In Windows itself this would not be a problem.

Bug or feature? You decide: http://www.tuxera.com/community/ntfs-3g-faq/#posixfilenames1

This function resolves the true case of each element in the path and returns the case-sensitive path.

Thus "guestfs_case_sensitive_path" ("/Windows/System32") might return "/WINDOWS/system32" (the exact return value would depend on details of how the directories were originally created under Windows).

Note: This function does not handle drive names, backslashes etc.

See also "guestfs_realpath".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.75)

guestfs_cat¶

 char *
 guestfs_cat (guestfs_h *g,
              const char *path);

Return the contents of the file named "path".

Because, in C, this function returns a "char *", there is no way to differentiate between a "\0" character in a file and end of string. To handle binary files, use the "guestfs_read_file" or "guestfs_download" functions.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 0.4)

guestfs_checksum¶

 char *
 guestfs_checksum (guestfs_h *g,
                   const char *csumtype,
                   const char *path);

This call computes the MD5, SHAx or CRC checksum of the file named "path".

The type of checksum to compute is given by the "csumtype" parameter which must have one of the following values:

"crc"

Compute the cyclic redundancy check (CRC) specified by POSIX for the "cksum" command.

"md5"

Compute the MD5 hash (using the "md5sum" program).

"sha1"

Compute the SHA1 hash (using the "sha1sum" program).

"sha224"

Compute the SHA224 hash (using the "sha224sum" program).

"sha256"

Compute the SHA256 hash (using the "sha256sum" program).

"sha384"

Compute the SHA384 hash (using the "sha384sum" program).

"sha512"

Compute the SHA512 hash (using the "sha512sum" program).

The checksum is returned as a printable string.

To get the checksum for a device, use "guestfs_checksum_device".

To get the checksums for many files, use "guestfs_checksums_out".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.2)

guestfs_checksum_device¶

 char *
 guestfs_checksum_device (guestfs_h *g,
                          const char *csumtype,
                          const char *device);

This call computes the MD5, SHAx or CRC checksum of the contents of the device named "device". For the types of checksums supported see the "guestfs_checksum" command.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.3.2)

guestfs_checksums_out¶

 int
 guestfs_checksums_out (guestfs_h *g,
                        const char *csumtype,
                        const char *directory,
                        const char *sumsfile);

This command computes the checksums of all regular files in "directory" and then emits a list of those checksums to the local output file "sumsfile".

This can be used for verifying the integrity of a virtual machine. However to be properly secure you should pay attention to the output of the checksum command (it uses the ones from GNU coreutils). In particular when the filename is not printable, coreutils uses a special backslash syntax. For more information, see the GNU coreutils info file.

This function returns 0 on success or -1 on error.

(Added in 1.3.7)

guestfs_chmod¶

 int
 guestfs_chmod (guestfs_h *g,
                int mode,
                const char *path);

Change the mode (permissions) of "path" to "mode". Only numeric modes are supported.

Note: When using this command from guestfish, "mode" by default would be decimal, unless you prefix it with 0 to get octal, ie. use 0700 not 700.

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_chown¶

 int
 guestfs_chown (guestfs_h *g,
                int owner,
                int group,
                const char *path);

Change the file owner to "owner" and group to "group".

Only numeric uid and gid are supported. If you want to use names, you will need to locate and parse the password file yourself (Augeas support makes this relatively easy).

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_command¶

 char *
 guestfs_command (guestfs_h *g,
                  char *const *arguments);

This call runs a command from the guest filesystem. The filesystem must be mounted, and must contain a compatible operating system (ie. something Linux, with the same or compatible processor architecture).

The single parameter is an argv-style list of arguments. The first element is the name of the program to run. Subsequent elements are parameters. The list must be non-empty (ie. must contain a program name). Note that the command runs directly, and is not invoked via the shell (see "guestfs_sh").

The return value is anything printed to stdout by the command.

If the command returns a non-zero exit status, then this function returns an error message. The error message string is the content of stderr from the command.

The $PATH environment variable will contain at least "/usr/bin" and "/bin". If you require a program from another location, you should provide the full path in the first parameter.

Shared libraries and data files required by the program must be available on filesystems which are mounted in the correct places. It is the caller's responsibility to ensure all filesystems that are needed are mounted at the right locations.

This function returns a string, or NULL on error. The caller must free the returned string after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 0.9.1)

guestfs_command_lines¶

 char **
 guestfs_command_lines (guestfs_h *g,
                        char *const *arguments);

This is the same as "guestfs_command", but splits the result into a list of lines.

See also: "guestfs_sh_lines"

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 0.9.1)

guestfs_compress_device_out¶

 int
 guestfs_compress_device_out (guestfs_h *g,
                              const char *ctype,
                              const char *device,
                              const char *zdevice,
                              ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_COMPRESS_DEVICE_OUT_LEVEL, int level,

This command compresses "device" and writes it out to the local file "zdevice".

The "ctype" and optional "level" parameters have the same meaning as in "guestfs_compress_out".

This function returns 0 on success or -1 on error.

(Added in 1.13.15)

guestfs_compress_device_out_va¶

 int
 guestfs_compress_device_out_va (guestfs_h *g,
                                 const char *ctype,
                                 const char *device,
                                 const char *zdevice,
                                 va_list args);

This is the "va_list variant" of "guestfs_compress_device_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_compress_device_out_argv¶

 int
 guestfs_compress_device_out_argv (guestfs_h *g,
                                   const char *ctype,
                                   const char *device,
                                   const char *zdevice,
                                   const struct guestfs_compress_device_out_argv *optargs);

This is the "argv variant" of "guestfs_compress_device_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_compress_out¶

 int
 guestfs_compress_out (guestfs_h *g,
                       const char *ctype,
                       const char *file,
                       const char *zfile,
                       ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_COMPRESS_OUT_LEVEL, int level,

This command compresses "file" and writes it out to the local file "zfile".

The compression program used is controlled by the "ctype" parameter. Currently this includes: "compress", "gzip", "bzip2", "xz" or "lzop". Some compression types may not be supported by particular builds of libguestfs, in which case you will get an error containing the substring "not supported".

The optional "level" parameter controls compression level. The meaning and default for this parameter depends on the compression program being used.

This function returns 0 on success or -1 on error.

(Added in 1.13.15)

guestfs_compress_out_va¶

 int
 guestfs_compress_out_va (guestfs_h *g,
                          const char *ctype,
                          const char *file,
                          const char *zfile,
                          va_list args);

This is the "va_list variant" of "guestfs_compress_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_compress_out_argv¶

 int
 guestfs_compress_out_argv (guestfs_h *g,
                            const char *ctype,
                            const char *file,
                            const char *zfile,
                            const struct guestfs_compress_out_argv *optargs);

This is the "argv variant" of "guestfs_compress_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_config¶

 int
 guestfs_config (guestfs_h *g,
                 const char *qemuparam,
                 const char *qemuvalue);

This can be used to add arbitrary qemu command line parameters of the form -param value. Actually it's not quite arbitrary - we prevent you from setting some parameters which would interfere with parameters that we use.

The first character of "qemuparam" string must be a "-" (dash).

"qemuvalue" can be NULL.

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_copy_device_to_device¶

 int
 guestfs_copy_device_to_device (guestfs_h *g,
                                const char *src,
                                const char *dest,
                                ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_COPY_DEVICE_TO_DEVICE_SRCOFFSET, int64_t srcoffset,
 GUESTFS_COPY_DEVICE_TO_DEVICE_DESTOFFSET, int64_t destoffset,
 GUESTFS_COPY_DEVICE_TO_DEVICE_SIZE, int64_t size,

The four calls "guestfs_copy_device_to_device", "guestfs_copy_device_to_file", "guestfs_copy_file_to_device", and "guestfs_copy_file_to_file" let you copy from a source (device|file) to a destination (device|file).

Partial copies can be made since you can specify optionally the source offset, destination offset and size to copy. These values are all specified in bytes. If not given, the offsets both default to zero, and the size defaults to copying as much as possible until we hit the end of the source.

The source and destination may be the same object. However overlapping regions may not be copied correctly.

If the destination is a file, it is created if required. If the destination file is not large enough, it is extended.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.13.25)

guestfs_copy_device_to_device_va¶

 int
 guestfs_copy_device_to_device_va (guestfs_h *g,
                                   const char *src,
                                   const char *dest,
                                   va_list args);

This is the "va_list variant" of "guestfs_copy_device_to_device".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_device_to_device_argv¶

 int
 guestfs_copy_device_to_device_argv (guestfs_h *g,
                                     const char *src,
                                     const char *dest,
                                     const struct guestfs_copy_device_to_device_argv *optargs);

This is the "argv variant" of "guestfs_copy_device_to_device".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_device_to_file¶

 int
 guestfs_copy_device_to_file (guestfs_h *g,
                              const char *src,
                              const char *dest,
                              ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_COPY_DEVICE_TO_FILE_SRCOFFSET, int64_t srcoffset,
 GUESTFS_COPY_DEVICE_TO_FILE_DESTOFFSET, int64_t destoffset,
 GUESTFS_COPY_DEVICE_TO_FILE_SIZE, int64_t size,

See "guestfs_copy_device_to_device" for a general overview of this call.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.13.25)

guestfs_copy_device_to_file_va¶

 int
 guestfs_copy_device_to_file_va (guestfs_h *g,
                                 const char *src,
                                 const char *dest,
                                 va_list args);

This is the "va_list variant" of "guestfs_copy_device_to_file".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_device_to_file_argv¶

 int
 guestfs_copy_device_to_file_argv (guestfs_h *g,
                                   const char *src,
                                   const char *dest,
                                   const struct guestfs_copy_device_to_file_argv *optargs);

This is the "argv variant" of "guestfs_copy_device_to_file".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_file_to_device¶

 int
 guestfs_copy_file_to_device (guestfs_h *g,
                              const char *src,
                              const char *dest,
                              ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_COPY_FILE_TO_DEVICE_SRCOFFSET, int64_t srcoffset,
 GUESTFS_COPY_FILE_TO_DEVICE_DESTOFFSET, int64_t destoffset,
 GUESTFS_COPY_FILE_TO_DEVICE_SIZE, int64_t size,

See "guestfs_copy_device_to_device" for a general overview of this call.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.13.25)

guestfs_copy_file_to_device_va¶

 int
 guestfs_copy_file_to_device_va (guestfs_h *g,
                                 const char *src,
                                 const char *dest,
                                 va_list args);

This is the "va_list variant" of "guestfs_copy_file_to_device".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_file_to_device_argv¶

 int
 guestfs_copy_file_to_device_argv (guestfs_h *g,
                                   const char *src,
                                   const char *dest,
                                   const struct guestfs_copy_file_to_device_argv *optargs);

This is the "argv variant" of "guestfs_copy_file_to_device".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_file_to_file¶

 int
 guestfs_copy_file_to_file (guestfs_h *g,
                            const char *src,
                            const char *dest,
                            ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_COPY_FILE_TO_FILE_SRCOFFSET, int64_t srcoffset,
 GUESTFS_COPY_FILE_TO_FILE_DESTOFFSET, int64_t destoffset,
 GUESTFS_COPY_FILE_TO_FILE_SIZE, int64_t size,

See "guestfs_copy_device_to_device" for a general overview of this call.

This is not the function you want for copying files. This is for copying blocks within existing files. See "guestfs_cp", "guestfs_cp_a" and "guestfs_mv" for general file copying and moving functions.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.13.25)

guestfs_copy_file_to_file_va¶

 int
 guestfs_copy_file_to_file_va (guestfs_h *g,
                               const char *src,
                               const char *dest,
                               va_list args);

This is the "va_list variant" of "guestfs_copy_file_to_file".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_file_to_file_argv¶

 int
 guestfs_copy_file_to_file_argv (guestfs_h *g,
                                 const char *src,
                                 const char *dest,
                                 const struct guestfs_copy_file_to_file_argv *optargs);

This is the "argv variant" of "guestfs_copy_file_to_file".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_copy_size¶

 int
 guestfs_copy_size (guestfs_h *g,
                    const char *src,
                    const char *dest,
                    int64_t size);

This function is deprecated. In new code, use the "guestfs_copy_device_to_device" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command copies exactly "size" bytes from one source device or file "src" to another destination device or file "dest".

Note this will fail if the source is too short or if the destination is not large enough.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.0.87)

guestfs_cp¶

 int
 guestfs_cp (guestfs_h *g,
             const char *src,
             const char *dest);

This copies a file from "src" to "dest" where "dest" is either a destination filename or destination directory.

This function returns 0 on success or -1 on error.

(Added in 1.0.18)

guestfs_cp_a¶

 int
 guestfs_cp_a (guestfs_h *g,
               const char *src,
               const char *dest);

This copies a file or directory from "src" to "dest" recursively using the "cp -a" command.

This function returns 0 on success or -1 on error.

(Added in 1.0.18)

guestfs_dd¶

 int
 guestfs_dd (guestfs_h *g,
             const char *src,
             const char *dest);

This function is deprecated. In new code, use the "guestfs_copy_device_to_device" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command copies from one source device or file "src" to another destination device or file "dest". Normally you would use this to copy to or from a device or partition, for example to duplicate a filesystem.

If the destination is a device, it must be as large or larger than the source file or device, otherwise the copy will fail. This command cannot do partial copies (see "guestfs_copy_device_to_device").

This function returns 0 on success or -1 on error.

(Added in 1.0.80)

guestfs_device_index¶

 int
 guestfs_device_index (guestfs_h *g,
                       const char *device);

This function takes a device name (eg. "/dev/sdb") and returns the index of the device in the list of devices.

Index numbers start from 0. The named device must exist, for example as a string returned from "guestfs_list_devices".

See also "guestfs_list_devices", "guestfs_part_to_dev".

On error this function returns -1.

(Added in 1.19.7)

guestfs_df¶

 char *
 guestfs_df (guestfs_h *g);

This command runs the "df" command to report disk space used.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string. Use "guestfs_statvfs" from programs.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.54)

guestfs_df_h¶

 char *
 guestfs_df_h (guestfs_h *g);

This command runs the "df -h" command to report disk space used in human-readable format.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string. Use "guestfs_statvfs" from programs.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.54)

guestfs_disk_format¶

 char *
 guestfs_disk_format (guestfs_h *g,
                      const char *filename);

Detect and return the format of the disk image called "filename". "filename" can also be a host device, etc. If the format of the image could not be detected, then "unknown" is returned.

Note that detecting the disk format can be insecure under some circumstances. See "CVE-2010-3851" in guestfs(3).

See also: "DISK IMAGE FORMATS" in guestfs(3)

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.38)

guestfs_disk_has_backing_file¶

 int
 guestfs_disk_has_backing_file (guestfs_h *g,
                                const char *filename);

Detect and return whether the disk image "filename" has a backing file.

Note that detecting disk features can be insecure under some circumstances. See "CVE-2010-3851" in guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.19.39)

guestfs_disk_virtual_size¶

 int64_t
 guestfs_disk_virtual_size (guestfs_h *g,
                            const char *filename);

Detect and return the virtual size in bytes of the disk image called "filename".

Note that detecting disk features can be insecure under some circumstances. See "CVE-2010-3851" in guestfs(3).

On error this function returns -1.

(Added in 1.19.39)

guestfs_dmesg¶

 char *
 guestfs_dmesg (guestfs_h *g);

This returns the kernel messages ("dmesg" output) from the guest kernel. This is sometimes useful for extended debugging of problems.

Another way to get the same information is to enable verbose messages with "guestfs_set_verbose" or by setting the environment variable "LIBGUESTFS_DEBUG=1" before running the program.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.18)

guestfs_download¶

 int
 guestfs_download (guestfs_h *g,
                   const char *remotefilename,
                   const char *filename);

Download file "remotefilename" and save it as "filename" on the local machine.

"filename" can also be a named pipe.

See also "guestfs_upload", "guestfs_cat".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.0.2)

guestfs_download_offset¶

 int
 guestfs_download_offset (guestfs_h *g,
                          const char *remotefilename,
                          const char *filename,
                          int64_t offset,
                          int64_t size);

Download file "remotefilename" and save it as "filename" on the local machine.

"remotefilename" is read for "size" bytes starting at "offset" (this region must be within the file or device).

Note that there is no limit on the amount of data that can be downloaded with this call, unlike with "guestfs_pread", and this call always reads the full amount unless an error occurs.

See also "guestfs_download", "guestfs_pread".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.5.17)

guestfs_drop_caches¶

 int
 guestfs_drop_caches (guestfs_h *g,
                      int whattodrop);

This instructs the guest kernel to drop its page cache, and/or dentries and inode caches. The parameter "whattodrop" tells the kernel what precisely to drop, see http://linux-mm.org/Drop_Caches

Setting "whattodrop" to 3 should drop everything.

This automatically calls sync(2) before the operation, so that the maximum guest memory is freed.

This function returns 0 on success or -1 on error.

(Added in 1.0.18)

guestfs_du¶

 int64_t
 guestfs_du (guestfs_h *g,
             const char *path);

This command runs the "du -s" command to estimate file space usage for "path".

"path" can be a file or a directory. If "path" is a directory then the estimate includes the contents of the directory and all subdirectories (recursively).

The result is the estimated size in kilobytes (ie. units of 1024 bytes).

On error this function returns -1.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.0.54)

guestfs_e2fsck¶

 int
 guestfs_e2fsck (guestfs_h *g,
                 const char *device,
                 ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_E2FSCK_CORRECT, int correct,
 GUESTFS_E2FSCK_FORCEALL, int forceall,

This runs the ext2/ext3 filesystem checker on "device". It can take the following optional arguments:

"correct"

Automatically repair the file system. This option will cause e2fsck to automatically fix any filesystem problems that can be safely fixed without human intervention.

This option may not be specified at the same time as the "forceall" option.

"forceall"

Assume an answer of 'yes' to all questions; allows e2fsck to be used non-interactively.

This option may not be specified at the same time as the "correct" option.

This function returns 0 on success or -1 on error.

(Added in 1.15.17)

guestfs_e2fsck_va¶

 int
 guestfs_e2fsck_va (guestfs_h *g,
                    const char *device,
                    va_list args);

This is the "va_list variant" of "guestfs_e2fsck".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_e2fsck_argv¶

 int
 guestfs_e2fsck_argv (guestfs_h *g,
                      const char *device,
                      const struct guestfs_e2fsck_argv *optargs);

This is the "argv variant" of "guestfs_e2fsck".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_e2fsck_f¶

 int
 guestfs_e2fsck_f (guestfs_h *g,
                   const char *device);

This function is deprecated. In new code, use the "guestfs_e2fsck" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This runs "e2fsck -p -f device", ie. runs the ext2/ext3 filesystem checker on "device", noninteractively (-p), even if the filesystem appears to be clean (-f).

This function returns 0 on success or -1 on error.

(Added in 1.0.29)

guestfs_echo_daemon¶

 char *
 guestfs_echo_daemon (guestfs_h *g,
                      char *const *words);

This command concatenates the list of "words" passed with single spaces between them and returns the resulting string.

You can use this command to test the connection through to the daemon.

See also "guestfs_ping_daemon".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.69)

guestfs_egrep¶

 char **
 guestfs_egrep (guestfs_h *g,
                const char *regex,
                const char *path);

This function is deprecated. In new code, use the "guestfs_grep" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This calls the external "egrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.66)

guestfs_egrepi¶

 char **
 guestfs_egrepi (guestfs_h *g,
                 const char *regex,
                 const char *path);

This function is deprecated. In new code, use the "guestfs_grep" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This calls the external "egrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.66)

guestfs_equal¶

 int
 guestfs_equal (guestfs_h *g,
                const char *file1,
                const char *file2);

This compares the two files "file1" and "file2" and returns true if their content is exactly equal, or false otherwise.

The external cmp(1) program is used for the comparison.

This function returns a C truth value on success or -1 on error.

(Added in 1.0.18)

guestfs_exists¶

 int
 guestfs_exists (guestfs_h *g,
                 const char *path);

This returns "true" if and only if there is a file, directory (or anything) with the given "path" name.

See also "guestfs_is_file", "guestfs_is_dir", "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 0.8)

guestfs_fallocate¶

 int
 guestfs_fallocate (guestfs_h *g,
                    const char *path,
                    int len);

This function is deprecated. In new code, use the "guestfs_fallocate64" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command preallocates a file (containing zero bytes) named "path" of size "len" bytes. If the file exists already, it is overwritten.

Do not confuse this with the guestfish-specific "alloc" command which allocates a file in the host and attaches it as a device.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_fallocate64¶

 int
 guestfs_fallocate64 (guestfs_h *g,
                      const char *path,
                      int64_t len);

This command preallocates a file (containing zero bytes) named "path" of size "len" bytes. If the file exists already, it is overwritten.

Note that this call allocates disk blocks for the file. To create a sparse file use "guestfs_truncate_size" instead.

The deprecated call "guestfs_fallocate" does the same, but owing to an oversight it only allowed 30 bit lengths to be specified, effectively limiting the maximum size of files created through that call to 1GB.

Do not confuse this with the guestfish-specific "alloc" and "sparse" commands which create a file in the host and attach it as a device.

This function returns 0 on success or -1 on error.

(Added in 1.3.17)

guestfs_fgrep¶

 char **
 guestfs_fgrep (guestfs_h *g,
                const char *pattern,
                const char *path);

This function is deprecated. In new code, use the "guestfs_grep" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This calls the external "fgrep" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.66)

guestfs_fgrepi¶

 char **
 guestfs_fgrepi (guestfs_h *g,
                 const char *pattern,
                 const char *path);

This function is deprecated. In new code, use the "guestfs_grep" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This calls the external "fgrep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.66)

guestfs_file¶

 char *
 guestfs_file (guestfs_h *g,
               const char *path);

This call uses the standard file(1) command to determine the type or contents of the file.

This call will also transparently look inside various types of compressed file.

The exact command which runs is "file -zb path". Note in particular that the filename is not prepended to the output (the -b option).

The output depends on the output of the underlying file(1) command and it can change in future in ways beyond our control. In other words, the output is not guaranteed by the ABI.

See also: file(1), "guestfs_vfs_type", "guestfs_lstat", "guestfs_is_file", "guestfs_is_blockdev" (etc), "guestfs_is_zero".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 0.9.1)

guestfs_file_architecture¶

 char *
 guestfs_file_architecture (guestfs_h *g,
                            const char *filename);

This detects the architecture of the binary "filename", and returns it if known.

Currently defined architectures are:

"i386"

This string is returned for all 32 bit i386, i486, i586, i686 binaries irrespective of the precise processor requirements of the binary.

"x86_64"

64 bit x86-64.

"sparc"

32 bit SPARC.

"sparc64"

64 bit SPARC V9 and above.

"ia64"

Intel Itanium.

"ppc"

32 bit Power PC.

"ppc64"

64 bit Power PC.

Libguestfs may return other architecture strings in future.

The function works on at least the following types of files:

• many types of Un*x and Linux binary
• many types of Un*x and Linux shared library
• Windows Win32 and Win64 binaries
• Windows Win32 and Win64 DLLs

  Win32 binaries and DLLs return "i386".

  Win64 binaries and DLLs return "x86_64".

• Linux kernel modules
• Linux new-style initrd images
• some non-x86 Linux vmlinuz kernels

What it can't do currently:

• static libraries (libfoo.a)
• Linux old-style initrd as compressed ext2 filesystem (RHEL 3)
• x86 Linux vmlinuz kernels

  x86 vmlinuz images (bzImage format) consist of a mix of 16-, 32- and compressed code, and are horribly hard to unpack. If you want to find the architecture of a kernel, use the architecture of the associated initrd or kernel module(s) instead.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_filesize¶

 int64_t
 guestfs_filesize (guestfs_h *g,
                   const char *file);

This command returns the size of "file" in bytes.

To get other stats about a file, use "guestfs_stat", "guestfs_lstat", "guestfs_is_dir", "guestfs_is_file" etc. To get the size of block devices, use "guestfs_blockdev_getsize64".

On error this function returns -1.

(Added in 1.0.82)

guestfs_filesystem_available¶

 int
 guestfs_filesystem_available (guestfs_h *g,
                               const char *filesystem);

Check whether libguestfs supports the named filesystem. The argument "filesystem" is a filesystem name, such as "ext3".

