src/mknod.c

   1 /* mknod -- make special files
   2    Copyright (C) 90, 91, 1995-2002 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 /* Written by David MacKenzie <djm@ai.mit.edu>  */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <getopt.h>
  23 #include <sys/types.h>
  24
  25 #include "system.h"
  26 #include "error.h"
  27 #include "modechange.h"
  28 #include "quote.h"
  29 #include "xstrtol.h"
  30
  31 /* The official name of this program (e.g., no `g' prefix).  */
  32 #define PROGRAM_NAME "mknod"
  33
  34 #define AUTHORS "David MacKenzie"
  35
  36 /* The name this program was run with. */
  37 char *program_name;
  38
  39 static struct option const longopts[] =
  40 {
  41   {"mode", required_argument, NULL, 'm'},
  42   {GETOPT_HELP_OPTION_DECL},
  43   {GETOPT_VERSION_OPTION_DECL},
  44   {NULL, 0, NULL, 0}
  45 };
  46
  47 void
  48 usage (int status)
  49 {
  50   if (status != 0)
  51     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  52              program_name);
  53   else
  54     {
  55       printf (_("Usage: %s [OPTION]... NAME TYPE [MAJOR MINOR]\n"),
  56               program_name);
  57       fputs (_("\
  58 Create the special file NAME of the given TYPE.\n\
  59 \n\
  60 "), stdout);
  61       fputs (_("\
  62 Mandatory arguments to long options are mandatory for short options too.\n\
  63 "), stdout);
  64       fputs (_("\
  65   -m, --mode=MODE   set permission mode (as in chmod), not a=rw - umask\n\
  66 "), stdout);
  67       fputs (HELP_OPTION_DESCRIPTION, stdout);
  68       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  69       fputs (_("\
  70 \n\
  71 Both MAJOR and MINOR must be specified when TYPE is b, c, or u, and they\n\
  72 must be omitted when TYPE is p.  If MAJOR or MINOR begins with 0x or 0X,\n\
  73 it is interpreted as hexadecimal; otherwise, if it begins with 0, as octal;\n\
  74 otherwise, as decimal.  TYPE may be:\n\
  75 "), stdout);
  76       fputs (_("\
  77 \n\
  78   b      create a block (buffered) special file\n\
  79   c, u   create a character (unbuffered) special file\n\
  80   p      create a FIFO\n\
  81 "), stdout);
  82       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  83     }
  84   exit (status);
  85 }
  86
  87 int
  88 main (int argc, char **argv)
  89 {
  90   mode_t newmode;
  91   struct mode_change *change;
  92   const char *specified_mode;
  93   int optc;
  94   mode_t node_type;
  95
  96   program_name = argv[0];
  97   setlocale (LC_ALL, "");
  98   bindtextdomain (PACKAGE, LOCALEDIR);
  99   textdomain (PACKAGE);
 100
 101   atexit (close_stdout);
 102
 103   specified_mode = NULL;
 104
 105   while ((optc = getopt_long (argc, argv, "m:", longopts, NULL)) != -1)
 106     {
 107       switch (optc)
 108         {
 109         case 0:
 110           break;
 111         case 'm':
 112           specified_mode = optarg;
 113           break;
 114         case_GETOPT_HELP_CHAR;
 115         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 116         default:
 117           usage (EXIT_FAILURE);
 118         }
 119     }
 120
 121   newmode = (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 122   if (specified_mode)
 123     {
 124       newmode &= ~ umask (0);
 125       change = mode_compile (specified_mode, 0);
 126       if (change == MODE_INVALID)
 127         error (EXIT_FAILURE, 0, _("invalid mode"));
 128       else if (change == MODE_MEMORY_EXHAUSTED)
 129         xalloc_die ();
 130       newmode = mode_adjust (newmode, change);
 131     }
 132
 133   if (argc - optind != 2 && argc - optind != 4)
 134     {
 135       const char *msg;
 136       if (argc - optind < 2)
 137         msg = _("too few arguments");
 138       else if (argc - optind > 4)
 139         msg = _("too many arguments");
 140       else
 141         msg = _("wrong number of arguments");
 142       error (0, 0, "%s", msg);
 143       usage (EXIT_FAILURE);
 144     }
 145
 146   /* Only check the first character, to allow mnemonic usage like
 147      `mknod /dev/rst0 character 18 0'. */
 148
 149   switch (argv[optind + 1][0])
 150     {
 151     case 'b':                   /* `block' or `buffered' */
 152 #ifndef S_IFBLK
 153       error (4, 0, _("block special files not supported"));
 154 #else
 155       node_type = S_IFBLK;
 156 #endif
 157       goto block_or_character;
 158
 159     case 'c':                   /* `character' */
 160     case 'u':                   /* `unbuffered' */
 161 #ifndef S_IFCHR
 162       error (4, 0, _("character special files not supported"));
 163 #else
 164       node_type = S_IFCHR;
 165 #endif
 166       goto block_or_character;
 167
 168     block_or_character:
 169       if (argc - optind != 4)
 170         {
 171           error (0, 0, _("\
 172 when creating special files, major and minor device\n\
 173 numbers must be specified"));
 174           usage (EXIT_FAILURE);
 175         }
 176
 177       {
 178         char const *s_major = argv[optind + 2];
 179         char const *s_minor = argv[optind + 3];
 180         uintmax_t i_major, i_minor;
 181         dev_t device;
 182
 183         if (xstrtoumax (s_major, NULL, 0, &i_major, NULL) != LONGINT_OK
 184             || i_major != (major_t) i_major)
 185           error (EXIT_FAILURE, 0,
 186                  _("invalid major device number %s"), quote (s_major));
 187
 188         if (xstrtoumax (s_minor, NULL, 0, &i_minor, NULL) != LONGINT_OK
 189             || i_minor != (minor_t) i_minor)
 190           error (EXIT_FAILURE, 0,
 191                  _("invalid minor device number %s"), quote (s_minor));
 192
 193         device = makedev (i_major, i_minor);
 194 #ifdef NODEV
 195         if (device == NODEV)
 196           error (EXIT_FAILURE, 0, _("invalid device %s %s"), s_major, s_minor);
 197 #endif
 198
 199         if (mknod (argv[optind], newmode | node_type, device) != 0)
 200           error (EXIT_FAILURE, errno, "%s", quote (argv[optind]));
 201       }
 202       break;
 203
 204     case 'p':                   /* `pipe' */
 205 #ifndef S_ISFIFO
 206       error (4, 0, _("fifo files not supported"));
 207 #else
 208       if (argc - optind != 2)
 209         {
 210           error (0, 0, _("\
 211 major and minor device numbers may not be specified for fifo files"));
 212           usage (EXIT_FAILURE);
 213         }
 214       if (mkfifo (argv[optind], newmode))
 215         error (EXIT_FAILURE, errno, "%s", quote (argv[optind]));
 216 #endif
 217       break;
 218
 219     default:
 220       error (0, 0, "invalid device type %s", quote (argv[optind + 1]));
 221       usage (EXIT_FAILURE);
 222     }
 223
 224   /* Perform an explicit chmod to ensure the file mode permission bits
 225      are set as specified.  This extra step is necessary in some cases
 226      when the containing directory has a default ACL.  */
 227
 228   if (specified_mode)
 229     {
 230       if (chmod (argv[optind], newmode))
 231         error (0, errno, _("cannot set permissions of %s"),
 232                quote (argv[optind]));
 233     }
 234
 235   exit (EXIT_SUCCESS);
 236 }