POSIX_OPENPT(3) 	   Linux Programmers Manual	      POSIX_OPENPT(3)



NAME
       posix_openpt - open a pseudo-terminal device

SYNOPSIS
       #include 
       #include 

       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 pro
	      cess.

RETURN VALUE
       On success, posix_openpt() returns a non-negative 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  implementa
       tions  that  support System V (aka Unix 98) pseudo-terminals dont 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 3.05 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)