NAME

       posix_openpt - open a pseudoterminal device

LIBRARY

       Standard C library (libc, -lc)

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 file descriptor (a nonnegative integer) which is the lowest numbered
       unused file descriptor.  On failure, -1 is returned, and errno is set to indicate the error.

ERRORS

       See open(2).

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                                     │ Attribute     │ Value   │
       ├──────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │posix_openpt()                                                                │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       POSIX.1-2008.

HISTORY

       glibc 2.2.1.  POSIX.1-2001.

       It is part of the UNIX 98 pseudoterminal support (see pts(4)).

NOTES

       Some  older  UNIX  implementations  that  support  System V (aka UNIX 98) pseudoterminals don't have this
       function, but it can be easily implemented by opening the pseudoterminal multiplexor device:

           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)