/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980 Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)groups.c	5.4 (Berkeley) 6/1/90";
#endif /* not lint */

/*
 * groups
 */

#include <sys/param.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>

main(argc, argv)
	int argc;
	char *argv[];
{
	int ngroups, i;
	char *sep = "";
	struct group *gr;
	int *groups;

	if (argc > 1)
		showgroups(argv[1]);

	ngroups = getgroups(0, 0);
	groups = (int *) malloc(ngroups * sizeof(int));
	ngroups = getgroups(ngroups, groups);
	for (i = 1; i < ngroups; i++) {
		gr = getgrgid(groups[i]);
		if (gr == NULL)
			printf("%s%d", sep, groups[i]);
		else
			printf("%s%s", sep, gr->gr_name);
		sep = " ";
	}
	printf("\n");
	exit(0);
}

showgroups(user)
	register char *user;
{
	register struct group *gr;
	register struct passwd *pw;
	register char **cp;
	char *sep = "";

	if ((pw = getpwnam(user)) == NULL) {
		fprintf(stderr, "groups: no such user.\n");
		exit(1);
	}
	while (gr = getgrent()) {
		if (pw->pw_gid == gr->gr_gid) {
			printf("%s%s", sep, gr->gr_name);
			sep = " ";
			continue;
		}
		for (cp = gr->gr_mem; cp && *cp; cp++)
			if (strcmp(*cp, user) == 0) {
				printf("%s%s", sep, gr->gr_name);
				sep = " ";
				break;
			}
	}
	printf("\n");
	exit(0);
}