You must call "guestfs_launch" before using this command.

This is mainly useful as a negative test. If this returns true, it doesn't mean that a particular filesystem can be created or mounted, since filesystems can fail for other reasons such as it being a later version of the filesystem, or having incompatible features, or lacking the right mkfs.<fs> tool.

See also "guestfs_available", "AVAILABILITY" in guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.19.5)

guestfs_fill¶

 int
 guestfs_fill (guestfs_h *g,
               int c,
               int len,
               const char *path);

This command creates a new file called "path". The initial content of the file is "len" octets of "c", where "c" must be a number in the range "[0..255]".

To fill a file with zero bytes (sparsely), it is much more efficient to use "guestfs_truncate_size". To create a file with a pattern of repeating bytes use "guestfs_fill_pattern".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.0.79)

guestfs_fill_dir¶

 int
 guestfs_fill_dir (guestfs_h *g,
                   const char *dir,
                   int nr);

This function, useful for testing filesystems, creates "nr" empty files in the directory "dir" with names 00000000 through "nr-1" (ie. each file name is 8 digits long padded with zeroes).

This function returns 0 on success or -1 on error.

(Added in 1.19.32)

guestfs_fill_pattern¶

 int
 guestfs_fill_pattern (guestfs_h *g,
                       const char *pattern,
                       int len,
                       const char *path);

This function is like "guestfs_fill" except that it creates a new file of length "len" containing the repeating pattern of bytes in "pattern". The pattern is truncated if necessary to ensure the length of the file is exactly "len" bytes.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.3.12)

guestfs_find¶

 char **
 guestfs_find (guestfs_h *g,
               const char *directory);

This command lists out all files and directories, recursively, starting at "directory". It is essentially equivalent to running the shell command "find directory -print" but some post-processing happens on the output, described below.

This returns a list of strings without any prefix. Thus if the directory structure was:

 /tmp/a
 /tmp/b
 /tmp/c/d

then the returned list from "guestfs_find" "/tmp" would be 4 elements:

 a
 b
 c
 c/d

If "directory" is not a directory, then this command returns an error.

The returned list is sorted.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.0.27)

guestfs_find0¶

 int
 guestfs_find0 (guestfs_h *g,
                const char *directory,
                const char *files);

This command lists out all files and directories, recursively, starting at "directory", placing the resulting list in the external file called "files".

This command works the same way as "guestfs_find" with the following exceptions:

• The resulting list is written to an external file.
• Items (filenames) in the result are separated by "\0" characters. See find(1) option -print0.
• The result list is not sorted.

This function returns 0 on success or -1 on error.

(Added in 1.0.74)

guestfs_findfs_label¶

 char *
 guestfs_findfs_label (guestfs_h *g,
                       const char *label);

This command searches the filesystems and returns the one which has the given label. An error is returned if no such filesystem can be found.

To find the label of a filesystem, use "guestfs_vfs_label".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_findfs_uuid¶

 char *
 guestfs_findfs_uuid (guestfs_h *g,
                      const char *uuid);

This command searches the filesystems and returns the one which has the given UUID. An error is returned if no such filesystem can be found.

To find the UUID of a filesystem, use "guestfs_vfs_uuid".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_fsck¶

 int
 guestfs_fsck (guestfs_h *g,
               const char *fstype,
               const char *device);

This runs the filesystem checker (fsck) on "device" which should have filesystem type "fstype".

The returned integer is the status. See fsck(8) for the list of status codes from "fsck".

Notes:

• Multiple status codes can be summed together.
• A non-zero return code can mean "success", for example if errors have been corrected on the filesystem.
• Checking or repairing NTFS volumes is not supported (by linux-ntfs).

This command is entirely equivalent to running "fsck -a -t fstype device".

On error this function returns -1.

(Added in 1.0.16)

guestfs_get_append¶

 const char *
 guestfs_get_append (guestfs_h *g);

Return the additional kernel options which are added to the libguestfs appliance kernel command line.

If "NULL" then no options are added.

This function returns a string which may be NULL. There is no way to return an error from this function. The string is owned by the guest handle and must not be freed.

(Added in 1.0.26)

guestfs_get_attach_method¶

 char *
 guestfs_get_attach_method (guestfs_h *g);

Return the current attach method.

See "guestfs_set_attach_method" and "ATTACH METHOD" in guestfs(3).

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.9.8)

guestfs_get_autosync¶

 int
 guestfs_get_autosync (guestfs_h *g);

Get the autosync flag.

This function returns a C truth value on success or -1 on error.

(Added in 0.3)

guestfs_get_cachedir¶

 char *
 guestfs_get_cachedir (guestfs_h *g);

Get the directory used by the handle to store the appliance cache.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.58)

guestfs_get_direct¶

 int
 guestfs_get_direct (guestfs_h *g);

Return the direct appliance mode flag.

This function returns a C truth value on success or -1 on error.

(Added in 1.0.72)

guestfs_get_e2attrs¶

 char *
 guestfs_get_e2attrs (guestfs_h *g,
                      const char *file);

This returns the file attributes associated with "file".

The attributes are a set of bits associated with each inode which affect the behaviour of the file. The attributes are returned as a string of letters (described below). The string may be empty, indicating that no file attributes are set for this file.

These attributes are only present when the file is located on an ext2/3/4 filesystem. Using this call on other filesystem types will result in an error.

The characters (file attributes) in the returned string are currently:

'A'

When the file is accessed, its atime is not modified.

'a'

The file is append-only.

'c'

The file is compressed on-disk.

'D'

(Directories only.) Changes to this directory are written synchronously to disk.

'd'

The file is not a candidate for backup (see dump(8)).

'E'

The file has compression errors.

'e'

The file is using extents.

'h'

The file is storing its blocks in units of the filesystem blocksize instead of sectors.

'I'

(Directories only.) The directory is using hashed trees.

'i'

The file is immutable. It cannot be modified, deleted or renamed. No link can be created to this file.

'j'

The file is data-journaled.

's'

When the file is deleted, all its blocks will be zeroed.

'S'

Changes to this file are written synchronously to disk.

'T'

(Directories only.) This is a hint to the block allocator that subdirectories contained in this directory should be spread across blocks. If not present, the block allocator will try to group subdirectories together.

't'

For a file, this disables tail-merging. (Not used by upstream implementations of ext2.)

'u'

When the file is deleted, its blocks will be saved, allowing the file to be undeleted.

'X'

The raw contents of the compressed file may be accessed.

'Z'

The compressed file is dirty.

More file attributes may be added to this list later. Not all file attributes may be set for all kinds of files. For detailed information, consult the chattr(1) man page.

See also "guestfs_set_e2attrs".

Don't confuse these attributes with extended attributes (see "guestfs_getxattr").

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.17.31)

guestfs_get_e2generation¶

 int64_t
 guestfs_get_e2generation (guestfs_h *g,
                           const char *file);

This returns the ext2 file generation of a file. The generation (which used to be called the "version") is a number associated with an inode. This is most commonly used by NFS servers.

The generation is only present when the file is located on an ext2/3/4 filesystem. Using this call on other filesystem types will result in an error.

See "guestfs_set_e2generation".

On error this function returns -1.

(Added in 1.17.31)

guestfs_get_e2label¶

 char *
 guestfs_get_e2label (guestfs_h *g,
                      const char *device);

This function is deprecated. In new code, use the "guestfs_vfs_label" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This returns the ext2/3/4 filesystem label of the filesystem on "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.15)

guestfs_get_e2uuid¶

 char *
 guestfs_get_e2uuid (guestfs_h *g,
                     const char *device);

This function is deprecated. In new code, use the "guestfs_vfs_uuid" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This returns the ext2/3/4 filesystem UUID of the filesystem on "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.15)

guestfs_get_libvirt_requested_credential_challenge¶

 char *
 guestfs_get_libvirt_requested_credential_challenge (guestfs_h *g,
                                                     int index);

Get the challenge (provided by libvirt) for the "index"'th requested credential. If libvirt did not provide a challenge, this returns the empty string "".

See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.52)

guestfs_get_libvirt_requested_credential_defresult¶

 char *
 guestfs_get_libvirt_requested_credential_defresult (guestfs_h *g,
                                                     int index);

Get the default result (provided by libvirt) for the "index"'th requested credential. If libvirt did not provide a default result, this returns the empty string "".

See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.52)

guestfs_get_libvirt_requested_credential_prompt¶

 char *
 guestfs_get_libvirt_requested_credential_prompt (guestfs_h *g,
                                                  int index);

Get the prompt (provided by libvirt) for the "index"'th requested credential. If libvirt did not provide a prompt, this returns the empty string "".

See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.52)

guestfs_get_libvirt_requested_credentials¶

 char **
 guestfs_get_libvirt_requested_credentials (guestfs_h *g);

This should only be called during the event callback for events of type "GUESTFS_EVENT_LIBVIRT_AUTH".

Return the list of credentials requested by libvirt. Possible values are a subset of the strings provided when you called "guestfs_set_libvirt_supported_credentials".

See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.19.52)

guestfs_get_memsize¶

 int
 guestfs_get_memsize (guestfs_h *g);

This gets the memory size in megabytes allocated to the qemu subprocess.

If "guestfs_set_memsize" was not called on this handle, and if "LIBGUESTFS_MEMSIZE" was not set, then this returns the compiled-in default value for memsize.

For more information on the architecture of libguestfs, see guestfs(3).

On error this function returns -1.

(Added in 1.0.55)

guestfs_get_network¶

 int
 guestfs_get_network (guestfs_h *g);

This returns the enable network flag.

This function returns a C truth value on success or -1 on error.

(Added in 1.5.4)

guestfs_get_path¶

 const char *
 guestfs_get_path (guestfs_h *g);

Return the current search path.

This is always non-NULL. If it wasn't set already, then this will return the default path.

This function returns a string, or NULL on error. The string is owned by the guest handle and must not be freed.

(Added in 0.3)

guestfs_get_pgroup¶

 int
 guestfs_get_pgroup (guestfs_h *g);

This returns the process group flag.

This function returns a C truth value on success or -1 on error.

(Added in 1.11.18)

guestfs_get_pid¶

 int
 guestfs_get_pid (guestfs_h *g);

Return the process ID of the qemu subprocess. If there is no qemu subprocess, then this will return an error.

This is an internal call used for debugging and testing.

On error this function returns -1.

(Added in 1.0.56)

guestfs_get_qemu¶

 const char *
 guestfs_get_qemu (guestfs_h *g);

Return the current qemu binary.

This is always non-NULL. If it wasn't set already, then this will return the default qemu binary name.

This function returns a string, or NULL on error. The string is owned by the guest handle and must not be freed.

(Added in 1.0.6)

guestfs_get_recovery_proc¶

 int
 guestfs_get_recovery_proc (guestfs_h *g);

Return the recovery process enabled flag.

This function returns a C truth value on success or -1 on error.

(Added in 1.0.77)

guestfs_get_selinux¶

 int
 guestfs_get_selinux (guestfs_h *g);

This returns the current setting of the selinux flag which is passed to the appliance at boot time. See "guestfs_set_selinux".

For more information on the architecture of libguestfs, see guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.0.67)

guestfs_get_smp¶

 int
 guestfs_get_smp (guestfs_h *g);

This returns the number of virtual CPUs assigned to the appliance.

On error this function returns -1.

(Added in 1.13.15)

guestfs_get_state¶

 int
 guestfs_get_state (guestfs_h *g);

This returns the current state as an opaque integer. This is only useful for printing debug and internal error messages.

For more information on states, see guestfs(3).

On error this function returns -1.

(Added in 1.0.2)

guestfs_get_tmpdir¶

 char *
 guestfs_get_tmpdir (guestfs_h *g);

Get the directory used by the handle to store temporary files.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.58)

guestfs_get_trace¶

 int
 guestfs_get_trace (guestfs_h *g);

Return the command trace flag.

This function returns a C truth value on success or -1 on error.

(Added in 1.0.69)

guestfs_get_umask¶

 int
 guestfs_get_umask (guestfs_h *g);

Return the current umask. By default the umask is 022 unless it has been set by calling "guestfs_umask".

On error this function returns -1.

(Added in 1.3.4)

guestfs_get_verbose¶

 int
 guestfs_get_verbose (guestfs_h *g);

This returns the verbose messages flag.

This function returns a C truth value on success or -1 on error.

(Added in 0.3)

guestfs_getcon¶

 char *
 guestfs_getcon (guestfs_h *g);

This gets the SELinux security context of the daemon.

See the documentation about SELINUX in guestfs(3), and "guestfs_setcon"

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.67)

guestfs_getxattr¶

 char *
 guestfs_getxattr (guestfs_h *g,
                   const char *path,
                   const char *name,
                   size_t *size_r);

Get a single extended attribute from file "path" named "name". This call follows symlinks. If you want to lookup an extended attribute for the symlink itself, use "guestfs_lgetxattr".

Normally it is better to get all extended attributes from a file in one go by calling "guestfs_getxattrs". However some Linux filesystem implementations are buggy and do not provide a way to list out attributes. For these filesystems (notably ntfs-3g) you have to know the names of the extended attributes you want in advance and call this function.

Extended attribute values are blobs of binary data. If there is no extended attribute named "name", this returns an error.

See also: "guestfs_getxattrs", "guestfs_lgetxattr", attr(5).

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

(Added in 1.7.24)

guestfs_getxattrs¶

 struct guestfs_xattr_list *
 guestfs_getxattrs (guestfs_h *g,
                    const char *path);

This call lists the extended attributes of the file or directory "path".

At the system call level, this is a combination of the listxattr(2) and getxattr(2) calls.

See also: "guestfs_lgetxattrs", attr(5).

This function returns a "struct guestfs_xattr_list *", or NULL if there was an error. The caller must call "guestfs_free_xattr_list" after use.

(Added in 1.0.59)

guestfs_glob_expand¶

 char **
 guestfs_glob_expand (guestfs_h *g,
                      const char *pattern);

This command searches for all the pathnames matching "pattern" according to the wildcard expansion rules used by the shell.

If no paths match, then this returns an empty list (note: not an error).

It is just a wrapper around the C glob(3) function with flags "GLOB_MARK|GLOB_BRACE". See that manual page for more details.

Notice that there is no equivalent command for expanding a device name (eg. "/dev/sd*"). Use "guestfs_list_devices", "guestfs_list_partitions" etc functions instead.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.0.50)

guestfs_grep¶

 char **
 guestfs_grep (guestfs_h *g,
               const char *regex,
               const char *path);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_grep_opts" with no optional arguments.

(Added in 1.0.66)

guestfs_grep_opts¶

 char **
 guestfs_grep_opts (guestfs_h *g,
                    const char *regex,
                    const char *path,
                    ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_GREP_OPTS_EXTENDED, int extended,
 GUESTFS_GREP_OPTS_FIXED, int fixed,
 GUESTFS_GREP_OPTS_INSENSITIVE, int insensitive,
 GUESTFS_GREP_OPTS_COMPRESSED, int compressed,

This calls the external "grep" program and returns the matching lines.

The optional flags are:

"extended"

Use extended regular expressions. This is the same as using the -E flag.

"fixed"

Match fixed (don't use regular expressions). This is the same as using the -F flag.

"insensitive"

Match case-insensitive. This is the same as using the -i flag.

"compressed"

Use "zgrep" instead of "grep". This allows the input to be compress- or gzip-compressed.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.19.28)

guestfs_grep_opts_va¶

 char **
 guestfs_grep_opts_va (guestfs_h *g,
                       const char *regex,
                       const char *path,
                       va_list args);

This is the "va_list variant" of "guestfs_grep_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_grep_opts_argv¶

 char **
 guestfs_grep_opts_argv (guestfs_h *g,
                         const char *regex,
                         const char *path,
                         const struct guestfs_grep_opts_argv *optargs);

This is the "argv variant" of "guestfs_grep_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_grepi¶

 char **
 guestfs_grepi (guestfs_h *g,
                const char *regex,
                const char *path);

This function is deprecated. In new code, use the "guestfs_grep" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This calls the external "grep -i" program and returns the matching lines.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.66)

guestfs_grub_install¶

 int
 guestfs_grub_install (guestfs_h *g,
                       const char *root,
                       const char *device);

This command installs GRUB 1 (the Grand Unified Bootloader) on "device", with the root directory being "root".

Notes:

• There is currently no way in the API to install grub2, which is used by most modern Linux guests. It is possible to run the grub2 command from the guest, although see the caveats in "RUNNING COMMANDS" in guestfs(3).
• This uses "grub-install" from the host. Unfortunately grub is not always compatible with itself, so this only works in rather narrow circumstances. Careful testing with each guest version is advisable.
• If grub-install reports the error "No suitable drive was found in the generated device map." it may be that you need to create a "/boot/grub/device.map" file first that contains the mapping between grub device names and Linux device names. It is usually sufficient to create a file containing:

   (hd0) /dev/vda
      

  replacing "/dev/vda" with the name of the installation device.

This function returns 0 on success or -1 on error.

(Added in 1.0.17)

guestfs_head¶

 char **
 guestfs_head (guestfs_h *g,
               const char *path);

This command returns up to the first 10 lines of a file as a list of strings.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.54)

guestfs_head_n¶

 char **
 guestfs_head_n (guestfs_h *g,
                 int nrlines,
                 const char *path);

If the parameter "nrlines" is a positive number, this returns the first "nrlines" lines of the file "path".

If the parameter "nrlines" is a negative number, this returns lines from the file "path", excluding the last "nrlines" lines.

If the parameter "nrlines" is zero, this returns an empty list.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.54)

guestfs_hexdump¶

 char *
 guestfs_hexdump (guestfs_h *g,
                  const char *path);

This runs "hexdump -C" on the given "path". The result is the human-readable, canonical hex dump of the file.

This function returns a string, or NULL on error. The caller must free the returned string after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.22)

guestfs_hivex_close¶

 int
 guestfs_hivex_close (guestfs_h *g);

Close the current hivex handle.

This is a wrapper around the hivex(3) call of the same name.

This function returns 0 on success or -1 on error.

(Added in 1.19.35)

guestfs_hivex_commit¶

 int
 guestfs_hivex_commit (guestfs_h *g,
                       const char *filename);

Commit (write) changes to the hive.

If the optional "filename" parameter is null, then the changes are written back to the same hive that was opened. If this is not null then they are written to the alternate filename given and the original hive is left untouched.

This is a wrapper around the hivex(3) call of the same name.

This function returns 0 on success or -1 on error.

(Added in 1.19.35)

guestfs_hivex_node_add_child¶

 int64_t
 guestfs_hivex_node_add_child (guestfs_h *g,
                               int64_t parent,
                               const char *name);

Add a child node to "parent" named "name".

This is a wrapper around the hivex(3) call of the same name.

On error this function returns -1.

(Added in 1.19.35)

guestfs_hivex_node_children¶

 struct guestfs_hivex_node_list *
 guestfs_hivex_node_children (guestfs_h *g,
                              int64_t nodeh);

Return the list of nodes which are subkeys of "nodeh".

This is a wrapper around the hivex(3) call of the same name.

This function returns a "struct guestfs_hivex_node_list *", or NULL if there was an error. The caller must call "guestfs_free_hivex_node_list" after use.

(Added in 1.19.35)

guestfs_hivex_node_delete_child¶

 int
 guestfs_hivex_node_delete_child (guestfs_h *g,
                                  int64_t nodeh);

Delete "nodeh", recursively if necessary.

This is a wrapper around the hivex(3) call of the same name.

This function returns 0 on success or -1 on error.

(Added in 1.19.35)

guestfs_hivex_node_get_child¶

 int64_t
 guestfs_hivex_node_get_child (guestfs_h *g,
                               int64_t nodeh,
                               const char *name);

Return the child of "nodeh" with the name "name", if it exists. This can return 0 meaning the name was not found.

This is a wrapper around the hivex(3) call of the same name.

On error this function returns -1.

(Added in 1.19.35)

guestfs_hivex_node_get_value¶

 int64_t
 guestfs_hivex_node_get_value (guestfs_h *g,
                               int64_t nodeh,
                               const char *key);

Return the value attached to "nodeh" which has the name "key", if it exists. This can return 0 meaning the key was not found.

This is a wrapper around the hivex(3) call of the same name.

On error this function returns -1.

(Added in 1.19.35)

guestfs_hivex_node_name¶

 char *
 guestfs_hivex_node_name (guestfs_h *g,
                          int64_t nodeh);

Return the name of "nodeh".

This is a wrapper around the hivex(3) call of the same name.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.35)

guestfs_hivex_node_parent¶

 int64_t
 guestfs_hivex_node_parent (guestfs_h *g,
                            int64_t nodeh);

Return the parent node of "nodeh".

This is a wrapper around the hivex(3) call of the same name.

On error this function returns -1.

(Added in 1.19.35)

guestfs_hivex_node_set_value¶

 int
 guestfs_hivex_node_set_value (guestfs_h *g,
                               int64_t nodeh,
                               const char *key,
                               int64_t t,
                               const char *val,
                               size_t val_size);

Set or replace a single value under the node "nodeh". The "key" is the name, "t" is the type, and "val" is the data.

This is a wrapper around the hivex(3) call of the same name.

This function returns 0 on success or -1 on error.

(Added in 1.19.35)

guestfs_hivex_node_values¶

 struct guestfs_hivex_value_list *
 guestfs_hivex_node_values (guestfs_h *g,
                            int64_t nodeh);

Return the array of (key, datatype, data) tuples attached to "nodeh".

This is a wrapper around the hivex(3) call of the same name.

This function returns a "struct guestfs_hivex_value_list *", or NULL if there was an error. The caller must call "guestfs_free_hivex_value_list" after use.

(Added in 1.19.35)

guestfs_hivex_open¶

 int
 guestfs_hivex_open (guestfs_h *g,
                     const char *filename,
                     ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_HIVEX_OPEN_VERBOSE, int verbose,
 GUESTFS_HIVEX_OPEN_DEBUG, int debug,
 GUESTFS_HIVEX_OPEN_WRITE, int write,

Open the Windows Registry hive file named "filename". If there was any previous hivex handle associated with this guestfs session, then it is closed.

This is a wrapper around the hivex(3) call of the same name.

This function returns 0 on success or -1 on error.

(Added in 1.19.35)

guestfs_hivex_open_va¶

 int
 guestfs_hivex_open_va (guestfs_h *g,
                        const char *filename,
                        va_list args);

This is the "va_list variant" of "guestfs_hivex_open".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_hivex_open_argv¶

 int
 guestfs_hivex_open_argv (guestfs_h *g,
                          const char *filename,
                          const struct guestfs_hivex_open_argv *optargs);

This is the "argv variant" of "guestfs_hivex_open".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_hivex_root¶

 int64_t
 guestfs_hivex_root (guestfs_h *g);

Return the root node of the hive.

This is a wrapper around the hivex(3) call of the same name.

On error this function returns -1.

(Added in 1.19.35)

guestfs_hivex_value_key¶

 char *
 guestfs_hivex_value_key (guestfs_h *g,
                          int64_t valueh);

Return the key (name) field of a (key, datatype, data) tuple.

This is a wrapper around the hivex(3) call of the same name.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.35)

guestfs_hivex_value_type¶

 int64_t
 guestfs_hivex_value_type (guestfs_h *g,
                           int64_t valueh);

Return the data type field from a (key, datatype, data) tuple.

This is a wrapper around the hivex(3) call of the same name.

On error this function returns -1.

(Added in 1.19.35)

guestfs_hivex_value_utf8¶

 char *
 guestfs_hivex_value_utf8 (guestfs_h *g,
                           int64_t valueh);

This calls "guestfs_hivex_value_value" (which returns the data field from a hivex value tuple). It then assumes that the field is a UTF-16LE string and converts the result to UTF-8 (or if this is not possible, it returns an error).

This is useful for reading strings out of the Windows registry. However it is not foolproof because the registry is not strongly-typed and fields can contain arbitrary or unexpected data.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.35)

guestfs_hivex_value_value¶

 char *
 guestfs_hivex_value_value (guestfs_h *g,
                            int64_t valueh,
                            size_t *size_r);

Return the data field of a (key, datatype, data) tuple.

