util-linux/hexdump.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * hexdump implementation for busybox
   4  * Based on code from util-linux v 2.11l
   5  *
   6  * Copyright (c) 1989
   7  * The Regents of the University of California.  All rights reserved.
   8  *
   9  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  10  */
  11 //config:config HEXDUMP
  12 //config:       bool "hexdump"
  13 //config:       default y
  14 //config:       help
  15 //config:         The hexdump utility is used to display binary data in a readable
  16 //config:         way that is comparable to the output from most hex editors.
  17 //config:
  18 //config:config FEATURE_HEXDUMP_REVERSE
  19 //config:       bool "Support -R, reverse of 'hexdump -Cv'"
  20 //config:       default y
  21 //config:       depends on HEXDUMP
  22 //config:       help
  23 //config:         The hexdump utility is used to display binary data in an ascii
  24 //config:         readable way. This option creates binary data from an ascii input.
  25 //config:         NB: this option is non-standard. It's unwise to use it in scripts
  26 //config:         aimed to be portable.
  27 //config:
  28 //config:config HD
  29 //config:       bool "hd"
  30 //config:       default y
  31 //config:       depends on HEXDUMP
  32 //config:       help
  33 //config:         hd is an alias to hexdump -C.
  34
  35 //applet:IF_HEXDUMP(APPLET_NOEXEC(hexdump, hexdump, BB_DIR_USR_BIN, BB_SUID_DROP, hexdump))
  36 //applet:IF_HD(APPLET_NOEXEC(hd, hexdump, BB_DIR_USR_BIN, BB_SUID_DROP, hd))
  37
  38 //kbuild:lib-$(CONFIG_HEXDUMP) += hexdump.o
  39 //kbuild:lib-$(CONFIG_HD) += hexdump.o
  40
  41 //usage:#define hexdump_trivial_usage
  42 //usage:       "[-bcCdefnosvx" IF_FEATURE_HEXDUMP_REVERSE("R") "] [FILE]..."
  43 //usage:#define hexdump_full_usage "\n\n"
  44 //usage:       "Display FILEs (or stdin) in a user specified format\n"
  45 //usage:     "\n        -b              One-byte octal display"
  46 //usage:     "\n        -c              One-byte character display"
  47 //usage:     "\n        -C              Canonical hex+ASCII, 16 bytes per line"
  48 //usage:     "\n        -d              Two-byte decimal display"
  49 //usage:     "\n        -e FORMAT_STRING"
  50 //usage:     "\n        -f FORMAT_FILE"
  51 //usage:     "\n        -n LENGTH       Interpret only LENGTH bytes of input"
  52 //usage:     "\n        -o              Two-byte octal display"
  53 //usage:     "\n        -s OFFSET       Skip OFFSET bytes"
  54 //usage:     "\n        -v              Display all input data"
  55 //usage:     "\n        -x              Two-byte hexadecimal display"
  56 //usage:        IF_FEATURE_HEXDUMP_REVERSE(
  57 //usage:     "\n        -R              Reverse of 'hexdump -Cv'")
  58 //usage:
  59 //usage:#define hd_trivial_usage
  60 //usage:       "FILE..."
  61 //usage:#define hd_full_usage "\n\n"
  62 //usage:       "hd is an alias for hexdump -C"
  63
  64 #include "libbb.h"
  65 #include "dump.h"
  66
  67 /* This is a NOEXEC applet. Be very careful! */
  68
  69 static void bb_dump_addfile(dumper_t *dumper, char *name)
  70 {
  71         char *p;
  72         FILE *fp;
  73         char *buf;
  74
  75         fp = xfopen_for_read(name);
  76         while ((buf = xmalloc_fgetline(fp)) != NULL) {
  77                 p = skip_whitespace(buf);
  78                 if (*p && (*p != '#')) {
  79                         bb_dump_add(dumper, p);
  80                 }
  81                 free(buf);
  82         }
  83         fclose(fp);
  84 }
  85
  86 static const char *const add_strings[] = {
  87         "\"%07.7_ax \" 16/1 \"%03o \" \"\\n\"",   /* b */
  88         "\"%07.7_ax \" 16/1 \"%3_c \" \"\\n\"",   /* c */
  89         "\"%07.7_ax \" 8/2 \"  %05u \" \"\\n\"",  /* d */
  90         "\"%07.7_ax \" 8/2 \" %06o \" \"\\n\"",   /* o */
  91         "\"%07.7_ax \" 8/2 \"   %04x \" \"\\n\"", /* x */
  92 };
  93
  94 static const char add_first[] ALIGN1 = "\"%07.7_Ax\n\"";
  95
  96 static const char hexdump_opts[] ALIGN1 = "bcdoxCe:f:n:s:v" IF_FEATURE_HEXDUMP_REVERSE("R");
  97
  98 int hexdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  99 int hexdump_main(int argc, char **argv)
 100 {
 101         dumper_t *dumper = alloc_dumper();
 102         const char *p;
 103         int ch;
 104 #if ENABLE_FEATURE_HEXDUMP_REVERSE
 105         FILE *fp;
 106         smallint rdump = 0;
 107 #endif
 108
 109         if (ENABLE_HD && !applet_name[2]) { /* we are "hd" */
 110                 ch = 'C';
 111                 goto hd_applet;
 112         }
 113
 114         /* We cannot use getopt32: in hexdump options are cumulative.
