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

NAME         top

       posix_openpt - open a pseudoterminal device

SYNOPSIS         top

       #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         top

       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         top

       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         top

       See open(2).

VERSIONS         top

       Glibc support for posix_openpt() has been provided since version 2.2.1.

CONFORMING TO         top

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

NOTES         top

       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         top

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

COLOPHON         top

       This page is part of release 3.32 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/.

                                      2010-10-04                      POSIX_OPENPT(3)

HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface

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