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UNLOCKPT(3) Linux Programmer's Manual UNLOCKPT(3)

unlockpt - unlock a pseudoterminal master/slave pair

#define _XOPEN_SOURCE
#include <stdlib.h>

int unlockpt(int fd);


Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

unlockpt():

Since glibc 2.24:
_XOPEN_SOURCE >= 500 ||
(_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED)
Glibc 2.23 and earlier:
_XOPEN_SOURCE

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.

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

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

unlockpt() is provided in glibc since version 2.1.

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

Interface Attribute Value
unlockpt () Thread safety MT-Safe

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

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

This page is part of release 4.16 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/.

2017-07-13