unlockpt man page

unlockpt — unlock a pseudoterminal master/slave pair

Synopsis

#define _XOPEN_SOURCE /* See feature_test_macros(7) */

#include <stdlib.h>

int unlockpt(int fd);

Description

The unlockpt() function unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by fd.

unlockpt() should be called before opening the slave side of a pseudoterminal.

Return Value

When successful, unlockpt() returns 0. Otherwise, it returns -1 and sets errno appropriately.

Errors

EBADF
The fd argument is not a file descriptor open for writing.
EINVAL
The fd argument is not associated with a master pseudoterminal.

Versions

unlockpt() is provided in glibc since version 2.1.

Attributes

For an explanation of the terms used in this section, see attributes(7).

InterfaceAttributeValue
unlockpt()Thread safetyMT-Safe

Conforming to

POSIX.1-2001, POSIX.1-2008.

See Also

grantpt(3), posix_openpt(3), ptsname(3), pts(4), pty(7)

Colophon

This page is part of release 4.08 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/.

Referenced By

getpt(3), grantpt(3), posix_openpt(3), pts(4), ptsname(3), pty(7), tty_ioctl(4).

2015-08-08 Linux Programmer's Manual