sysdeps/unix/sysv/linux/unlockpt.c

   1 /* Copyright (C) 1998-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdlib.h>
  20 #include <sys/ioctl.h>
  21 #include <termios.h>
  22
  23
  24 /* Unlock the slave pseudo terminal associated with the master pseudo
  25    terminal specified by FD.  */
  26 int
  27 unlockpt (int fd)
  28 {
  29   int unlock = 0;
  30
  31   int ret = __ioctl (fd, TIOCSPTLCK, &unlock);
  32   if (ret != 0 && errno == ENOTTY)
  33     /* POSIX mandates EINVAL for non-ptmx descriptors.  */
  34     __set_errno (EINVAL);
  35   return ret;
  36 }
  37 libc_hidden_def (unlockpt)