unlockpt - unlock a pseudoterminal master/slave pair

NAME  LIBRARY  SYNOPSIS  DESCRIPTION  RETURN VALUE  ERRORS  ATTRIBUTES  STANDARDS  HISTORY  SEE ALSO 

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NAME

unlockpt − unlock a pseudoterminal master/slave pair

LIBRARY

Standard C library (libc, −lc)

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
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 to indicate the error.

ERRORS

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

ATTRIBUTES

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

STANDARDS

POSIX.1-2008.

HISTORY

glibc 2.1. POSIX.1-2001.

SEE ALSO

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

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