table of contents
POSIX_OPENPT(3) | Linux Programmer's Manual | POSIX_OPENPT(3) |
NAME¶
posix_openpt - open a pseudoterminal device
SYNOPSIS¶
#include <stdlib.h> #include <fcntl.h>
int posix_openpt(int flags);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
posix_openpt(): _XOPEN_SOURCE >= 600
DESCRIPTION¶
The posix_openpt() function opens an unused pseudoterminal master device, returning a file descriptor that can be used to refer to that device.
The flags argument is a bit mask that ORs together zero or more of the following flags:
RETURN VALUE¶
On success, posix_openpt() returns a nonnegative file descriptor which is the lowest numbered unused file descriptor. On failure, -1 is returned, and errno is set to indicate the error.
ERRORS¶
See open(2).
VERSIONS¶
Glibc support for posix_openpt() has been provided since version 2.2.1.
ATTRIBUTES¶
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
posix_openpt () | Thread safety | MT-Safe |
CONFORMING TO¶
POSIX.1-2001, POSIX.1-2008.
posix_openpt() is part of the UNIX 98 pseudoterminal support (see pts(4)).
NOTES¶
Some older UNIX implementations that support System V (aka UNIX 98) pseudoterminals don't have this function, but it is easy to implement:
int posix_openpt(int flags) {
return open("/dev/ptmx", flags); }
Calling posix_openpt() creates a pathname for the corresponding pseudoterminal slave device. The pathname of the slave device can be obtained using ptsname(3). The slave device pathname exists only as long as the master device is open.
SEE ALSO¶
open(2), getpt(3), grantpt(3), ptsname(3), unlockpt(3), pts(4), pty(7)
COLOPHON¶
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
2017-09-15 |