src/mknod.c

   1 /* mknod -- make special files
   2    Copyright (C) 90, 91, 1995-2001 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       fputs (_("\
  67 Create the special file NAME of the given TYPE.\n\
  68 \n\
  69 "), stdout);
  70       fputs (_("\
  71 Mandatory arguments to long options are mandatory for short options too.\n\
  72 "), stdout);
  73       fputs (_("\
  74   -m, --mode=MODE   set permission mode (as in chmod), not a=rw - umask\n\
  75 "), stdout);
  76       fputs (HELP_OPTION_DESCRIPTION, stdout);
  77       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  78       fputs (_("\
  79 \n\
  80 MAJOR MINOR are forbidden for TYPE p, mandatory otherwise.  TYPE may be:\n\
  81 \n\
  82   b      create a block (buffered) special file\n\
  83   c, u   create a character (unbuffered) special file\n\
  84   p      create a FIFO\n\
  85 "), stdout);
  86       puts (_("\nReport bugs to <bug-fileutils@gnu.org>."));
  87     }
  88   exit (status);
  89 }
  90
  91 int
  92 main (int argc, char **argv)
  93 {
  94   mode_t newmode;
  95   struct mode_change *change;
  96   const char *specified_mode;
  97   int optc;
  98   mode_t node_type;
  99
 100   program_name = argv[0];
 101   setlocale (LC_ALL, "");
 102   bindtextdomain (PACKAGE, LOCALEDIR);
 103   textdomain (PACKAGE);
 104
 105   atexit (close_stdout);
 106
 107   specified_mode = NULL;
 108
 109   while ((optc = getopt_long (argc, argv, "m:", longopts, NULL)) != -1)
 110     {
 111       switch (optc)
 112         {
 113         case 0:
 114           break;
 115         case 'm':
 116           specified_mode = optarg;
 117           break;
 118         case_GETOPT_HELP_CHAR;
 119         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 120         default:
 121           usage (1);
 122         }
 123     }
 124
 125   newmode = (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 126   if (specified_mode)
 127     {
 128       newmode &= ~ umask (0);
 129       change = mode_compile (specified_mode, 0);
 130       if (change == MODE_INVALID)
 131         error (1, 0, _("invalid mode"));
 132       else if (change == MODE_MEMORY_EXHAUSTED)
 133         xalloc_die ();
 134       newmode = mode_adjust (newmode, change);
 135     }
 136
 137   if (argc - optind != 2 && argc - optind != 4)
 138     {
 139       const char *msg;
 140       if (argc - optind < 2)
 141         msg = _("too few arguments");
 142       else if (argc - optind > 4)
 143         msg = _("too many arguments");
 144       else
 145         msg = _("wrong number of arguments");
 146       error (0, 0, "%s", msg);
 147       usage (1);
 148     }
 149
 150   /* Only check the first character, to allow mnemonic usage like
 151      `mknod /dev/rst0 character 18 0'. */
 152
 153   switch (argv[optind + 1][0])
 154     {
 155     case 'b':                   /* `block' or `buffered' */
 156 #ifndef S_IFBLK
 157       error (4, 0, _("block special files not supported"));
 158 #else
 159       node_type = S_IFBLK;
 160 #endif
 161       goto block_or_character;
 162
 163     case 'c':                   /* `character' */
 164     case 'u':                   /* `unbuffered' */
 165 #ifndef S_IFCHR
 166       error (4, 0, _("character special files not supported"));
 167 #else
 168       node_type = S_IFCHR;
 169 #endif
 170       goto block_or_character;
 171
 172     block_or_character:
 173       if (argc - optind != 4)
 174         {
 175           error (0, 0, _("\
 176 when creating special files, major and minor device\n\
 177 numbers must be specified"));
 178           usage (1);
 179         }
 180
 181       {
 182         char const *s_major = argv[optind + 2];
 183         char const *s_minor = argv[optind + 3];
 184         uintmax_t i_major, i_minor;
 185         dev_t device;
 186
 187         if (xstrtoumax (s_major, NULL, 0, &i_major, NULL) != LONGINT_OK
 188             || i_major != (major_t) i_major)
 189           error (1, 0, _("invalid major device number %s"), quote (s_major));
 190
 191         if (xstrtoumax (s_minor, NULL, 0, &i_minor, NULL) != LONGINT_OK
 192             || i_minor != (minor_t) i_minor)
 193           error (1, 0, _("invalid minor device number %s"), quote (s_minor));
 194
 195         device = makedev (i_major, i_minor);
 196 #ifdef NODEV
 197         if (device == NODEV)
 198           error (1, 0, _("invalid device %s %s"), s_major, s_minor);
 199 #endif
 200
 201         if (mknod (argv[optind], newmode | node_type, device) != 0)
 202           error (1, errno, "%s", quote (argv[optind]));
 203       }
 204       break;
 205
 206     case 'p':                   /* `pipe' */
 207 #ifndef S_ISFIFO
 208       error (4, 0, _("fifo files not supported"));
 209 #else
 210       if (argc - optind != 2)
 211         {
 212           error (0, 0, _("\
 213 major and minor device numbers may not be specified for fifo files"));
 214           usage (1);
 215         }
 216       if (mkfifo (argv[optind], newmode))
 217         error (1, errno, "%s", quote (argv[optind]));
 218 #endif
 219       break;
 220
 221     default:
 222       error (0, 0, "invalid device type %s", quote (argv[optind + 1]));
 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 }