1 /* getugroups.c -- return a list of the groups a user is in
3 Copyright (C) 1990, 1991, 1998, 1999, 2000, 2003, 2004, 2005, 2006
4 Free Software Foundation.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20 /* Written by David MacKenzie. */
24 #include <sys/types.h>
25 #include <stdio.h> /* grp.h on alpha OSF1 V2.0 uses "FILE *". */
32 # define EOVERFLOW EINVAL
35 /* Some old header files might not declare setgrent, getgrent, and endgrent.
36 If you don't have them at all, we can't implement this function.
38 struct group *getgrent ();
42 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
44 /* Like `getgroups', but for user USERNAME instead of for the current
45 process. Store at most MAXCOUNT group IDs in the GROUPLIST array.
46 If GID is not -1, store it first (if possible). GID should be the
47 group ID (pw_gid) obtained from getpwuid, in case USERNAME is not
48 listed in /etc/groups.
49 Always return the number of groups of which USERNAME is a member. */
52 getugroups (int maxcount, GETGROUPS_T *grouplist, char *username, gid_t gid)
56 register int count = 0;
58 if (gid != (gid_t) -1)
61 grouplist[count] = gid;
66 while ((grp = getgrent ()) != 0)
68 for (cp = grp->gr_mem; *cp; ++cp)
72 if ( ! STREQ (username, *cp))
75 /* See if this group number is already on the list. */
76 for (n = 0; n < count; ++n)
77 if (grouplist && grouplist[n] == grp->gr_gid)
80 /* If it's a new group number, then try to add it to the list. */
85 if (count >= maxcount)
90 grouplist[count] = grp->gr_gid;