commands/hexdump.c

   1 /* hexdump.c - command to dump the contents of a file or memory */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2007  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/normal.h>
  21 #include <grub/dl.h>
  22 #include <grub/arg.h>
  23 #include <grub/file.h>
  24 #include <grub/disk.h>
  25 #include <grub/misc.h>
  26 #include <grub/gzio.h>
  27 #include <grub/hexdump.h>
  28
  29 static const struct grub_arg_option options[] = {
  30   {"skip", 's', 0, "skip offset bytes from the beginning of file.", 0,
  31    ARG_TYPE_INT},
  32   {"length", 'n', 0, "read only length bytes", 0, ARG_TYPE_INT},
  33   {0, 0, 0, 0, 0, 0}
  34 };
  35
  36 void
  37 hexdump (unsigned long bse, char *buf, int len)
  38 {
  39   int pos;
  40   char line[80];
  41
  42   while (len > 0)
  43     {
  44       int cnt, i;
  45
  46       pos = grub_sprintf (line, "%08lx  ", bse);
  47       cnt = 16;
  48       if (cnt > len)
  49         cnt = len;
  50
  51       for (i = 0; i < cnt; i++)
  52         {
  53           pos += grub_sprintf (&line[pos], "%02x ", (unsigned char) buf[i]);
  54           if ((i & 7) == 7)
  55             line[pos++] = ' ';
  56         }
  57
  58       for (; i < 16; i++)
  59         {
  60           pos += grub_sprintf (&line[pos], "   ");
  61           if ((i & 7) == 7)
  62             line[pos++] = ' ';
  63         }
  64
  65       line[pos++] = '|';
  66
  67       for (i = 0; i < cnt; i++)
  68         line[pos++] = ((buf[i] >= 32) && (buf[i] < 127)) ? buf[i] : '.';
  69
  70       line[pos++] = '|';
  71
  72       line[pos] = 0;
  73
  74       grub_printf ("%s\n", line);
  75
  76       bse += 16;
  77       buf += 16;
  78       len -= cnt;
  79     }
  80 }
  81
  82 static grub_err_t
  83 grub_cmd_hexdump (struct grub_arg_list *state, int argc, char **args)
  84 {
  85   grub_file_t file;
  86   char buf[GRUB_DISK_SECTOR_SIZE];
  87   grub_ssize_t size, length;
  88   unsigned long skip;
  89   int is_file;
  90
  91   if (argc != 1)
  92     return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name required");
  93
  94   skip = (state[0].set) ? grub_strtoul (state[0].arg, 0, 0) : 0;
  95   length = (state[1].set) ? grub_strtoul (state[1].arg, 0, 0) : 0;
  96
  97   is_file = (grub_strcmp (args[0], "(mem)"));
  98   if ((!is_file) && (!length))
  99     length = 256;
 100
 101   if (is_file)
 102     {
 103       file = grub_gzfile_open (args[0], 1);
 104       if (!file)
 105         return 0;
 106
 107       file->offset = skip;
 108
 109       while ((size = grub_file_read (file, buf, sizeof (buf))) > 0)
 110         {
 111           unsigned long len;
 112
 113           len = ((length) && (size > length)) ? length : size;
 114           hexdump (skip, buf, len);
 115           skip += len;
 116           if (length)
 117             {
 118               length -= len;
 119               if (!length)
 120                 break;
 121             }
 122         }
 123
 124       grub_file_close (file);
 125     }
 126   else
 127     hexdump (skip, (char *) skip, length);
 128
 129   return 0;
 130 }
 131 \f
 132
 133 GRUB_MOD_INIT (hexdump)
 134 {
 135   (void) mod;                   /* To stop warning. */
 136   grub_register_command ("hexdump", grub_cmd_hexdump, GRUB_COMMAND_FLAG_BOTH,
 137                          "hexdump  [ -s offset ] [-n length] { FILE | (mem) }",
 138                          "Dump the contents of a file or memory.", options);
 139 }
 140
 141 GRUB_MOD_FINI (hexdump)
 142 {
 143   grub_unregister_command ("hexdump");
 144 }