src/mknod.c

   1 /* mknod -- make special files
   2    Copyright (C) 90, 91, 1995-2000 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will 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 to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Usage: mknod [-m mode] [--mode=mode] path {bcu} major minor
  19                 make a block or character device node
  20           mknod [-m mode] [--mode=mode] path p
  21                 make a FIFO (named pipe)
  22
  23    Options:
  24    -m, --mode=mode      Set the mode of created nodes to MODE, which is
  25                         symbolic as in chmod and uses the umask as a point of
  26                         departure.
  27
  28    David MacKenzie <djm@ai.mit.edu>  */
  29
  30 #include <config.h>
  31 #include <stdio.h>
  32 #include <getopt.h>
  33 #include <sys/types.h>
  34
  35 #include "system.h"
  36 #include "error.h"
  37 #include "modechange.h"
  38 #include "quote.h"
  39 #include "xstrtol.h"
  40
  41 /* The official name of this program (e.g., no `g' prefix).  */
  42 #define PROGRAM_NAME "mknod"
  43
  44 #define AUTHORS "David MacKenzie"
  45
  46 /* The name this program was run with. */
  47 char *program_name;
  48
  49 static struct option const longopts[] =
  50 {
  51   {"mode", required_argument, NULL, 'm'},
  52   {GETOPT_HELP_OPTION_DECL},
  53   {GETOPT_VERSION_OPTION_DECL},
  54   {NULL, 0, NULL, 0}
  55 };
  56
  57 void
  58 usage (int status)
  59 {
  60   if (status != 0)
  61     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  62              program_name);
  63   else
  64     {
  65       printf (_("Usage: %s [OPTION]... NAME TYPE [MAJOR MINOR]\n"), program_name);
  66       printf (_("\
  67 Create the special file NAME of the given TYPE.\n\
  68 \n\
  69   -m, --mode=MODE   set permission mode (as in chmod), not a=rw - umask\n\
  70       --help        display this help and exit\n\
  71       --version     output version information and exit\n\
  72 \n\
  73 MAJOR MINOR are forbidden for TYPE p, mandatory otherwise.  TYPE may be:\n\
  74 \n\
  75   b      create a block (buffered) special file\n\
  76   c, u   create a character (unbuffered) special file\n\
  77   p      create a FIFO\n\
  78 "));
  79       puts (_("\nReport bugs to <bug-fileutils@gnu.org>."));
  80     }
  81   exit (status);
  82 }
  83
  84 int
  85 main (int argc, char **argv)
  86 {
  87   mode_t newmode;
  88   struct mode_change *change;
  89   const char *specified_mode;
  90   int optc;
  91   int i_major, i_minor;
  92   long int tmp_major, tmp_minor;
  93   char *s;
  94
  95   program_name = argv[0];
  96   setlocale (LC_ALL, "");
  97   bindtextdomain (PACKAGE, LOCALEDIR);
  98   textdomain (PACKAGE);
  99
 100   atexit (close_stdout);
 101
 102   specified_mode = NULL;
 103
 104   while ((optc = getopt_long (argc, argv, "m:", longopts, NULL)) != -1)
 105     {
 106       switch (optc)
 107         {
 108         case 0:
 109           break;
 110         case 'm':
 111           specified_mode = optarg;
 112           break;
 113         case_GETOPT_HELP_CHAR;
 114         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 115         default:
 116           usage (1);
 117         }
 118     }
 119
 120   newmode = (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 121   if (specified_mode)
 122     {
 123       newmode &= ~ umask (0);
 124       change = mode_compile (specified_mode, 0);
 125       if (change == MODE_INVALID)
 126         error (1, 0, _("invalid mode"));
 127       else if (change == MODE_MEMORY_EXHAUSTED)
 128         xalloc_die ();
 129       newmode = mode_adjust (newmode, change);
 130     }
 131
 132   if (argc - optind != 2 && argc - optind != 4)
 133     {
 134       const char *msg;
 135       if (argc - optind < 2)
 136         msg = _("too few arguments");
 137       else if (argc - optind > 4)
 138         msg = _("too many arguments");
 139       else
 140         msg = _("wrong number of arguments");
 141       error (0, 0, msg);
 142       usage (1);
 143     }
 144
 145   /* Only check the first character, to allow mnemonic usage like
 146      `mknod /dev/rst0 character 18 0'. */
 147
 148   switch (argv[optind + 1][0])
 149     {
 150     case 'b':                   /* `block' or `buffered' */
 151 #ifndef S_IFBLK
 152       error (4, 0, _("block special files not supported"));
 153 #else
 154       if (argc - optind != 4)
 155         {
 156           error (0, 0, _("\
 157 when creating block special files, major and minor device\n\
 158 numbers must be specified"));
 159           usage (1);
 160         }
 161
 162       s = argv[optind + 2];
 163       if (xstrtol (s, NULL, 0, &tmp_major, NULL) != LONGINT_OK)
 164         error (1, 0, _("invalid major device number %s"), quote (s));
 165
 166       s = argv[optind + 3];
 167       if (xstrtol (s, NULL, 0, &tmp_minor, NULL) != LONGINT_OK)
 168         error (1, 0, _("invalid minor device number %s"), quote (s));
 169
 170       i_major = (int) tmp_major;
 171       i_minor = (int) tmp_minor;
 172
 173       if (mknod (argv[optind], newmode | S_IFBLK, makedev (i_major, i_minor)))
 174         error (1, errno, "%s", quote (argv[optind]));
 175 #endif
 176       break;
 177
 178     case 'c':                   /* `character' */
 179     case 'u':                   /* `unbuffered' */
 180 #ifndef S_IFCHR
 181       error (4, 0, _("character special files not supported"));
 182 #else
 183       if (argc - optind != 4)
 184         {
 185           error (0, 0, _("\
 186 when creating character special files, major and minor device\n\
 187 numbers must be specified"));
 188           usage (1);
 189         }
 190
 191       s = argv[optind + 2];
 192       if (xstrtol (s, NULL, 0, &tmp_major, NULL) != LONGINT_OK)
 193         error (1, 0, _("invalid major device number %s"), quote (s));
 194
 195       s = argv[optind + 3];
 196       if (xstrtol (s, NULL, 0, &tmp_minor, NULL) != LONGINT_OK)
 197         error (1, 0, _("invalid minor device number %s"), quote (s));
 198
 199       i_major = (int) tmp_major;
 200       i_minor = (int) tmp_minor;
 201
 202       if (mknod (argv[optind], newmode | S_IFCHR, makedev (i_major, i_minor)))
 203         error (1, errno, "%s", quote (argv[optind]));
 204 #endif
 205       break;
 206
 207     case 'p':                   /* `pipe' */
 208 #ifndef S_ISFIFO
 209       error (4, 0, _("fifo files not supported"));
 210 #else
 211       if (argc - optind != 2)
 212         {
 213           error (0, 0, _("\
 214 major and minor device numbers may not be specified for fifo files"));
 215           usage (1);
 216         }
 217       if (mkfifo (argv[optind], newmode))
 218         error (1, errno, "%s", quote (argv[optind]));
 219 #endif
 220       break;
 221
 222     default:
 223       usage (1);
 224     }
 225
 226   /* Perform an explicit chmod to ensure the file mode permission bits
 227      are set as specified.  This extra step is necessary in some cases
 228      when the containing directory has a default ACL.  */
 229
 230   if (specified_mode)
 231     {
 232       if (chmod (argv[optind], newmode))
 233         error (0, errno, _("cannot set permissions of `%s'"),
 234                quote (argv[optind]));
 235     }
 236
 237   exit (0);
 238 }