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 (8.8 kb)"
  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 (8 kb)"
  30 //config:       default y
  31 //config:       help
  32 //config:       hd is an alias to hexdump -C.
  33
  34 //applet:IF_HEXDUMP(APPLET_NOEXEC(hexdump, hexdump, BB_DIR_USR_BIN, BB_SUID_DROP, hexdump))
  35 //applet:IF_HD(APPLET_NOEXEC(hd, hexdump, BB_DIR_USR_BIN, BB_SUID_DROP, hd))
  36
  37 //kbuild:lib-$(CONFIG_HEXDUMP) += hexdump.o
  38 //kbuild:lib-$(CONFIG_HD) += hexdump.o
  39
  40 //usage:#define hexdump_trivial_usage
  41 //usage:       "[-bcCdefnosvx" IF_FEATURE_HEXDUMP_REVERSE("R") "] [FILE]..."
  42 //usage:#define hexdump_full_usage "\n\n"
  43 //usage:       "Display FILEs (or stdin) in a user specified format\n"
  44 //usage:     "\n        -b              1-byte octal display"
  45 //usage:     "\n        -c              1-byte character display"
  46 //usage:     "\n        -d              2-byte decimal display"
  47 //usage:     "\n        -o              2-byte octal display"
  48 //usage:     "\n        -x              2-byte hex display"
  49 //usage:     "\n        -C              hex+ASCII 16 bytes per line"
  50 //usage:     "\n        -v              Show all (no dup folding)"
  51 //usage:     "\n        -e FORMAT_STR   Example: '16/1 \"%02x|\"\"\\n\"'"
  52 //usage:     "\n        -f FORMAT_FILE"
  53 // exactly the same help text lines in hexdump and xxd:
  54 //usage:     "\n        -n LENGTH       Show only first LENGTH bytes"
  55 //usage:     "\n        -s OFFSET       Skip OFFSET bytes"
  56 //usage:        IF_FEATURE_HEXDUMP_REVERSE(
  57 //usage:     "\n        -R              Reverse of 'hexdump -Cv'")
  58 // TODO: NONCOMPAT!!! move -R to xxd -r
  59 //usage:
  60 //usage:#define hd_trivial_usage
  61 //usage:       "FILE..."
  62 //usage:#define hd_full_usage "\n\n"
  63 //usage:       "hd is an alias for hexdump -C"
  64
  65 #include "libbb.h"
  66 #include "dump.h"
  67
  68 /* This is a NOEXEC applet. Be very careful! */
  69
  70 static void bb_dump_addfile(dumper_t *dumper, char *name)
  71 {
  72         char *p;
  73         FILE *fp;
  74         char *buf;
  75
  76         fp = xfopen_for_read(name);
  77         while ((buf = xmalloc_fgetline(fp)) != NULL) {
  78                 p = skip_whitespace(buf);
  79                 if (*p && (*p != '#')) {
  80                         bb_dump_add(dumper, p);
  81                 }
  82                 free(buf);
  83         }
  84         fclose(fp);
  85 }
  86
  87 static const char *const add_strings[] = {
  88         "\"%07.7_ax \"16/1 \"%03o \"\"\n\"",   /* b */
  89         "\"%07.7_ax \"16/1 \"%3_c \"\"\n\"",   /* c */
  90         "\"%07.7_ax \"8/2 \"  %05u \"\"\n\"",  /* d */
  91         "\"%07.7_ax \"8/2 \" %06o \"\"\n\"",   /* o */
  92         "\"%07.7_ax \"8/2 \"   %04x \"\"\n\"", /* x */
  93 };
  94
  95 static const char add_first[] ALIGN1 = "\"%07.7_Ax\n\"";
  96
  97 static const char hexdump_opts[] ALIGN1 = "bcdoxCe:f:n:s:v" IF_FEATURE_HEXDUMP_REVERSE("R");
  98
  99 int hexdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 100 int hexdump_main(int argc, char **argv)
 101 {
 102         dumper_t *dumper = alloc_dumper();
 103         const char *p;
 104         int ch;
 105 #if ENABLE_FEATURE_HEXDUMP_REVERSE
 106         FILE *fp;
 107         smallint rdump = 0;
 108 #endif
 109
 110         if (ENABLE_HD
 111          && (!ENABLE_HEXDUMP || !applet_name[2])
 112         ) { /* we are "hd" */
 113                 ch = 'C';
 114                 goto hd_applet;
 115         }
 116
 117         /* We cannot use getopt32: in hexdump options are cumulative.
