sysdeps/unix/bsd/tcgetpgrp.c

   1 /* Copyright (C) 1991-2024 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 <sys/ioctl.h>
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <sys/types.h>
  22
  23 /* Return the foreground process group ID of FD.  */
  24 pid_t
  25 tcgetpgrp (int fd)
  26 {
  27   int pgrp;
  28
  29   if (__ioctl (fd, TIOCGPGRP, &pgrp) < 0)
  30     return (pid_t) -1;
  31   return (pid_t) pgrp;
  32 }
  33 libc_hidden_def (tcgetpgrp)