1 /* group-member.c -- determine whether group id is in calling user's group list
2 Copyright (C) 1994, 1997, 1998, 2003 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program 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
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
23 #include <sys/types.h>
33 #include "group-member.h"
45 free_group_info (struct group_info *g)
51 static struct group_info *
56 struct group_info *gi;
59 /* getgroups () returns the number of elements that it was able to
60 place into the array. We simply continue to call getgroups ()
61 until the number of elements placed into the array is smaller than
62 the physical size of the array. */
67 while (n_groups == n_group_slots)
70 group = xrealloc (group, n_group_slots * sizeof (GETGROUPS_T));
71 n_groups = getgroups (n_group_slots, group);
74 /* In case of error, the user loses. */
81 gi = xmalloc (sizeof (*gi));
82 gi->n_groups = n_groups;
88 #endif /* not HAVE_GETGROUPS */
90 /* Return non-zero if GID is one that we have in our groups list.
91 If there is no getgroups function, return non-zero if GID matches
92 either of the current or effective group IDs. */
95 group_member (gid_t gid)
97 #ifndef HAVE_GETGROUPS
98 return ((gid == getgid ()) || (gid == getegid ()));
102 struct group_info *gi;
104 gi = get_group_info ();
108 /* Search through the list looking for GID. */
110 for (i = 0; i < gi->n_groups; i++)
112 if (gid == gi->group[i])
119 free_group_info (gi);
122 #endif /* HAVE_GETGROUPS */
130 main (int argc, char** argv)
134 program_name = argv[0];
136 for (i=1; i<argc; i++)
140 gid = atoi (argv[i]);
141 printf ("%d: %s\n", gid, group_member (gid) ? "yes" : "no");