 118          * E.g. "hexdump -C -C file" should dump each line twice */
 119         while ((ch = getopt(argc, argv, hexdump_opts)) > 0) {
 120                 p = strchr(hexdump_opts, ch);
 121                 if (!p)
 122                         bb_show_usage();
 123                 if ((p - hexdump_opts) < 5) {
 124                         bb_dump_add(dumper, add_first);
 125                         bb_dump_add(dumper, add_strings[(int)(p - hexdump_opts)]);
 126                 }
 127                 /* Save a little bit of space below by omitting the 'else's. */
 128                 if (ch == 'C') {
 129  hd_applet:
 130                         bb_dump_add(dumper, "\"%08.8_Ax\n\""); // final address line after dump
 131                         //------------------- "address  "   8 * "xx "    "  "  8 * "xx "
 132                         bb_dump_add(dumper, "\"%08.8_ax  \"8/1 \"%02x \"\"  \"8/1 \"%02x \"");
 133                         //------------------- "  |ASCII...........|\n"
 134                         bb_dump_add(dumper, "\"  |\"16/1 \"%_p\"\"|\n\"");
 135                 }
 136                 if (ch == 'e') {
 137                         bb_dump_add(dumper, optarg);
 138                 } /* else */
 139                 if (ch == 'f') {
 140                         bb_dump_addfile(dumper, optarg);
 141                 } /* else */
 142                 if (ch == 'n') {
 143                         dumper->dump_length = xatoi_positive(optarg);
 144                 } /* else */
 145                 if (ch == 's') { /* compat: -s accepts hex numbers too */
 146                         dumper->dump_skip = xstrtoull_range_sfx(
 147                                 optarg,
 148                                 /*base:*/ 0,
 149                                 /*lo:*/ 0, /*hi:*/ OFF_T_MAX,
 150                                 bkm_suffixes
 151                         );
 152                 } /* else */
 153                 if (ch == 'v') {
 154                         dumper->dump_vflag = ALL;
 155                 }
 156 #if ENABLE_FEATURE_HEXDUMP_REVERSE
 157                 if (ch == 'R') {
 158                         rdump = 1;
 159                 }
 160 #endif
 161         }
 162
 163         if (!dumper->fshead) {
 164                 bb_dump_add(dumper, add_first);
 165                 bb_dump_add(dumper, "\"%07.7_ax \"8/2 \"%04x \"\"\n\"");
 166         }
 167
 168         argv += optind;
 169
 170 #if !ENABLE_FEATURE_HEXDUMP_REVERSE
 171         return bb_dump_dump(dumper, argv);
 172 #else
 173         if (!rdump) {
 174                 return bb_dump_dump(dumper, argv);
 175         }
 176
 177         /* -R: reverse of 'hexdump -Cv' */
 178         fp = stdin;
 179         if (!*argv) {
 180                 argv--;
 181                 goto jump_in;
 182         }
 183
 184         do {
 185                 char *buf;
 186                 fp = xfopen_for_read(*argv);
 187  jump_in:
 188                 while ((buf = xmalloc_fgetline(fp)) != NULL) {
 189                         p = buf;
 190                         while (1) {
 191                                 /* skip address or previous byte */
 192                                 while (isxdigit(*p)) p++;
 193                                 while (*p == ' ') p++;
 194                                 /* '|' char will break the line */
 195                                 if (!isxdigit(*p) || sscanf(p, "%x ", &ch) != 1)
 196                                         break;
 197                                 putchar(ch);
 198                         }
 199                         free(buf);
 200                 }
 201                 fclose(fp);
 202         } while (*++argv);
 203
 204         fflush_stdout_and_exit(EXIT_SUCCESS);
 205 #endif
 206 }