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:
- 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 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 3.25 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/.