1 /* vi: set sw=4 ts=4: */
3 * xxd implementation for busybox
5 * Copyright (c) 2017 Denys Vlasenko <vda.linux@gmail.com>
7 * Licensed under GPLv2, see file LICENSE in this source tree.
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.
16 //applet:IF_XXD(APPLET_NOEXEC(xxd, xxd, BB_DIR_USR_BIN, BB_SUID_DROP, xxd))
18 //kbuild:lib-$(CONFIG_XXD) += hexdump_xxd.o
21 // xxd V1.10 27oct98 by Juergen Weigert
24 // xxd [options] [infile [outfile]]
26 // xxd -r [-s [-]offset] [-c cols] [-ps] [infile [outfile]]
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.
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)
58 /* This is a NOEXEC applet. Be very careful! */
60 int xxd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
61 int xxd_main(int argc UNUSED_PARAM, char **argv)
70 dumper = alloc_dumper();
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_complementary = "?1"; /* 1 argument max */
77 opt = getopt32(argv, "l:s:apg:+c:+", &opt_l, &opt_s, &bytes, &cols);
80 dumper->dump_vflag = ALL;
82 // dumper->dump_vflag = SKIPNUL; ..does not exist
84 dumper->dump_length = xstrtou_range(
87 /*lo:*/ 0, /*hi:*/ INT_MAX
91 dumper->dump_skip = xstrtoull_range(
94 /*lo:*/ 0, /*hi:*/ OFF_T_MAX
96 //BUGGY for /proc/version (unseekable?)
102 bytes = cols; /* -p ignores -gN */
106 bb_dump_add(dumper, "\"%08.8_ax: \""); // "address: "
109 if (bytes < 1 || bytes >= cols) {
110 sprintf(buf, "%u/1 \"%%02x\"", cols); // cols * "xx"
111 bb_dump_add(dumper, buf);
113 else if (bytes == 1) {
114 sprintf(buf, "%u/1 \"%%02x \"", cols); // cols * "xx "
115 bb_dump_add(dumper, buf);
118 /* Format "print byte" with and without trailing space */
119 #define BS "/1 \"%02x \""
120 #define B "/1 \"%02x\""
122 char *bigbuf = xmalloc(cols * (sizeof(BS)-1));
124 for (i = 1; i <= cols; i++) {
125 if (i == cols || i % bytes)
130 // for -g3, this results in B B BS B B BS... B = "xxxxxx xxxxxx .....xx"
131 // todo: can be more clever and use
132 // one "cols-1/B" format instead of many "B B B..." formats
133 //bb_error_msg("ADDED:'%s'", bigbuf);
134 bb_dump_add(dumper, bigbuf);
138 if (!(opt & OPT_p)) {
139 sprintf(buf, "\" \"%u/1 \"%%_p\"\"\n\"", cols); // " ASCII\n"
140 bb_dump_add(dumper, buf);
143 return bb_dump_dump(dumper, argv);