/* 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.
 */

//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              One-byte octal display"
//usage:     "\n        -c              One-byte character display"
//usage:     "\n        -C              Canonical hex+ASCII, 16 bytes per line"
//usage:     "\n        -d              Two-byte decimal display"
//usage:     "\n        -e FORMAT_STRING"
//usage:     "\n        -f FORMAT_FILE"
//usage:     "\n        -n LENGTH       Interpret only LENGTH bytes of input"
//usage:     "\n        -o              Two-byte octal display"
//usage:     "\n        -s OFFSET       Skip OFFSET bytes"
//usage:     "\n        -v              Display all input data"
//usage:     "\n        -x              Two-byte hexadecimal display"
//usage:        IF_FEATURE_HEXDUMP_REVERSE(
//usage:     "\n        -R              Reverse of 'hexdump -Cv'")
//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");

static const struct suffix_mult suffixes[] = {
        { "b", 512 },
        { "k", 1024 },
        { "m", 1024*1024 },
        { "", 0 }
};

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 && !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\"");
                        bb_dump_add(dumper, "\"%08.8_ax  \" 8/1 \"%02x \" \"  \" 8/1 \"%02x \" ");
                        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 = xstrtoul_range_sfx(optarg, /*base:*/ 0, /*lo:*/ 0, /*hi:*/ LONG_MAX, 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
}