1 files changed, 242 insertions, 0 deletions
diff --git a/src/lzmainfo/lzmainfo.c b/src/lzmainfo/lzmainfo.c
new file mode 100644
index 00000000..d9ae311a
--- /dev/null
+++ b/src/lzmainfo/lzmainfo.c
@@ -0,0 +1,242 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       lzmainfo.c
+/// \brief      lzmainfo tool for compatibility with LZMA Utils
+//
+//  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>
+
+#ifdef ENABLE_NLS
+#	include <libintl.h>
+#	define _(msgid) gettext(msgid)
+#else
+#	define _(msgid) msgid
+#endif
+
+#include "lzma.h"
+#include "getopt.h"
+
+
+/// Name of the program from argv[0]
+static const char *argv0;
+
+
+/// Close stdout unless we are already going to exit with EXIT_FAILURE.
+/// If closing stdout fails, set exit status to EXIT_FAILURE and print
+/// an error message to stderr. We don't care about closing stderr,
+/// because we don't print anything to stderr unless we are going to
+/// use EXIT_FAILURE anyway.
+static void lzma_attribute((noreturn))
+my_exit(int status)
+{
+	if (status != EXIT_FAILURE) {
+		const int ferror_err = ferror(stdout);
+		const int fclose_err = fclose(stdout);
+
+		if (ferror_err || fclose_err) {
+			// If it was fclose() that failed, we have the reason
+			// in errno. If only ferror() indicated an error,
+			// we have no idea what the reason was.
+			fprintf(stderr, "%s: %s: %s\n", argv0,
+					_("Writing to standard output "
+						"failed"),
+					fclose_err ? strerror(errno)
+						: _("Unknown error"));
+			status = EXIT_FAILURE;
+		}
+	}
+
+	exit(status);
+}
+
+
+static void lzma_attribute((noreturn))
+help(void)
+{
+	printf(
+_("Usage: %s [--help] [--version] [FILE]...\n"
+"Show information stored in the .lzma file header"), argv0);
+
+	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_HOMEPAGE);
+
+	my_exit(EXIT_SUCCESS);
+}
+
+
+static void lzma_attribute((noreturn))
+version(void)
+{
+	puts("lzmainfo (" PACKAGE_NAME ") " PACKAGE_VERSION);
+	my_exit(EXIT_SUCCESS);
+}
+
+
+/// Parse command line options.
+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;
+}
+
+
+/// Primitive base-2 logarithm for integers
+static uint32_t
+my_log2(uint32_t n)
+{
+	uint32_t e;
+	for (e = 0; n > 1; ++e, n /= 2) ;
+	return e;
+}
+
+
+/// Parse the .lzma header and display information about it.
+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", argv0, 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", argv0, name,
+				_("Not a .lzma file"));
+		return true;
+
+	case LZMA_MEM_ERROR:
+		fprintf(stderr, "%s: %s\n", argv0, strerror(ENOMEM));
+		exit(EXIT_FAILURE);
+
+	default:
+		fprintf(stderr, "%s: %s\n", argv0, _("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:               "
+			"%u MB (2^%u 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)
+{
+	int ret = EXIT_SUCCESS;
+	argv0 = argv[0];
+
+	parse_args(argc, argv);
+
+	// 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) {
+		lzmainfo("(stdin)", stdin);
+	} 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",
+							argv0, argv[optind],
+							strerror(errno));
+					continue;
+				}
+
+				if (lzmainfo(argv[optind], f))
+					ret = EXIT_FAILURE;
+
+				printf("\n");
+				fclose(f);
+			}
+		} while (++optind < argc);
+	}
+
+	my_exit(ret);
+}