src/xz/main.c - xz - Git at Google

 ///////////////////////////////////////////////////////////////////////////////
 //
 /// \file       main.c
 /// \brief      main()
 //
 //  Author:     Lasse Collin
 //
 //  This file has been put into the public domain.
 //  You can do whatever you want with this file.
 //
 ///////////////////////////////////////////////////////////////////////////////

 #include "private.h"
 #include <ctype.h>


 /// Exit status to use. This can be changed with set_exit_status().
 static enum exit_status_type exit_status = E_SUCCESS;

 /// True if --no-warn is specified. When this is true, we don't set
 /// the exit status to E_WARNING when something worth a warning happens.
 static bool no_warn = false;


 extern void
 set_exit_status(enum exit_status_type new_status)
 {
 	assert(new_status == E_WARNING || new_status == E_ERROR);

 	if (exit_status != E_ERROR)
 		exit_status = new_status;

 	return;
 }


 extern void
 set_exit_no_warn(void)
 {
 	no_warn = true;
 	return;
 }


 extern void
 my_exit(enum exit_status_type status)
 {
 	// Close stdout. If something goes wrong, print an error message
 	// to stderr.
 	{
 		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.
 			message(V_ERROR, "%s: %s", _("Writing to standard "
 						"output failed"),
 					fclose_err ? strerror(errno)
 						: _("Unknown error"));
 			status = E_ERROR;
 		}
 	}

 	// Close stderr. If something goes wrong, there's nothing where we
 	// could print an error message. Just set the exit status.
 	{
 		const int ferror_err = ferror(stderr);
 		const int fclose_err = fclose(stderr);
 		if (fclose_err || ferror_err)
 			status = E_ERROR;
 	}

 	// Suppress the exit status indicating a warning if --no-warn
 	// was specified.
 	if (status == E_WARNING && no_warn)
 		status = E_SUCCESS;

 	// If we have got a signal, raise it to kill the program.
 	// Otherwise we just call exit().
 	signals_exit();
 	exit(status);
 }


 static const char *
 read_name(const args_info *args)
 {
 	// FIXME: Maybe we should have some kind of memory usage limit here
 	// like the tool has for the actual compression and uncompression.
 	// Giving some huge text file with --files0 makes us to read the
 	// whole file in RAM.
 	static char *name = NULL;
 	static size_t size = 256;

 	// Allocate the initial buffer. This is never freed, since after it
 	// is no longer needed, the program exits very soon. It is safe to
 	// use xmalloc() and xrealloc() in this function, because while
 	// executing this function, no files are open for writing, and thus
 	// there's no need to cleanup anything before exiting.
 	if (name == NULL)
 		name = xmalloc(size);

 	// Write position in name
 	size_t pos = 0;

 	// Read one character at a time into name.
 	while (!user_abort) {
 		const int c = fgetc(args->files_file);

 		if (ferror(args->files_file)) {
 			// Take care of EINTR since we have established
 			// the signal handlers already.
 			if (errno == EINTR)
 				continue;

 			message_error(_("%s: Error reading filenames: %s"),
 					args->files_name, strerror(errno));
 			return NULL;
 		}

 		if (feof(args->files_file)) {
 			if (pos != 0)
 				message_error(_("%s: Unexpected end of input "
 						"when reading filenames"),
 						args->files_name);

 			return NULL;
 		}

 		if (c == args->files_delim) {
 			// We allow consecutive newline (--files) or '\0'
 			// characters (--files0), and ignore such empty
 			// filenames.
 			if (pos == 0)
 				continue;

 			// A non-empty name was read. Terminate it with '\0'
 			// and return it.
 			name[pos] = '\0';
 			return name;
 		}

 		if (c == '\0') {
 			// A null character was found when using --files,
 			// which expects plain text input separated with
 			// newlines.
 			message_error(_("%s: Null character found when "
 					"reading filenames; maybe you meant "
 					"to use `--files0' instead "
 					"of `--files'?"), args->files_name);
 			return NULL;
 		}

 		name[pos++] = c;

