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

NAME

       posix_openpt - open a pseudo-terminal 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(): _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600

DESCRIPTION

       The  posix_openpt()  function  opens an unused pseudo-terminal 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 Unix98 pseudo-terminal support (see pts(4)).  This function is specified in POSIX.1-2001.

NOTES

       This  function  is  a recent invention in POSIX.  Some Unix implementations that support System V (aka Unix 98) pseudo-terminals don't have
       this function, but it is easy to implement:

	   int
	   posix_openpt(int flags)
	   {
	       return open("/dev/ptmx", flags);
	   }

SEE ALSO

       open(2), getpt(3), grantpt(3), ptsname(3), unlockpt(3), pts(4), pty(7)

COLOPHON

       This page is part of release 3.27 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/.

								    2007-07-26							   POSIX_OPENPT(3)