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

NAME

posix_openpt - open a pseudo-terminal 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(): _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:

Open the device for both reading and writing. It is usual to specify this flag.
Do not make this device the controlling terminal for the process.

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 implementations that support System V (aka Unix 98) pseudo-terminals 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 3.22 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