POSIX_OPENPT
Section: Linux Programmer's Manual (3)
Updated: 2021-03-22
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NAME
posix_openpt - open a pseudoterminal 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():
_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).
VERSIONS
Glibc support for
posix_openpt()
has been provided since version 2.2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
posix_openpt()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
posix_openpt()
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)
COLOPHON
This page is part of release 5.11 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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Time: 06:22:44 GMT, May 09, 2021