busybox/util-linux/hexdump_xxd.c

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/* vi: set sw=4 ts=4: */
/*
* xxd implementation for busybox
*
* Copyright (c) 2017 Denys Vlasenko <vda.linux@gmail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config XXD
//config: bool "xxd"
//config: default y
//config: help
//config: The xxd utility is used to display binary data in a readable
//config: way that is comparable to the output from most hex editors.
//applet:IF_XXD(APPLET_NOEXEC(xxd, xxd, BB_DIR_USR_BIN, BB_SUID_DROP, xxd))
//kbuild:lib-$(CONFIG_XXD) += hexdump_xxd.o
// $ xxd --version
// xxd V1.10 27oct98 by Juergen Weigert
// $ xxd --help
// Usage:
// xxd [options] [infile [outfile]]
// or
// xxd -r [-s [-]offset] [-c cols] [-ps] [infile [outfile]]
// Options:
// -a toggle autoskip: A single '*' replaces nul-lines. Default off.
// -b binary digit dump (incompatible with -ps,-i,-r). Default hex.
// -c cols format <cols> octets per line. Default 16 (-i: 12, -ps: 30).
// -E show characters in EBCDIC. Default ASCII.
// -e little-endian dump (incompatible with -ps,-i,-r).
// -g number of octets per group in normal output. Default 2 (-e: 4).
// -i output in C include file style.
// -l len stop after <len> octets.
// -o off add <off> to the displayed file position.
// -ps output in postscript plain hexdump style.
// -r reverse operation: convert (or patch) hexdump into binary.
// -r -s off revert with <off> added to file positions found in hexdump.
// -s [+][-]seek start at <seek> bytes abs. (or +: rel.) infile offset.
// -u use upper case hex letters.
//usage:#define xxd_trivial_usage
//usage: "[OPTIONS] [FILE]"
//usage:#define xxd_full_usage "\n\n"
//usage: "Hex dump FILE (or stdin)\n"
//usage: "\n -g N Bytes per group"
//usage: "\n -c N Bytes per line"
//usage: "\n -p Show only hex bytes, assumes -c30"
// exactly the same help text lines in hexdump and xxd:
//usage: "\n -l LENGTH Show only first LENGTH bytes"
//usage: "\n -s OFFSET Skip OFFSET bytes"
// TODO: implement -r (see hexdump -R)
#include "libbb.h"
#include "dump.h"
/* This is a NOEXEC applet. Be very careful! */
int xxd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int xxd_main(int argc UNUSED_PARAM, char **argv)
{
char buf[80];
dumper_t *dumper;
char *opt_l, *opt_s;
unsigned bytes = 2;
unsigned cols = 0;
unsigned opt;
dumper = alloc_dumper();
#define OPT_l (1 << 0)
#define OPT_s (1 << 1)
#define OPT_a (1 << 2)
#define OPT_p (1 << 3)
opt_complementary = "?1"; /* 1 argument max */
opt = getopt32(argv, "l:s:apg:+c:+", &opt_l, &opt_s, &bytes, &cols);
argv += optind;
dumper->dump_vflag = ALL;
// if (opt & OPT_a)
// dumper->dump_vflag = SKIPNUL; ..does not exist
if (opt & OPT_l) {
dumper->dump_length = xstrtou_range(
opt_l,
/*base:*/ 0,
/*lo:*/ 0, /*hi:*/ INT_MAX
);
}
if (opt & OPT_s) {
dumper->dump_skip = xstrtoull_range(
opt_s,
/*base:*/ 0,
/*lo:*/ 0, /*hi:*/ OFF_T_MAX
);
//BUGGY for /proc/version (unseekable?)
}
if (opt & OPT_p) {
if (cols == 0)
cols = 30;
bytes = cols; /* -p ignores -gN */
} else {
if (cols == 0)
cols = 16;
bb_dump_add(dumper, "\"%08.8_ax: \""); // "address: "
}
if (bytes < 1 || bytes >= cols) {
sprintf(buf, "%u/1 \"%%02x\"", cols); // cols * "xx"
bb_dump_add(dumper, buf);
}
else if (bytes == 1) {
sprintf(buf, "%u/1 \"%%02x \"", cols); // cols * "xx "
bb_dump_add(dumper, buf);
}
else {
/* Format "print byte" with and without trailing space */
#define BS "/1 \"%02x \""
#define B "/1 \"%02x\""
unsigned i;
char *bigbuf = xmalloc(cols * (sizeof(BS)-1));
char *p = bigbuf;
for (i = 1; i <= cols; i++) {
if (i == cols || i % bytes)
p = stpcpy(p, B);
else
p = stpcpy(p, BS);
}
// for -g3, this results in B B BS B B BS... B = "xxxxxx xxxxxx .....xx"
// todo: can be more clever and use
// one 'bytes-1/1 "%02x"' format instead of many "B B B..." formats
//bb_error_msg("ADDED:'%s'", bigbuf);
bb_dump_add(dumper, bigbuf);
free(bigbuf);
}
if (!(opt & OPT_p)) {
sprintf(buf, "\" \"%u/1 \"%%_p\"\"\n\"", cols); // " ASCII\n"
bb_dump_add(dumper, buf);
} else {
bb_dump_add(dumper, "\"\n\"");
}
return bb_dump_dump(dumper, argv);
}