This is a wrapper around the hivex(3) call of the same name.

See also: "guestfs_hivex_value_utf8".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

(Added in 1.19.35)

guestfs_initrd_cat¶

 char *
 guestfs_initrd_cat (guestfs_h *g,
                     const char *initrdpath,
                     const char *filename,
                     size_t *size_r);

This command unpacks the file "filename" from the initrd file called "initrdpath". The filename must be given without the initial "/" character.

For example, in guestfish you could use the following command to examine the boot script (usually called "/init") contained in a Linux initrd or initramfs image:

 initrd-cat /boot/initrd-<version>.img init

See also "guestfs_initrd_list".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.84)

guestfs_initrd_list¶

 char **
 guestfs_initrd_list (guestfs_h *g,
                      const char *path);

This command lists out files contained in an initrd.

The files are listed without any initial "/" character. The files are listed in the order they appear (not necessarily alphabetical). Directory names are listed as separate items.

Old Linux kernels (2.4 and earlier) used a compressed ext2 filesystem as initrd. We only support the newer initramfs format (compressed cpio files).

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.0.54)

guestfs_inotify_add_watch¶

 int64_t
 guestfs_inotify_add_watch (guestfs_h *g,
                            const char *path,
                            int mask);

Watch "path" for the events listed in "mask".

Note that if "path" is a directory then events within that directory are watched, but this does not happen recursively (in subdirectories).

Note for non-C or non-Linux callers: the inotify events are defined by the Linux kernel ABI and are listed in "/usr/include/sys/inotify.h".

On error this function returns -1.

(Added in 1.0.66)

guestfs_inotify_close¶

 int
 guestfs_inotify_close (guestfs_h *g);

This closes the inotify handle which was previously opened by inotify_init. It removes all watches, throws away any pending events, and deallocates all resources.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_inotify_files¶

 char **
 guestfs_inotify_files (guestfs_h *g);

This function is a helpful wrapper around "guestfs_inotify_read" which just returns a list of pathnames of objects that were touched. The returned pathnames are sorted and deduplicated.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.0.66)

guestfs_inotify_init¶

 int
 guestfs_inotify_init (guestfs_h *g,
                       int maxevents);

This command creates a new inotify handle. The inotify subsystem can be used to notify events which happen to objects in the guest filesystem.

"maxevents" is the maximum number of events which will be queued up between calls to "guestfs_inotify_read" or "guestfs_inotify_files". If this is passed as 0, then the kernel (or previously set) default is used. For Linux 2.6.29 the default was 16384 events. Beyond this limit, the kernel throws away events, but records the fact that it threw them away by setting a flag "IN_Q_OVERFLOW" in the returned structure list (see "guestfs_inotify_read").

Before any events are generated, you have to add some watches to the internal watch list. See: "guestfs_inotify_add_watch" and "guestfs_inotify_rm_watch".

Queued up events should be read periodically by calling "guestfs_inotify_read" (or "guestfs_inotify_files" which is just a helpful wrapper around "guestfs_inotify_read"). If you don't read the events out often enough then you risk the internal queue overflowing.

The handle should be closed after use by calling "guestfs_inotify_close". This also removes any watches automatically.

See also inotify(7) for an overview of the inotify interface as exposed by the Linux kernel, which is roughly what we expose via libguestfs. Note that there is one global inotify handle per libguestfs instance.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_inotify_read¶

 struct guestfs_inotify_event_list *
 guestfs_inotify_read (guestfs_h *g);

Return the complete queue of events that have happened since the previous read call.

If no events have happened, this returns an empty list.

Note: In order to make sure that all events have been read, you must call this function repeatedly until it returns an empty list. The reason is that the call will read events up to the maximum appliance-to-host message size and leave remaining events in the queue.

This function returns a "struct guestfs_inotify_event_list *", or NULL if there was an error. The caller must call "guestfs_free_inotify_event_list" after use.

(Added in 1.0.66)

guestfs_inotify_rm_watch¶

 int
 guestfs_inotify_rm_watch (guestfs_h *g,
                           int wd);

Remove a previously defined inotify watch. See "guestfs_inotify_add_watch".

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_inspect_get_arch¶

 char *
 guestfs_inspect_get_arch (guestfs_h *g,
                           const char *root);

This returns the architecture of the inspected operating system. The possible return values are listed under "guestfs_file_architecture".

If the architecture could not be determined, then the string "unknown" is returned.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_inspect_get_distro¶

 char *
 guestfs_inspect_get_distro (guestfs_h *g,
                             const char *root);

This returns the distro (distribution) of the inspected operating system.

Currently defined distros are:

"archlinux"

Arch Linux.

"buildroot"

Buildroot-derived distro, but not one we specifically recognize.

"centos"

CentOS.

"cirros"

Cirros.

"debian"

Debian.

"fedora"

Fedora.

"freedos"

FreeDOS.

"gentoo"

Gentoo.

"linuxmint"

Linux Mint.

"mageia"

Mageia.

"mandriva"

Mandriva.

"meego"

MeeGo.

"openbsd"

OpenBSD.

"opensuse"

OpenSUSE.

"pardus"

Pardus.

"redhat-based"

Some Red Hat-derived distro.

"rhel"

Red Hat Enterprise Linux.

"scientificlinux"

Scientific Linux.

"slackware"

Slackware.

"sles"

SuSE Linux Enterprise Server or Desktop.

"suse-based"

Some openSuSE-derived distro.

"ttylinux"

ttylinux.

"ubuntu"

Ubuntu.

"unknown"

The distro could not be determined.

"windows"

Windows does not have distributions. This string is returned if the OS type is Windows.

Future versions of libguestfs may return other strings here. The caller should be prepared to handle any string.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_inspect_get_drive_mappings¶

 char **
 guestfs_inspect_get_drive_mappings (guestfs_h *g,
                                     const char *root);

This call is useful for Windows which uses a primitive system of assigning drive letters (like "C:") to partitions. This inspection API examines the Windows Registry to find out how disks/partitions are mapped to drive letters, and returns a hash table as in the example below:

 C      =>     /dev/vda2
 E      =>     /dev/vdb1
 F      =>     /dev/vdc1

Note that keys are drive letters. For Windows, the key is case insensitive and just contains the drive letter, without the customary colon separator character.

In future we may support other operating systems that also used drive letters, but the keys for those might not be case insensitive and might be longer than 1 character. For example in OS-9, hard drives were named "h0", "h1" etc.

For Windows guests, currently only hard drive mappings are returned. Removable disks (eg. DVD-ROMs) are ignored.

For guests that do not use drive mappings, or if the drive mappings could not be determined, this returns an empty hash table.

Please read "INSPECTION" in guestfs(3) for more details. See also "guestfs_inspect_get_mountpoints", "guestfs_inspect_get_filesystems".

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.9.17)

guestfs_inspect_get_filesystems¶

 char **
 guestfs_inspect_get_filesystems (guestfs_h *g,
                                  const char *root);

This returns a list of all the filesystems that we think are associated with this operating system. This includes the root filesystem, other ordinary filesystems, and non-mounted devices like swap partitions.

In the case of a multi-boot virtual machine, it is possible for a filesystem to be shared between operating systems.

Please read "INSPECTION" in guestfs(3) for more details. See also "guestfs_inspect_get_mountpoints".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.5.3)

guestfs_inspect_get_format¶

 char *
 guestfs_inspect_get_format (guestfs_h *g,
                             const char *root);

This returns the format of the inspected operating system. You can use it to detect install images, live CDs and similar.

Currently defined formats are:

"installed"

This is an installed operating system.

"installer"

The disk image being inspected is not an installed operating system, but a bootable install disk, live CD, or similar.

"unknown"

The format of this disk image is not known.

Future versions of libguestfs may return other strings here. The caller should be prepared to handle any string.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.9.4)

guestfs_inspect_get_hostname¶

 char *
 guestfs_inspect_get_hostname (guestfs_h *g,
                               const char *root);

This function returns the hostname of the operating system as found by inspection of the guest's configuration files.

If the hostname could not be determined, then the string "unknown" is returned.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.7.9)

guestfs_inspect_get_icon¶

 char *
 guestfs_inspect_get_icon (guestfs_h *g,
                           const char *root,
                           size_t *size_r,
                           ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_INSPECT_GET_ICON_FAVICON, int favicon,
 GUESTFS_INSPECT_GET_ICON_HIGHQUALITY, int highquality,

This function returns an icon corresponding to the inspected operating system. The icon is returned as a buffer containing a PNG image (re-encoded to PNG if necessary).

If it was not possible to get an icon this function returns a zero-length (non-NULL) buffer. Callers must check for this case.

Libguestfs will start by looking for a file called "/etc/favicon.png" or "C:\etc\favicon.png" and if it has the correct format, the contents of this file will be returned. You can disable favicons by passing the optional "favicon" boolean as false (default is true).

If finding the favicon fails, then we look in other places in the guest for a suitable icon.

If the optional "highquality" boolean is true then only high quality icons are returned, which means only icons of high resolution with an alpha channel. The default (false) is to return any icon we can, even if it is of substandard quality.

Notes:

• Unlike most other inspection API calls, the guest's disks must be mounted up before you call this, since it needs to read information from the guest filesystem during the call.
• Security: The icon data comes from the untrusted guest, and should be treated with caution. PNG files have been known to contain exploits. Ensure that libpng (or other relevant libraries) are fully up to date before trying to process or display the icon.
• The PNG image returned can be any size. It might not be square. Libguestfs tries to return the largest, highest quality icon available. The application must scale the icon to the required size.
• Extracting icons from Windows guests requires the external "wrestool" program from the "icoutils" package, and several programs ("bmptopnm", "pnmtopng", "pamcut") from the "netpbm" package. These must be installed separately.
• Operating system icons are usually trademarks. Seek legal advice before using trademarks in applications.

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

(Added in 1.11.12)

guestfs_inspect_get_icon_va¶

 char *
 guestfs_inspect_get_icon_va (guestfs_h *g,
                              const char *root,
                              size_t *size_r,
                              va_list args);

This is the "va_list variant" of "guestfs_inspect_get_icon".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_inspect_get_icon_argv¶

 char *
 guestfs_inspect_get_icon_argv (guestfs_h *g,
                                const char *root,
                                size_t *size_r,
                                const struct guestfs_inspect_get_icon_argv *optargs);

This is the "argv variant" of "guestfs_inspect_get_icon".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_inspect_get_major_version¶

 int
 guestfs_inspect_get_major_version (guestfs_h *g,
                                    const char *root);

This returns the major version number of the inspected operating system.

Windows uses a consistent versioning scheme which is not reflected in the popular public names used by the operating system. Notably the operating system known as "Windows 7" is really version 6.1 (ie. major = 6, minor = 1). You can find out the real versions corresponding to releases of Windows by consulting Wikipedia or MSDN.

If the version could not be determined, then 0 is returned.

Please read "INSPECTION" in guestfs(3) for more details.

On error this function returns -1.

(Added in 1.5.3)

guestfs_inspect_get_minor_version¶

 int
 guestfs_inspect_get_minor_version (guestfs_h *g,
                                    const char *root);

This returns the minor version number of the inspected operating system.

If the version could not be determined, then 0 is returned.

Please read "INSPECTION" in guestfs(3) for more details. See also "guestfs_inspect_get_major_version".

On error this function returns -1.

(Added in 1.5.3)

guestfs_inspect_get_mountpoints¶

 char **
 guestfs_inspect_get_mountpoints (guestfs_h *g,
                                  const char *root);

This returns a hash of where we think the filesystems associated with this operating system should be mounted. Callers should note that this is at best an educated guess made by reading configuration files such as "/etc/fstab". In particular note that this may return filesystems which are non-existent or not mountable and callers should be prepared to handle or ignore failures if they try to mount them.

Each element in the returned hashtable has a key which is the path of the mountpoint (eg. "/boot") and a value which is the filesystem that would be mounted there (eg. "/dev/sda1").

Non-mounted devices such as swap devices are not returned in this list.

For operating systems like Windows which still use drive letters, this call will only return an entry for the first drive "mounted on" "/". For information about the mapping of drive letters to partitions, see "guestfs_inspect_get_drive_mappings".

Please read "INSPECTION" in guestfs(3) for more details. See also "guestfs_inspect_get_filesystems".

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.5.3)

guestfs_inspect_get_package_format¶

 char *
 guestfs_inspect_get_package_format (guestfs_h *g,
                                     const char *root);

This function and "guestfs_inspect_get_package_management" return the package format and package management tool used by the inspected operating system. For example for Fedora these functions would return "rpm" (package format) and "yum" (package management).

This returns the string "unknown" if we could not determine the package format or if the operating system does not have a real packaging system (eg. Windows).

Possible strings include: "rpm", "deb", "ebuild", "pisi", "pacman", "pkgsrc". Future versions of libguestfs may return other strings.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.7.5)

guestfs_inspect_get_package_management¶

 char *
 guestfs_inspect_get_package_management (guestfs_h *g,
                                         const char *root);

"guestfs_inspect_get_package_format" and this function return the package format and package management tool used by the inspected operating system. For example for Fedora these functions would return "rpm" (package format) and "yum" (package management).

This returns the string "unknown" if we could not determine the package management tool or if the operating system does not have a real packaging system (eg. Windows).

Possible strings include: "yum", "up2date", "apt" (for all Debian derivatives), "portage", "pisi", "pacman", "urpmi", "zypper". Future versions of libguestfs may return other strings.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.7.5)

guestfs_inspect_get_product_name¶

 char *
 guestfs_inspect_get_product_name (guestfs_h *g,
                                   const char *root);

This returns the product name of the inspected operating system. The product name is generally some freeform string which can be displayed to the user, but should not be parsed by programs.

If the product name could not be determined, then the string "unknown" is returned.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_inspect_get_product_variant¶

 char *
 guestfs_inspect_get_product_variant (guestfs_h *g,
                                      const char *root);

This returns the product variant of the inspected operating system.

For Windows guests, this returns the contents of the Registry key "HKLM\Software\Microsoft\Windows NT\CurrentVersion" "InstallationType" which is usually a string such as "Client" or "Server" (other values are possible). This can be used to distinguish consumer and enterprise versions of Windows that have the same version number (for example, Windows 7 and Windows 2008 Server are both version 6.1, but the former is "Client" and the latter is "Server").

For enterprise Linux guests, in future we intend this to return the product variant such as "Desktop", "Server" and so on. But this is not implemented at present.

If the product variant could not be determined, then the string "unknown" is returned.

Please read "INSPECTION" in guestfs(3) for more details. See also "guestfs_inspect_get_product_name", "guestfs_inspect_get_major_version".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.9.13)

guestfs_inspect_get_roots¶

 char **
 guestfs_inspect_get_roots (guestfs_h *g);

This function is a convenient way to get the list of root devices, as returned from a previous call to "guestfs_inspect_os", but without redoing the whole inspection process.

This returns an empty list if either no root devices were found or the caller has not called "guestfs_inspect_os".

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.7.3)

guestfs_inspect_get_type¶

 char *
 guestfs_inspect_get_type (guestfs_h *g,
                           const char *root);

This returns the type of the inspected operating system. Currently defined types are:

"linux"

Any Linux-based operating system.

"windows"

Any Microsoft Windows operating system.

"freebsd"

FreeBSD.

"netbsd"

NetBSD.

"openbsd"

OpenBSD.

"hurd"

GNU/Hurd.

"dos"

MS-DOS, FreeDOS and others.

"unknown"

The operating system type could not be determined.

Future versions of libguestfs may return other strings here. The caller should be prepared to handle any string.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.3)

guestfs_inspect_get_windows_current_control_set¶

 char *
 guestfs_inspect_get_windows_current_control_set (guestfs_h *g,
                                                  const char *root);

This returns the Windows CurrentControlSet of the inspected guest. The CurrentControlSet is a registry key name such as "ControlSet001".

This call assumes that the guest is Windows and that the Registry could be examined by inspection. If this is not the case then an error is returned.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.9.17)

guestfs_inspect_get_windows_systemroot¶

 char *
 guestfs_inspect_get_windows_systemroot (guestfs_h *g,
                                         const char *root);

This returns the Windows systemroot of the inspected guest. The systemroot is a directory path such as "/WINDOWS".

This call assumes that the guest is Windows and that the systemroot could be determined by inspection. If this is not the case then an error is returned.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.25)

guestfs_inspect_is_live¶

 int
 guestfs_inspect_is_live (guestfs_h *g,
                          const char *root);

If "guestfs_inspect_get_format" returns "installer" (this is an install disk), then this returns true if a live image was detected on the disk.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a C truth value on success or -1 on error.

(Added in 1.9.4)

guestfs_inspect_is_multipart¶

 int
 guestfs_inspect_is_multipart (guestfs_h *g,
                               const char *root);

If "guestfs_inspect_get_format" returns "installer" (this is an install disk), then this returns true if the disk is part of a set.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a C truth value on success or -1 on error.

(Added in 1.9.4)

guestfs_inspect_is_netinst¶

 int
 guestfs_inspect_is_netinst (guestfs_h *g,
                             const char *root);

If "guestfs_inspect_get_format" returns "installer" (this is an install disk), then this returns true if the disk is a network installer, ie. not a self-contained install CD but one which is likely to require network access to complete the install.

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a C truth value on success or -1 on error.

(Added in 1.9.4)

guestfs_inspect_list_applications¶

 struct guestfs_application_list *
 guestfs_inspect_list_applications (guestfs_h *g,
                                    const char *root);

This function is deprecated. In new code, use the "guestfs_inspect_list_applications2" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

Return the list of applications installed in the operating system.

Note: This call works differently from other parts of the inspection API. You have to call "guestfs_inspect_os", then "guestfs_inspect_get_mountpoints", then mount up the disks, before calling this. Listing applications is a significantly more difficult operation which requires access to the full filesystem. Also note that unlike the other "guestfs_inspect_get_*" calls which are just returning data cached in the libguestfs handle, this call actually reads parts of the mounted filesystems during the call.

This returns an empty list if the inspection code was not able to determine the list of applications.

The application structure contains the following fields:

"app_name"

The name of the application. For Red Hat-derived and Debian-derived Linux guests, this is the package name.

"app_display_name"

The display name of the application, sometimes localized to the install language of the guest operating system.

If unavailable this is returned as an empty string "". Callers needing to display something can use "app_name" instead.

"app_epoch"

For package managers which use epochs, this contains the epoch of the package (an integer). If unavailable, this is returned as 0.

"app_version"

The version string of the application or package. If unavailable this is returned as an empty string "".

"app_release"

The release string of the application or package, for package managers that use this. If unavailable this is returned as an empty string "".

"app_install_path"

The installation path of the application (on operating systems such as Windows which use installation paths). This path is in the format used by the guest operating system, it is not a libguestfs path.

If unavailable this is returned as an empty string "".

"app_trans_path"

The install path translated into a libguestfs path. If unavailable this is returned as an empty string "".

"app_publisher"

The name of the publisher of the application, for package managers that use this. If unavailable this is returned as an empty string "".

"app_url"

The URL (eg. upstream URL) of the application. If unavailable this is returned as an empty string "".

"app_source_package"

For packaging systems which support this, the name of the source package. If unavailable this is returned as an empty string "".

"app_summary"

A short (usually one line) description of the application or package. If unavailable this is returned as an empty string "".

"app_description"

A longer description of the application or package. If unavailable this is returned as an empty string "".

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a "struct guestfs_application_list *", or NULL if there was an error. The caller must call "guestfs_free_application_list" after use.

(Added in 1.7.8)

guestfs_inspect_list_applications2¶

 struct guestfs_application2_list *
 guestfs_inspect_list_applications2 (guestfs_h *g,
                                     const char *root);

Return the list of applications installed in the operating system.

Note: This call works differently from other parts of the inspection API. You have to call "guestfs_inspect_os", then "guestfs_inspect_get_mountpoints", then mount up the disks, before calling this. Listing applications is a significantly more difficult operation which requires access to the full filesystem. Also note that unlike the other "guestfs_inspect_get_*" calls which are just returning data cached in the libguestfs handle, this call actually reads parts of the mounted filesystems during the call.

This returns an empty list if the inspection code was not able to determine the list of applications.

The application structure contains the following fields:

"app2_name"

The name of the application. For Red Hat-derived and Debian-derived Linux guests, this is the package name.

"app2_display_name"

The display name of the application, sometimes localized to the install language of the guest operating system.

If unavailable this is returned as an empty string "". Callers needing to display something can use "app2_name" instead.

"app2_epoch"

For package managers which use epochs, this contains the epoch of the package (an integer). If unavailable, this is returned as 0.

"app2_version"

The version string of the application or package. If unavailable this is returned as an empty string "".

"app2_release"

The release string of the application or package, for package managers that use this. If unavailable this is returned as an empty string "".

"app2_arch"

The architecture string of the application or package, for package managers that use this. If unavailable this is returned as an empty string "".

"app2_install_path"

The installation path of the application (on operating systems such as Windows which use installation paths). This path is in the format used by the guest operating system, it is not a libguestfs path.

If unavailable this is returned as an empty string "".

"app2_trans_path"

The install path translated into a libguestfs path. If unavailable this is returned as an empty string "".

"app2_publisher"

The name of the publisher of the application, for package managers that use this. If unavailable this is returned as an empty string "".

"app2_url"

The URL (eg. upstream URL) of the application. If unavailable this is returned as an empty string "".

"app2_source_package"

For packaging systems which support this, the name of the source package. If unavailable this is returned as an empty string "".

"app2_summary"

A short (usually one line) description of the application or package. If unavailable this is returned as an empty string "".

"app2_description"

A longer description of the application or package. If unavailable this is returned as an empty string "".

Please read "INSPECTION" in guestfs(3) for more details.

This function returns a "struct guestfs_application2_list *", or NULL if there was an error. The caller must call "guestfs_free_application2_list" after use.

(Added in 1.19.56)

guestfs_inspect_os¶

 char **
 guestfs_inspect_os (guestfs_h *g);

This function uses other libguestfs functions and certain heuristics to inspect the disk(s) (usually disks belonging to a virtual machine), looking for operating systems.

The list returned is empty if no operating systems were found.

If one operating system was found, then this returns a list with a single element, which is the name of the root filesystem of this operating system. It is also possible for this function to return a list containing more than one element, indicating a dual-boot or multi-boot virtual machine, with each element being the root filesystem of one of the operating systems.

You can pass the root string(s) returned to other "guestfs_inspect_get_*" functions in order to query further information about each operating system, such as the name and version.

This function uses other libguestfs features such as "guestfs_mount_ro" and "guestfs_umount_all" in order to mount and unmount filesystems and look at the contents. This should be called with no disks currently mounted. The function may also use Augeas, so any existing Augeas handle will be closed.

This function cannot decrypt encrypted disks. The caller must do that first (supplying the necessary keys) if the disk is encrypted.

Please read "INSPECTION" in guestfs(3) for more details.

See also "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.5.3)

guestfs_is_blockdev¶

 int
 guestfs_is_blockdev (guestfs_h *g,
                      const char *path);

This returns "true" if and only if there is a block device with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 1.5.10)

guestfs_is_busy¶

 int
 guestfs_is_busy (guestfs_h *g);

This always returns false. This function is deprecated with no replacement. Do not use this function.

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.0.2)

guestfs_is_chardev¶

 int
 guestfs_is_chardev (guestfs_h *g,
                     const char *path);

This returns "true" if and only if there is a character device with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 1.5.10)

guestfs_is_config¶

 int
 guestfs_is_config (guestfs_h *g);

This returns true iff this handle is being configured (in the "CONFIG" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.0.2)

guestfs_is_dir¶

 int
 guestfs_is_dir (guestfs_h *g,
                 const char *path);

This returns "true" if and only if there is a directory with the given "path" name. Note that it returns false for other objects like files.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 0.8)

guestfs_is_fifo¶

 int
 guestfs_is_fifo (guestfs_h *g,
                  const char *path);

This returns "true" if and only if there is a FIFO (named pipe) with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 1.5.10)

guestfs_is_file¶

 int
 guestfs_is_file (guestfs_h *g,
                  const char *path);

This returns "true" if and only if there is a regular file with the given "path" name. Note that it returns false for other objects like directories.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 0.8)

guestfs_is_launching¶

 int
 guestfs_is_launching (guestfs_h *g);

This returns true iff this handle is launching the subprocess (in the "LAUNCHING" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.0.2)

guestfs_is_lv¶

 int
 guestfs_is_lv (guestfs_h *g,
                const char *device);

This command tests whether "device" is a logical volume, and returns true iff this is the case.

