[thirdparty/git.git] / archive-zip.c

/*
 * Copyright (c) 2006 Rene Scharfe
 */
#include <time.h>
#include "cache.h"
#include "commit.h"
#include "blob.h"
#include "tree.h"
#include "quote.h"
#include "builtin.h"
#include "archive.h"

static int verbose;
static int zip_date;
static int zip_time;

static unsigned char *zip_dir;
static unsigned int zip_dir_size;

static unsigned int zip_offset;
static unsigned int zip_dir_offset;
static unsigned int zip_dir_entries;

#define ZIP_DIRECTORY_MIN_SIZE	(1024 * 1024)

struct zip_local_header {
	unsigned char magic[4];
	unsigned char version[2];
	unsigned char flags[2];
	unsigned char compression_method[2];
	unsigned char mtime[2];
	unsigned char mdate[2];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char filename_length[2];
	unsigned char extra_length[2];
	unsigned char _end[1];
};

struct zip_dir_header {
	unsigned char magic[4];
	unsigned char creator_version[2];
	unsigned char version[2];
	unsigned char flags[2];
	unsigned char compression_method[2];
	unsigned char mtime[2];
	unsigned char mdate[2];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char filename_length[2];
	unsigned char extra_length[2];
	unsigned char comment_length[2];
	unsigned char disk[2];
	unsigned char attr1[2];
	unsigned char attr2[4];
	unsigned char offset[4];
	unsigned char _end[1];
};

struct zip_dir_trailer {
	unsigned char magic[4];
	unsigned char disk[2];
	unsigned char directory_start_disk[2];
	unsigned char entries_on_this_disk[2];
	unsigned char entries[2];
	unsigned char size[4];
	unsigned char offset[4];
	unsigned char comment_length[2];
	unsigned char _end[1];
};

/*
 * On ARM, padding is added at the end of the struct, so a simple
 * sizeof(struct ...) reports two bytes more than the payload size
 * we're interested in.
 */
#define ZIP_LOCAL_HEADER_SIZE	offsetof(struct zip_local_header, _end)
#define ZIP_DIR_HEADER_SIZE	offsetof(struct zip_dir_header, _end)
#define ZIP_DIR_TRAILER_SIZE	offsetof(struct zip_dir_trailer, _end)

static void copy_le16(unsigned char *dest, unsigned int n)
{
	dest[0] = 0xff & n;
	dest[1] = 0xff & (n >> 010);
}

static void copy_le32(unsigned char *dest, unsigned int n)
{
	dest[0] = 0xff & n;
	dest[1] = 0xff & (n >> 010);
	dest[2] = 0xff & (n >> 020);
	dest[3] = 0xff & (n >> 030);
}

static void *zlib_deflate(void *data, unsigned long size,
                          unsigned long *compressed_size)
{
	z_stream stream;
	unsigned long maxsize;
	void *buffer;
	int result;

	memset(&stream, 0, sizeof(stream));
	deflateInit(&stream, zlib_compression_level);
	maxsize = deflateBound(&stream, size);
	buffer = xmalloc(maxsize);

	stream.next_in = data;
	stream.avail_in = size;
	stream.next_out = buffer;
	stream.avail_out = maxsize;

	do {
		result = deflate(&stream, Z_FINISH);
	} while (result == Z_OK);

	if (result != Z_STREAM_END) {
		free(buffer);
		return NULL;
	}

	deflateEnd(&stream);
	*compressed_size = stream.total_out;

	return buffer;
}

static char *construct_path(const char *base, int baselen,
                            const char *filename, int isdir, int *pathlen)
{
	int filenamelen = strlen(filename);
	int len = baselen + filenamelen;
	char *path, *p;

	if (isdir)
		len++;
	p = path = xmalloc(len + 1);

	memcpy(p, base, baselen);
	p += baselen;
	memcpy(p, filename, filenamelen);
	p += filenamelen;
	if (isdir)
		*p++ = '/';
	*p = '\0';

