LXR busybox/util-linux/hexdump

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * xxd implementation for busybox
   4 *
   5 * Copyright (c) 2017 Denys Vlasenko <vda.linux@gmail.com>
   6 *
   7 * Licensed under GPLv2, see file LICENSE in this source tree.
   8 */
   9//config:config XXD
  10//config:       bool "xxd (8.9 kb)"
  11//config:       default y
  12//config:       help
  13//config:       The xxd utility is used to display binary data in a readable
  14//config:       way that is comparable to the output from most hex editors.
  15
  16//applet:IF_XXD(APPLET_NOEXEC(xxd, xxd, BB_DIR_USR_BIN, BB_SUID_DROP, xxd))
  17
  18//kbuild:lib-$(CONFIG_XXD) += hexdump_xxd.o
  19
  20// $ xxd --version
  21// xxd V1.10 27oct98 by Juergen Weigert
  22// $ xxd --help
  23// Usage:
  24//       xxd [options] [infile [outfile]]
  25//    or
  26//       xxd -r [-s [-]offset] [-c cols] [-ps] [infile [outfile]]
  27// Options:
  28//    -a          toggle autoskip: A single '*' replaces nul-lines. Default off.
  29//    -b          binary digit dump (incompatible with -ps,-i,-r). Default hex.
  30//    -c cols     format <cols> octets per line. Default 16 (-i: 12, -ps: 30).
  31//    -E          show characters in EBCDIC. Default ASCII.
  32//    -e          little-endian dump (incompatible with -ps,-i,-r).
  33//    -g          number of octets per group in normal output. Default 2 (-e: 4).
  34//    -i          output in C include file style.
  35//    -l len      stop after <len> octets.
  36//    -o off      add <off> to the displayed file position.
  37//    -ps         output in postscript plain hexdump style.
  38//    -r          reverse operation: convert (or patch) hexdump into binary.
  39//    -r -s off   revert with <off> added to file positions found in hexdump.
  40//    -s [+][-]seek  start at <seek> bytes abs. (or +: rel.) infile offset.
  41//    -u          use upper case hex letters.
  42
  43//usage:#define xxd_trivial_usage
  44//usage:       "[OPTIONS] [FILE]"
  45//usage:#define xxd_full_usage "\n\n"
  46//usage:       "Hex dump FILE (or stdin)\n"
  47//usage:     "\n        -g N            Bytes per group"
  48//usage:     "\n        -c N            Bytes per line"
  49//usage:     "\n        -p              Show only hex bytes, assumes -c30"
  50// exactly the same help text lines in hexdump and xxd:
  51//usage:     "\n        -l LENGTH       Show only first LENGTH bytes"
  52//usage:     "\n        -s OFFSET       Skip OFFSET bytes"
  53// TODO: implement -r (see hexdump -R)
  54
  55#include "libbb.h"
  56#include "dump.h"
  57
  58/* This is a NOEXEC applet. Be very careful! */
  59
  60int xxd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  61int xxd_main(int argc UNUSED_PARAM, char **argv)
  62{
  63        char buf[80];
  64        dumper_t *dumper;
  65        char *opt_l, *opt_s;
  66        unsigned bytes = 2;
  67        unsigned cols = 0;
  68        unsigned opt;
  69
  70        dumper = alloc_dumper();
  71
  72#define OPT_l (1 << 0)
  73#define OPT_s (1 << 1)
  74#define OPT_a (1 << 2)
  75#define OPT_p (1 << 3)
  76        opt = getopt32(argv, "^" "l:s:apg:+c:+" "\0" "?1" /* 1 argument max */,
  77                        &opt_l, &opt_s, &bytes, &cols
  78        );
  79        argv += optind;
  80
  81        dumper->dump_vflag = ALL;
  82//      if (opt & OPT_a)
  83//              dumper->dump_vflag = SKIPNUL; ..does not exist
  84        if (opt & OPT_l) {
  85                dumper->dump_length = xstrtou_range(
  86                                opt_l,
  87                                /*base:*/ 0,
  88                                /*lo:*/ 0, /*hi:*/ INT_MAX
  89                );
  90        }
  91        if (opt & OPT_s) {
  92                dumper->dump_skip = xstrtoull_range(
  93                                opt_s,
  94                                /*base:*/ 0,
  95                                /*lo:*/ 0, /*hi:*/ OFF_T_MAX
  96                );
  97                //BUGGY for /proc/version (unseekable?)
  98        }
  99
 100        if (opt & OPT_p) {
 101                if (cols == 0)
 102                        cols = 30;
 103                bytes = cols; /* -p ignores -gN */
 104        } else {
 105                if (cols == 0)
 106                        cols = 16;
 107                bb_dump_add(dumper, "\"%08.8_ax: \""); // "address: "
 108        }
 109
 110        if (bytes < 1 || bytes >= cols) {
 111                sprintf(buf, "%u/1 \"%%02x\"", cols); // cols * "xx"
 112                bb_dump_add(dumper, buf);
 113        }
 114        else if (bytes == 1) {
 115                sprintf(buf, "%u/1 \"%%02x \"", cols); // cols * "xx "
 116                bb_dump_add(dumper, buf);
 117        }
 118        else {
 119/* Format "print byte" with and without trailing space */
 120#define BS "/1 \"%02x \""
 121#define B  "/1 \"%02x\""
 122                unsigned i;
 123                char *bigbuf = xmalloc(cols * (sizeof(BS)-1));
 124                char *p = bigbuf;
 125                for (i = 1; i <= cols; i++) {
 126                        if (i == cols || i % bytes)
 127                                p = stpcpy(p, B);
 128                        else
 129                                p = stpcpy(p, BS);
 130                }
 131                // for -g3, this results in B B BS B B BS... B = "xxxxxx xxxxxx .....xx"
 132                // todo: can be more clever and use
 133                // one 'bytes-1/1 "%02x"' format instead of many "B B B..." formats
 134                //bb_error_msg("ADDED:'%s'", bigbuf);
 135                bb_dump_add(dumper, bigbuf);
 136                free(bigbuf);
 137        }
 138
 139        if (!(opt & OPT_p)) {
 140                sprintf(buf, "\"  \"%u/1 \"%%_p\"\"\n\"", cols); // "  ASCII\n"
 141                bb_dump_add(dumper, buf);
 142        } else {
 143                bb_dump_add(dumper, "\"\n\"");
 144        }
 145
 146        return bb_dump_dump(dumper, argv);
 147}
 148