UNLOCKPT

Section: Linux Programmer's Manual (3)
Updated: 2017-07-13
Page Index
 

NAME

unlockpt - unlock a pseudoterminal master/slave pair  

SYNOPSIS

#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
 

DESCRIPTION

The unlockpt() function unlocks the slave pseudoterminal device corresponding to the master pseudoterminal referred to by the file descriptor 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

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Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
VERSIONS
ATTRIBUTES
CONFORMING TO
SEE ALSO
COLOPHON