sysdeps/mach/hurd/getegid.c

   1 /* Copyright (C) 1993, 1994, 1995, 1997 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <hurd.h>
  22 #include <hurd/id.h>
  23
  24 /* Get the effective group ID of the calling process.  */
  25 gid_t
  26 __getegid ()
  27 {
  28   error_t err;
  29   gid_t egid;
  30
  31   HURD_CRITICAL_BEGIN;
  32   __mutex_lock (&_hurd_id.lock);
  33
  34   if (err = _hurd_check_ids ())
  35     {
  36       errno = err;
  37       egid = -1;
  38     }
  39   else if (_hurd_id.gen.ngids >= 1)
  40     egid = _hurd_id.gen.gids[0];
  41   else if (_hurd_id.aux.ngids >= 1)
  42     /* We have no effective gids.  Return the real gid.  */
  43     egid = _hurd_id.aux.gids[0];
  44   else
  45     {
  46       /* We do not even have a real gid.  */
  47       errno = EGRATUITOUS;
  48       egid = -1;
  49     }
  50
  51   __mutex_unlock (&_hurd_id.lock);
  52   HURD_CRITICAL_END;
  53
  54   return egid;
  55 }
  56
  57 weak_alias (__getegid, getegid)