coreutils/lib/getugroups.c
1992-11-01 05:44:29 +00:00

87 lines
2.4 KiB
C

/* getugroups.c -- return a list of the groups a user is in
Copyright (C) 1990, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Written by David MacKenzie. */
#include <sys/types.h>
#include <grp.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
/* Even though SunOS 4, Ultrix 4, and 386BSD are mostly POSIX.1 compliant,
their getgroups system call (except in the `System V' environment, which
is troublesome in other ways) fills in an array of int, not gid_t
(which is `short' on those systems). We do the same, for consistency.
Kludge, kludge. */
#ifdef _POSIX_VERSION
#if !defined(sun) && !defined(ultrix) && !defined(__386BSD__)
#define GETGROUPS_T gid_t
#else /* sun or ultrix or 386BSD */
#define GETGROUPS_T int
#endif /* sun or ultrix or 386BSD */
#else /* not _POSIX_VERSION */
#define GETGROUPS_T int
#endif /* not _POSIX_VERSION */
/* 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(USG) || defined(STDC_HEADERS)
#include <string.h>
#else
#include <strings.h>
#endif
/* Like `getgroups', but for user USERNAME instead of for
the current process. */
int
getugroups (maxcount, grouplist, username)
int maxcount;
GETGROUPS_T *grouplist;
char *username;
{
struct group *grp;
register char **cp;
register int count = 0;
setgrent ();
while ((grp = getgrent ()) != 0)
for (cp = grp->gr_mem; *cp; ++cp)
if (!strcmp (username, *cp))
{
if (maxcount != 0)
{
if (count >= maxcount)
{
endgrent ();
return count;
}
grouplist[count] = grp->gr_gid;
}
count++;
}
endgrent ();
return count;
}