This function returns a C truth value on success or -1 on error.

(Added in 1.5.3)

guestfs_is_ready¶

 int
 guestfs_is_ready (guestfs_h *g);

This returns true iff this handle is ready to accept commands (in the "READY" state).

For more information on states, see guestfs(3).

This function returns a C truth value on success or -1 on error.

(Added in 1.0.2)

guestfs_is_socket¶

 int
 guestfs_is_socket (guestfs_h *g,
                    const char *path);

This returns "true" if and only if there is a Unix domain socket with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 1.5.10)

guestfs_is_symlink¶

 int
 guestfs_is_symlink (guestfs_h *g,
                     const char *path);

This returns "true" if and only if there is a symbolic link with the given "path" name.

See also "guestfs_stat".

This function returns a C truth value on success or -1 on error.

(Added in 1.5.10)

guestfs_is_zero¶

 int
 guestfs_is_zero (guestfs_h *g,
                  const char *path);

This returns true iff the file exists and the file is empty or it contains all zero bytes.

This function returns a C truth value on success or -1 on error.

(Added in 1.11.8)

guestfs_is_zero_device¶

 int
 guestfs_is_zero_device (guestfs_h *g,
                         const char *device);

This returns true iff the device exists and contains all zero bytes.

Note that for large devices this can take a long time to run.

This function returns a C truth value on success or -1 on error.

(Added in 1.11.8)

guestfs_isoinfo¶

 struct guestfs_isoinfo *
 guestfs_isoinfo (guestfs_h *g,
                  const char *isofile);

This is the same as "guestfs_isoinfo_device" except that it works for an ISO file located inside some other mounted filesystem. Note that in the common case where you have added an ISO file as a libguestfs device, you would not call this. Instead you would call "guestfs_isoinfo_device".

This function returns a "struct guestfs_isoinfo *", or NULL if there was an error. The caller must call "guestfs_free_isoinfo" after use.

(Added in 1.17.19)

guestfs_isoinfo_device¶

 struct guestfs_isoinfo *
 guestfs_isoinfo_device (guestfs_h *g,
                         const char *device);

"device" is an ISO device. This returns a struct of information read from the primary volume descriptor (the ISO equivalent of the superblock) of the device.

Usually it is more efficient to use the isoinfo(1) command with the -d option on the host to analyze ISO files, instead of going through libguestfs.

For information on the primary volume descriptor fields, see http://wiki.osdev.org/ISO_9660#The_Primary_Volume_Descriptor

This function returns a "struct guestfs_isoinfo *", or NULL if there was an error. The caller must call "guestfs_free_isoinfo" after use.

(Added in 1.17.19)

guestfs_kill_subprocess¶

 int
 guestfs_kill_subprocess (guestfs_h *g);

This function is deprecated. In new code, use the "guestfs_shutdown" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This kills the qemu subprocess.

Do not call this. See: "guestfs_shutdown" instead.

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_launch¶

 int
 guestfs_launch (guestfs_h *g);

Internally libguestfs is implemented by running a virtual machine using qemu(1).

You should call this after configuring the handle (eg. adding drives) but before performing any actions.

Do not call "guestfs_launch" twice on the same handle. Although it will not give an error (for historical reasons), the precise behaviour when you do this is not well defined. Handles are very cheap to create, so create a new one for each launch.

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 0.3)

guestfs_lchown¶

 int
 guestfs_lchown (guestfs_h *g,
                 int owner,
                 int group,
                 const char *path);

Change the file owner to "owner" and group to "group". This is like "guestfs_chown" but if "path" is a symlink then the link itself is changed, not the target.

Only numeric uid and gid are supported. If you want to use names, you will need to locate and parse the password file yourself (Augeas support makes this relatively easy).

This function returns 0 on success or -1 on error.

(Added in 1.0.77)

guestfs_ldmtool_create_all¶

 int
 guestfs_ldmtool_create_all (guestfs_h *g);

This function scans all block devices looking for Windows dynamic disk volumes and partitions, and creates devices for any that were found.

Call "guestfs_list_ldm_volumes" and "guestfs_list_ldm_partitions" to return all devices.

Note that you don't normally need to call this explicitly, since it is done automatically at "guestfs_launch" time. However you might want to call this function if you have hotplugged disks or have just created a Windows dynamic disk.

This function returns 0 on success or -1 on error.

guestfs_ldmtool_diskgroup_disks¶

 char **
 guestfs_ldmtool_diskgroup_disks (guestfs_h *g,
                                  const char *diskgroup);

Return the disks in a Windows dynamic disk group. The "diskgroup" parameter should be the GUID of a disk group, one element from the list returned by "guestfs_ldmtool_scan".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_ldmtool_diskgroup_name¶

 char *
 guestfs_ldmtool_diskgroup_name (guestfs_h *g,
                                 const char *diskgroup);

Return the name of a Windows dynamic disk group. The "diskgroup" parameter should be the GUID of a disk group, one element from the list returned by "guestfs_ldmtool_scan".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_ldmtool_diskgroup_volumes¶

 char **
 guestfs_ldmtool_diskgroup_volumes (guestfs_h *g,
                                    const char *diskgroup);

Return the volumes in a Windows dynamic disk group. The "diskgroup" parameter should be the GUID of a disk group, one element from the list returned by "guestfs_ldmtool_scan".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_ldmtool_remove_all¶

 int
 guestfs_ldmtool_remove_all (guestfs_h *g);

This is essentially the opposite of "guestfs_ldmtool_create_all". It removes the device mapper mappings for all Windows dynamic disk volumes

This function returns 0 on success or -1 on error.

guestfs_ldmtool_scan¶

 char **
 guestfs_ldmtool_scan (guestfs_h *g);

This function scans for Windows dynamic disks. It returns a list of identifiers (GUIDs) for all disk groups that were found. These identifiers can be passed to other "guestfs_ldmtool_*" functions.

This function scans all block devices. To scan a subset of block devices, call "guestfs_ldmtool_scan_devices" instead.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_ldmtool_scan_devices¶

 char **
 guestfs_ldmtool_scan_devices (guestfs_h *g,
                               char *const *devices);

This function scans for Windows dynamic disks. It returns a list of identifiers (GUIDs) for all disk groups that were found. These identifiers can be passed to other "guestfs_ldmtool_*" functions.

The parameter "devices" is a list of block devices which are scanned. If this list is empty, all block devices are scanned.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_ldmtool_volume_hint¶

 char *
 guestfs_ldmtool_volume_hint (guestfs_h *g,
                              const char *diskgroup,
                              const char *volume);

Return the hint field of the volume named "volume" in the disk group with GUID "diskgroup". This may not be defined, in which case the empty string is returned. The hint field is often, though not always, the name of a Windows drive, eg. "E:".

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_ldmtool_volume_partitions¶

 char **
 guestfs_ldmtool_volume_partitions (guestfs_h *g,
                                    const char *diskgroup,
                                    const char *volume);

Return the list of partitions in the volume named "volume" in the disk group with GUID "diskgroup".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_ldmtool_volume_type¶

 char *
 guestfs_ldmtool_volume_type (guestfs_h *g,
                              const char *diskgroup,
                              const char *volume);

Return the type of the volume named "volume" in the disk group with GUID "diskgroup".

Possible volume types that can be returned here include: "simple", "spanned", "striped", "mirrored", "raid5". Other types may also be returned.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_lgetxattr¶

 char *
 guestfs_lgetxattr (guestfs_h *g,
                    const char *path,
                    const char *name,
                    size_t *size_r);

Get a single extended attribute from file "path" named "name". If "path" is a symlink, then this call returns an extended attribute from the symlink.

Normally it is better to get all extended attributes from a file in one go by calling "guestfs_getxattrs". However some Linux filesystem implementations are buggy and do not provide a way to list out attributes. For these filesystems (notably ntfs-3g) you have to know the names of the extended attributes you want in advance and call this function.

Extended attribute values are blobs of binary data. If there is no extended attribute named "name", this returns an error.

See also: "guestfs_lgetxattrs", "guestfs_getxattr", attr(5).

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

(Added in 1.7.24)

guestfs_lgetxattrs¶

 struct guestfs_xattr_list *
 guestfs_lgetxattrs (guestfs_h *g,
                     const char *path);

This is the same as "guestfs_getxattrs", but if "path" is a symbolic link, then it returns the extended attributes of the link itself.

This function returns a "struct guestfs_xattr_list *", or NULL if there was an error. The caller must call "guestfs_free_xattr_list" after use.

(Added in 1.0.59)

guestfs_list_devices¶

 char **
 guestfs_list_devices (guestfs_h *g);

List all the block devices.

The full block device names are returned, eg. "/dev/sda".

See also "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.4)

guestfs_list_disk_labels¶

 char **
 guestfs_list_disk_labels (guestfs_h *g);

If you add drives using the optional "label" parameter of "guestfs_add_drive_opts", you can use this call to map between disk labels, and raw block device and partition names (like "/dev/sda" and "/dev/sda1").

This returns a hashtable, where keys are the disk labels (without the "/dev/disk/guestfs" prefix), and the values are the full raw block device and partition names (eg. "/dev/sda" and "/dev/sda1").

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.19.49)

guestfs_list_dm_devices¶

 char **
 guestfs_list_dm_devices (guestfs_h *g);

List all device mapper devices.

The returned list contains "/dev/mapper/*" devices, eg. ones created by a previous call to "guestfs_luks_open".

Device mapper devices which correspond to logical volumes are not returned in this list. Call "guestfs_lvs" if you want to list logical volumes.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.11.15)

guestfs_list_filesystems¶

 char **
 guestfs_list_filesystems (guestfs_h *g);

This inspection command looks for filesystems on partitions, block devices and logical volumes, returning a list of devices containing filesystems and their type.

The return value is a hash, where the keys are the devices containing filesystems, and the values are the filesystem types. For example:

 "/dev/sda1" => "ntfs"
 "/dev/sda2" => "ext2"
 "/dev/vg_guest/lv_root" => "ext4"
 "/dev/vg_guest/lv_swap" => "swap"

The value can have the special value "unknown", meaning the content of the device is undetermined or empty. "swap" means a Linux swap partition.

This command runs other libguestfs commands, which might include "guestfs_mount" and "guestfs_umount", and therefore you should use this soon after launch and only when nothing is mounted.

Not all of the filesystems returned will be mountable. In particular, swap partitions are returned in the list. Also this command does not check that each filesystem found is valid and mountable, and some filesystems might be mountable but require special options. Filesystems may not all belong to a single logical operating system (use "guestfs_inspect_os" to look for OSes).

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.5.15)

guestfs_list_ldm_partitions¶

 char **
 guestfs_list_ldm_partitions (guestfs_h *g);

This function returns all Windows dynamic disk partitions that were found at launch time. It returns a list of device names.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_list_ldm_volumes¶

 char **
 guestfs_list_ldm_volumes (guestfs_h *g);

This function returns all Windows dynamic disk volumes that were found at launch time. It returns a list of device names.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

guestfs_list_md_devices¶

 char **
 guestfs_list_md_devices (guestfs_h *g);

List all Linux md devices.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.15.4)

guestfs_list_partitions¶

 char **
 guestfs_list_partitions (guestfs_h *g);

List all the partitions detected on all block devices.

The full partition device names are returned, eg. "/dev/sda1"

This does not return logical volumes. For that you will need to call "guestfs_lvs".

See also "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.4)

guestfs_ll¶

 char *
 guestfs_ll (guestfs_h *g,
             const char *directory);

List the files in "directory" (relative to the root directory, there is no cwd) in the format of 'ls -la'.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 0.4)

guestfs_llz¶

 char *
 guestfs_llz (guestfs_h *g,
              const char *directory);

List the files in "directory" in the format of 'ls -laZ'.

This command is mostly useful for interactive sessions. It is not intended that you try to parse the output string.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.17.6)

guestfs_ln¶

 int
 guestfs_ln (guestfs_h *g,
             const char *target,
             const char *linkname);

This command creates a hard link using the "ln" command.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_ln_f¶

 int
 guestfs_ln_f (guestfs_h *g,
               const char *target,
               const char *linkname);

This command creates a hard link using the "ln -f" command. The -f option removes the link ("linkname") if it exists already.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_ln_s¶

 int
 guestfs_ln_s (guestfs_h *g,
               const char *target,
               const char *linkname);

This command creates a symbolic link using the "ln -s" command.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_ln_sf¶

 int
 guestfs_ln_sf (guestfs_h *g,
                const char *target,
                const char *linkname);

This command creates a symbolic link using the "ln -sf" command, The -f option removes the link ("linkname") if it exists already.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_lremovexattr¶

 int
 guestfs_lremovexattr (guestfs_h *g,
                       const char *xattr,
                       const char *path);

This is the same as "guestfs_removexattr", but if "path" is a symbolic link, then it removes an extended attribute of the link itself.

This function returns 0 on success or -1 on error.

(Added in 1.0.59)

guestfs_ls¶

 char **
 guestfs_ls (guestfs_h *g,
             const char *directory);

List the files in "directory" (relative to the root directory, there is no cwd). The '.' and '..' entries are not returned, but hidden files are shown.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.4)

guestfs_ls0¶

 int
 guestfs_ls0 (guestfs_h *g,
              const char *dir,
              const char *filenames);

This specialized command is used to get a listing of the filenames in the directory "dir". The list of filenames is written to the local file "filenames" (on the host).

In the output file, the filenames are separated by "\0" characters.

"." and ".." are not returned. The filenames are not sorted.

This function returns 0 on success or -1 on error.

(Added in 1.19.32)

guestfs_lsetxattr¶

 int
 guestfs_lsetxattr (guestfs_h *g,
                    const char *xattr,
                    const char *val,
                    int vallen,
                    const char *path);

This is the same as "guestfs_setxattr", but if "path" is a symbolic link, then it sets an extended attribute of the link itself.

This function returns 0 on success or -1 on error.

(Added in 1.0.59)

guestfs_lstat¶

 struct guestfs_stat *
 guestfs_lstat (guestfs_h *g,
                const char *path);

Returns file information for the given "path".

This is the same as "guestfs_stat" except that if "path" is a symbolic link, then the link is stat-ed, not the file it refers to.

This is the same as the lstat(2) system call.

This function returns a "struct guestfs_stat *", or NULL if there was an error. The caller must call "guestfs_free_stat" after use.

(Added in 0.9.2)

guestfs_lstatlist¶

 struct guestfs_stat_list *
 guestfs_lstatlist (guestfs_h *g,
                    const char *path,
                    char *const *names);

This call allows you to perform the "guestfs_lstat" operation on multiple files, where all files are in the directory "path". "names" is the list of files from this directory.

On return you get a list of stat structs, with a one-to-one correspondence to the "names" list. If any name did not exist or could not be lstat'd, then the "ino" field of that structure is set to "-1".

This call is intended for programs that want to efficiently list a directory contents without making many round-trips. See also "guestfs_lxattrlist" for a similarly efficient call for getting extended attributes.

This function returns a "struct guestfs_stat_list *", or NULL if there was an error. The caller must call "guestfs_free_stat_list" after use.

(Added in 1.0.77)

guestfs_luks_add_key¶

 int
 guestfs_luks_add_key (guestfs_h *g,
                       const char *device,
                       const char *key,
                       const char *newkey,
                       int keyslot);

This command adds a new key on LUKS device "device". "key" is any existing key, and is used to access the device. "newkey" is the new key to add. "keyslot" is the key slot that will be replaced.

Note that if "keyslot" already contains a key, then this command will fail. You have to use "guestfs_luks_kill_slot" first to remove that key.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section "KEYS AND PASSPHRASES" for more information.

(Added in 1.5.2)

guestfs_luks_close¶

 int
 guestfs_luks_close (guestfs_h *g,
                     const char *device);

This closes a LUKS device that was created earlier by "guestfs_luks_open" or "guestfs_luks_open_ro". The "device" parameter must be the name of the LUKS mapping device (ie. "/dev/mapper/mapname") and not the name of the underlying block device.

This function returns 0 on success or -1 on error.

(Added in 1.5.1)

guestfs_luks_format¶

 int
 guestfs_luks_format (guestfs_h *g,
                      const char *device,
                      const char *key,
                      int keyslot);

This command erases existing data on "device" and formats the device as a LUKS encrypted device. "key" is the initial key, which is added to key slot "slot". (LUKS supports 8 key slots, numbered 0-7).

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section "KEYS AND PASSPHRASES" for more information.

(Added in 1.5.2)

guestfs_luks_format_cipher¶

 int
 guestfs_luks_format_cipher (guestfs_h *g,
                             const char *device,
                             const char *key,
                             int keyslot,
                             const char *cipher);

This command is the same as "guestfs_luks_format" but it also allows you to set the "cipher" used.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section "KEYS AND PASSPHRASES" for more information.

(Added in 1.5.2)

guestfs_luks_kill_slot¶

 int
 guestfs_luks_kill_slot (guestfs_h *g,
                         const char *device,
                         const char *key,
                         int keyslot);

This command deletes the key in key slot "keyslot" from the encrypted LUKS device "device". "key" must be one of the other keys.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section "KEYS AND PASSPHRASES" for more information.

(Added in 1.5.2)

guestfs_luks_open¶

 int
 guestfs_luks_open (guestfs_h *g,
                    const char *device,
                    const char *key,
                    const char *mapname);

This command opens a block device which has been encrypted according to the Linux Unified Key Setup (LUKS) standard.

"device" is the encrypted block device or partition.

The caller must supply one of the keys associated with the LUKS block device, in the "key" parameter.

This creates a new block device called "/dev/mapper/mapname". Reads and writes to this block device are decrypted from and encrypted to the underlying "device" respectively.

If this block device contains LVM volume groups, then calling "guestfs_vgscan" followed by "guestfs_vg_activate_all" will make them visible.

Use "guestfs_list_dm_devices" to list all device mapper devices.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section "KEYS AND PASSPHRASES" for more information.

(Added in 1.5.1)

guestfs_luks_open_ro¶

 int
 guestfs_luks_open_ro (guestfs_h *g,
                       const char *device,
                       const char *key,
                       const char *mapname);

This is the same as "guestfs_luks_open" except that a read-only mapping is created.

This function returns 0 on success or -1 on error.

This function takes a key or passphrase parameter which could contain sensitive material. Read the section "KEYS AND PASSPHRASES" for more information.

(Added in 1.5.1)

guestfs_lvcreate¶

 int
 guestfs_lvcreate (guestfs_h *g,
                   const char *logvol,
                   const char *volgroup,
                   int mbytes);

This creates an LVM logical volume called "logvol" on the volume group "volgroup", with "size" megabytes.

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_lvcreate_free¶

 int
 guestfs_lvcreate_free (guestfs_h *g,
                        const char *logvol,
                        const char *volgroup,
                        int percent);

Create an LVM logical volume called "/dev/volgroup/logvol", using approximately "percent" % of the free space remaining in the volume group. Most usefully, when "percent" is 100 this will create the largest possible LV.

This function returns 0 on success or -1 on error.

(Added in 1.17.18)

guestfs_lvm_canonical_lv_name¶

 char *
 guestfs_lvm_canonical_lv_name (guestfs_h *g,
                                const char *lvname);

This converts alternative naming schemes for LVs that you might find to the canonical name. For example, "/dev/mapper/VG-LV" is converted to "/dev/VG/LV".

This command returns an error if the "lvname" parameter does not refer to a logical volume.

See also "guestfs_is_lv", "guestfs_canonical_device_name".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.24)

guestfs_lvm_clear_filter¶

 int
 guestfs_lvm_clear_filter (guestfs_h *g);

This undoes the effect of "guestfs_lvm_set_filter". LVM will be able to see every block device.

This command also clears the LVM cache and performs a volume group scan.

This function returns 0 on success or -1 on error.

(Added in 1.5.1)

guestfs_lvm_remove_all¶

 int
 guestfs_lvm_remove_all (guestfs_h *g);

This command removes all LVM logical volumes, volume groups and physical volumes.

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_lvm_set_filter¶

 int
 guestfs_lvm_set_filter (guestfs_h *g,
                         char *const *devices);

This sets the LVM device filter so that LVM will only be able to "see" the block devices in the list "devices", and will ignore all other attached block devices.

Where disk image(s) contain duplicate PVs or VGs, this command is useful to get LVM to ignore the duplicates, otherwise LVM can get confused. Note also there are two types of duplication possible: either cloned PVs/VGs which have identical UUIDs; or VGs that are not cloned but just happen to have the same name. In normal operation you cannot create this situation, but you can do it outside LVM, eg. by cloning disk images or by bit twiddling inside the LVM metadata.

This command also clears the LVM cache and performs a volume group scan.

You can filter whole block devices or individual partitions.

You cannot use this if any VG is currently in use (eg. contains a mounted filesystem), even if you are not filtering out that VG.

This function returns 0 on success or -1 on error.

(Added in 1.5.1)

guestfs_lvremove¶

 int
 guestfs_lvremove (guestfs_h *g,
                   const char *device);

Remove an LVM logical volume "device", where "device" is the path to the LV, such as "/dev/VG/LV".

You can also remove all LVs in a volume group by specifying the VG name, "/dev/VG".

This function returns 0 on success or -1 on error.

(Added in 1.0.13)

guestfs_lvrename¶

 int
 guestfs_lvrename (guestfs_h *g,
                   const char *logvol,
                   const char *newlogvol);

Rename a logical volume "logvol" with the new name "newlogvol".

This function returns 0 on success or -1 on error.

(Added in 1.0.83)

guestfs_lvresize¶

 int
 guestfs_lvresize (guestfs_h *g,
                   const char *device,
                   int mbytes);

This resizes (expands or shrinks) an existing LVM logical volume to "mbytes". When reducing, data in the reduced part is lost.

This function returns 0 on success or -1 on error.

(Added in 1.0.27)

guestfs_lvresize_free¶

 int
 guestfs_lvresize_free (guestfs_h *g,
                        const char *lv,
                        int percent);

This expands an existing logical volume "lv" so that it fills "pc"% of the remaining free space in the volume group. Commonly you would call this with pc = 100 which expands the logical volume as much as possible, using all remaining free space in the volume group.

This function returns 0 on success or -1 on error.

(Added in 1.3.3)

guestfs_lvs¶

 char **
 guestfs_lvs (guestfs_h *g);

List all the logical volumes detected. This is the equivalent of the lvs(8) command.

This returns a list of the logical volume device names (eg. "/dev/VolGroup00/LogVol00").

See also "guestfs_lvs_full", "guestfs_list_filesystems".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.4)

guestfs_lvs_full¶

 struct guestfs_lvm_lv_list *
 guestfs_lvs_full (guestfs_h *g);

List all the logical volumes detected. This is the equivalent of the lvs(8) command. The "full" version includes all fields.

This function returns a "struct guestfs_lvm_lv_list *", or NULL if there was an error. The caller must call "guestfs_free_lvm_lv_list" after use.

(Added in 0.4)

guestfs_lvuuid¶

 char *
 guestfs_lvuuid (guestfs_h *g,
                 const char *device);

This command returns the UUID of the LVM LV "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.87)

guestfs_lxattrlist¶

 struct guestfs_xattr_list *
 guestfs_lxattrlist (guestfs_h *g,
                     const char *path,
                     char *const *names);

This call allows you to get the extended attributes of multiple files, where all files are in the directory "path". "names" is the list of files from this directory.

On return you get a flat list of xattr structs which must be interpreted sequentially. The first xattr struct always has a zero-length "attrname". "attrval" in this struct is zero-length to indicate there was an error doing "lgetxattr" for this file, or is a C string which is a decimal number (the number of following attributes for this file, which could be "0"). Then after the first xattr struct are the zero or more attributes for the first named file. This repeats for the second and subsequent files.

