sysdeps/unix/bsd/unlockpt.c

   1 /* Copyright (C) 1998-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <paths.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <errno.h>
  24
  25
  26 /* Unlock the slave pseudo terminal associated with the master pseudo
  27    terminal specified by FD.  */
  28 int
  29 unlockpt (int fd)
  30 {
  31   char buf[sizeof (_PATH_TTY) + 2];
  32
  33   /* BSD doesn't have a lock, but it does have `revoke'.  */
  34   if (__ptsname_r (fd, buf, sizeof (buf)))
  35     {
  36       if (errno == ENOTTY)
  37         __set_errno (EINVAL);
  38       return -1;
  39     }
  40   return __revoke (buf);
  41 }