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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

       This  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);
           }

SEE ALSO

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

COLOPHON

       This  page  is  part of release 3.35 of the Linux man-pages project.  A description of the
       project, and information about reporting bugs, can be found at  http://man7.org/linux/man-
       pages/.

                                            2010-10-04                            POSIX_OPENPT(3)