 		// Allocate more memory if needed. There must always be space
 		// at least for one character to allow terminating the string
 		// with '\0'.
 		if (pos == size) {
 			size *= 2;
 			name = xrealloc(name, size);
 		}
 	}

 	return NULL;
 }


 int
 main(int argc, char **argv)
 {
 	// Initialize the file I/O as the very first step. This makes sure
 	// that stdin, stdout, and stderr are something valid.
 	io_init();

 #ifdef DOSLIKE
 	// Adjust argv[0] to make it look nicer in messages, and also to
 	// help the code in args.c.
 	{
 		// Strip the leading path.
 		char *p = argv[0] + strlen(argv[0]);
 		while (argv[0] < p && p[-1] != '/' && p[-1] != '\\')
 			--p;

 		argv[0] = p;

 		// Strip the .exe suffix.
 		p = strrchr(p, '.');
 		if (p != NULL)
 			*p = '\0';

 		// Make it lowercase.
 		for (p = argv[0]; *p != '\0'; ++p)
 			if (*p >= 'A' && *p <= 'Z')
 				*p = *p - 'A' + 'a';
 	}
 #endif

 	// Set up the locale.
 	setlocale(LC_ALL, "");

 #ifdef ENABLE_NLS
 	// Set up the message translations too.
 	bindtextdomain(PACKAGE, LOCALEDIR);
 	textdomain(PACKAGE);
 #endif

 	// Set the program invocation name used in various messages, and
 	// do other message handling related initializations.
 	message_init(argv[0]);

 	// Set hardware-dependent default values. These can be overriden
 	// on the command line, thus this must be done before parse_args().
 	hardware_init();

 	// Parse the command line arguments and get an array of filenames.
 	// This doesn't return if something is wrong with the command line
 	// arguments. If there are no arguments, one filename ("-") is still
 	// returned to indicate stdin.
 	args_info args;
 	args_parse(&args, argc, argv);

 	// Tell the message handling code how many input files there are if
 	// we know it. This way the progress indicator can show it.
 	if (args.files_name != NULL)
 		message_set_files(0);
 	else
 		message_set_files(args.arg_count);

 	// Refuse to write compressed data to standard output if it is
 	// a terminal and --force wasn't used.
 	if (opt_mode == MODE_COMPRESS && !opt_force) {
 		if (opt_stdout || (args.arg_count == 1
 				&& strcmp(args.arg_names[0], "-") == 0)) {
 			if (is_tty_stdout()) {
 				message_try_help();
 				my_exit(E_ERROR);
 			}
 		}
 	}

 	if (opt_mode == MODE_LIST) {
 		message_fatal("--list is not implemented yet.");
 	}

 	// Hook the signal handlers. We don't need these before we start
 	// the actual action, so this is done after parsing the command
 	// line arguments.
 	signals_init();

 	// Process the files given on the command line. Note that if no names
 	// were given, parse_args() gave us a fake "-" filename.
 	for (size_t i = 0; i < args.arg_count && !user_abort; ++i) {
 		if (strcmp("-", args.arg_names[i]) == 0) {
 			// Processing from stdin to stdout. Unless --force
 			// was used, check that we aren't writing compressed
 			// data to a terminal or reading it from terminal.
 			if (!opt_force) {
 				if (opt_mode == MODE_COMPRESS) {
 					if (is_tty_stdout())
 						continue;
 				} else if (is_tty_stdin()) {
 					continue;
 				}
 			}

 			// It doesn't make sense to compress data from stdin
 			// if we are supposed to read filenames from stdin
 			// too (enabled with --files or --files0).
 			if (args.files_name == stdin_filename) {
 				message_error(_("Cannot read data from "
 						"standard input when "
 						"reading filenames "
 						"from standard input"));
 				continue;
 			}

 			// Replace the "-" with a special pointer, which is
 			// recognized by coder_run() and other things.
 			// This way error messages get a proper filename
 			// string and the code still knows that it is
 			// handling the special case of stdin.
 			args.arg_names[i] = (char *)stdin_filename;
 		}

 		// Do the actual compression or uncompression.
 		coder_run(args.arg_names[i]);
 	}

 	// If --files or --files0 was used, process the filenames from the
 	// given file or stdin. Note that here we don't consider "-" to
 	// indicate stdin like we do with the command line arguments.
 	if (args.files_name != NULL) {
 		// read_name() checks for user_abort so we don't need to
 		// check it as loop termination condition.
 		while (true) {
 			const char *name = read_name(&args);
 			if (name == NULL)
 				break;

