lzmainfo.c

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//
//
//  Author:     Lasse Collin
//
//  This file has been put into the public domain.
//  You can do whatever you want with this file.
//
 
#include "sysdefs.h"
#include <stdio.h>
#include <errno.h>
 
#include "lzma.h"
#include "getopt.h"
#include "tuklib_gettext.h"
#include "tuklib_progname.h"
#include "tuklib_exit.h"
 
#ifdef TUKLIB_DOSLIKE
#   include <fcntl.h>
#   include <io.h>
#endif
 
 
static void lzma_attribute((__noreturn__))
help(void)
{
    printf(
_("Usage: %s [--help] [--version] [FILE]...\n"
"Show information stored in the .lzma file header"), progname);
 
    printf(_(
"\nWith no FILE, or when FILE is -, read standard input.\n"));
    printf("\n");
 
    printf(_("Report bugs to <%s> (in English or Finnish).\n"),
            PACKAGE_BUGREPORT);
    printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
 
    tuklib_exit(EXIT_SUCCESS, EXIT_FAILURE, true);
}
 
 
static void lzma_attribute((__noreturn__))
version(void)
{
    puts("lzmainfo (" PACKAGE_NAME ") " LZMA_VERSION_STRING);
    tuklib_exit(EXIT_SUCCESS, EXIT_FAILURE, true);
}
 
 
static void
parse_args(int argc, char **argv)
{
    enum {
        OPT_HELP,
        OPT_VERSION,
    };
 
    static const struct option long_opts[] = {
        { "help",    no_argument, NULL, OPT_HELP },
        { "version", no_argument, NULL, OPT_VERSION },
        { NULL,      0,           NULL, 0 }
    };
 
    int c;
    while ((c = getopt_long(argc, argv, "", long_opts, NULL)) != -1) {
        switch (c) {
        case OPT_HELP:
            help();
 
        case OPT_VERSION:
            version();
 
        default:
            exit(EXIT_FAILURE);
        }
    }
 
    return;
}
 
 
static uint32_t
my_log2(uint32_t n)
{
    uint32_t e;
    for (e = 0; n > 1; ++e, n /= 2) ;
    return e;
}
 
 
static bool
lzmainfo(const char *name, FILE *f)
{
    uint8_t buf[13];
    const size_t size = fread(buf, 1, sizeof(buf), f);
    if (size != 13) {
        fprintf(stderr, "%s: %s: %s\n", progname, name,
                ferror(f) ? strerror(errno)
                : _("File is too small to be a .lzma file"));
        return true;
    }
 
    lzma_filter filter = { .id = LZMA_FILTER_LZMA1 };
 
    // Parse the first five bytes.
    switch (lzma_properties_decode(&filter, NULL, buf, 5)) {
    case LZMA_OK:
        break;
 
    case LZMA_OPTIONS_ERROR:
        fprintf(stderr, "%s: %s: %s\n", progname, name,
                _("Not a .lzma file"));
        return true;
 
    case LZMA_MEM_ERROR:
        fprintf(stderr, "%s: %s\n", progname, strerror(ENOMEM));
        exit(EXIT_FAILURE);
 
    default:
        fprintf(stderr, "%s: %s\n", progname,
                _("Internal error (bug)"));
        exit(EXIT_FAILURE);
    }
 
    // Uncompressed size
    uint64_t uncompressed_size = 0;
    for (size_t i = 0; i < 8; ++i)
        uncompressed_size |= (uint64_t)(buf[5 + i]) << (i * 8);
 
    // Display the results. We don't want to translate these and also
    // will use MB instead of MiB, because someone could be parsing
    // this output and we don't want to break that when people move
    // from LZMA Utils to XZ Utils.
    if (f != stdin)
        printf("%s\n", name);
 
    printf("Uncompressed size:             ");
    if (uncompressed_size == UINT64_MAX)
        printf("Unknown");
    else
        printf("%" PRIu64 " MB (%" PRIu64 " bytes)",
                (uncompressed_size + 512 * 1024)
                    / (1024 * 1024),
                uncompressed_size);
 
    lzma_options_lzma *opt = filter.options;
 
    printf("\nDictionary size:               "
            "%" PRIu32 " MB (2^%" PRIu32 " bytes)\n"
            "Literal context bits (lc):     %" PRIu32 "\n"
            "Literal pos bits (lp):         %" PRIu32 "\n"
            "Number of pos bits (pb):       %" PRIu32 "\n",
            (opt->dict_size + 512 * 1024) / (1024 * 1024),
            my_log2(opt->dict_size), opt->lc, opt->lp, opt->pb);
 
    free(opt);
 
    return false;
}
 
 
extern int
main(int argc, char **argv)
{
    tuklib_progname_init(argv);
    tuklib_gettext_init(PACKAGE, LOCALEDIR);
 
    parse_args(argc, argv);
 
#ifdef TUKLIB_DOSLIKE
    setmode(fileno(stdin), O_BINARY);
#endif
 
    int ret = EXIT_SUCCESS;
 
    // We print empty lines around the output only when reading from
    // files specified on the command line. This is due to how
    // LZMA Utils did it.
    if (optind == argc) {
        if (lzmainfo("(stdin)", stdin))
            ret = EXIT_FAILURE;
    } else {
        printf("\n");
 
        do {
            if (strcmp(argv[optind], "-") == 0) {
                if (lzmainfo("(stdin)", stdin))
                    ret = EXIT_FAILURE;
            } else {
                FILE *f = fopen(argv[optind], "r");
                if (f == NULL) {
                    ret = EXIT_FAILURE;
                    fprintf(stderr, "%s: %s: %s\n",
                            progname,
                            argv[optind],
                            strerror(errno));
                    continue;
                }
 
                if (lzmainfo(argv[optind], f))
                    ret = EXIT_FAILURE;
 
                printf("\n");
                fclose(f);
            }
        } while (++optind < argc);
    }
 
    tuklib_exit(ret, EXIT_FAILURE, true);
}