This call is intended for programs that want to efficiently list a directory contents without making many round-trips. See also "guestfs_lstatlist" for a similarly efficient call for getting standard stats.

This function returns a "struct guestfs_xattr_list *", or NULL if there was an error. The caller must call "guestfs_free_xattr_list" after use.

(Added in 1.0.77)

guestfs_max_disks¶

 int
 guestfs_max_disks (guestfs_h *g);

Return the maximum number of disks that may be added to a handle (eg. by "guestfs_add_drive_opts" and similar calls).

This function was added in libguestfs 1.19.7. In previous versions of libguestfs the limit was 25.

See "MAXIMUM NUMBER OF DISKS" in guestfs(3) for additional information on this topic.

On error this function returns -1.

(Added in 1.19.7)

guestfs_md_create¶

 int
 guestfs_md_create (guestfs_h *g,
                    const char *name,
                    char *const *devices,
                    ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MD_CREATE_MISSINGBITMAP, int64_t missingbitmap,
 GUESTFS_MD_CREATE_NRDEVICES, int nrdevices,
 GUESTFS_MD_CREATE_SPARE, int spare,
 GUESTFS_MD_CREATE_CHUNK, int64_t chunk,
 GUESTFS_MD_CREATE_LEVEL, const char *level,

Create a Linux md (RAID) device named "name" on the devices in the list "devices".

The optional parameters are:

"missingbitmap"

A bitmap of missing devices. If a bit is set it means that a missing device is added to the array. The least significant bit corresponds to the first device in the array.

As examples:

If "devices = ["/dev/sda"]" and "missingbitmap = 0x1" then the resulting array would be "[<missing>, "/dev/sda"]".

If "devices = ["/dev/sda"]" and "missingbitmap = 0x2" then the resulting array would be "["/dev/sda", <missing>]".

This defaults to 0 (no missing devices).

The length of "devices" + the number of bits set in "missingbitmap" must equal "nrdevices" + "spare".

"nrdevices"

The number of active RAID devices.

If not set, this defaults to the length of "devices" plus the number of bits set in "missingbitmap".

"spare"

The number of spare devices.

If not set, this defaults to 0.

"chunk"

The chunk size in bytes.

"level"

The RAID level, which can be one of: linear, raid0, 0, stripe, raid1, 1, mirror, raid4, 4, raid5, 5, raid6, 6, raid10, 10. Some of these are synonymous, and more levels may be added in future.

If not set, this defaults to "raid1".

This function returns 0 on success or -1 on error.

(Added in 1.15.6)

guestfs_md_create_va¶

 int
 guestfs_md_create_va (guestfs_h *g,
                       const char *name,
                       char *const *devices,
                       va_list args);

This is the "va_list variant" of "guestfs_md_create".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_md_create_argv¶

 int
 guestfs_md_create_argv (guestfs_h *g,
                         const char *name,
                         char *const *devices,
                         const struct guestfs_md_create_argv *optargs);

This is the "argv variant" of "guestfs_md_create".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_md_detail¶

 char **
 guestfs_md_detail (guestfs_h *g,
                    const char *md);

This command exposes the output of 'mdadm -DY <md>'. The following fields are usually present in the returned hash. Other fields may also be present.

"level"

The raid level of the MD device.

"devices"

The number of underlying devices in the MD device.

"metadata"

The metadata version used.

"uuid"

The UUID of the MD device.

"name"

The name of the MD device.

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.15.6)

guestfs_md_stat¶

 struct guestfs_mdstat_list *
 guestfs_md_stat (guestfs_h *g,
                  const char *md);

This call returns a list of the underlying devices which make up the single software RAID array device "md".

To get a list of software RAID devices, call "guestfs_list_md_devices".

Each structure returned corresponds to one device along with additional status information:

"mdstat_device"

The name of the underlying device.

"mdstat_index"

The index of this device within the array.

"mdstat_flags"

Flags associated with this device. This is a string containing (in no specific order) zero or more of the following flags:

This function returns a "struct guestfs_mdstat_list *", or NULL if there was an error. The caller must call "guestfs_free_mdstat_list" after use.

(Added in 1.17.21)

guestfs_md_stop¶

 int
 guestfs_md_stop (guestfs_h *g,
                  const char *md);

This command deactivates the MD array named "md". The device is stopped, but it is not destroyed or zeroed.

This function returns 0 on success or -1 on error.

(Added in 1.15.6)

guestfs_mkdir¶

 int
 guestfs_mkdir (guestfs_h *g,
                const char *path);

Create a directory named "path".

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_mkdir_mode¶

 int
 guestfs_mkdir_mode (guestfs_h *g,
                     const char *path,
                     int mode);

This command creates a directory, setting the initial permissions of the directory to "mode".

For common Linux filesystems, the actual mode which is set will be "mode & ~umask & 01777". Non-native-Linux filesystems may interpret the mode in other ways.

See also "guestfs_mkdir", "guestfs_umask"

This function returns 0 on success or -1 on error.

(Added in 1.0.77)

guestfs_mkdir_p¶

 int
 guestfs_mkdir_p (guestfs_h *g,
                  const char *path);

Create a directory named "path", creating any parent directories as necessary. This is like the "mkdir -p" shell command.

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_mkdtemp¶

 char *
 guestfs_mkdtemp (guestfs_h *g,
                  const char *tmpl);

This command creates a temporary directory. The "tmpl" parameter should be a full pathname for the temporary directory name with the final six characters being "XXXXXX".

For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX", the second one being suitable for Windows filesystems.

The name of the temporary directory that was created is returned.

The temporary directory is created with mode 0700 and is owned by root.

The caller is responsible for deleting the temporary directory and its contents after use.

See also: mkdtemp(3)

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.54)

guestfs_mke2fs¶

 int
 guestfs_mke2fs (guestfs_h *g,
                 const char *device,
                 ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MKE2FS_BLOCKSCOUNT, int64_t blockscount,
 GUESTFS_MKE2FS_BLOCKSIZE, int64_t blocksize,
 GUESTFS_MKE2FS_FRAGSIZE, int64_t fragsize,
 GUESTFS_MKE2FS_BLOCKSPERGROUP, int64_t blockspergroup,
 GUESTFS_MKE2FS_NUMBEROFGROUPS, int64_t numberofgroups,
 GUESTFS_MKE2FS_BYTESPERINODE, int64_t bytesperinode,
 GUESTFS_MKE2FS_INODESIZE, int64_t inodesize,
 GUESTFS_MKE2FS_JOURNALSIZE, int64_t journalsize,
 GUESTFS_MKE2FS_NUMBEROFINODES, int64_t numberofinodes,
 GUESTFS_MKE2FS_STRIDESIZE, int64_t stridesize,
 GUESTFS_MKE2FS_STRIPEWIDTH, int64_t stripewidth,
 GUESTFS_MKE2FS_MAXONLINERESIZE, int64_t maxonlineresize,
 GUESTFS_MKE2FS_RESERVEDBLOCKSPERCENTAGE, int reservedblockspercentage,
 GUESTFS_MKE2FS_MMPUPDATEINTERVAL, int mmpupdateinterval,
 GUESTFS_MKE2FS_JOURNALDEVICE, const char *journaldevice,
 GUESTFS_MKE2FS_LABEL, const char *label,
 GUESTFS_MKE2FS_LASTMOUNTEDDIR, const char *lastmounteddir,
 GUESTFS_MKE2FS_CREATOROS, const char *creatoros,
 GUESTFS_MKE2FS_FSTYPE, const char *fstype,
 GUESTFS_MKE2FS_USAGETYPE, const char *usagetype,
 GUESTFS_MKE2FS_UUID, const char *uuid,
 GUESTFS_MKE2FS_FORCECREATE, int forcecreate,
 GUESTFS_MKE2FS_WRITESBANDGROUPONLY, int writesbandgrouponly,
 GUESTFS_MKE2FS_LAZYITABLEINIT, int lazyitableinit,
 GUESTFS_MKE2FS_LAZYJOURNALINIT, int lazyjournalinit,
 GUESTFS_MKE2FS_TESTFS, int testfs,
 GUESTFS_MKE2FS_DISCARD, int discard,
 GUESTFS_MKE2FS_QUOTATYPE, int quotatype,
 GUESTFS_MKE2FS_EXTENT, int extent,
 GUESTFS_MKE2FS_FILETYPE, int filetype,
 GUESTFS_MKE2FS_FLEXBG, int flexbg,
 GUESTFS_MKE2FS_HASJOURNAL, int hasjournal,
 GUESTFS_MKE2FS_JOURNALDEV, int journaldev,
 GUESTFS_MKE2FS_LARGEFILE, int largefile,
 GUESTFS_MKE2FS_QUOTA, int quota,
 GUESTFS_MKE2FS_RESIZEINODE, int resizeinode,
 GUESTFS_MKE2FS_SPARSESUPER, int sparsesuper,
 GUESTFS_MKE2FS_UNINITBG, int uninitbg,

"mke2fs" is used to create an ext2, ext3, or ext4 filesystem on "device".

The optional "blockscount" is the size of the filesystem in blocks. If omitted it defaults to the size of "device". Note if the filesystem is too small to contain a journal, "mke2fs" will silently create an ext2 filesystem instead.

This function returns 0 on success or -1 on error.

(Added in 1.19.44)

guestfs_mke2fs_va¶

 int
 guestfs_mke2fs_va (guestfs_h *g,
                    const char *device,
                    va_list args);

This is the "va_list variant" of "guestfs_mke2fs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mke2fs_argv¶

 int
 guestfs_mke2fs_argv (guestfs_h *g,
                      const char *device,
                      const struct guestfs_mke2fs_argv *optargs);

This is the "argv variant" of "guestfs_mke2fs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mke2fs_J¶

 int
 guestfs_mke2fs_J (guestfs_h *g,
                   const char *fstype,
                   int blocksize,
                   const char *device,
                   const char *journal);

This function is deprecated. In new code, use the "guestfs_mke2fs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This creates an ext2/3/4 filesystem on "device" with an external journal on "journal". It is equivalent to the command:

 mke2fs -t fstype -b blocksize -J device=<journal> <device>

See also "guestfs_mke2journal".

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mke2fs_JL¶

 int
 guestfs_mke2fs_JL (guestfs_h *g,
                    const char *fstype,
                    int blocksize,
                    const char *device,
                    const char *label);

This function is deprecated. In new code, use the "guestfs_mke2fs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This creates an ext2/3/4 filesystem on "device" with an external journal on the journal labeled "label".

See also "guestfs_mke2journal_L".

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mke2fs_JU¶

 int
 guestfs_mke2fs_JU (guestfs_h *g,
                    const char *fstype,
                    int blocksize,
                    const char *device,
                    const char *uuid);

This function is deprecated. In new code, use the "guestfs_mke2fs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This creates an ext2/3/4 filesystem on "device" with an external journal on the journal with UUID "uuid".

See also "guestfs_mke2journal_U".

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mke2journal¶

 int
 guestfs_mke2journal (guestfs_h *g,
                      int blocksize,
                      const char *device);

This function is deprecated. In new code, use the "guestfs_mke2fs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This creates an ext2 external journal on "device". It is equivalent to the command:

 mke2fs -O journal_dev -b blocksize device

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mke2journal_L¶

 int
 guestfs_mke2journal_L (guestfs_h *g,
                        int blocksize,
                        const char *label,
                        const char *device);

This function is deprecated. In new code, use the "guestfs_mke2fs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This creates an ext2 external journal on "device" with label "label".

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mke2journal_U¶

 int
 guestfs_mke2journal_U (guestfs_h *g,
                        int blocksize,
                        const char *uuid,
                        const char *device);

This function is deprecated. In new code, use the "guestfs_mke2fs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This creates an ext2 external journal on "device" with UUID "uuid".

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mkfifo¶

 int
 guestfs_mkfifo (guestfs_h *g,
                 int mode,
                 const char *path);

This call creates a FIFO (named pipe) called "path" with mode "mode". It is just a convenient wrapper around "guestfs_mknod".

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_mkfs¶

 int
 guestfs_mkfs (guestfs_h *g,
               const char *fstype,
               const char *device);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_mkfs_opts" with no optional arguments.

(Added in 0.8)

guestfs_mkfs_opts¶

 int
 guestfs_mkfs_opts (guestfs_h *g,
                    const char *fstype,
                    const char *device,
                    ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MKFS_OPTS_BLOCKSIZE, int blocksize,
 GUESTFS_MKFS_OPTS_FEATURES, const char *features,
 GUESTFS_MKFS_OPTS_INODE, int inode,
 GUESTFS_MKFS_OPTS_SECTORSIZE, int sectorsize,

This function creates a filesystem on "device". The filesystem type is "fstype", for example "ext3".

The optional arguments are:

"blocksize"

The filesystem block size. Supported block sizes depend on the filesystem type, but typically they are 1024, 2048 or 4096 for Linux ext2/3 filesystems.

For VFAT and NTFS the "blocksize" parameter is treated as the requested cluster size.

For UFS block sizes, please see mkfs.ufs(8).

"features"

This passes the -O parameter to the external mkfs program.

For certain filesystem types, this allows extra filesystem features to be selected. See mke2fs(8) and mkfs.ufs(8) for more details.

You cannot use this optional parameter with the "gfs" or "gfs2" filesystem type.

"inode"

This passes the -I parameter to the external mke2fs(8) program which sets the inode size (only for ext2/3/4 filesystems at present).

"sectorsize"

This passes the -S parameter to external mkfs.ufs(8) program, which sets sector size for ufs filesystem.

This function returns 0 on success or -1 on error.

(Added in 1.7.19)

guestfs_mkfs_opts_va¶

 int
 guestfs_mkfs_opts_va (guestfs_h *g,
                       const char *fstype,
                       const char *device,
                       va_list args);

This is the "va_list variant" of "guestfs_mkfs_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mkfs_opts_argv¶

 int
 guestfs_mkfs_opts_argv (guestfs_h *g,
                         const char *fstype,
                         const char *device,
                         const struct guestfs_mkfs_opts_argv *optargs);

This is the "argv variant" of "guestfs_mkfs_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mkfs_b¶

 int
 guestfs_mkfs_b (guestfs_h *g,
                 const char *fstype,
                 int blocksize,
                 const char *device);

This function is deprecated. In new code, use the "guestfs_mkfs" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This call is similar to "guestfs_mkfs", but it allows you to control the block size of the resulting filesystem. Supported block sizes depend on the filesystem type, but typically they are 1024, 2048 or 4096 only.

For VFAT and NTFS the "blocksize" parameter is treated as the requested cluster size.

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mkfs_btrfs¶

 int
 guestfs_mkfs_btrfs (guestfs_h *g,
                     char *const *devices,
                     ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MKFS_BTRFS_ALLOCSTART, int64_t allocstart,
 GUESTFS_MKFS_BTRFS_BYTECOUNT, int64_t bytecount,
 GUESTFS_MKFS_BTRFS_DATATYPE, const char *datatype,
 GUESTFS_MKFS_BTRFS_LEAFSIZE, int leafsize,
 GUESTFS_MKFS_BTRFS_LABEL, const char *label,
 GUESTFS_MKFS_BTRFS_METADATA, const char *metadata,
 GUESTFS_MKFS_BTRFS_NODESIZE, int nodesize,
 GUESTFS_MKFS_BTRFS_SECTORSIZE, int sectorsize,

Create a btrfs filesystem, allowing all configurables to be set. For more information on the optional arguments, see mkfs.btrfs(8).

Since btrfs filesystems can span multiple devices, this takes a non-empty list of devices.

To create general filesystems, use "guestfs_mkfs".

This function returns 0 on success or -1 on error.

(Added in 1.17.25)

guestfs_mkfs_btrfs_va¶

 int
 guestfs_mkfs_btrfs_va (guestfs_h *g,
                        char *const *devices,
                        va_list args);

This is the "va_list variant" of "guestfs_mkfs_btrfs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mkfs_btrfs_argv¶

 int
 guestfs_mkfs_btrfs_argv (guestfs_h *g,
                          char *const *devices,
                          const struct guestfs_mkfs_btrfs_argv *optargs);

This is the "argv variant" of "guestfs_mkfs_btrfs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mklost_and_found¶

 int
 guestfs_mklost_and_found (guestfs_h *g,
                           const char *mountpoint);

Make the "lost+found" directory, normally in the root directory of an ext2/3/4 filesystem. "mountpoint" is the directory under which we try to create the "lost+found" directory.

This function returns 0 on success or -1 on error.

(Added in 1.19.56)

guestfs_mkmountpoint¶

 int
 guestfs_mkmountpoint (guestfs_h *g,
                       const char *exemptpath);

"guestfs_mkmountpoint" and "guestfs_rmmountpoint" are specialized calls that can be used to create extra mountpoints before mounting the first filesystem.

These calls are only necessary in some very limited circumstances, mainly the case where you want to mount a mix of unrelated and/or read-only filesystems together.

For example, live CDs often contain a "Russian doll" nest of filesystems, an ISO outer layer, with a squashfs image inside, with an ext2/3 image inside that. You can unpack this as follows in guestfish:

 add-ro Fedora-11-i686-Live.iso
 run
 mkmountpoint /cd
 mkmountpoint /sqsh
 mkmountpoint /ext3fs
 mount /dev/sda /cd
 mount-loop /cd/LiveOS/squashfs.img /sqsh
 mount-loop /sqsh/LiveOS/ext3fs.img /ext3fs

The inner filesystem is now unpacked under the /ext3fs mountpoint.

"guestfs_mkmountpoint" is not compatible with "guestfs_umount_all". You may get unexpected errors if you try to mix these calls. It is safest to manually unmount filesystems and remove mountpoints after use.

"guestfs_umount_all" unmounts filesystems by sorting the paths longest first, so for this to work for manual mountpoints, you must ensure that the innermost mountpoints have the longest pathnames, as in the example code above.

For more details see https://bugzilla.redhat.com/show_bug.cgi?id=599503

Autosync [see "guestfs_set_autosync", this is set by default on handles] can cause "guestfs_umount_all" to be called when the handle is closed which can also trigger these issues.

This function returns 0 on success or -1 on error.

(Added in 1.0.62)

guestfs_mknod¶

 int
 guestfs_mknod (guestfs_h *g,
                int mode,
                int devmajor,
                int devminor,
                const char *path);

This call creates block or character special devices, or named pipes (FIFOs).

The "mode" parameter should be the mode, using the standard constants. "devmajor" and "devminor" are the device major and minor numbers, only used when creating block and character special devices.

Note that, just like mknod(2), the mode must be bitwise OR'd with S_IFBLK, S_IFCHR, S_IFIFO or S_IFSOCK (otherwise this call just creates a regular file). These constants are available in the standard Linux header files, or you can use "guestfs_mknod_b", "guestfs_mknod_c" or "guestfs_mkfifo" which are wrappers around this command which bitwise OR in the appropriate constant for you.

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_mknod_b¶

 int
 guestfs_mknod_b (guestfs_h *g,
                  int mode,
                  int devmajor,
                  int devminor,
                  const char *path);

This call creates a block device node called "path" with mode "mode" and device major/minor "devmajor" and "devminor". It is just a convenient wrapper around "guestfs_mknod".

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_mknod_c¶

 int
 guestfs_mknod_c (guestfs_h *g,
                  int mode,
                  int devmajor,
                  int devminor,
                  const char *path);

This call creates a char device node called "path" with mode "mode" and device major/minor "devmajor" and "devminor". It is just a convenient wrapper around "guestfs_mknod".

The mode actually set is affected by the umask.

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_mkswap¶

 int
 guestfs_mkswap (guestfs_h *g,
                 const char *device);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_mkswap_opts" with no optional arguments.

(Added in 1.0.55)

guestfs_mkswap_opts¶

 int
 guestfs_mkswap_opts (guestfs_h *g,
                      const char *device,
                      ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MKSWAP_OPTS_LABEL, const char *label,
 GUESTFS_MKSWAP_OPTS_UUID, const char *uuid,

Create a Linux swap partition on "device".

The option arguments "label" and "uuid" allow you to set the label and/or UUID of the new swap partition.

This function returns 0 on success or -1 on error.

(Added in 1.19.34)

guestfs_mkswap_opts_va¶

 int
 guestfs_mkswap_opts_va (guestfs_h *g,
                         const char *device,
                         va_list args);

This is the "va_list variant" of "guestfs_mkswap_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mkswap_opts_argv¶

 int
 guestfs_mkswap_opts_argv (guestfs_h *g,
                           const char *device,
                           const struct guestfs_mkswap_opts_argv *optargs);

This is the "argv variant" of "guestfs_mkswap_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mkswap_L¶

 int
 guestfs_mkswap_L (guestfs_h *g,
                   const char *label,
                   const char *device);

This function is deprecated. In new code, use the "guestfs_mkswap" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

Create a swap partition on "device" with label "label".

Note that you cannot attach a swap label to a block device (eg. "/dev/sda"), just to a partition. This appears to be a limitation of the kernel or swap tools.

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_mkswap_U¶

 int
 guestfs_mkswap_U (guestfs_h *g,
                   const char *uuid,
                   const char *device);

This function is deprecated. In new code, use the "guestfs_mkswap" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

Create a swap partition on "device" with UUID "uuid".

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_mkswap_file¶

 int
 guestfs_mkswap_file (guestfs_h *g,
                      const char *path);

Create a swap file.

This command just writes a swap file signature to an existing file. To create the file itself, use something like "guestfs_fallocate".

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_mktemp¶

 char *
 guestfs_mktemp (guestfs_h *g,
                 const char *tmpl,
                 ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MKTEMP_SUFFIX, const char *suffix,

This command creates a temporary file. The "tmpl" parameter should be a full pathname for the temporary directory name with the final six characters being "XXXXXX".

For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX", the second one being suitable for Windows filesystems.

The name of the temporary file that was created is returned.

The temporary file is created with mode 0600 and is owned by root.

The caller is responsible for deleting the temporary file after use.

If the optional "suffix" parameter is given, then the suffix (eg. ".txt") is appended to the temporary name.

See also: "guestfs_mkdtemp".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.19.53)

guestfs_mktemp_va¶

 char *
 guestfs_mktemp_va (guestfs_h *g,
                    const char *tmpl,
                    va_list args);

This is the "va_list variant" of "guestfs_mktemp".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mktemp_argv¶

 char *
 guestfs_mktemp_argv (guestfs_h *g,
                      const char *tmpl,
                      const struct guestfs_mktemp_argv *optargs);

This is the "argv variant" of "guestfs_mktemp".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_modprobe¶

 int
 guestfs_modprobe (guestfs_h *g,
                   const char *modulename);

This loads a kernel module in the appliance.

The kernel module must have been whitelisted when libguestfs was built (see "appliance/kmod.whitelist.in" in the source).

This function returns 0 on success or -1 on error.

(Added in 1.0.68)

guestfs_mount¶

 int
 guestfs_mount (guestfs_h *g,
                const char *device,
                const char *mountpoint);

Mount a guest disk at a position in the filesystem. Block devices are named "/dev/sda", "/dev/sdb" and so on, as they were added to the guest. If those block devices contain partitions, they will have the usual names (eg. "/dev/sda1"). Also LVM "/dev/VG/LV"-style names can be used.

The rules are the same as for mount(2): A filesystem must first be mounted on "/" before others can be mounted. Other filesystems can only be mounted on directories which already exist.

The mounted filesystem is writable, if we have sufficient permissions on the underlying device.

Before libguestfs 1.13.16, this call implicitly added the options "sync" and "noatime". The "sync" option greatly slowed writes and caused many problems for users. If your program might need to work with older versions of libguestfs, use "guestfs_mount_options" instead (using an empty string for the first parameter if you don't want any options).

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_mount_local¶

 int
 guestfs_mount_local (guestfs_h *g,
                      const char *localmountpoint,
                      ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_MOUNT_LOCAL_READONLY, int readonly,
 GUESTFS_MOUNT_LOCAL_OPTIONS, const char *options,
 GUESTFS_MOUNT_LOCAL_CACHETIMEOUT, int cachetimeout,
 GUESTFS_MOUNT_LOCAL_DEBUGCALLS, int debugcalls,

This call exports the libguestfs-accessible filesystem to a local mountpoint (directory) called "localmountpoint". Ordinary reads and writes to files and directories under "localmountpoint" are redirected through libguestfs.

