php man page for getpt

GETPT(3)						     Linux Programmer's Manual							  GETPT(3)

NAME
       getpt - open the pseudoterminal master (PTM)

SYNOPSIS
       #define _GNU_SOURCE	       /* See feature_test_macros(7) */
       #include <stdlib.h>

       int getpt(void);

DESCRIPTION
       getpt() opens a pseudoterminal master and returns its file descriptor.  It is equivalent to

	   open(/dev/ptmx, O_RDWR | O_NOCTTY);

       on Linux systems, though the pseudoterminal master is located elsewhere on some systems that use GNU Libc.

RETURN VALUE
       getpt() returns an open file descriptor upon successful completion.  Otherwise, it returns -1 and sets errno to indicate the error.

ERRORS
       getpt() can fail with various errors described in open(2).

VERSIONS
       getpt() is provided in glibc since version 2.1.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       +----------+---------------+---------+
       |Interface | Attribute	  | Value   |
       +----------+---------------+---------+
       |getpt()   | Thread safety | MT-Safe |
       +----------+---------------+---------+
CONFORMING TO
       getpt() is glibc-specific; use posix_openpt(3) instead.

SEE ALSO
       grantpt(3), posix_openpt(3), ptsname(3), unlockpt(3), ptmx(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/.

GNU
								    2015-03-02								  GETPT(3)