nuttx/libs/libc/termios/lib_tcgetsid.c

/****************************************************************************
 * libs/libc/termios/lib_tcgetsid.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/ioctl.h>

#include <termios.h>

#include <nuttx/serial/tioctl.h>

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: tcgetsid
 *
 * Description:
 *   Obtain the process group ID of the session for which the terminal is
 *   the controlling terminal.
 *
 * Input Parameters:
 *   fd - The 'fd' argument is an open file descriptor associated with a
 *        terminal.
 *
 * Returned Value:
 *   Upon successful completion, the session leader's process group ID is
 *   returned.  Otherwise, (pid_t)-1 is returned and errno is set to
 *   indicate the error.
 *
 ****************************************************************************/

pid_t tcgetsid(int fd)
{
  pid_t sid;

  if (ioctl(fd, TIOCGSID, &sid) < 0)
    {
      return (pid_t)-1;
    }

  return sid;
}