1 files changed, 323 insertions, 0 deletions
diff --git a/src/xzdec/xzdec.c b/src/xzdec/xzdec.c
new file mode 100644
index 0000000..c1bd199
--- /dev/null
+++ b/src/xzdec/xzdec.c
@@ -0,0 +1,323 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       xzdec.c
+/// \brief      Simple single-threaded tool to uncompress .xz or .lzma files
+//
+//  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 "lzma.h"
+
+#include <stdarg.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "getopt.h"
+#include "tuklib_progname.h"
+#include "tuklib_exit.h"
+
+#ifdef TUKLIB_DOSLIKE
+#	include <fcntl.h>
+#	include <io.h>
+#endif
+
+
+#ifdef LZMADEC
+#	define TOOL_FORMAT "lzma"
+#else
+#	define TOOL_FORMAT "xz"
+#endif
+
+
+/// Error messages are suppressed if this is zero, which is the case when
+/// --quiet has been given at least twice.
+static int display_errors = 2;
+
+
+static void lzma_attribute((__format__(__printf__, 1, 2)))
+my_errorf(const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+
+	if (display_errors) {
+		fprintf(stderr, "%s: ", progname);
+		vfprintf(stderr, fmt, ap);
+		fprintf(stderr, "\n");
+	}
+
+	va_end(ap);
+	return;
+}
+
+
+static void lzma_attribute((__noreturn__))
+help(void)
+{
+	printf(
+"Usage: %s [OPTION]... [FILE]...\n"
+"Decompress files in the ." TOOL_FORMAT " format to standard output.\n"
+"\n"
+"  -d, --decompress   (ignored, only decompression is supported)\n"
+"  -k, --keep         (ignored, files are never deleted)\n"
+"  -c, --stdout       (ignored, output is always written to standard output)\n"
+"  -q, --quiet        specify *twice* to suppress errors\n"
+"  -Q, --no-warn      (ignored, the exit status 2 is never used)\n"
+"  -h, --help         display this help and exit\n"
+"  -V, --version      display the version number and exit\n"
+"\n"
+"With no FILE, or when FILE is -, read standard input.\n"
+"\n"
+"Report bugs to <" PACKAGE_BUGREPORT "> (in English or Finnish).\n"
+PACKAGE_NAME " home page: <" PACKAGE_URL ">\n", progname);
+
+	tuklib_exit(EXIT_SUCCESS, EXIT_FAILURE, display_errors);
+}
+
+
+static void lzma_attribute((__noreturn__))
+version(void)
+{
+	printf(TOOL_FORMAT "dec (" PACKAGE_NAME ") " LZMA_VERSION_STRING "\n"
+			"liblzma %s\n", lzma_version_string());
+
+	tuklib_exit(EXIT_SUCCESS, EXIT_FAILURE, display_errors);
+}
+
+
+/// Parses command line options.
+static void
+parse_options(int argc, char **argv)
+{
+	static const char short_opts[] = "cdkM:hqQV";
+	static const struct option long_opts[] = {
+		{ "stdout",       no_argument,         NULL, 'c' },
+		{ "to-stdout",    no_argument,         NULL, 'c' },
+		{ "decompress",   no_argument,         NULL, 'd' },
+		{ "uncompress",   no_argument,         NULL, 'd' },
+		{ "keep",         no_argument,         NULL, 'k' },
+		{ "quiet",        no_argument,         NULL, 'q' },
+		{ "no-warn",      no_argument,         NULL, 'Q' },
+		{ "help",         no_argument,         NULL, 'h' },
+		{ "version",      no_argument,         NULL, 'V' },
+		{ NULL,           0,                   NULL, 0   }
+	};
+
+	int c;
+
+	while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL))
+			!= -1) {
+		switch (c) {
+		case 'c':
+		case 'd':
+		case 'k':
+		case 'Q':
+			break;
+
+		case 'q':
+			if (display_errors > 0)
+				--display_errors;
+
+			break;
+
+		case 'h':
+			help();
+
+		case 'V':
+			version();
+
+		default:
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	return;
+}
+
+
+static void
+uncompress(lzma_stream *strm, FILE *file, const char *filename)
+{
+	lzma_ret ret;
+
+	// Initialize the decoder
+#ifdef LZMADEC
+	ret = lzma_alone_decoder(strm, UINT64_MAX);
+#else
+	ret = lzma_stream_decoder(strm, UINT64_MAX, LZMA_CONCATENATED);
+#endif
+
+	// The only reasonable error here is LZMA_MEM_ERROR.
