/* Copyright (C) 1998-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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
   <https://www.gnu.org/licenses/>.  */

#include <paths.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>


/* Unlock the slave pseudo terminal associated with the master pseudo
   terminal specified by FD.  */
int
unlockpt (int fd)
{
  char buf[sizeof (_PATH_TTY) + 2];

  /* BSD doesn't have a lock, but it does have `revoke'.  */
  if (__ptsname_r (fd, buf, sizeof (buf)))
    {
      if (errno == ENOTTY)
	__set_errno (EINVAL);
      return -1;
    }
  return __revoke (buf);
}
libc_hidden_def (unlockpt)
