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:

       O_RDWR Open the device for both reading and writing.  It is usual to specify this flag.

       O_NOCTTY
	      Do not make this device the controlling terminal for the process.

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							   POSIX_OPENPT(3)