If the optional "readonly" flag is set to true, then writes to the filesystem return error "EROFS".

"options" is a comma-separated list of mount options. See guestmount(1) for some useful options.

"cachetimeout" sets the timeout (in seconds) for cached directory entries. The default is 60 seconds. See guestmount(1) for further information.

If "debugcalls" is set to true, then additional debugging information is generated for every FUSE call.

When "guestfs_mount_local" returns, the filesystem is ready, but is not processing requests (access to it will block). You have to call "guestfs_mount_local_run" to run the main loop.

See "MOUNT LOCAL" in guestfs(3) for full documentation.

This function returns 0 on success or -1 on error.

(Added in 1.17.22)

guestfs_mount_local_va¶

 int
 guestfs_mount_local_va (guestfs_h *g,
                         const char *localmountpoint,
                         va_list args);

This is the "va_list variant" of "guestfs_mount_local".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mount_local_argv¶

 int
 guestfs_mount_local_argv (guestfs_h *g,
                           const char *localmountpoint,
                           const struct guestfs_mount_local_argv *optargs);

This is the "argv variant" of "guestfs_mount_local".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_mount_local_run¶

 int
 guestfs_mount_local_run (guestfs_h *g);

Run the main loop which translates kernel calls to libguestfs calls.

This should only be called after "guestfs_mount_local" returns successfully. The call will not return until the filesystem is unmounted.

Note you must not make concurrent libguestfs calls on the same handle from another thread.

You may call this from a different thread than the one which called "guestfs_mount_local", subject to the usual rules for threads and libguestfs (see "MULTIPLE HANDLES AND MULTIPLE THREADS" in guestfs(3)).

See "MOUNT LOCAL" in guestfs(3) for full documentation.

This function returns 0 on success or -1 on error.

(Added in 1.17.22)

guestfs_mount_loop¶

 int
 guestfs_mount_loop (guestfs_h *g,
                     const char *file,
                     const char *mountpoint);

This command lets you mount "file" (a filesystem image in a file) on a mount point. It is entirely equivalent to the command "mount -o loop file mountpoint".

This function returns 0 on success or -1 on error.

(Added in 1.0.54)

guestfs_mount_options¶

 int
 guestfs_mount_options (guestfs_h *g,
                        const char *options,
                        const char *device,
                        const char *mountpoint);

This is the same as the "guestfs_mount" command, but it allows you to set the mount options as for the mount(8) -o flag.

If the "options" parameter is an empty string, then no options are passed (all options default to whatever the filesystem uses).

This function returns 0 on success or -1 on error.

(Added in 1.0.10)

guestfs_mount_ro¶

 int
 guestfs_mount_ro (guestfs_h *g,
                   const char *device,
                   const char *mountpoint);

This is the same as the "guestfs_mount" command, but it mounts the filesystem with the read-only (-o ro) flag.

This function returns 0 on success or -1 on error.

(Added in 1.0.10)

guestfs_mount_vfs¶

 int
 guestfs_mount_vfs (guestfs_h *g,
                    const char *options,
                    const char *vfstype,
                    const char *device,
                    const char *mountpoint);

This is the same as the "guestfs_mount" command, but it allows you to set both the mount options and the vfstype as for the mount(8) -o and -t flags.

This function returns 0 on success or -1 on error.

(Added in 1.0.10)

guestfs_mountpoints¶

 char **
 guestfs_mountpoints (guestfs_h *g);

This call is similar to "guestfs_mounts". That call returns a list of devices. This one returns a hash table (map) of device name to directory where the device is mounted.

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 1.0.62)

guestfs_mounts¶

 char **
 guestfs_mounts (guestfs_h *g);

This returns the list of currently mounted filesystems. It returns the list of devices (eg. "/dev/sda1", "/dev/VG/LV").

Some internal mounts are not shown.

See also: "guestfs_mountpoints"

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.8)

guestfs_mv¶

 int
 guestfs_mv (guestfs_h *g,
             const char *src,
             const char *dest);

This moves a file from "src" to "dest" where "dest" is either a destination filename or destination directory.

See also: "guestfs_rename".

This function returns 0 on success or -1 on error.

(Added in 1.0.18)

guestfs_nr_devices¶

 int
 guestfs_nr_devices (guestfs_h *g);

This returns the number of whole block devices that were added. This is the same as the number of devices that would be returned if you called "guestfs_list_devices".

To find out the maximum number of devices that could be added, call "guestfs_max_disks".

On error this function returns -1.

(Added in 1.19.15)

guestfs_ntfs_3g_probe¶

 int
 guestfs_ntfs_3g_probe (guestfs_h *g,
                        int rw,
                        const char *device);

This command runs the ntfs-3g.probe(8) command which probes an NTFS "device" for mountability. (Not all NTFS volumes can be mounted read-write, and some cannot be mounted at all).

"rw" is a boolean flag. Set it to true if you want to test if the volume can be mounted read-write. Set it to false if you want to test if the volume can be mounted read-only.

The return value is an integer which 0 if the operation would succeed, or some non-zero value documented in the ntfs-3g.probe(8) manual page.

On error this function returns -1.

(Added in 1.0.43)

guestfs_ntfsclone_in¶

 int
 guestfs_ntfsclone_in (guestfs_h *g,
                       const char *backupfile,
                       const char *device);

Restore the "backupfile" (from a previous call to "guestfs_ntfsclone_out") to "device", overwriting any existing contents of this device.

This function returns 0 on success or -1 on error.

(Added in 1.17.9)

guestfs_ntfsclone_out¶

 int
 guestfs_ntfsclone_out (guestfs_h *g,
                        const char *device,
                        const char *backupfile,
                        ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_NTFSCLONE_OUT_METADATAONLY, int metadataonly,
 GUESTFS_NTFSCLONE_OUT_RESCUE, int rescue,
 GUESTFS_NTFSCLONE_OUT_IGNOREFSCHECK, int ignorefscheck,
 GUESTFS_NTFSCLONE_OUT_PRESERVETIMESTAMPS, int preservetimestamps,
 GUESTFS_NTFSCLONE_OUT_FORCE, int force,

Stream the NTFS filesystem "device" to the local file "backupfile". The format used for the backup file is a special format used by the ntfsclone(8) tool.

If the optional "metadataonly" flag is true, then only the metadata is saved, losing all the user data (this is useful for diagnosing some filesystem problems).

The optional "rescue", "ignorefscheck", "preservetimestamps" and "force" flags have precise meanings detailed in the ntfsclone(8) man page.

Use "guestfs_ntfsclone_in" to restore the file back to a libguestfs device.

This function returns 0 on success or -1 on error.

(Added in 1.17.9)

guestfs_ntfsclone_out_va¶

 int
 guestfs_ntfsclone_out_va (guestfs_h *g,
                           const char *device,
                           const char *backupfile,
                           va_list args);

This is the "va_list variant" of "guestfs_ntfsclone_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_ntfsclone_out_argv¶

 int
 guestfs_ntfsclone_out_argv (guestfs_h *g,
                             const char *device,
                             const char *backupfile,
                             const struct guestfs_ntfsclone_out_argv *optargs);

This is the "argv variant" of "guestfs_ntfsclone_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_ntfsfix¶

 int
 guestfs_ntfsfix (guestfs_h *g,
                  const char *device,
                  ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_NTFSFIX_CLEARBADSECTORS, int clearbadsectors,

This command repairs some fundamental NTFS inconsistencies, resets the NTFS journal file, and schedules an NTFS consistency check for the first boot into Windows.

This is not an equivalent of Windows "chkdsk". It does not scan the filesystem for inconsistencies.

The optional "clearbadsectors" flag clears the list of bad sectors. This is useful after cloning a disk with bad sectors to a new disk.

This function returns 0 on success or -1 on error.

(Added in 1.17.9)

guestfs_ntfsfix_va¶

 int
 guestfs_ntfsfix_va (guestfs_h *g,
                     const char *device,
                     va_list args);

This is the "va_list variant" of "guestfs_ntfsfix".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_ntfsfix_argv¶

 int
 guestfs_ntfsfix_argv (guestfs_h *g,
                       const char *device,
                       const struct guestfs_ntfsfix_argv *optargs);

This is the "argv variant" of "guestfs_ntfsfix".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_ntfsresize¶

 int
 guestfs_ntfsresize (guestfs_h *g,
                     const char *device);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_ntfsresize_opts" with no optional arguments.

(Added in 1.3.2)

guestfs_ntfsresize_opts¶

 int
 guestfs_ntfsresize_opts (guestfs_h *g,
                          const char *device,
                          ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_NTFSRESIZE_OPTS_SIZE, int64_t size,
 GUESTFS_NTFSRESIZE_OPTS_FORCE, int force,

This command resizes an NTFS filesystem, expanding or shrinking it to the size of the underlying device.

The optional parameters are:

"size"

The new size (in bytes) of the filesystem. If omitted, the filesystem is resized to fit the container (eg. partition).

"force"

If this option is true, then force the resize of the filesystem even if the filesystem is marked as requiring a consistency check.

After the resize operation, the filesystem is always marked as requiring a consistency check (for safety). You have to boot into Windows to perform this check and clear this condition. If you don't set the "force" option then it is not possible to call "guestfs_ntfsresize" multiple times on a single filesystem without booting into Windows between each resize.

See also ntfsresize(8).

This function returns 0 on success or -1 on error.

(Added in 1.11.15)

guestfs_ntfsresize_opts_va¶

 int
 guestfs_ntfsresize_opts_va (guestfs_h *g,
                             const char *device,
                             va_list args);

This is the "va_list variant" of "guestfs_ntfsresize_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_ntfsresize_opts_argv¶

 int
 guestfs_ntfsresize_opts_argv (guestfs_h *g,
                               const char *device,
                               const struct guestfs_ntfsresize_opts_argv *optargs);

This is the "argv variant" of "guestfs_ntfsresize_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_ntfsresize_size¶

 int
 guestfs_ntfsresize_size (guestfs_h *g,
                          const char *device,
                          int64_t size);

This function is deprecated. In new code, use the "guestfs_ntfsresize" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command is the same as "guestfs_ntfsresize" except that it allows you to specify the new size (in bytes) explicitly.

This function returns 0 on success or -1 on error.

(Added in 1.3.14)

guestfs_parse_environment¶

 int
 guestfs_parse_environment (guestfs_h *g);

Parse the program's environment and set flags in the handle accordingly. For example if "LIBGUESTFS_DEBUG=1" then the 'verbose' flag is set in the handle.

Most programs do not need to call this. It is done implicitly when you call "guestfs_create".

See "ENVIRONMENT VARIABLES" in guestfs(3) for a list of environment variables that can affect libguestfs handles. See also "guestfs_create_flags" in guestfs(3), and "guestfs_parse_environment_list".

This function returns 0 on success or -1 on error.

(Added in 1.19.53)

guestfs_parse_environment_list¶

 int
 guestfs_parse_environment_list (guestfs_h *g,
                                 char *const *environment);

Parse the list of strings in the argument "environment" and set flags in the handle accordingly. For example if "LIBGUESTFS_DEBUG=1" is a string in the list, then the 'verbose' flag is set in the handle.

This is the same as "guestfs_parse_environment" except that it parses an explicit list of strings instead of the program's environment.

This function returns 0 on success or -1 on error.

(Added in 1.19.53)

guestfs_part_add¶

 int
 guestfs_part_add (guestfs_h *g,
                   const char *device,
                   const char *prlogex,
                   int64_t startsect,
                   int64_t endsect);

This command adds a partition to "device". If there is no partition table on the device, call "guestfs_part_init" first.

The "prlogex" parameter is the type of partition. Normally you should pass "p" or "primary" here, but MBR partition tables also support "l" (or "logical") and "e" (or "extended") partition types.

"startsect" and "endsect" are the start and end of the partition in sectors. "endsect" may be negative, which means it counts backwards from the end of the disk ("-1" is the last sector).

Creating a partition which covers the whole disk is not so easy. Use "guestfs_part_disk" to do that.

This function returns 0 on success or -1 on error.

(Added in 1.0.78)

guestfs_part_del¶

 int
 guestfs_part_del (guestfs_h *g,
                   const char *device,
                   int partnum);

This command deletes the partition numbered "partnum" on "device".

Note that in the case of MBR partitioning, deleting an extended partition also deletes any logical partitions it contains.

This function returns 0 on success or -1 on error.

(Added in 1.3.2)

guestfs_part_disk¶

 int
 guestfs_part_disk (guestfs_h *g,
                    const char *device,
                    const char *parttype);

This command is simply a combination of "guestfs_part_init" followed by "guestfs_part_add" to create a single primary partition covering the whole disk.

"parttype" is the partition table type, usually "mbr" or "gpt", but other possible values are described in "guestfs_part_init".

This function returns 0 on success or -1 on error.

(Added in 1.0.78)

guestfs_part_get_bootable¶

 int
 guestfs_part_get_bootable (guestfs_h *g,
                            const char *device,
                            int partnum);

This command returns true if the partition "partnum" on "device" has the bootable flag set.

See also "guestfs_part_set_bootable".

This function returns a C truth value on success or -1 on error.

(Added in 1.3.2)

guestfs_part_get_gpt_type¶

 char *
 guestfs_part_get_gpt_type (guestfs_h *g,
                            const char *device,
                            int partnum);

Return the type GUID of numbered GPT partition "partnum". For MBR partitions, return an appropriate GUID corresponding to the MBR type. Behaviour is undefined for other partition types.

This function returns a string, or NULL on error. The caller must free the returned string after use.

guestfs_part_get_mbr_id¶

 int
 guestfs_part_get_mbr_id (guestfs_h *g,
                          const char *device,
                          int partnum);

Returns the MBR type byte (also known as the ID byte) from the numbered partition "partnum".

Note that only MBR (old DOS-style) partitions have type bytes. You will get undefined results for other partition table types (see "guestfs_part_get_parttype").

On error this function returns -1.

(Added in 1.3.2)

guestfs_part_get_parttype¶

 char *
 guestfs_part_get_parttype (guestfs_h *g,
                            const char *device);

This command examines the partition table on "device" and returns the partition table type (format) being used.

Common return values include: "msdos" (a DOS/Windows style MBR partition table), "gpt" (a GPT/EFI-style partition table). Other values are possible, although unusual. See "guestfs_part_init" for a full list.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.78)

guestfs_part_init¶

 int
 guestfs_part_init (guestfs_h *g,
                    const char *device,
                    const char *parttype);

This creates an empty partition table on "device" of one of the partition types listed below. Usually "parttype" should be either "msdos" or "gpt" (for large disks).

Initially there are no partitions. Following this, you should call "guestfs_part_add" for each partition required.

Possible values for "parttype" are:

efi

gpt

Intel EFI / GPT partition table.

This is recommended for >= 2 TB partitions that will be accessed from Linux and Intel-based Mac OS X. It also has limited backwards compatibility with the "mbr" format.

mbr

msdos

The standard PC "Master Boot Record" (MBR) format used by MS-DOS and Windows. This partition type will only work for device sizes up to 2 TB. For large disks we recommend using "gpt".

Other partition table types that may work but are not supported include:

aix

AIX disk labels.

amiga

rdb

Amiga "Rigid Disk Block" format.

bsd

BSD disk labels.

dasd

DASD, used on IBM mainframes.

dvh

MIPS/SGI volumes.

mac

Old Mac partition format. Modern Macs use "gpt".

pc98

NEC PC-98 format, common in Japan apparently.

sun

Sun disk labels.

This function returns 0 on success or -1 on error.

(Added in 1.0.78)

guestfs_part_list¶

 struct guestfs_partition_list *
 guestfs_part_list (guestfs_h *g,
                    const char *device);

This command parses the partition table on "device" and returns the list of partitions found.

The fields in the returned structure are:

part_num

Partition number, counting from 1.

part_start

Start of the partition in bytes. To get sectors you have to divide by the device's sector size, see "guestfs_blockdev_getss".

part_end

End of the partition in bytes.

part_size

Size of the partition in bytes.

This function returns a "struct guestfs_partition_list *", or NULL if there was an error. The caller must call "guestfs_free_partition_list" after use.

(Added in 1.0.78)

guestfs_part_set_bootable¶

 int
 guestfs_part_set_bootable (guestfs_h *g,
                            const char *device,
                            int partnum,
                            int bootable);

This sets the bootable flag on partition numbered "partnum" on device "device". Note that partitions are numbered from 1.

The bootable flag is used by some operating systems (notably Windows) to determine which partition to boot from. It is by no means universally recognized.

This function returns 0 on success or -1 on error.

(Added in 1.0.78)

guestfs_part_set_gpt_type¶

 int
 guestfs_part_set_gpt_type (guestfs_h *g,
                            const char *device,
                            int partnum,
                            const char *guid);

Set the type GUID of numbered GPT partition "partnum" to "guid". Return an error if the partition table of "device" isn't GPT, or if "guid" is not a valid GUID.

See http://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs for a useful list of type GUIDs.

This function returns 0 on success or -1 on error.

guestfs_part_set_mbr_id¶

 int
 guestfs_part_set_mbr_id (guestfs_h *g,
                          const char *device,
                          int partnum,
                          int idbyte);

Sets the MBR type byte (also known as the ID byte) of the numbered partition "partnum" to "idbyte". Note that the type bytes quoted in most documentation are in fact hexadecimal numbers, but usually documented without any leading "0x" which might be confusing.

Note that only MBR (old DOS-style) partitions have type bytes. You will get undefined results for other partition table types (see "guestfs_part_get_parttype").

This function returns 0 on success or -1 on error.

(Added in 1.3.2)

guestfs_part_set_name¶

 int
 guestfs_part_set_name (guestfs_h *g,
                        const char *device,
                        int partnum,
                        const char *name);

This sets the partition name on partition numbered "partnum" on device "device". Note that partitions are numbered from 1.

The partition name can only be set on certain types of partition table. This works on "gpt" but not on "mbr" partitions.

This function returns 0 on success or -1 on error.

(Added in 1.0.78)

guestfs_part_to_dev¶

 char *
 guestfs_part_to_dev (guestfs_h *g,
                      const char *partition);

This function takes a partition name (eg. "/dev/sdb1") and removes the partition number, returning the device name (eg. "/dev/sdb").

The named partition must exist, for example as a string returned from "guestfs_list_partitions".

See also "guestfs_part_to_partnum", "guestfs_device_index".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.5.15)

guestfs_part_to_partnum¶

 int
 guestfs_part_to_partnum (guestfs_h *g,
                          const char *partition);

This function takes a partition name (eg. "/dev/sdb1") and returns the partition number (eg. 1).

The named partition must exist, for example as a string returned from "guestfs_list_partitions".

See also "guestfs_part_to_dev".

On error this function returns -1.

(Added in 1.13.25)

guestfs_ping_daemon¶

 int
 guestfs_ping_daemon (guestfs_h *g);

This is a test probe into the guestfs daemon running inside the qemu subprocess. Calling this function checks that the daemon responds to the ping message, without affecting the daemon or attached block device(s) in any other way.

This function returns 0 on success or -1 on error.

(Added in 1.0.18)

guestfs_pread¶

 char *
 guestfs_pread (guestfs_h *g,
                const char *path,
                int count,
                int64_t offset,
                size_t *size_r);

This command lets you read part of a file. It reads "count" bytes of the file, starting at "offset", from file "path".

This may read fewer bytes than requested. For further details see the pread(2) system call.

See also "guestfs_pwrite", "guestfs_pread_device".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.77)

guestfs_pread_device¶

 char *
 guestfs_pread_device (guestfs_h *g,
                       const char *device,
                       int count,
                       int64_t offset,
                       size_t *size_r);

This command lets you read part of a block device. It reads "count" bytes of "device", starting at "offset".

This may read fewer bytes than requested. For further details see the pread(2) system call.

See also "guestfs_pread".

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.5.21)

guestfs_pvchange_uuid¶

 int
 guestfs_pvchange_uuid (guestfs_h *g,
                        const char *device);

Generate a new random UUID for the physical volume "device".

This function returns 0 on success or -1 on error.

(Added in 1.19.26)

guestfs_pvchange_uuid_all¶

 int
 guestfs_pvchange_uuid_all (guestfs_h *g);

Generate new random UUIDs for all physical volumes.

This function returns 0 on success or -1 on error.

(Added in 1.19.26)

guestfs_pvcreate¶

 int
 guestfs_pvcreate (guestfs_h *g,
                   const char *device);

This creates an LVM physical volume on the named "device", where "device" should usually be a partition name such as "/dev/sda1".

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_pvremove¶

 int
 guestfs_pvremove (guestfs_h *g,
                   const char *device);

This wipes a physical volume "device" so that LVM will no longer recognise it.

The implementation uses the "pvremove" command which refuses to wipe physical volumes that contain any volume groups, so you have to remove those first.

This function returns 0 on success or -1 on error.

(Added in 1.0.13)

guestfs_pvresize¶

 int
 guestfs_pvresize (guestfs_h *g,
                   const char *device);

This resizes (expands or shrinks) an existing LVM physical volume to match the new size of the underlying device.

This function returns 0 on success or -1 on error.

(Added in 1.0.26)

guestfs_pvresize_size¶

 int
 guestfs_pvresize_size (guestfs_h *g,
                        const char *device,
                        int64_t size);

This command is the same as "guestfs_pvresize" except that it allows you to specify the new size (in bytes) explicitly.

This function returns 0 on success or -1 on error.

(Added in 1.3.14)

guestfs_pvs¶

 char **
 guestfs_pvs (guestfs_h *g);

List all the physical volumes detected. This is the equivalent of the pvs(8) command.

This returns a list of just the device names that contain PVs (eg. "/dev/sda2").

See also "guestfs_pvs_full".

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.4)

guestfs_pvs_full¶

 struct guestfs_lvm_pv_list *
 guestfs_pvs_full (guestfs_h *g);

List all the physical volumes detected. This is the equivalent of the pvs(8) command. The "full" version includes all fields.

This function returns a "struct guestfs_lvm_pv_list *", or NULL if there was an error. The caller must call "guestfs_free_lvm_pv_list" after use.

(Added in 0.4)

guestfs_pvuuid¶

 char *
 guestfs_pvuuid (guestfs_h *g,
                 const char *device);

This command returns the UUID of the LVM PV "device".

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.87)

guestfs_pwrite¶

 int
 guestfs_pwrite (guestfs_h *g,
                 const char *path,
                 const char *content,
                 size_t content_size,
                 int64_t offset);

This command writes to part of a file. It writes the data buffer "content" to the file "path" starting at offset "offset".

This command implements the pwrite(2) system call, and like that system call it may not write the full data requested. The return value is the number of bytes that were actually written to the file. This could even be 0, although short writes are unlikely for regular files in ordinary circumstances.

See also "guestfs_pread", "guestfs_pwrite_device".

On error this function returns -1.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.3.14)

guestfs_pwrite_device¶

 int
 guestfs_pwrite_device (guestfs_h *g,
                        const char *device,
                        const char *content,
                        size_t content_size,
                        int64_t offset);

This command writes to part of a device. It writes the data buffer "content" to "device" starting at offset "offset".

This command implements the pwrite(2) system call, and like that system call it may not write the full data requested (although short writes to disk devices and partitions are probably impossible with standard Linux kernels).

See also "guestfs_pwrite".

On error this function returns -1.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.5.20)

guestfs_read_file¶

 char *
 guestfs_read_file (guestfs_h *g,
                    const char *path,
                    size_t *size_r);

This calls returns the contents of the file "path" as a buffer.

Unlike "guestfs_cat", this function can correctly handle files that contain embedded ASCII NUL characters.

This function returns a buffer, or NULL on error. The size of the returned buffer is written to *size_r. The caller must free the returned buffer after use.

(Added in 1.0.63)

guestfs_read_lines¶

 char **
 guestfs_read_lines (guestfs_h *g,
                     const char *path);

Return the contents of the file named "path".

The file contents are returned as a list of lines. Trailing "LF" and "CRLF" character sequences are not returned.

