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 3.54 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)