coreutils/lib/getugroups.c
Jim Meyering 985cf06296 (getugroups): Cast -1 to gid_t, for systems like
SunOS4.1.4 for which gid_t is an unsigned type.
2000-06-04 06:47:31 +00:00

102 lines
2.7 KiB
C

/* getugroups.c -- return a list of the groups a user is in
Copyright (C) 1990, 1991, 1998, 1999, 2000 Free Software Foundation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by David MacKenzie. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#include <stdio.h> /* grp.h on alpha OSF1 V2.0 uses "FILE *". */
#include <grp.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
/* setgrent, getgrent, and endgrent are not specified by POSIX.1,
so header files might not declare them.
If you don't have them at all, we can't implement this function.
You lose! */
struct group *getgrent ();
#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
# include <string.h>
#else
# include <strings.h>
#endif
#define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
/* Like `getgroups', but for user USERNAME instead of for the current
process. Store at most MAXCOUNT group IDs in the GROUPLIST array.
If GID is not -1, store it first (if possible). GID should be the
group ID (pw_gid) obtained from getpwuid, in case USERNAME is not
listed in /etc/groups.
Always return the number of groups of which USERNAME is a member. */
int
getugroups (int maxcount, GETGROUPS_T *grouplist, char *username, gid_t gid)
{
struct group *grp;
register char **cp;
register int count = 0;
if (gid != (gid_t) -1)
{
if (maxcount != 0)
grouplist[count] = gid;
++count;
}
setgrent ();
while ((grp = getgrent ()) != 0)
{
for (cp = grp->gr_mem; *cp; ++cp)
{
int n;
if ( ! STREQ (username, *cp))
continue;
/* See if this group number is already on the list. */
for (n = 0; n < count; ++n)
if (grouplist && grouplist[n] == grp->gr_gid)
break;
/* If it's a new group number, then try to add it to the list. */
if (n == count)
{
if (maxcount != 0)
{
if (count >= maxcount)
{
endgrent ();
return count;
}
grouplist[count] = grp->gr_gid;
}
count++;
}
}
}
endgrent ();
return count;
}