Name
posix_openpt — open a pseudoterminal device
Synopsis
#include <stdlib.h> #include <fcntl.h>
int
posix_openpt( |
int flags); |
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Note | ||
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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.
CONFORMING TO
posix_openpt() is part of
the UNIX 98 pseudoterminal support (see pts(4)). This function is
specified in POSIX.1-2001.
NOTES
The posix_openpt() 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); }
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.
COLOPHON
This page is part of release 3.52 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/.
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