busybox/util-linux/hexdump.c

/* vi: set sw=4 ts=4: */
/*
 * hexdump implementation for busybox
 * Based on code from util-linux v 2.11l
 *
 * Copyright (c) 1989
 * The Regents of the University of California.  All rights reserved.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
//config:config HEXDUMP
//config:	bool "hexdump (8.7 kb)"
//config:	default y
//config:	help
//config:	The hexdump utility is used to display binary data in a readable
//config:	way that is comparable to the output from most hex editors.
//config:
//config:config HD
//config:	bool "hd (8.3 kb)"
//config:	default y
//config:	help
//config:	hd is an alias to hexdump -C.

//applet:IF_HEXDUMP(APPLET_NOEXEC(hexdump, hexdump, BB_DIR_USR_BIN, BB_SUID_DROP, hexdump))
//applet:IF_HD(APPLET_NOEXEC(hd, hexdump, BB_DIR_USR_BIN, BB_SUID_DROP, hd))

//kbuild:lib-$(CONFIG_HEXDUMP) += hexdump.o
//kbuild:lib-$(CONFIG_HD) += hexdump.o

//usage:#define hexdump_trivial_usage
//usage:       "[-bcdoxCv] [-e FMT] [-f FMT_FILE] [-n LEN] [-s OFS] [FILE]..."
//usage:#define hexdump_full_usage "\n\n"
//usage:       "Display FILEs (or stdin) in a user specified format\n"
//usage:     "\n	-b		1-byte octal display"
//usage:     "\n	-c		1-byte character display"
//usage:     "\n	-d		2-byte decimal display"
//usage:     "\n	-o		2-byte octal display"
//usage:     "\n	-x		2-byte hex display"
//usage:     "\n	-C		hex+ASCII 16 bytes per line"
//usage:     "\n	-v		Show all (no dup folding)"
//usage:     "\n	-e FORMAT_STR	Example: '16/1 \"%02x|\"\"\\n\"'"
//usage:     "\n	-f FORMAT_FILE"
// exactly the same help text lines in hexdump and xxd:
//usage:     "\n	-n LENGTH	Show only first LENGTH bytes"
//usage:     "\n	-s OFFSET	Skip OFFSET bytes"
//usage:
//usage:#define hd_trivial_usage
//usage:       "FILE..."
//usage:#define hd_full_usage "\n\n"
//usage:       "hd is an alias for hexdump -C"

#include "libbb.h"
#include "dump.h"

/* This is a NOEXEC applet. Be very careful! */

static void bb_dump_addfile(dumper_t *dumper, char *name)
{
	char *p;
	FILE *fp;
	char *buf;

	fp = xfopen_for_read(name);
	while ((buf = xmalloc_fgetline(fp)) != NULL) {
		p = skip_whitespace(buf);
		if (*p && (*p != '#')) {
			bb_dump_add(dumper, p);
		}
		free(buf);
	}
	fclose(fp);
}

static const char *const add_strings[] ALIGN_PTR = {
	"16/1 \" %03o"  , /* b */
	"16/1 \" %3_c"  , /* c */
	"8/2 \"   %05u" , /* d */
	"8/2 \"  %06o"  , /* o */
	"8/2 \"    %04x", /* x */
};

static void add_format(dumper_t *dumper, const char *fmt)
{
	char fmtbuf[sizeof("\"%07_ax\"" "%s\"" "\"\n\"") + 16];
	sprintf(fmtbuf, "\"%%07_ax\"" "%s\"" "\"\n\"", fmt);
	bb_dump_add(dumper, "\"%07_Ax\n\"");
	bb_dump_add(dumper, fmtbuf);
}

static const char hexdump_opts[] ALIGN1 = "bcdoxCe:f:n:s:v";

int hexdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hexdump_main(int argc, char **argv)
{
	dumper_t *dumper = alloc_dumper();
	const char *p;
	int ch;

	if (ENABLE_HD
	 && (!ENABLE_HEXDUMP || !applet_name[2])
	) { /* we are "hd" */
		ch = 'C';
		goto hd_applet;
	}

	/* We cannot use getopt32: in hexdump options are cumulative.
	 * E.g. "hexdump -C -C file" should dump each line twice */
	while ((ch = getopt(argc, argv, hexdump_opts)) > 0) {
		p = strchr(hexdump_opts, ch);
		if (!p)
			bb_show_usage();
		if ((p - hexdump_opts) < 5) {
			add_format(dumper, add_strings[(int)(p - hexdump_opts)]);
		}
		/* Save a little bit of space below by omitting the 'else's. */
		if (ch == 'C') {
 hd_applet:
			bb_dump_add(dumper, "\"%08_Ax\n\""); // final address line after dump
			//------------------- "address "   8 * " xx"  " "  8 * " xx"
			bb_dump_add(dumper, "\"%08_ax \"8/1 \" %02x\"\" \"8/1 \" %02x\"");
			//------------------- "  |ASCII...........|\n"
			bb_dump_add(dumper, "\"  |\"16/1 \"%_p\"\"|\n\"");
		}
		if (ch == 'e') {
			bb_dump_add(dumper, optarg);
		} /* else */
		if (ch == 'f') {
			bb_dump_addfile(dumper, optarg);
		} /* else */
		if (ch == 'n') { /* compat: -n accepts hex numbers too */
			dumper->dump_length = xstrtou_range_sfx(
				optarg,
				/*base:*/ 0,
				/*lo:*/ 0, /*hi:*/ INT_MAX,
				kmg_i_suffixes
			);
		} /* else */
		if (ch == 's') { /* compat: -s accepts hex numbers too */
			dumper->dump_skip = xstrtoull_range_sfx(
				optarg,
				/*base:*/ 0,
				/*lo:*/ 0, /*hi:*/ OFF_T_MAX,
				kmg_i_suffixes
			);
		} /* else */
		if (ch == 'v') {
			dumper->dump_vflag = ALL;
		}
	}

	if (!dumper->fshead) {
		add_format(dumper, "8/2 \" %04x");
	}

	argv += optind;

	return bb_dump_dump(dumper, argv);
}