/* 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 (8.6 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 FEATURE_HEXDUMP_REVERSE
//config:       bool "Support -R, reverse of 'hexdump -Cv'"
//config:       default y
//config:       depends on HEXDUMP
//config:       help
//config:       The hexdump utility is used to display binary data in an ascii
//config:       readable way. This option creates binary data from an ascii input.
//config:       NB: this option is non-standard. It's unwise to use it in scripts
//config:       aimed to be portable.
//config:
//config:config HD
//config:       bool "hd (7.8 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:       "[-bcCdefnosvx" IF_FEATURE_HEXDUMP_REVERSE("R") "] [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:        IF_FEATURE_HEXDUMP_REVERSE(
//usage:     "\n        -R              Reverse of 'hexdump -Cv'")
// TODO: NONCOMPAT!!! move -R to xxd -r
//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[] = {
        "\"%07.7_ax \"16/1 \"%03o \"\"\n\"",   /* b */
        "\"%07.7_ax \"16/1 \"%3_c \"\"\n\"",   /* c */
        "\"%07.7_ax \"8/2 \"  %05u \"\"\n\"",  /* d */
        "\"%07.7_ax \"8/2 \" %06o \"\"\n\"",   /* o */
        "\"%07.7_ax \"8/2 \"   %04x \"\"\n\"", /* x */
};

static const char add_first[] ALIGN1 = "\"%07.7_Ax\n\"";

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

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_FEATURE_HEXDUMP_REVERSE
        FILE *fp;
        smallint rdump = 0;
#endif

        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) {
                        bb_dump_add(dumper, add_first);
                        bb_dump_add(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, "\"%08.8_Ax\n\""); // final address line after dump
                        //------------------- "address  "   8 * "xx "    "  "  8 * "xx "
                        bb_dump_add(dumper, "\"%08.8_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') {
                        dumper->dump_length = xatoi_positive(optarg);
                } /* 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,
                                bkm_suffixes
                        );
                } /* else */
                if (ch == 'v') {
                        dumper->dump_vflag = ALL;
                }
#if ENABLE_FEATURE_HEXDUMP_REVERSE
                if (ch == 'R') {
                        rdump = 1;
                }
#endif
        }

        if (!dumper->fshead) {
                bb_dump_add(dumper, add_first);
                bb_dump_add(dumper, "\"%07.7_ax \"8/2 \"%04x \"\"\n\"");
        }

        argv += optind;

#if !ENABLE_FEATURE_HEXDUMP_REVERSE
        return bb_dump_dump(dumper, argv);
#else
        if (!rdump) {
                return bb_dump_dump(dumper, argv);
        }

        /* -R: reverse of 'hexdump -Cv' */
        fp = stdin;
        if (!*argv) {
                argv--;
                goto jump_in;
        }

        do {
                char *buf;
                fp = xfopen_for_read(*argv);
 jump_in:
                while ((buf = xmalloc_fgetline(fp)) != NULL) {
                        p = buf;
                        while (1) {
                                /* skip address or previous byte */
                                while (isxdigit(*p)) p++;
                                while (*p == ' ') p++;
                                /* '|' char will break the line */
                                if (!isxdigit(*p) || sscanf(p, "%x ", &ch) != 1)
                                        break;
                                putchar(ch);
                        }
                        free(buf);
                }
                fclose(fp);
        } while (*++argv);

        fflush_stdout_and_exit(EXIT_SUCCESS);
#endif
}