1  /* Copyright (C) 1991-2023 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 <unistd.h>
      20  #include <hurd.h>
      21  #include <hurd/port.h>
      22  
      23  /* Get the process group ID of process PID.  */
      24  int
      25  __getpgid (pid_t pid)
      26  {
      27    error_t err;
      28    pid_t pgrp;
      29  
      30    if (pid == 0)
      31      {
      32        /* Assume atomic word fetch and store, so don't lock _hurd_pid_lock.  */
      33        pgrp = _hurd_pgrp;
      34        err = 0;
      35      }
      36    else
      37      err = __USEPORT (PROC, __proc_getpgrp (port, pid, &pgrp));
      38  
      39    return err ? __hurd_fail (err) : pgrp;
      40  }
      41  libc_hidden_def (__getpgid)
      42  weak_alias (__getpgid, getpgid)