Note that this function cannot correctly handle binary files (specifically, files containing "\0" character which is treated as end of string). For those you need to use the "guestfs_read_file" function and split the buffer into lines yourself.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 0.7)

guestfs_readdir¶

 struct guestfs_dirent_list *
 guestfs_readdir (guestfs_h *g,
                  const char *dir);

This returns the list of directory entries in directory "dir".

All entries in the directory are returned, including "." and "..". The entries are not sorted, but returned in the same order as the underlying filesystem.

Also this call returns basic file type information about each file. The "ftyp" field will contain one of the following characters:

'b'

Block special

'c'

Char special

'd'

Directory

'f'

FIFO (named pipe)

'l'

Symbolic link

'r'

Regular file

's'

Socket

'u'

Unknown file type

'?'

The readdir(3) call returned a "d_type" field with an unexpected value

This function is primarily intended for use by programs. To get a simple list of names, use "guestfs_ls". To get a printable directory for human consumption, use "guestfs_ll".

This function returns a "struct guestfs_dirent_list *", or NULL if there was an error. The caller must call "guestfs_free_dirent_list" after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.55)

guestfs_readlink¶

 char *
 guestfs_readlink (guestfs_h *g,
                   const char *path);

This command reads the target of a symbolic link.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.66)

guestfs_readlinklist¶

 char **
 guestfs_readlinklist (guestfs_h *g,
                       const char *path,
                       char *const *names);

This call allows you to do a "readlink" operation on multiple files, where all files are in the directory "path". "names" is the list of files from this directory.

On return you get a list of strings, with a one-to-one correspondence to the "names" list. Each string is the value of the symbolic link.

If the readlink(2) operation fails on any name, then the corresponding result string is the empty string "". However the whole operation is completed even if there were readlink(2) errors, and so you can call this function with names where you don't know if they are symbolic links already (albeit slightly less efficient).

This call is intended for programs that want to efficiently list a directory contents without making many round-trips.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.0.77)

guestfs_realpath¶

 char *
 guestfs_realpath (guestfs_h *g,
                   const char *path);

Return the canonicalized absolute pathname of "path". The returned path has no ".", ".." or symbolic link path elements.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.66)

guestfs_remove_drive¶

 int
 guestfs_remove_drive (guestfs_h *g,
                       const char *label);

This function is conceptually the opposite of "guestfs_add_drive_opts". It removes the drive that was previously added with label "label".

Note that in order to remove drives, you have to add them with labels (see the optional "label" argument to "guestfs_add_drive_opts"). If you didn't use a label, then they cannot be removed.

You can call this function before or after launching the handle. If called after launch, if the attach-method supports it, we try to hot unplug the drive: see "HOTPLUGGING" in guestfs(3). The disk must not be in use (eg. mounted) when you do this. We try to detect if the disk is in use and stop you from doing this.

This function returns 0 on success or -1 on error.

(Added in 1.19.49)

guestfs_removexattr¶

 int
 guestfs_removexattr (guestfs_h *g,
                      const char *xattr,
                      const char *path);

This call removes the extended attribute named "xattr" of the file "path".

See also: "guestfs_lremovexattr", attr(5).

This function returns 0 on success or -1 on error.

(Added in 1.0.59)

guestfs_rename¶

 int
 guestfs_rename (guestfs_h *g,
                 const char *oldpath,
                 const char *newpath);

Rename a file to a new place on the same filesystem. This is the same as the Linux rename(2) system call. In most cases you are better to use "guestfs_mv" instead.

This function returns 0 on success or -1 on error.

guestfs_resize2fs¶

 int
 guestfs_resize2fs (guestfs_h *g,
                    const char *device);

This resizes an ext2, ext3 or ext4 filesystem to match the size of the underlying device.

See also "RESIZE2FS ERRORS" in guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.0.27)

guestfs_resize2fs_M¶

 int
 guestfs_resize2fs_M (guestfs_h *g,
                      const char *device);

This command is the same as "guestfs_resize2fs", but the filesystem is resized to its minimum size. This works like the -M option to the "resize2fs" command.

To get the resulting size of the filesystem you should call "guestfs_tune2fs_l" and read the "Block size" and "Block count" values. These two numbers, multiplied together, give the resulting size of the minimal filesystem in bytes.

See also "RESIZE2FS ERRORS" in guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.9.4)

guestfs_resize2fs_size¶

 int
 guestfs_resize2fs_size (guestfs_h *g,
                         const char *device,
                         int64_t size);

This command is the same as "guestfs_resize2fs" except that it allows you to specify the new size (in bytes) explicitly.

See also "RESIZE2FS ERRORS" in guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.3.14)

guestfs_rm¶

 int
 guestfs_rm (guestfs_h *g,
             const char *path);

Remove the single file "path".

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_rm_f¶

 int
 guestfs_rm_f (guestfs_h *g,
               const char *path);

Remove the file "path".

If the file doesn't exist, that error is ignored. (Other errors, eg. I/O errors or bad paths, are not ignored)

This call cannot remove directories. Use "guestfs_rmdir" to remove an empty directory, or "guestfs_rm_rf" to remove directories recursively.

This function returns 0 on success or -1 on error.

(Added in 1.19.42)

guestfs_rm_rf¶

 int
 guestfs_rm_rf (guestfs_h *g,
                const char *path);

Remove the file or directory "path", recursively removing the contents if its a directory. This is like the "rm -rf" shell command.

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_rmdir¶

 int
 guestfs_rmdir (guestfs_h *g,
                const char *path);

Remove the single directory "path".

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_rmmountpoint¶

 int
 guestfs_rmmountpoint (guestfs_h *g,
                       const char *exemptpath);

This calls removes a mountpoint that was previously created with "guestfs_mkmountpoint". See "guestfs_mkmountpoint" for full details.

This function returns 0 on success or -1 on error.

(Added in 1.0.62)

guestfs_rsync¶

 int
 guestfs_rsync (guestfs_h *g,
                const char *src,
                const char *dest,
                ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_RSYNC_ARCHIVE, int archive,
 GUESTFS_RSYNC_DELETEDEST, int deletedest,

This call may be used to copy or synchronize two directories under the same libguestfs handle. This uses the rsync(1) program which uses a fast algorithm that avoids copying files unnecessarily.

"src" and "dest" are the source and destination directories. Files are copied from "src" to "dest".

The optional arguments are:

"archive"

Turns on archive mode. This is the same as passing the --archive flag to "rsync".

"deletedest"

Delete files at the destination that do not exist at the source.

This function returns 0 on success or -1 on error.

(Added in 1.19.29)

guestfs_rsync_va¶

 int
 guestfs_rsync_va (guestfs_h *g,
                   const char *src,
                   const char *dest,
                   va_list args);

This is the "va_list variant" of "guestfs_rsync".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_rsync_argv¶

 int
 guestfs_rsync_argv (guestfs_h *g,
                     const char *src,
                     const char *dest,
                     const struct guestfs_rsync_argv *optargs);

This is the "argv variant" of "guestfs_rsync".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_rsync_in¶

 int
 guestfs_rsync_in (guestfs_h *g,
                   const char *remote,
                   const char *dest,
                   ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_RSYNC_IN_ARCHIVE, int archive,
 GUESTFS_RSYNC_IN_DELETEDEST, int deletedest,

This call may be used to copy or synchronize the filesystem on the host or on a remote computer with the filesystem within libguestfs. This uses the rsync(1) program which uses a fast algorithm that avoids copying files unnecessarily.

This call only works if the network is enabled. See "guestfs_set_network" or the --network option to various tools like guestfish(1).

Files are copied from the remote server and directory specified by "remote" to the destination directory "dest".

The format of the remote server string is defined by rsync(1). Note that there is no way to supply a password or passphrase so the target must be set up not to require one.

The optional arguments are the same as those of "guestfs_rsync".

This function returns 0 on success or -1 on error.

(Added in 1.19.29)

guestfs_rsync_in_va¶

 int
 guestfs_rsync_in_va (guestfs_h *g,
                      const char *remote,
                      const char *dest,
                      va_list args);

This is the "va_list variant" of "guestfs_rsync_in".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_rsync_in_argv¶

 int
 guestfs_rsync_in_argv (guestfs_h *g,
                        const char *remote,
                        const char *dest,
                        const struct guestfs_rsync_in_argv *optargs);

This is the "argv variant" of "guestfs_rsync_in".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_rsync_out¶

 int
 guestfs_rsync_out (guestfs_h *g,
                    const char *src,
                    const char *remote,
                    ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_RSYNC_OUT_ARCHIVE, int archive,
 GUESTFS_RSYNC_OUT_DELETEDEST, int deletedest,

This call may be used to copy or synchronize the filesystem within libguestfs with a filesystem on the host or on a remote computer. This uses the rsync(1) program which uses a fast algorithm that avoids copying files unnecessarily.

This call only works if the network is enabled. See "guestfs_set_network" or the --network option to various tools like guestfish(1).

Files are copied from the source directory "src" to the remote server and directory specified by "remote".

The format of the remote server string is defined by rsync(1). Note that there is no way to supply a password or passphrase so the target must be set up not to require one.

The optional arguments are the same as those of "guestfs_rsync".

Globbing does not happen on the "src" parameter. In programs which use the API directly you have to expand wildcards yourself (see "guestfs_glob_expand"). In guestfish you can use the "glob" command (see "glob" in guestfish(1)), for example:

 ><fs> glob rsync-out /* rsync://remote/

This function returns 0 on success or -1 on error.

(Added in 1.19.29)

guestfs_rsync_out_va¶

 int
 guestfs_rsync_out_va (guestfs_h *g,
                       const char *src,
                       const char *remote,
                       va_list args);

This is the "va_list variant" of "guestfs_rsync_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_rsync_out_argv¶

 int
 guestfs_rsync_out_argv (guestfs_h *g,
                         const char *src,
                         const char *remote,
                         const struct guestfs_rsync_out_argv *optargs);

This is the "argv variant" of "guestfs_rsync_out".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_scrub_device¶

 int
 guestfs_scrub_device (guestfs_h *g,
                       const char *device);

This command writes patterns over "device" to make data retrieval more difficult.

It is an interface to the scrub(1) program. See that manual page for more details.

This function returns 0 on success or -1 on error.

(Added in 1.0.52)

guestfs_scrub_file¶

 int
 guestfs_scrub_file (guestfs_h *g,
                     const char *file);

This command writes patterns over a file to make data retrieval more difficult.

The file is removed after scrubbing.

It is an interface to the scrub(1) program. See that manual page for more details.

This function returns 0 on success or -1 on error.

(Added in 1.0.52)

guestfs_scrub_freespace¶

 int
 guestfs_scrub_freespace (guestfs_h *g,
                          const char *dir);

This command creates the directory "dir" and then fills it with files until the filesystem is full, and scrubs the files as for "guestfs_scrub_file", and deletes them. The intention is to scrub any free space on the partition containing "dir".

It is an interface to the scrub(1) program. See that manual page for more details.

This function returns 0 on success or -1 on error.

(Added in 1.0.52)

guestfs_set_append¶

 int
 guestfs_set_append (guestfs_h *g,
                     const char *append);

This function is used to add additional options to the libguestfs appliance kernel command line.

The default is "NULL" unless overridden by setting "LIBGUESTFS_APPEND" environment variable.

Setting "append" to "NULL" means no additional options are passed (libguestfs always adds a few of its own).

This function returns 0 on success or -1 on error.

(Added in 1.0.26)

guestfs_set_attach_method¶

 int
 guestfs_set_attach_method (guestfs_h *g,
                            const char *attachmethod);

Set the method that libguestfs uses to connect to the back end guestfsd daemon.

See "ATTACH METHOD" in guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.9.8)

guestfs_set_autosync¶

 int
 guestfs_set_autosync (guestfs_h *g,
                       int autosync);

If "autosync" is true, this enables autosync. Libguestfs will make a best effort attempt to make filesystems consistent and synchronized when the handle is closed (also if the program exits without closing handles).

This is enabled by default (since libguestfs 1.5.24, previously it was disabled by default).

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_set_cachedir¶

 int
 guestfs_set_cachedir (guestfs_h *g,
                       const char *cachedir);

Set the directory used by the handle to store the appliance cache, when using a supermin appliance. The appliance is cached and shared between all handles which have the same effective user ID.

The environment variables "LIBGUESTFS_CACHEDIR" and "TMPDIR" control the default value: If "LIBGUESTFS_CACHEDIR" is set, then that is the default. Else if "TMPDIR" is set, then that is the default. Else "/var/tmp" is the default.

This function returns 0 on success or -1 on error.

(Added in 1.19.58)

guestfs_set_direct¶

 int
 guestfs_set_direct (guestfs_h *g,
                     int direct);

If the direct appliance mode flag is enabled, then stdin and stdout are passed directly through to the appliance once it is launched.

One consequence of this is that log messages aren't caught by the library and handled by "guestfs_set_log_message_callback", but go straight to stdout.

You probably don't want to use this unless you know what you are doing.

The default is disabled.

This function returns 0 on success or -1 on error.

(Added in 1.0.72)

guestfs_set_e2attrs¶

 int
 guestfs_set_e2attrs (guestfs_h *g,
                      const char *file,
                      const char *attrs,
                      ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_SET_E2ATTRS_CLEAR, int clear,

This sets or clears the file attributes "attrs" associated with the inode "file".

"attrs" is a string of characters representing file attributes. See "guestfs_get_e2attrs" for a list of possible attributes. Not all attributes can be changed.

If optional boolean "clear" is not present or false, then the "attrs" listed are set in the inode.

If "clear" is true, then the "attrs" listed are cleared in the inode.

In both cases, other attributes not present in the "attrs" string are left unchanged.

These attributes are only present when the file is located on an ext2/3/4 filesystem. Using this call on other filesystem types will result in an error.

This function returns 0 on success or -1 on error.

(Added in 1.17.31)

guestfs_set_e2attrs_va¶

 int
 guestfs_set_e2attrs_va (guestfs_h *g,
                         const char *file,
                         const char *attrs,
                         va_list args);

This is the "va_list variant" of "guestfs_set_e2attrs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_set_e2attrs_argv¶

 int
 guestfs_set_e2attrs_argv (guestfs_h *g,
                           const char *file,
                           const char *attrs,
                           const struct guestfs_set_e2attrs_argv *optargs);

This is the "argv variant" of "guestfs_set_e2attrs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_set_e2generation¶

 int
 guestfs_set_e2generation (guestfs_h *g,
                           const char *file,
                           int64_t generation);

This sets the ext2 file generation of a file.

See "guestfs_get_e2generation".

This function returns 0 on success or -1 on error.

(Added in 1.17.31)

guestfs_set_e2label¶

 int
 guestfs_set_e2label (guestfs_h *g,
                      const char *device,
                      const char *label);

This function is deprecated. In new code, use the "guestfs_set_label" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This sets the ext2/3/4 filesystem label of the filesystem on "device" to "label". Filesystem labels are limited to 16 characters.

You can use either "guestfs_tune2fs_l" or "guestfs_get_e2label" to return the existing label on a filesystem.

This function returns 0 on success or -1 on error.

(Added in 1.0.15)

guestfs_set_e2uuid¶

 int
 guestfs_set_e2uuid (guestfs_h *g,
                     const char *device,
                     const char *uuid);

This sets the ext2/3/4 filesystem UUID of the filesystem on "device" to "uuid". The format of the UUID and alternatives such as "clear", "random" and "time" are described in the tune2fs(8) manpage.

You can use either "guestfs_tune2fs_l" or "guestfs_get_e2uuid" to return the existing UUID of a filesystem.

This function returns 0 on success or -1 on error.

(Added in 1.0.15)

guestfs_set_label¶

 int
 guestfs_set_label (guestfs_h *g,
                    const char *device,
                    const char *label);

Set the filesystem label on "device" to "label".

Only some filesystem types support labels, and libguestfs supports setting labels on only a subset of these.

ext2, ext3, ext4

Labels are limited to 16 bytes.

NTFS

Labels are limited to 128 unicode characters.

XFS

The label is limited to 12 bytes. The filesystem must not be mounted when trying to set the label.

btrfs

The label is limited to 255 bytes and some characters are not allowed. Setting the label on a btrfs subvolume will set the label on its parent filesystem. The filesystem must not be mounted when trying to set the label.

To read the label on a filesystem, call "guestfs_vfs_label".

This function returns 0 on success or -1 on error.

(Added in 1.17.9)

guestfs_set_libvirt_requested_credential¶

 int
 guestfs_set_libvirt_requested_credential (guestfs_h *g,
                                           int index,
                                           const char *cred,
                                           size_t cred_size);

After requesting the "index"'th credential from the user, call this function to pass the answer back to libvirt.

See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.

This function returns 0 on success or -1 on error.

(Added in 1.19.52)

guestfs_set_libvirt_supported_credentials¶

 int
 guestfs_set_libvirt_supported_credentials (guestfs_h *g,
                                            char *const *creds);

Call this function before setting an event handler for "GUESTFS_EVENT_LIBVIRT_AUTH", to supply the list of credential types that the program knows how to process.

The "creds" list must be a non-empty list of strings. Possible strings are:

"username"

"authname"

"language"

"cnonce"

"passphrase"

"echoprompt"

"noechoprompt"

"realm"

"external"

See libvirt documentation for the meaning of these credential types.

See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.

This function returns 0 on success or -1 on error.

(Added in 1.19.52)

guestfs_set_memsize¶

 int
 guestfs_set_memsize (guestfs_h *g,
                      int memsize);

This sets the memory size in megabytes allocated to the qemu subprocess. This only has any effect if called before "guestfs_launch".

You can also change this by setting the environment variable "LIBGUESTFS_MEMSIZE" before the handle is created.

For more information on the architecture of libguestfs, see guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_set_network¶

 int
 guestfs_set_network (guestfs_h *g,
                      int network);

If "network" is true, then the network is enabled in the libguestfs appliance. The default is false.

This affects whether commands are able to access the network (see "RUNNING COMMANDS" in guestfs(3)).

You must call this before calling "guestfs_launch", otherwise it has no effect.

This function returns 0 on success or -1 on error.

(Added in 1.5.4)

guestfs_set_path¶

 int
 guestfs_set_path (guestfs_h *g,
                   const char *searchpath);

Set the path that libguestfs searches for kernel and initrd.img.

The default is "$libdir/guestfs" unless overridden by setting "LIBGUESTFS_PATH" environment variable.

Setting "path" to "NULL" restores the default path.

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_set_pgroup¶

 int
 guestfs_set_pgroup (guestfs_h *g,
                     int pgroup);

If "pgroup" is true, child processes are placed into their own process group.

The practical upshot of this is that signals like "SIGINT" (from users pressing "^C") won't be received by the child process.

The default for this flag is false, because usually you want "^C" to kill the subprocess. Guestfish sets this flag to true when used interactively, so that "^C" can cancel long-running commands gracefully (see "guestfs_user_cancel").

This function returns 0 on success or -1 on error.

(Added in 1.11.18)

guestfs_set_qemu¶

 int
 guestfs_set_qemu (guestfs_h *g,
                   const char *qemu);

Set the qemu binary that we will use.

The default is chosen when the library was compiled by the configure script.

You can also override this by setting the "LIBGUESTFS_QEMU" environment variable.

Setting "qemu" to "NULL" restores the default qemu binary.

Note that you should call this function as early as possible after creating the handle. This is because some pre-launch operations depend on testing qemu features (by running "qemu -help"). If the qemu binary changes, we don't retest features, and so you might see inconsistent results. Using the environment variable "LIBGUESTFS_QEMU" is safest of all since that picks the qemu binary at the same time as the handle is created.

This function returns 0 on success or -1 on error.

(Added in 1.0.6)

guestfs_set_recovery_proc¶

 int
 guestfs_set_recovery_proc (guestfs_h *g,
                            int recoveryproc);

If this is called with the parameter "false" then "guestfs_launch" does not create a recovery process. The purpose of the recovery process is to stop runaway qemu processes in the case where the main program aborts abruptly.

This only has any effect if called before "guestfs_launch", and the default is true.

About the only time when you would want to disable this is if the main process will fork itself into the background ("daemonize" itself). In this case the recovery process thinks that the main program has disappeared and so kills qemu, which is not very helpful.

This function returns 0 on success or -1 on error.

(Added in 1.0.77)

guestfs_set_selinux¶

 int
 guestfs_set_selinux (guestfs_h *g,
                      int selinux);

This sets the selinux flag that is passed to the appliance at boot time. The default is "selinux=0" (disabled).

Note that if SELinux is enabled, it is always in Permissive mode ("enforcing=0").

For more information on the architecture of libguestfs, see guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.0.67)

guestfs_set_smp¶

 int
 guestfs_set_smp (guestfs_h *g,
                  int smp);

Change the number of virtual CPUs assigned to the appliance. The default is 1. Increasing this may improve performance, though often it has no effect.

This function must be called before "guestfs_launch".

This function returns 0 on success or -1 on error.

(Added in 1.13.15)

guestfs_set_tmpdir¶

 int
 guestfs_set_tmpdir (guestfs_h *g,
                     const char *tmpdir);

Set the directory used by the handle to store temporary files.

The environment variables "LIBGUESTFS_TMPDIR" and "TMPDIR" control the default value: If "LIBGUESTFS_TMPDIR" is set, then that is the default. Else if "TMPDIR" is set, then that is the default. Else "/tmp" is the default.

This function returns 0 on success or -1 on error.

(Added in 1.19.58)

guestfs_set_trace¶

 int
 guestfs_set_trace (guestfs_h *g,
                    int trace);

If the command trace flag is set to 1, then libguestfs calls, parameters and return values are traced.

If you want to trace C API calls into libguestfs (and other libraries) then possibly a better way is to use the external ltrace(1) command.

Command traces are disabled unless the environment variable "LIBGUESTFS_TRACE" is defined and set to 1.

Trace messages are normally sent to "stderr", unless you register a callback to send them somewhere else (see "guestfs_set_event_callback").

This function returns 0 on success or -1 on error.

(Added in 1.0.69)

guestfs_set_verbose¶

 int
 guestfs_set_verbose (guestfs_h *g,
                      int verbose);

If "verbose" is true, this turns on verbose messages.

Verbose messages are disabled unless the environment variable "LIBGUESTFS_DEBUG" is defined and set to 1.

Verbose messages are normally sent to "stderr", unless you register a callback to send them somewhere else (see "guestfs_set_event_callback").

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_setcon¶

 int
 guestfs_setcon (guestfs_h *g,
                 const char *context);

This sets the SELinux security context of the daemon to the string "context".

See the documentation about SELINUX in guestfs(3).

This function returns 0 on success or -1 on error.

(Added in 1.0.67)

guestfs_setxattr¶

 int
 guestfs_setxattr (guestfs_h *g,
                   const char *xattr,
                   const char *val,
                   int vallen,
                   const char *path);

This call sets the extended attribute named "xattr" of the file "path" to the value "val" (of length "vallen"). The value is arbitrary 8 bit data.

See also: "guestfs_lsetxattr", attr(5).

This function returns 0 on success or -1 on error.

(Added in 1.0.59)

guestfs_sfdisk¶

 int
 guestfs_sfdisk (guestfs_h *g,
                 const char *device,
                 int cyls,
                 int heads,
                 int sectors,
                 char *const *lines);

This function is deprecated. In new code, use the "guestfs_part_add" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This is a direct interface to the sfdisk(8) program for creating partitions on block devices.

"device" should be a block device, for example "/dev/sda".

"cyls", "heads" and "sectors" are the number of cylinders, heads and sectors on the device, which are passed directly to sfdisk as the -C, -H and -S parameters. If you pass 0 for any of these, then the corresponding parameter is omitted. Usually for 'large' disks, you can just pass 0 for these, but for small (floppy-sized) disks, sfdisk (or rather, the kernel) cannot work out the right geometry and you will need to tell it.

"lines" is a list of lines that we feed to "sfdisk". For more information refer to the sfdisk(8) manpage.

To create a single partition occupying the whole disk, you would pass "lines" as a single element list, when the single element being the string "," (comma).