+	if (ret != LZMA_OK) {
+		my_errorf("%s", ret == LZMA_MEM_ERROR ? strerror(ENOMEM)
+				: "Internal error (bug)");
+		exit(EXIT_FAILURE);
+	}
+
+	// Input and output buffers
+	uint8_t in_buf[BUFSIZ];
+	uint8_t out_buf[BUFSIZ];
+
+	strm->avail_in = 0;
+	strm->next_out = out_buf;
+	strm->avail_out = BUFSIZ;
+
+	lzma_action action = LZMA_RUN;
+
+	while (true) {
+		if (strm->avail_in == 0) {
+			strm->next_in = in_buf;
+			strm->avail_in = fread(in_buf, 1, BUFSIZ, file);
+
+			if (ferror(file)) {
+				// POSIX says that fread() sets errno if
+				// an error occurred. ferror() doesn't
+				// touch errno.
+				my_errorf("%s: Error reading input file: %s",
+						filename, strerror(errno));
+				exit(EXIT_FAILURE);
+			}
+
+#ifndef LZMADEC
+			// When using LZMA_CONCATENATED, we need to tell
+			// liblzma when it has got all the input.
+			if (feof(file))
+				action = LZMA_FINISH;
+#endif
+		}
+
+		ret = lzma_code(strm, action);
+
+		// Write and check write error before checking decoder error.
+		// This way as much data as possible gets written to output
+		// even if decoder detected an error.
+		if (strm->avail_out == 0 || ret != LZMA_OK) {
+			const size_t write_size = BUFSIZ - strm->avail_out;
+
+			if (fwrite(out_buf, 1, write_size, stdout)
+					!= write_size) {
+				// Wouldn't be a surprise if writing to stderr
+				// would fail too but at least try to show an
+				// error message.
+				my_errorf("Cannot write to standard output: "
+						"%s", strerror(errno));
+				exit(EXIT_FAILURE);
+			}
+
+			strm->next_out = out_buf;
+			strm->avail_out = BUFSIZ;
+		}
+
+		if (ret != LZMA_OK) {
+			if (ret == LZMA_STREAM_END) {
+#ifdef LZMADEC
+				// Check that there's no trailing garbage.
+				if (strm->avail_in != 0
+						|| fread(in_buf, 1, 1, file)
+							!= 0
+						|| !feof(file))
+					ret = LZMA_DATA_ERROR;
+				else
+					return;
+#else
+				// lzma_stream_decoder() already guarantees
+				// that there's no trailing garbage.
+				assert(strm->avail_in == 0);
+				assert(action == LZMA_FINISH);
+				assert(feof(file));
+				return;
+#endif
+			}
+
+			const char *msg;
+			switch (ret) {
+			case LZMA_MEM_ERROR:
+				msg = strerror(ENOMEM);
+				break;
+
+			case LZMA_FORMAT_ERROR:
+				msg = "File format not recognized";
+				break;
+
+			case LZMA_OPTIONS_ERROR:
+				// FIXME: Better message?
+				msg = "Unsupported compression options";
+				break;
+
+			case LZMA_DATA_ERROR:
+				msg = "File is corrupt";
+				break;
+
+			case LZMA_BUF_ERROR:
+				msg = "Unexpected end of input";
+				break;
+
+			default:
+				msg = "Internal error (bug)";
+				break;
+			}
+
+			my_errorf("%s: %s", filename, msg);
+			exit(EXIT_FAILURE);
+		}
+	}
+}
+
+
+int
+main(int argc, char **argv)
+{
+	// Initialize progname which we will be used in error messages.
+	tuklib_progname_init(argv);
+
+	// Parse the command line options.
+	parse_options(argc, argv);
+
+	// The same lzma_stream is used for all files that we decode. This way
+	// we don't need to reallocate memory for every file if they use same
+	// compression settings.
+	lzma_stream strm = LZMA_STREAM_INIT;
+
+	// Some systems require setting stdin and stdout to binary mode.
+#ifdef TUKLIB_DOSLIKE
+	setmode(fileno(stdin), O_BINARY);
+	setmode(fileno(stdout), O_BINARY);
+#endif
+
+	if (optind == argc) {
+		// No filenames given, decode from stdin.
+		uncompress(&strm, stdin, "(stdin)");
+	} else {
+		// Loop through the filenames given on the command line.
+		do {
+			// "-" indicates stdin.
+			if (strcmp(argv[optind], "-") == 0) {
+				uncompress(&strm, stdin, "(stdin)");
+			} else {
+				FILE *file = fopen(argv[optind], "rb");
+				if (file == NULL) {
+					my_errorf("%s: %s", argv[optind],
+							strerror(errno));
+					exit(EXIT_FAILURE);
+				}
+
+				uncompress(&strm, file, argv[optind]);
+				fclose(file);
+			}
+		} while (++optind < argc);
+	}
+
+#ifndef NDEBUG
+	// Free the memory only when debugging. Freeing wastes some time,
+	// but allows detecting possible memory leaks with Valgrind.
+	lzma_end(&strm);
+#endif
+
+	tuklib_exit(EXIT_SUCCESS, EXIT_FAILURE, display_errors);
+}