 			// read_name() doesn't return empty names.
 			assert(name[0] != '\0');
 			coder_run(name);
 		}

 		if (args.files_name != stdin_filename)
 			(void)fclose(args.files_file);
 	}

 	my_exit(exit_status);
 }
	///////////////////////////////////////////////////////////////////////////////
	//
	/// \file main.c
	/// \brief main()
	//
	// Author: Lasse Collin
	//
	// This file has been put into the public domain.
	// You can do whatever you want with this file.
	//
	///////////////////////////////////////////////////////////////////////////////

	#include "private.h"
	#include <ctype.h>


	/// Exit status to use. This can be changed with set_exit_status().
	static enum exit_status_type exit_status = E_SUCCESS;

	/// True if --no-warn is specified. When this is true, we don't set
	/// the exit status to E_WARNING when something worth a warning happens.
	static bool no_warn = false;


	extern void
	set_exit_status(enum exit_status_type new_status)
	{
	assert(new_status == E_WARNING \|\| new_status == E_ERROR);

	if (exit_status != E_ERROR)
	exit_status = new_status;

	return;
	}


	extern void
	set_exit_no_warn(void)
	{
	no_warn = true;
	return;
	}


	extern void
	my_exit(enum exit_status_type status)
	{
	// Close stdout. If something goes wrong, print an error message
	// to stderr.
	{
	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.
	message(V_ERROR, "%s: %s", _("Writing to standard "
	"output failed"),
	fclose_err ? strerror(errno)
	: _("Unknown error"));
	status = E_ERROR;
	}
	}

	// Close stderr. If something goes wrong, there's nothing where we
	// could print an error message. Just set the exit status.
	{
	const int ferror_err = ferror(stderr);
	const int fclose_err = fclose(stderr);
	if (fclose_err \|\| ferror_err)
	status = E_ERROR;
	}

	// Suppress the exit status indicating a warning if --no-warn
	// was specified.
	if (status == E_WARNING && no_warn)
	status = E_SUCCESS;

	// If we have got a signal, raise it to kill the program.
	// Otherwise we just call exit().
	signals_exit();
	exit(status);
	}


	static const char *
	read_name(const args_info *args)
	{
	// FIXME: Maybe we should have some kind of memory usage limit here
	// like the tool has for the actual compression and uncompression.
	// Giving some huge text file with --files0 makes us to read the
	// whole file in RAM.
	static char *name = NULL;
	static size_t size = 256;

	// Allocate the initial buffer. This is never freed, since after it
	// is no longer needed, the program exits very soon. It is safe to
	// use xmalloc() and xrealloc() in this function, because while
	// executing this function, no files are open for writing, and thus
	// there's no need to cleanup anything before exiting.
	if (name == NULL)
	name = xmalloc(size);

	// Write position in name
	size_t pos = 0;

	// Read one character at a time into name.
	while (!user_abort) {
	const int c = fgetc(args->files_file);

	if (ferror(args->files_file)) {
	// Take care of EINTR since we have established
	// the signal handlers already.
	if (errno == EINTR)
	continue;

	message_error(_("%s: Error reading filenames: %s"),
	args->files_name, strerror(errno));
	return NULL;
	}

	if (feof(args->files_file)) {
	if (pos != 0)
	message_error(_("%s: Unexpected end of input "
	"when reading filenames"),
	args->files_name);

	return NULL;
	}

	if (c == args->files_delim) {
	// We allow consecutive newline (--files) or '\0'
	// characters (--files0), and ignore such empty
	// filenames.
	if (pos == 0)
	continue;

	// A non-empty name was read. Terminate it with '\0'
	// and return it.
	name[pos] = '\0';
	return name;
	}

	if (c == '\0') {
	// A null character was found when using --files,
	// which expects plain text input separated with
	// newlines.
	message_error(_("%s: Null character found when "
	"reading filenames; maybe you meant "
	"to use `--files0' instead "
	"of `--files'?"), args->files_name);
	return NULL;
	}

	name[pos++] = c;

