Improved to add the default gid if it is missing from the list.

[rsync/rsync.git] / getgroups.c

/*
 * Copyright (C) 2002 by Martin Pool
 * 
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/**
 * @file getgroups.c
 *
 * Print out the gids of all groups for the current user.  This is
 * like `id -G` on Linux, but it's too hard to find a portable
 * equivalent.
 **/

#include "rsync.h"

#ifndef NGROUPS_MAX
/* It ought to be defined, but just in case. */
#  define NGROUPS_MAX 32
#endif

int
main(UNUSED(int argc), UNUSED(char *argv[]))
{
	int n, i;
	gid_t list[NGROUPS_MAX];
	gid_t gid = getgid();
	int gid_in_list = 0;

	if ((n = getgroups(NGROUPS_MAX, list)) < 0) {
		perror("getgroups");
		return 1;
	}

	for (i = 0; i < n; i++)  {
		printf("%lu ", (unsigned long)list[i]);
		if (list[i] == gid)
			gid_in_list = 1;
	}
	/* The default gid might not be in the list on some systems. */
	if (!gid_in_list)
		printf("%lu", (unsigned long)gid);
	printf("\n");
		
	return 0;
}