glibc/login/unlockpt.c

/* Copyright (C) 1998-2021 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 <stdlib.h>
#include <errno.h>

/* Given a fd on a master pseudoterminal, clear a kernel lock so that
   the slave can be opened.  This is to avoid a race between opening the
   master and calling grantpt() to take possession of the slave. */
int
unlockpt (int fd __attribute__ ((unused)))
{
  __set_errno (ENOSYS);
  return -1;
}

stub_warning (unlockpt)