Update.
[glibc.git] / sysdeps / generic / group_member.c
blob0c941f84062b2569da1ab41d65aa23ed0ddb72ca
1 /* `group_member' -- test if process is in a given group.
2 Copyright (C) 1995, 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
20 #include <sys/types.h>
21 #include <unistd.h>
22 #include <stdlib.h>
23 #include <limits.h>
25 #ifndef NGROUPS_MAX
26 #define NGROUPS_MAX 16 /* First guess. */
27 #endif
29 int
30 __group_member (gid)
31 gid_t gid;
33 int n, size;
34 gid_t *groups;
36 size = NGROUPS_MAX;
39 groups = __alloca (size * sizeof *groups);
40 n = __getgroups (size, groups);
41 size *= 2;
42 } while (n == size / 2);
44 while (n > 0)
45 if (groups[n--] == gid)
46 return 1;
48 return 0;
50 weak_alias (__group_member, group_member)