The bootstrapping technique¶

A typical way to install local::lib is using what is known as the "bootstrapping" technique. You would do this if your system administrator hasn't already installed local::lib. In this case, you'll need to install local::lib in your home directory.

Even if you do have administrative privileges, you will still want to set up your environment variables, as discussed in step 4. Without this, you would still install the modules into the system CPAN installation and also your Perl scripts will not use the lib/ path you bootstrapped with local::lib.

By default local::lib installs itself and the CPAN modules into ~/perl5.

Windows users must also see "Differences when using this module under Win32".

1.

Download and unpack the local::lib tarball from CPAN (search for "Download" on the CPAN page about local::lib). Do this as an ordinary user, not as root or administrator. Unpack the file in your home directory or in any other convenient location.

2.

Run this:

  perl Makefile.PL --bootstrap
    

If the system asks you whether it should automatically configure as much as possible, you would typically answer yes.

In order to install local::lib into a directory other than the default, you need to specify the name of the directory when you call bootstrap, as follows:

  perl Makefile.PL --bootstrap=~/foo
    

3.

Run this: (local::lib assumes you have make installed on your system)

  make test && make install
    

4.

Now we need to setup the appropriate environment variables, so that Perl starts using our newly generated lib/ directory. If you are using bash or any other Bourne shells, you can add this to your shell startup script this way:

  echo 'eval "$(perl -I$HOME/perl5/lib/perl5 -Mlocal::lib)"' >>~/.bashrc
    

If you are using C shell, you can do this as follows:

  /bin/csh
  echo $SHELL
  /bin/csh
  echo 'eval `perl -I$HOME/perl5/lib/perl5 -Mlocal::lib`' >> ~/.cshrc
    

If you passed to bootstrap a directory other than default, you also need to give that as import parameter to the call of the local::lib module like this way:

  echo 'eval "$(perl -I$HOME/foo/lib/perl5 -Mlocal::lib=$HOME/foo)"' >>~/.bashrc
    

After writing your shell configuration file, be sure to re-read it to get the changed settings into your current shell's environment. Bourne shells use ". ~/.bashrc" for this, whereas C shells use "source ~/.cshrc".

If you're on a slower machine, or are operating under draconian disk space limitations, you can disable the automatic generation of manpages from POD when installing modules by using the "--no-manpages" argument when bootstrapping:

  perl Makefile.PL --bootstrap --no-manpages

To avoid doing several bootstrap for several Perl module environments on the same account, for example if you use it for several different deployed applications independently, you can use one bootstrapped local::lib installation to install modules in different directories directly this way:

  cd ~/mydir1
  perl -Mlocal::lib=./
  eval $(perl -Mlocal::lib=./)  ### To set the environment for this shell alone
  printenv                      ### You will see that ~/mydir1 is in the PERL5LIB
  perl -MCPAN -e install ...    ### whatever modules you want
  cd ../mydir2
  ... REPEAT ...

If you use .bashrc to activate a local::lib automatically, the local::lib will be re-enabled in any sub-shells used, overriding adjustments you may have made in the parent shell. To avoid this, you can initialize the local::lib in .bash_profile rather than .bashrc, or protect the local::lib invocation with a $SHLVL check:

  [ $SHLVL -eq 1 ] && eval "$(perl -I$HOME/perl5/lib/perl5 -Mlocal::lib)"

If you are working with several "local::lib" environments, you may want to remove some of them from the current environment without disturbing the others. You can deactivate one environment like this (using bourne sh):

  eval $(perl -Mlocal::lib=--deactivate,~/path)

which will generate and run the commands needed to remove "~/path" from your various search paths. Whichever environment was activated most recently will remain the target for module installations. That is, if you activate "~/path_A" and then you activate "~/path_B", new modules you install will go in "~/path_B". If you deactivate "~/path_B" then modules will be installed into "~/pathA" -- but if you deactivate "~/path_A" then they will still be installed in "~/pathB" because pathB was activated later.

You can also ask "local::lib" to clean itself completely out of the current shell's environment with the "--deactivate-all" option. For multiple environments for multiple apps you may need to include a modified version of the "use FindBin" instructions in the "In code" sample above. If you did something like the above, you have a set of Perl modules at "~/mydir1/lib". If you have a script at "~/mydir1/scripts/myscript.pl", you need to tell it where to find the modules you installed for it at "~/mydir1/lib".

In "~/mydir1/scripts/myscript.pl":

  use strict;
  use warnings;
  use local::lib "$FindBin::Bin/..";  ### points to ~/mydir1 and local::lib finds lib
  use lib "$FindBin::Bin/../lib";     ### points to ~/mydir1/lib

Put this before any BEGIN { ... } blocks that require the modules you installed.

Differences when using this module under Win32¶

To set up the proper environment variables for your current session of "CMD.exe", you can use this:

  C:\>perl -Mlocal::lib
  set PERL_MB_OPT=--install_base C:\DOCUME~1\ADMINI~1\perl5
  set PERL_MM_OPT=INSTALL_BASE=C:\DOCUME~1\ADMINI~1\perl5
  set PERL5LIB=C:\DOCUME~1\ADMINI~1\perl5\lib\perl5
  set PATH=C:\DOCUME~1\ADMINI~1\perl5\bin;%PATH%
  ### To set the environment for this shell alone
  C:\>perl -Mlocal::lib > %TEMP%\tmp.bat && %TEMP%\tmp.bat && del %TEMP%\tmp.bat
  ### instead of $(perl -Mlocal::lib=./)

If you want the environment entries to persist, you'll need to add them to the Control Panel's System applet yourself or use App::local::lib::Win32Helper.

