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	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.

CONFORMING TO

       posix_openpt() is part of the UNIX 98 pseudoterminal support (see pts(4)).  This function is specified in POSIX.1-2001.

NOTES

       The  posix_openpt() function is a recent invention in POSIX.  Some 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 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

								    2012-04-20							   POSIX_OPENPT(3)