See also: "guestfs_sfdisk_l", "guestfs_sfdisk_N", "guestfs_part_init"

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_sfdiskM¶

 int
 guestfs_sfdiskM (guestfs_h *g,
                  const char *device,
                  char *const *lines);

This function is deprecated. In new code, use the "guestfs_part_add" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This is a simplified interface to the "guestfs_sfdisk" command, where partition sizes are specified in megabytes only (rounded to the nearest cylinder) and you don't need to specify the cyls, heads and sectors parameters which were rarely if ever used anyway.

See also: "guestfs_sfdisk", the sfdisk(8) manpage and "guestfs_part_disk"

This function returns 0 on success or -1 on error.

(Added in 1.0.55)

guestfs_sfdisk_N¶

 int
 guestfs_sfdisk_N (guestfs_h *g,
                   const char *device,
                   int partnum,
                   int cyls,
                   int heads,
                   int sectors,
                   const char *line);

This function is deprecated. In new code, use the "guestfs_part_add" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This runs sfdisk(8) option to modify just the single partition "n" (note: "n" counts from 1).

For other parameters, see "guestfs_sfdisk". You should usually pass 0 for the cyls/heads/sectors parameters.

See also: "guestfs_part_add"

This function returns 0 on success or -1 on error.

(Added in 1.0.26)

guestfs_sfdisk_disk_geometry¶

 char *
 guestfs_sfdisk_disk_geometry (guestfs_h *g,
                               const char *device);

This displays the disk geometry of "device" read from the partition table. Especially in the case where the underlying block device has been resized, this can be different from the kernel's idea of the geometry (see "guestfs_sfdisk_kernel_geometry").

The result is in human-readable format, and not designed to be parsed.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.26)

guestfs_sfdisk_kernel_geometry¶

 char *
 guestfs_sfdisk_kernel_geometry (guestfs_h *g,
                                 const char *device);

This displays the kernel's idea of the geometry of "device".

The result is in human-readable format, and not designed to be parsed.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.26)

guestfs_sfdisk_l¶

 char *
 guestfs_sfdisk_l (guestfs_h *g,
                   const char *device);

This function is deprecated. In new code, use the "guestfs_part_list" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This displays the partition table on "device", in the human-readable output of the sfdisk(8) command. It is not intended to be parsed.

See also: "guestfs_part_list"

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.26)

guestfs_sh¶

 char *
 guestfs_sh (guestfs_h *g,
             const char *command);

This call runs a command from the guest filesystem via the guest's "/bin/sh".

This is like "guestfs_command", but passes the command to:

 /bin/sh -c "command"

Depending on the guest's shell, this usually results in wildcards being expanded, shell expressions being interpolated and so on.

All the provisos about "guestfs_command" apply to this call.

This function returns a string, or NULL on error. The caller must free the returned string after use.

(Added in 1.0.50)

guestfs_sh_lines¶

 char **
 guestfs_sh_lines (guestfs_h *g,
                   const char *command);

This is the same as "guestfs_sh", but splits the result into a list of lines.

See also: "guestfs_command_lines"

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

(Added in 1.0.50)

guestfs_shutdown¶

 int
 guestfs_shutdown (guestfs_h *g);

This is the opposite of "guestfs_launch". It performs an orderly shutdown of the backend process(es). If the autosync flag is set (which is the default) then the disk image is synchronized.

If the subprocess exits with an error then this function will return an error, which should not be ignored (it may indicate that the disk image could not be written out properly).

It is safe to call this multiple times. Extra calls are ignored.

This call does not close or free up the handle. You still need to call "guestfs_close" afterwards.

"guestfs_close" will call this if you don't do it explicitly, but note that any errors are ignored in that case.

This function returns 0 on success or -1 on error.

(Added in 1.19.16)

guestfs_sleep¶

 int
 guestfs_sleep (guestfs_h *g,
                int secs);

Sleep for "secs" seconds.

This function returns 0 on success or -1 on error.

(Added in 1.0.41)

guestfs_stat¶

 struct guestfs_stat *
 guestfs_stat (guestfs_h *g,
               const char *path);

Returns file information for the given "path".

This is the same as the stat(2) system call.

This function returns a "struct guestfs_stat *", or NULL if there was an error. The caller must call "guestfs_free_stat" after use.

(Added in 0.9.2)

guestfs_statvfs¶

 struct guestfs_statvfs *
 guestfs_statvfs (guestfs_h *g,
                  const char *path);

Returns file system statistics for any mounted file system. "path" should be a file or directory in the mounted file system (typically it is the mount point itself, but it doesn't need to be).

This is the same as the statvfs(2) system call.

This function returns a "struct guestfs_statvfs *", or NULL if there was an error. The caller must call "guestfs_free_statvfs" after use.

(Added in 0.9.2)

guestfs_strings¶

 char **
 guestfs_strings (guestfs_h *g,
                  const char *path);

This runs the strings(1) command on a file and returns the list of printable strings found.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.22)

guestfs_strings_e¶

 char **
 guestfs_strings_e (guestfs_h *g,
                    const char *encoding,
                    const char *path);

This is like the "guestfs_strings" command, but allows you to specify the encoding of strings that are looked for in the source file "path".

Allowed encodings are:

s

Single 7-bit-byte characters like ASCII and the ASCII-compatible parts of ISO-8859-X (this is what "guestfs_strings" uses).

S

Single 8-bit-byte characters.

b

16-bit big endian strings such as those encoded in UTF-16BE or UCS-2BE.

l (lower case letter L)

16-bit little endian such as UTF-16LE and UCS-2LE. This is useful for examining binaries in Windows guests.

B

32-bit big endian such as UCS-4BE.

L

32-bit little endian such as UCS-4LE.

The returned strings are transcoded to UTF-8.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.22)

guestfs_swapoff_device¶

 int
 guestfs_swapoff_device (guestfs_h *g,
                         const char *device);

This command disables the libguestfs appliance swap device or partition named "device". See "guestfs_swapon_device".

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapoff_file¶

 int
 guestfs_swapoff_file (guestfs_h *g,
                       const char *file);

This command disables the libguestfs appliance swap on file.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapoff_label¶

 int
 guestfs_swapoff_label (guestfs_h *g,
                        const char *label);

This command disables the libguestfs appliance swap on labeled swap partition.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapoff_uuid¶

 int
 guestfs_swapoff_uuid (guestfs_h *g,
                       const char *uuid);

This command disables the libguestfs appliance swap partition with the given UUID.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapon_device¶

 int
 guestfs_swapon_device (guestfs_h *g,
                        const char *device);

This command enables the libguestfs appliance to use the swap device or partition named "device". The increased memory is made available for all commands, for example those run using "guestfs_command" or "guestfs_sh".

Note that you should not swap to existing guest swap partitions unless you know what you are doing. They may contain hibernation information, or other information that the guest doesn't want you to trash. You also risk leaking information about the host to the guest this way. Instead, attach a new host device to the guest and swap on that.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapon_file¶

 int
 guestfs_swapon_file (guestfs_h *g,
                      const char *file);

This command enables swap to a file. See "guestfs_swapon_device" for other notes.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapon_label¶

 int
 guestfs_swapon_label (guestfs_h *g,
                       const char *label);

This command enables swap to a labeled swap partition. See "guestfs_swapon_device" for other notes.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_swapon_uuid¶

 int
 guestfs_swapon_uuid (guestfs_h *g,
                      const char *uuid);

This command enables swap to a swap partition with the given UUID. See "guestfs_swapon_device" for other notes.

This function returns 0 on success or -1 on error.

(Added in 1.0.66)

guestfs_sync¶

 int
 guestfs_sync (guestfs_h *g);

This syncs the disk, so that any writes are flushed through to the underlying disk image.

You should always call this if you have modified a disk image, before closing the handle.

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_tail¶

 char **
 guestfs_tail (guestfs_h *g,
               const char *path);

This command returns up to the last 10 lines of a file as a list of strings.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.54)

guestfs_tail_n¶

 char **
 guestfs_tail_n (guestfs_h *g,
                 int nrlines,
                 const char *path);

If the parameter "nrlines" is a positive number, this returns the last "nrlines" lines of the file "path".

If the parameter "nrlines" is a negative number, this returns lines from the file "path", starting with the "-nrlines"th line.

If the parameter "nrlines" is zero, this returns an empty list.

This function returns a NULL-terminated array of strings (like environ(3)), or NULL if there was an error. The caller must free the strings and the array after use.

Because of the message protocol, there is a transfer limit of somewhere between 2MB and 4MB. See "PROTOCOL LIMITS" in guestfs(3).

(Added in 1.0.54)

guestfs_tar_in¶

 int
 guestfs_tar_in (guestfs_h *g,
                 const char *tarfile,
                 const char *directory);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_tar_in_opts" with no optional arguments.

(Added in 1.0.3)

guestfs_tar_in_opts¶

 int
 guestfs_tar_in_opts (guestfs_h *g,
                      const char *tarfile,
                      const char *directory,
                      ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_TAR_IN_OPTS_COMPRESS, const char *compress,

This command uploads and unpacks local file "tarfile" into "directory".

The optional "compress" flag controls compression. If not given, then the input should be an uncompressed tar file. Otherwise one of the following strings may be given to select the compression type of the input file: "compress", "gzip", "bzip2", "xz", "lzop". (Note that not all builds of libguestfs will support all of these compression types).

This function returns 0 on success or -1 on error.

(Added in 1.19.30)

guestfs_tar_in_opts_va¶

 int
 guestfs_tar_in_opts_va (guestfs_h *g,
                         const char *tarfile,
                         const char *directory,
                         va_list args);

This is the "va_list variant" of "guestfs_tar_in_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_tar_in_opts_argv¶

 int
 guestfs_tar_in_opts_argv (guestfs_h *g,
                           const char *tarfile,
                           const char *directory,
                           const struct guestfs_tar_in_opts_argv *optargs);

This is the "argv variant" of "guestfs_tar_in_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_tar_out¶

 int
 guestfs_tar_out (guestfs_h *g,
                  const char *directory,
                  const char *tarfile);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_tar_out_opts" with no optional arguments.

(Added in 1.0.3)

guestfs_tar_out_opts¶

 int
 guestfs_tar_out_opts (guestfs_h *g,
                       const char *directory,
                       const char *tarfile,
                       ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_TAR_OUT_OPTS_COMPRESS, const char *compress,
 GUESTFS_TAR_OUT_OPTS_NUMERICOWNER, int numericowner,
 GUESTFS_TAR_OUT_OPTS_EXCLUDES, char *const *excludes,

This command packs the contents of "directory" and downloads it to local file "tarfile".

The optional "compress" flag controls compression. If not given, then the output will be an uncompressed tar file. Otherwise one of the following strings may be given to select the compression type of the output file: "compress", "gzip", "bzip2", "xz", "lzop". (Note that not all builds of libguestfs will support all of these compression types).

The other optional arguments are:

"excludes"

A list of wildcards. Files are excluded if they match any of the wildcards.

"numericowner"

If set to true, the output tar file will contain UID/GID numbers instead of user/group names.

This function returns 0 on success or -1 on error.

(Added in 1.19.30)

guestfs_tar_out_opts_va¶

 int
 guestfs_tar_out_opts_va (guestfs_h *g,
                          const char *directory,
                          const char *tarfile,
                          va_list args);

This is the "va_list variant" of "guestfs_tar_out_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_tar_out_opts_argv¶

 int
 guestfs_tar_out_opts_argv (guestfs_h *g,
                            const char *directory,
                            const char *tarfile,
                            const struct guestfs_tar_out_opts_argv *optargs);

This is the "argv variant" of "guestfs_tar_out_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_tgz_in¶

 int
 guestfs_tgz_in (guestfs_h *g,
                 const char *tarball,
                 const char *directory);

This function is deprecated. In new code, use the "guestfs_tar_in" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command uploads and unpacks local file "tarball" (a gzip compressed tar file) into "directory".

This function returns 0 on success or -1 on error.

(Added in 1.0.3)

guestfs_tgz_out¶

 int
 guestfs_tgz_out (guestfs_h *g,
                  const char *directory,
                  const char *tarball);

This function is deprecated. In new code, use the "guestfs_tar_out" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command packs the contents of "directory" and downloads it to local file "tarball".

This function returns 0 on success or -1 on error.

(Added in 1.0.3)

guestfs_touch¶

 int
 guestfs_touch (guestfs_h *g,
                const char *path);

Touch acts like the touch(1) command. It can be used to update the timestamps on a file, or, if the file does not exist, to create a new zero-length file.

This command only works on regular files, and will fail on other file types such as directories, symbolic links, block special etc.

This function returns 0 on success or -1 on error.

(Added in 0.3)

guestfs_truncate¶

 int
 guestfs_truncate (guestfs_h *g,
                   const char *path);

This command truncates "path" to a zero-length file. The file must exist already.

This function returns 0 on success or -1 on error.

(Added in 1.0.77)

guestfs_truncate_size¶

 int
 guestfs_truncate_size (guestfs_h *g,
                        const char *path,
                        int64_t size);

This command truncates "path" to size "size" bytes. The file must exist already.

If the current file size is less than "size" then the file is extended to the required size with zero bytes. This creates a sparse file (ie. disk blocks are not allocated for the file until you write to it). To create a non-sparse file of zeroes, use "guestfs_fallocate64" instead.

This function returns 0 on success or -1 on error.

(Added in 1.0.77)

guestfs_tune2fs¶

 int
 guestfs_tune2fs (guestfs_h *g,
                  const char *device,
                  ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_TUNE2FS_FORCE, int force,
 GUESTFS_TUNE2FS_MAXMOUNTCOUNT, int maxmountcount,
 GUESTFS_TUNE2FS_MOUNTCOUNT, int mountcount,
 GUESTFS_TUNE2FS_ERRORBEHAVIOR, const char *errorbehavior,
 GUESTFS_TUNE2FS_GROUP, int64_t group,
 GUESTFS_TUNE2FS_INTERVALBETWEENCHECKS, int intervalbetweenchecks,
 GUESTFS_TUNE2FS_RESERVEDBLOCKSPERCENTAGE, int reservedblockspercentage,
 GUESTFS_TUNE2FS_LASTMOUNTEDDIRECTORY, const char *lastmounteddirectory,
 GUESTFS_TUNE2FS_RESERVEDBLOCKSCOUNT, int64_t reservedblockscount,
 GUESTFS_TUNE2FS_USER, int64_t user,

This call allows you to adjust various filesystem parameters of an ext2/ext3/ext4 filesystem called "device".

The optional parameters are:

"force"

Force tune2fs to complete the operation even in the face of errors. This is the same as the tune2fs "-f" option.

"maxmountcount"

Set the number of mounts after which the filesystem is checked by e2fsck(8). If this is 0 then the number of mounts is disregarded. This is the same as the tune2fs "-c" option.

"mountcount"

Set the number of times the filesystem has been mounted. This is the same as the tune2fs "-C" option.

"errorbehavior"

Change the behavior of the kernel code when errors are detected. Possible values currently are: "continue", "remount-ro", "panic". In practice these options don't really make any difference, particularly for write errors.

This is the same as the tune2fs "-e" option.

"group"

Set the group which can use reserved filesystem blocks. This is the same as the tune2fs "-g" option except that it can only be specified as a number.

"intervalbetweenchecks"

Adjust the maximal time between two filesystem checks (in seconds). If the option is passed as 0 then time-dependent checking is disabled.

This is the same as the tune2fs "-i" option.

"reservedblockspercentage"

Set the percentage of the filesystem which may only be allocated by privileged processes. This is the same as the tune2fs "-m" option.

"lastmounteddirectory"

Set the last mounted directory. This is the same as the tune2fs "-M" option.

"reservedblockscount" Set the number of reserved filesystem blocks. This is the same as the tune2fs "-r" option.

"user"

Set the user who can use the reserved filesystem blocks. This is the same as the tune2fs "-u" option except that it can only be specified as a number.

To get the current values of filesystem parameters, see "guestfs_tune2fs_l". For precise details of how tune2fs works, see the tune2fs(8) man page.

This function returns 0 on success or -1 on error.

(Added in 1.15.4)

guestfs_tune2fs_va¶

 int
 guestfs_tune2fs_va (guestfs_h *g,
                     const char *device,
                     va_list args);

This is the "va_list variant" of "guestfs_tune2fs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_tune2fs_argv¶

 int
 guestfs_tune2fs_argv (guestfs_h *g,
                       const char *device,
                       const struct guestfs_tune2fs_argv *optargs);

This is the "argv variant" of "guestfs_tune2fs".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_tune2fs_l¶

 char **
 guestfs_tune2fs_l (guestfs_h *g,
                    const char *device);

This returns the contents of the ext2, ext3 or ext4 filesystem superblock on "device".

It is the same as running "tune2fs -l device". See tune2fs(8) manpage for more details. The list of fields returned isn't clearly defined, and depends on both the version of "tune2fs" that libguestfs was built against, and the filesystem itself.

This function returns a NULL-terminated array of strings, or NULL if there was an error. The array of strings will always have length "2n+1", where "n" keys and values alternate, followed by the trailing NULL entry. The caller must free the strings and the array after use.

(Added in 0.9.2)

guestfs_txz_in¶

 int
 guestfs_txz_in (guestfs_h *g,
                 const char *tarball,
                 const char *directory);

This function is deprecated. In new code, use the "guestfs_tar_in" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command uploads and unpacks local file "tarball" (an xz compressed tar file) into "directory".

This function returns 0 on success or -1 on error.

(Added in 1.3.2)

guestfs_txz_out¶

 int
 guestfs_txz_out (guestfs_h *g,
                  const char *directory,
                  const char *tarball);

This function is deprecated. In new code, use the "guestfs_tar_out" call instead.

Deprecated functions will not be removed from the API, but the fact that they are deprecated indicates that there are problems with correct use of these functions.

This command packs the contents of "directory" and downloads it to local file "tarball" (as an xz compressed tar archive).

This function returns 0 on success or -1 on error.

(Added in 1.3.2)

guestfs_umask¶

 int
 guestfs_umask (guestfs_h *g,
                int mask);

This function sets the mask used for creating new files and device nodes to "mask & 0777".

Typical umask values would be 022 which creates new files with permissions like "-rw-r--r--" or "-rwxr-xr-x", and 002 which creates new files with permissions like "-rw-rw-r--" or "-rwxrwxr-x".

The default umask is 022. This is important because it means that directories and device nodes will be created with 0644 or 0755 mode even if you specify 0777.

See also "guestfs_get_umask", umask(2), "guestfs_mknod", "guestfs_mkdir".

This call returns the previous umask.

On error this function returns -1.

(Added in 1.0.55)

guestfs_umount¶

 int
 guestfs_umount (guestfs_h *g,
                 const char *pathordevice);

This function is provided for backwards compatibility with earlier versions of libguestfs. It simply calls "guestfs_umount_opts" with no optional arguments.

(Added in 0.8)

guestfs_umount_opts¶

 int
 guestfs_umount_opts (guestfs_h *g,
                      const char *pathordevice,
                      ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_UMOUNT_OPTS_FORCE, int force,
 GUESTFS_UMOUNT_OPTS_LAZYUNMOUNT, int lazyunmount,

This unmounts the given filesystem. The filesystem may be specified either by its mountpoint (path) or the device which contains the filesystem.

This function returns 0 on success or -1 on error.

(Added in 1.19.25)

guestfs_umount_opts_va¶

 int
 guestfs_umount_opts_va (guestfs_h *g,
                         const char *pathordevice,
                         va_list args);

This is the "va_list variant" of "guestfs_umount_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_umount_opts_argv¶

 int
 guestfs_umount_opts_argv (guestfs_h *g,
                           const char *pathordevice,
                           const struct guestfs_umount_opts_argv *optargs);

This is the "argv variant" of "guestfs_umount_opts".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_umount_all¶

 int
 guestfs_umount_all (guestfs_h *g);

This unmounts all mounted filesystems.

Some internal mounts are not unmounted by this call.

This function returns 0 on success or -1 on error.

(Added in 0.8)

guestfs_umount_local¶

 int
 guestfs_umount_local (guestfs_h *g,
                       ...);

You may supply a list of optional arguments to this call. Use zero or more of the following pairs of parameters, and terminate the list with "-1" on its own. See "CALLS WITH OPTIONAL ARGUMENTS".

 GUESTFS_UMOUNT_LOCAL_RETRY, int retry,

If libguestfs is exporting the filesystem on a local mountpoint, then this unmounts it.

See "MOUNT LOCAL" in guestfs(3) for full documentation.

This function returns 0 on success or -1 on error.

(Added in 1.17.22)

guestfs_umount_local_va¶

 int
 guestfs_umount_local_va (guestfs_h *g,
                          va_list args);

This is the "va_list variant" of "guestfs_umount_local".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_umount_local_argv¶

 int
 guestfs_umount_local_argv (guestfs_h *g,
                            const struct guestfs_umount_local_argv *optargs);

This is the "argv variant" of "guestfs_umount_local".

See "CALLS WITH OPTIONAL ARGUMENTS".

guestfs_upload¶

 int
 guestfs_upload (guestfs_h *g,
                 const char *filename,
                 const char *remotefilename);

Upload local file "filename" to "remotefilename" on the filesystem.

"filename" can also be a named pipe.

See also "guestfs_download".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.0.2)

guestfs_upload_offset¶

 int
 guestfs_upload_offset (guestfs_h *g,
                        const char *filename,
                        const char *remotefilename,
                        int64_t offset);

Upload local file "filename" to "remotefilename" on the filesystem.

"remotefilename" is overwritten starting at the byte "offset" specified. The intention is to overwrite parts of existing files or devices, although if a non-existent file is specified then it is created with a "hole" before "offset". The size of the data written is implicit in the size of the source "filename".

Note that there is no limit on the amount of data that can be uploaded with this call, unlike with "guestfs_pwrite", and this call always writes the full amount unless an error occurs.

See also "guestfs_upload", "guestfs_pwrite".

This function returns 0 on success or -1 on error.

This long-running command can generate progress notification messages so that the caller can display a progress bar or indicator. To receive these messages, the caller must register a progress event callback. See "GUESTFS_EVENT_PROGRESS" in guestfs(3).

(Added in 1.5.17)

guestfs_user_cancel¶

 int
 guestfs_user_cancel (guestfs_h *g);

This function cancels the current upload or download operation.

Unlike most other libguestfs calls, this function is signal safe and thread safe. You can call it from a signal handler or from another thread, without needing to do any locking.

The transfer that was in progress (if there is one) will stop shortly afterwards, and will return an error. The errno (see "guestfs_last_errno") is set to "EINTR", so you can test for this to find out if the operation was cancelled or failed because of another error.

No cleanup is performed: for example, if a file was being uploaded then after cancellation there may be a partially uploaded file. It is the caller's responsibility to clean up if necessary.

There are two common places that you might call "guestfs_user_cancel":

In an interactive text-based program, you might call it from a "SIGINT" signal handler so that pressing "^C" cancels the current operation. (You also need to call "guestfs_set_pgroup" so that child processes don't receive the "^C" signal).

In a graphical program, when the main thread is displaying a progress bar with a cancel button, wire up the cancel button to call this function.

This function returns 0 on success or -1 on error.

(Added in 1.11.18)

guestfs_utimens¶

 int
 guestfs_utimens (guestfs_h *g,
                  const char *path,
                  int64_t atsecs,
                  int64_t atnsecs,
                  int64_t mtsecs,
                  int64_t mtnsecs);

This command sets the timestamps of a file with nanosecond precision.

"atsecs, atnsecs" are the last access time (atime) in secs and nanoseconds from the epoch.

"mtsecs, mtnsecs" are the last modification time (mtime) in secs and nanoseconds from the epoch.

If the *nsecs field contains the special value "-1" then the corresponding timestamp is set to the current time. (The *secs field is ignored in this case).

If the *nsecs field contains the special value "-2" then the corresponding timestamp is left unchanged. (The *secs field is ignored in this case).

This function returns 0 on success or -1 on error.

(Added in 1.0.77)

guestfs_utsname¶

 struct guestfs_utsname *
 guestfs_utsname (guestfs_h *g);

This returns the kernel version of the appliance, where this is available. This information is only useful for debugging. Nothing in the returned structure is defined by the API.

This function returns a "struct guestfs_utsname *", or NULL if there was an error. The caller must call "guestfs_free_utsname" after use.

(Added in 1.19.27)