busybox/coreutils/id.c

/* vi: set sw=4 ts=4: */
/*
 * Mini id implementation for busybox
 *
 * Copyright (C) 2000 by Randolph Chung <tausq@debian.org>
 *
 * 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 of the License, 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
 *
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- option -G is not currently supported. */

#include "busybox.h"
#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include <sys/types.h>

#define NO_GROUP          1
#define NO_USER           2
#define PRINT_REAL        4
#define NAME_NOT_NUMBER   8

extern int id_main(int argc, char **argv)
{
	char user[9], group[9];
	long pwnam, grnam;
	int uid, gid;
	int flags;
	
	flags = bb_getopt_ulflags(argc, argv, "ugrn");

	if (((flags & (NO_USER | NO_GROUP)) == (NO_USER | NO_GROUP))
		|| (argc > optind + 1)
	) {
		bb_show_usage();
	}

	if (argv[optind] == NULL) {
		if (flags & PRINT_REAL) {
			uid = getuid();
			gid = getgid();
		} else {
			uid = geteuid();
			gid = getegid();
		}
		my_getpwuid(user, uid);
	} else {
		safe_strncpy(user, argv[optind], sizeof(user));
	    gid = my_getpwnamegid(user);
	}
	my_getgrgid(group, gid);

	pwnam=my_getpwnam(user);
	grnam=my_getgrnam(group);

	if (flags & (NO_GROUP | NO_USER)) {
		char *s = group;
		if (flags & NO_GROUP) {
			s = user;
			grnam = pwnam;
		}
		if (flags & NAME_NOT_NUMBER) {
			puts(s);
		} else {
			printf("%ld\n", grnam);
		}
	} else {
		printf("uid=%ld(%s) gid=%ld(%s)\n", pwnam, user, grnam, group);
	}

	bb_fflush_stdout_and_exit(0);
}