mkfs/fstyp.c

   1 /*
   2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18
  19 #include <xfs/libxfs.h>
  20 #include <disk/fstyp.h>
  21
  22 /*
  23  * fstyp allows the user to determine the filesystem identifier of
  24  * mounted or unmounted filesystems using heuristics.
  25  *
  26  * The filesystem type is required by mount(2) and sometimes by mount(8)
  27  * to mount filesystems of different types.  fstyp uses exactly the same
  28  * heuristics that mount does to determine whether the supplied device
  29  * special file is of a known filesystem type.  If it is, fstyp prints
  30  * on standard output the usual filesystem identifier for that type and
  31  * exits with a zero return code.  If no filesystem is identified, fstyp
  32  * prints "Unknown" to indicate failure and exits with a non-zero status.
  33  *
  34  * WARNING: The use of heuristics implies that the result of fstyp is not
  35  * guaranteed to be accurate.
  36  */
  37
  38 int
  39 main(int argc, char *argv[])
  40 {
  41         char    *type;
  42
  43         if (argc != 2) {
  44                 fprintf(stderr, "Usage: %s <device>\n", basename(argv[0]));
  45                 exit(1);
  46         }
  47
  48         if (access(argv[1], R_OK) < 0) {
  49                 perror(argv[1]);
  50                 exit(1);
  51         }
  52
  53         if ((type = fstype(argv[1])) == NULL) {
  54                 printf("Unknown\n");
  55                 exit(1);
  56         }
  57         printf("%s\n", type);
  58         exit(0);
  59 }