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 pseu-
       doterminal 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 4.10 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/.



				  2016-03-15		       POSIX_OPENPT(3)