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POSIX_OPENPT

Section: Linux Programmer's Manual (3)
Updated: 2010-10-04
Index Return to Main Contents

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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 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 UNIX 98 pseudoterminal 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) pseudoterminals 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 3.35 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://man7.org/linux/man-pages/.

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Index

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUE

ERRORS

VERSIONS

CONFORMING TO

NOTES

SEE ALSO

COLOPHON

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