busybox/util-linux/hexdump_xxd.c
Denys Vlasenko f318adaaab xxd -r: without -p, stop at more than one whitespace, closes 14786
function                                             old     new   delta
xxd_main                                             888    1076    +188

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2022-08-22 15:40:47 +02:00

300 lines
8.1 KiB
C

/* 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 (8.9 kb)"
//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: "[-pri] [-g N] [-c N] [-n LEN] [-s OFS] [-o OFS] [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"
//usage: "\n -i C include file style"
// 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"
//usage: "\n -o OFFSET Add OFFSET to displayed offset"
//usage: "\n -r Reverse (with -p, assumes no offsets in input)"
#include "libbb.h"
#include "dump.h"
/* This is a NOEXEC applet. Be very careful! */
#define OPT_l (1 << 0)
#define OPT_s (1 << 1)
#define OPT_a (1 << 2)
#define OPT_p (1 << 3)
#define OPT_i (1 << 4)
#define OPT_r (1 << 5)
#define OPT_g (1 << 6)
#define OPT_c (1 << 7)
#define OPT_o (1 << 8)
static void reverse(unsigned opt, const char *filename)
{
FILE *fp;
char *buf;
fp = filename ? xfopen_for_read(filename) : stdin;
get_new_line:
while ((buf = xmalloc_fgetline(fp)) != NULL) {
char *p;
p = buf;
if (!(opt & OPT_p)) {
skip_address:
p = skip_whitespace(p);
while (isxdigit(*p)) p++;
/* NB: for xxd -r, first hex portion is address even without colon */
/* If it's there, skip it: */
if (*p == ':') p++;
//TODO: seek (or zero-pad if unseekable) to the address position
//NOTE: -s SEEK value should be added to the address before seeking
}
/* Process hex bytes optionally separated by whitespace */
for (;;) {
uint8_t val, c;
int badchar = 0;
nibble1:
if (opt & OPT_p)
p = skip_whitespace(p);
c = *p++;
if (isdigit(c))
val = c - '0';
else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
val = (c|0x20) - ('a' - 10);
else {
/* xxd V1.10 allows one non-hexnum char:
* echo -e "31 !3 0a 0a" | xxd -r -p
* is "10<a0>" (no <cr>) - "!" is ignored,
* but stops for more than one:
* echo -e "31 !!343434\n30 0a" | xxd -r -p
* is "10<cr>" - "!!" drops rest of the line.
* Note: this also covers whitespace chars:
* xxxxxxxx: 3031 3233 3435 3637 3839 3a3b 3c3d 3e3f 0123456789:;<=>?
* detects this ^ - skips this one space
* xxxxxxxx: 3031 3233 3435 3637 3839 3a3b 3c3d 3e3f 0123456789:;<=>?
* detects this ^^ - skips the rest
*/
if (c == '\0' || badchar)
break;
badchar++;
goto nibble1;
}
val <<= 4;
nibble2:
if (opt & OPT_p) {
/* Works the same with xxd V1.10:
* echo "31 09 32 0a" | xxd -r -p
* echo "31 0 9 32 0a" | xxd -r -p
* thus allow whitespace (even multiple chars)
* after byte's 1st char:
*/
p = skip_whitespace(p);
}
c = *p++;
if (isdigit(c))
val |= c - '0';
else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
val |= (c|0x20) - ('a' - 10);
else {
if (c != '\0') {
/* "...3<not_hex_char>...": ignore "3",
* skip everything up to next hexchar or newline:
*/
while (!isxdigit(*p)) {
if (*p == '\0') {
free(buf);
goto get_new_line;
}
p++;
}
goto nibble1;
}
/* Nibbles can join even through newline:
* echo -e "31 3\n2 0a" | xxd -r -p
* is "12<cr>".
*/
free(buf);
p = buf = xmalloc_fgetline(fp);
if (!buf)
break;
if (!(opt & OPT_p)) /* -p and !-p: different behavior */
goto skip_address;
goto nibble2;
}
putchar(val);
} /* for(;;) */
free(buf);
}
//fclose(fp);
fflush_stdout_and_exit_SUCCESS();
}
static void print_C_style(const char *p, const char *hdr)
{
printf(hdr, isdigit(p[0]) ? "__" : "");
while (*p) {
bb_putchar(isalnum(*p) ? *p : '_');
p++;
}
}
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, *opt_o;
unsigned bytes = 2;
unsigned cols = 0;
unsigned opt;
int r;
dumper = alloc_dumper();
opt = getopt32(argv, "^" "l:s:apirg:+c:+o:" "\0" "?1" /* 1 argument max */,
&opt_l, &opt_s, &bytes, &cols, &opt_o
);
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_r) {
reverse(opt, argv[0]);
}
if (opt & OPT_o) {
/* -o accepts negative numbers too */
dumper->xxd_displayoff = xstrtoll(opt_o, /*base:*/ 0);
}
if (opt & OPT_p) {
if (cols == 0)
cols = 30;
bytes = cols; /* -p ignores -gN */
} else {
if (cols == 0)
cols = (opt & OPT_i) ? 12 : 16;
if (opt & OPT_i) {
bytes = 1; // -i ignores -gN
// output is " 0xXX, 0xXX, 0xXX...", add leading space
bb_dump_add(dumper, "\" \"");
} else
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) {
if (opt & OPT_i)
sprintf(buf, "%u/1 \" 0x%%02x,\"", cols); // cols * " 0xXX,"
//TODO: compat: omit the last comma after the very last byte
else
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|OPT_i))) {
sprintf(buf, "\" \"%u/1 \"%%_p\"\"\n\"", cols); // " ASCII\n"
bb_dump_add(dumper, buf);
} else {
bb_dump_add(dumper, "\"\n\"");
dumper->xxd_eofstring = "\n";
}
if ((opt & OPT_i) && argv[0]) {
print_C_style(argv[0], "unsigned char %s");
printf("[] = {\n");
}
r = bb_dump_dump(dumper, argv);
if (r == 0 && (opt & OPT_i) && argv[0]) {
print_C_style(argv[0], "};\nunsigned int %s");
printf("_len = %"OFF_FMT"u;\n", dumper->address);
}
return r;
}