glibc/sysdeps/unix/sysv/linux/unlockpt.c

49 lines
1.4 KiB
C

/* Copyright (C) 1998-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <termios.h>
/* Unlock the slave pseudo terminal associated with the master pseudo
terminal specified by FD. */
int
unlockpt (int fd)
{
#ifdef TIOCSPTLCK
int save_errno = errno;
int unlock = 0;
if (__ioctl (fd, TIOCSPTLCK, &unlock))
{
if (errno == EINVAL)
{
__set_errno (save_errno);
return 0;
}
else
return -1;
}
#endif
/* If we have no TIOCSPTLCK ioctl, all slave pseudo terminals are
unlocked by default. */
return 0;
}