mkfs/fstyp.c

/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <xfs/libxfs.h>
#include <disk/fstyp.h>

/*
 * fstyp allows the user to determine the filesystem identifier of
 * mounted or unmounted filesystems using heuristics.
 *
 * The filesystem type is required by mount(2) and sometimes by mount(8)
 * to mount filesystems of different types.  fstyp uses exactly the same
 * heuristics that mount does to determine whether the supplied device
 * special file is of a known filesystem type.  If it is, fstyp prints
 * on standard output the usual filesystem identifier for that type and
 * exits with a zero return code.  If no filesystem is identified, fstyp
 * prints "Unknown" to indicate failure and exits with a non-zero status.
 *
 * WARNING: The use of heuristics implies that the result of fstyp is not
 * guaranteed to be accurate.
 */

int
main(int argc, char *argv[])
{
	char	*type;

	if (argc != 2) {
		fprintf(stderr, "Usage: %s <device>\n", basename(argv[0]));
		exit(1);
	}

	if (access(argv[1], R_OK) < 0) {
		perror(argv[1]);
		exit(1);
	}

	if ((type = fstype(argv[1])) == NULL) {
		printf("Unknown\n");
		exit(1);
	}
	printf("%s\n", type);
	exit(0);
}