The "~" is translated to the user's profile directory (the directory named for the user under "Documents and Settings" (Windows XP or earlier) or "Users" (Windows Vista or later)) unless $ENV{HOME} exists. After that, the home directory is translated to a short name (which means the directory must exist) and the subdirectories are created.

PowerShell

local::lib also supports PowerShell, and can be used with the "Invoke-Expression" cmdlet.

  Invoke-Expression "$(perl -Mlocal::lib)"

--deactivate¶

Remove the chosen path (or the default path) from the module search paths if it was added by "local::lib", instead of adding it.

--deactivate-all¶

Remove all directories that were added to search paths by "local::lib" from the search paths.

--shelltype¶

Specify the shell type to use for output. By default, the shell will be detected based on the environment. Should be one of: "bourne", "csh", "cmd", or "powershell".

--no-create¶

Prevents "local::lib" from creating directories when activating dirs. This is likely to cause issues on Win32 systems.

ensure_dir_structure_for¶

Arguments: $path

Return value: None

Attempts to create a local::lib directory, including subdirectories and all required parent directories. Throws an exception on failure.

print_environment_vars_for¶

Arguments: $path

Return value: None

Prints to standard output the variables listed above, properly set to use the given path as the base directory.

build_environment_vars_for¶

Arguments: $path

Return value: %environment_vars

Returns a hash with the variables listed above, properly set to use the given path as the base directory.

setup_env_hash_for¶

Arguments: $path

Return value: None

Constructs the %ENV keys for the given path, by calling "build_environment_vars_for".

active_paths¶

Arguments: None

Return value: @paths

Returns a list of active "local::lib" paths, according to the "PERL_LOCAL_LIB_ROOT" environment variable and verified against what is really in @INC.

install_base_perl_path¶

Arguments: $path

Return value: $install_base_perl_path

Returns a path describing where to install the Perl modules for this local library installation. Appends the directories "lib" and "perl5" to the given path.

lib_paths_for¶

Arguments: $path

Return value: @lib_paths

Returns the list of paths perl will search for libraries, given a base path. This includes the base path itself, the architecture specific subdirectory, and perl version specific subdirectories. These paths may not all exist.

install_base_bin_path¶

Arguments: $path

Return value: $install_base_bin_path

Returns a path describing where to install the executable programs for this local library installation. Appends the directory "bin" to the given path.

installer_options_for¶

Arguments: $path

Return value: %installer_env_vars

Returns a hash of environment variables that should be set to cause installation into the given path.

resolve_empty_path¶

Arguments: $path

Return value: $base_path

Builds and returns the base path into which to set up the local module installation. Defaults to "~/perl5".

resolve_home_path¶

Arguments: $path

Return value: $home_path

Attempts to find the user's home directory. If installed, uses "File::HomeDir" for this purpose. If no definite answer is available, throws an exception.

resolve_relative_path¶

Arguments: $path

Return value: $absolute_path

Translates the given path into an absolute path.

resolve_path¶

Arguments: $path

Return value: $absolute_path

Calls the following in a pipeline, passing the result from the previous to the next, in an attempt to find where to configure the environment for a local library installation: "resolve_empty_path", "resolve_home_path", "resolve_relative_path". Passes the given path argument to "resolve_empty_path" which then returns a result that is passed to "resolve_home_path", which then has its result passed to "resolve_relative_path". The result of this final call is returned from "resolve_path".

new¶

Arguments: %attributes

Return value: $local_lib

Constructs a new "local::lib" object, representing the current state of @INC and the relevant environment variables.

roots¶

An arrayref representing active "local::lib" directories.

inc¶

An arrayref representing @INC.

libs¶

An arrayref representing the PERL5LIB environment variable.

bins¶

An arrayref representing the PATH environment variable.

extra¶

A hashref of extra environment variables (e.g. "PERL_MM_OPT" and "PERL_MB_OPT")

no_create¶

If set, "local::lib" will not try to create directories when activating them.

clone¶

Arguments: %attributes

Return value: $local_lib

Constructs a new "local::lib" object based on the existing one, overriding the specified attributes.

activate¶

Arguments: $path

Return value: $new_local_lib

Constructs a new instance with the specified path active.

deactivate¶

Arguments: $path

Return value: $new_local_lib

Constructs a new instance with the specified path deactivated.

deactivate_all¶

Arguments: None

Return value: $new_local_lib

Constructs a new instance with all "local::lib" directories deactivated.

environment_vars_string¶

Arguments: [ $shelltype ]

Return value: $shell_env_string

Returns a string to set up the "local::lib", meant to be run by a shell.

build_environment_vars¶

Arguments: None

Return value: %environment_vars

Returns a hash with the variables listed above, properly set to use the given path as the base directory.

setup_env_hash¶

Arguments: None

Return value: None

Constructs the %ENV keys for the given path, by calling "build_environment_vars".

setup_local_lib¶

Constructs the %ENV hash using "setup_env_hash", and set up @INC.