2017-07-13
manpages-dev
Manual pages about using GNU/Linux for development
man-pages
Linux kernel and C library user-space interface documentation
NAME
unlockpt - unlock a pseudoterminal master/slave pair
SYNOPSIS
#define _XOPEN_SOURCE
#include <stdlib.h>
Since glibc 2.24:
_XOPEN_SOURCE >= 500 ||
(_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED)
Glibc 2.23 and earlier:
_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
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).
| Interface | Attribute | Value |
| Thread safety | MT-Safe |
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