 115          * E.g. "hexdump -C -C file" should dump each line twice */
 116         while ((ch = getopt(argc, argv, hexdump_opts)) > 0) {
 117                 p = strchr(hexdump_opts, ch);
 118                 if (!p)
 119                         bb_show_usage();
 120                 if ((p - hexdump_opts) < 5) {
 121                         bb_dump_add(dumper, add_first);
 122                         bb_dump_add(dumper, add_strings[(int)(p - hexdump_opts)]);
 123                 }
 124                 /* Save a little bit of space below by omitting the 'else's. */
 125                 if (ch == 'C') {
 126  hd_applet:
 127                         bb_dump_add(dumper, "\"%08.8_Ax\n\"");
 128                         bb_dump_add(dumper, "\"%08.8_ax  \" 8/1 \"%02x \" \"  \" 8/1 \"%02x \" ");
 129                         bb_dump_add(dumper, "\"  |\" 16/1 \"%_p\" \"|\\n\"");
 130                 }
 131                 if (ch == 'e') {
 132                         bb_dump_add(dumper, optarg);
 133                 } /* else */
 134                 if (ch == 'f') {
 135                         bb_dump_addfile(dumper, optarg);
 136                 } /* else */
 137                 if (ch == 'n') {
 138                         dumper->dump_length = xatoi_positive(optarg);
 139                 } /* else */
 140                 if (ch == 's') { /* compat: -s accepts hex numbers too */
 141                         dumper->dump_skip = xstrtoull_range_sfx(
 142                                 optarg,
 143                                 /*base:*/ 0,
 144                                 /*lo:*/ 0, /*hi:*/ OFF_T_MAX,
 145                                 bkm_suffixes
 146                         );
 147                 } /* else */
 148                 if (ch == 'v') {
 149                         dumper->dump_vflag = ALL;
 150                 }
 151 #if ENABLE_FEATURE_HEXDUMP_REVERSE
 152                 if (ch == 'R') {
 153                         rdump = 1;
 154                 }
 155 #endif
 156         }
 157
 158         if (!dumper->fshead) {
 159                 bb_dump_add(dumper, add_first);
 160                 bb_dump_add(dumper, "\"%07.7_ax \" 8/2 \"%04x \" \"\\n\"");
 161         }
 162
 163         argv += optind;
 164
 165 #if !ENABLE_FEATURE_HEXDUMP_REVERSE
 166         return bb_dump_dump(dumper, argv);
 167 #else
 168         if (!rdump) {
 169                 return bb_dump_dump(dumper, argv);
 170         }
 171
 172         /* -R: reverse of 'hexdump -Cv' */
 173         fp = stdin;
 174         if (!*argv) {
 175                 argv--;
 176                 goto jump_in;
 177         }
 178
 179         do {
 180                 char *buf;
 181                 fp = xfopen_for_read(*argv);
 182  jump_in:
 183                 while ((buf = xmalloc_fgetline(fp)) != NULL) {
 184                         p = buf;
 185                         while (1) {
 186                                 /* skip address or previous byte */
 187                                 while (isxdigit(*p)) p++;
 188                                 while (*p == ' ') p++;
 189                                 /* '|' char will break the line */
 190                                 if (!isxdigit(*p) || sscanf(p, "%x ", &ch) != 1)
 191                                         break;
 192                                 putchar(ch);
 193                         }
 194                         free(buf);
 195                 }
 196                 fclose(fp);
 197         } while (*++argv);
 198
 199         fflush_stdout_and_exit(EXIT_SUCCESS);
 200 #endif
 201 }