sysdeps/mach/hurd/getegid.c

   1 /* Copyright (C) 1993, 1994, 1995 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <hurd.h>
  23 #include <hurd/id.h>
  24
  25 /* Get the effective group ID of the calling process.  */
  26 gid_t
  27 DEFUN_VOID(__getegid)
  28 {
  29   error_t err;
  30   gid_t egid;
  31
  32   HURD_CRITICAL_BEGIN;
  33   __mutex_lock (&_hurd_id.lock);
  34
  35   if (err = _hurd_check_ids ())
  36     {
  37       errno = err;
  38       egid = -1;
  39     }
  40   else if (_hurd_id.gen.ngids >= 1)
  41     egid = _hurd_id.gen.gids[0];
  42   else if (_hurd_id.aux.ngids >= 1)
  43     /* We have no effective gids.  Return the real gid.  */
  44     egid = _hurd_id.aux.gids[0];
  45   else
  46     {
  47       /* We do not even have a real gid.  */
  48       errno = EGRATUITOUS;
  49       egid = -1;
  50     }
  51
  52   __mutex_unlock (&_hurd_id.lock);
  53   HURD_CRITICAL_END;
  54
  55   return egid;
  56 }
  57
  58 weak_alias (__getegid, getegid)