	// Allocate more memory if needed. There must always be space
	// at least for one character to allow terminating the string
	// with '\0'.
	if (pos == size) {
	size *= 2;
	name = xrealloc(name, size);
	}
	}

	return NULL;
	}


	int
	main(int argc, char **argv)
	{
	// Initialize the file I/O as the very first step. This makes sure
	// that stdin, stdout, and stderr are something valid.
	io_init();

	#ifdef DOSLIKE
	// Adjust argv[0] to make it look nicer in messages, and also to
	// help the code in args.c.
	{
	// Strip the leading path.
	char *p = argv[0] + strlen(argv[0]);
	while (argv[0] < p && p[-1] != '/' && p[-1] != '\\')
	--p;

	argv[0] = p;

	// Strip the .exe suffix.
	p = strrchr(p, '.');
	if (p != NULL)
	*p = '\0';

	// Make it lowercase.
	for (p = argv[0]; *p != '\0'; ++p)
	if (p >= 'A' && p <= 'Z')
	p = p - 'A' + 'a';
	}
	#endif

	// Set up the locale.
	setlocale(LC_ALL, "");

	#ifdef ENABLE_NLS
	// Set up the message translations too.
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);
	#endif

	// Set the program invocation name used in various messages, and
	// do other message handling related initializations.
	message_init(argv[0]);

	// Set hardware-dependent default values. These can be overriden
	// on the command line, thus this must be done before parse_args().
	hardware_init();

	// Parse the command line arguments and get an array of filenames.
	// This doesn't return if something is wrong with the command line
	// arguments. If there are no arguments, one filename ("-") is still
	// returned to indicate stdin.
	args_info args;
	args_parse(&args, argc, argv);

	// Tell the message handling code how many input files there are if
	// we know it. This way the progress indicator can show it.
	if (args.files_name != NULL)
	message_set_files(0);
	else
	message_set_files(args.arg_count);

	// Refuse to write compressed data to standard output if it is
	// a terminal and --force wasn't used.
	if (opt_mode == MODE_COMPRESS && !opt_force) {
	if (opt_stdout \|\| (args.arg_count == 1
	&& strcmp(args.arg_names[0], "-") == 0)) {
	if (is_tty_stdout()) {
	message_try_help();
	my_exit(E_ERROR);
	}
	}
	}

	if (opt_mode == MODE_LIST) {
	message_fatal("--list is not implemented yet.");
	}

	// Hook the signal handlers. We don't need these before we start
	// the actual action, so this is done after parsing the command
	// line arguments.
	signals_init();

	// Process the files given on the command line. Note that if no names
	// were given, parse_args() gave us a fake "-" filename.
	for (size_t i = 0; i < args.arg_count && !user_abort; ++i) {
	if (strcmp("-", args.arg_names[i]) == 0) {
	// Processing from stdin to stdout. Unless --force
	// was used, check that we aren't writing compressed
	// data to a terminal or reading it from terminal.
	if (!opt_force) {
	if (opt_mode == MODE_COMPRESS) {
	if (is_tty_stdout())
	continue;
	} else if (is_tty_stdin()) {
	continue;
	}
	}

	// It doesn't make sense to compress data from stdin
	// if we are supposed to read filenames from stdin
	// too (enabled with --files or --files0).
	if (args.files_name == stdin_filename) {
	message_error(_("Cannot read data from "
	"standard input when "
	"reading filenames "
	"from standard input"));
	continue;
	}

	// Replace the "-" with a special pointer, which is
	// recognized by coder_run() and other things.
	// This way error messages get a proper filename
	// string and the code still knows that it is
	// handling the special case of stdin.
	args.arg_names[i] = (char *)stdin_filename;
	}

	// Do the actual compression or uncompression.
	coder_run(args.arg_names[i]);
	}

	// If --files or --files0 was used, process the filenames from the
	// given file or stdin. Note that here we don't consider "-" to
	// indicate stdin like we do with the command line arguments.
	if (args.files_name != NULL) {
	// read_name() checks for user_abort so we don't need to
	// check it as loop termination condition.
	while (true) {
	const char *name = read_name(&args);
	if (name == NULL)
	break;

	// read_name() doesn't return empty names.
	assert(name[0] != '\0');
	coder_run(name);
	}

	if (args.files_name != stdin_filename)
	(void)fclose(args.files_file);
	}

	my_exit(exit_status);
	}