	*pathlen = len;

	return path;
}

static int write_zip_entry(const unsigned char *sha1,
                           const char *base, int baselen,
                           const char *filename, unsigned mode, int stage)
{
	struct zip_local_header header;
	struct zip_dir_header dirent;
	unsigned long attr2;
	unsigned long compressed_size;
	unsigned long uncompressed_size;
	unsigned long crc;
	unsigned long direntsize;
	unsigned long size;
	int method;
	int result = -1;
	int pathlen;
	unsigned char *out;
	char *path;
	char type[20];
	void *buffer = NULL;
	void *deflated = NULL;

	crc = crc32(0, NULL, 0);

	path = construct_path(base, baselen, filename, S_ISDIR(mode), &pathlen);
	if (verbose)
		fprintf(stderr, "%s\n", path);
	if (pathlen > 0xffff) {
		error("path too long (%d chars, SHA1: %s): %s", pathlen,
		      sha1_to_hex(sha1), path);
		goto out;
	}

	if (S_ISDIR(mode)) {
		method = 0;
		attr2 = 16;
		result = READ_TREE_RECURSIVE;
		out = NULL;
		uncompressed_size = 0;
		compressed_size = 0;
	} else if (S_ISREG(mode) || S_ISLNK(mode)) {
		method = 0;
		attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) : 0;
		if (S_ISREG(mode) && zlib_compression_level != 0)
			method = 8;
		result = 0;
		buffer = read_sha1_file(sha1, type, &size);
		if (!buffer)
			die("cannot read %s", sha1_to_hex(sha1));
		crc = crc32(crc, buffer, size);
		out = buffer;
		uncompressed_size = size;
		compressed_size = size;
	} else {
		error("unsupported file mode: 0%o (SHA1: %s)", mode,
		      sha1_to_hex(sha1));
		goto out;
	}

	if (method == 8) {
		deflated = zlib_deflate(buffer, size, &compressed_size);
		if (deflated && compressed_size - 6 < size) {
			/* ZLIB --> raw compressed data (see RFC 1950) */
			/* CMF and FLG ... */
			out = (unsigned char *)deflated + 2;
			compressed_size -= 6;	/* ... and ADLER32 */
		} else {
			method = 0;
			compressed_size = size;
		}
	}

	/* make sure we have enough free space in the dictionary */
	direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
	while (zip_dir_size < zip_dir_offset + direntsize) {
		zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
		zip_dir = xrealloc(zip_dir, zip_dir_size);
	}

	copy_le32(dirent.magic, 0x02014b50);
	copy_le16(dirent.creator_version, S_ISLNK(mode) ? 0x0317 : 0);
	copy_le16(dirent.version, 10);
	copy_le16(dirent.flags, 0);
	copy_le16(dirent.compression_method, method);
	copy_le16(dirent.mtime, zip_time);
	copy_le16(dirent.mdate, zip_date);
	copy_le32(dirent.crc32, crc);
	copy_le32(dirent.compressed_size, compressed_size);
	copy_le32(dirent.size, uncompressed_size);
	copy_le16(dirent.filename_length, pathlen);
	copy_le16(dirent.extra_length, 0);
	copy_le16(dirent.comment_length, 0);
	copy_le16(dirent.disk, 0);
	copy_le16(dirent.attr1, 0);
	copy_le32(dirent.attr2, attr2);
	copy_le32(dirent.offset, zip_offset);
	memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
	zip_dir_offset += ZIP_DIR_HEADER_SIZE;
	memcpy(zip_dir + zip_dir_offset, path, pathlen);
	zip_dir_offset += pathlen;
	zip_dir_entries++;

	copy_le32(header.magic, 0x04034b50);
	copy_le16(header.version, 10);
	copy_le16(header.flags, 0);
	copy_le16(header.compression_method, method);
	copy_le16(header.mtime, zip_time);
	copy_le16(header.mdate, zip_date);
	copy_le32(header.crc32, crc);
	copy_le32(header.compressed_size, compressed_size);
	copy_le32(header.size, uncompressed_size);
	copy_le16(header.filename_length, pathlen);
	copy_le16(header.extra_length, 0);
	write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
	zip_offset += ZIP_LOCAL_HEADER_SIZE;
	write_or_die(1, path, pathlen);
	zip_offset += pathlen;
	if (compressed_size > 0) {
		write_or_die(1, out, compressed_size);
		zip_offset += compressed_size;
	}

out:
	free(buffer);
	free(deflated);
	free(path);

	return result;
}

static void write_zip_trailer(const unsigned char *sha1)
{
	struct zip_dir_trailer trailer;

	copy_le32(trailer.magic, 0x06054b50);
	copy_le16(trailer.disk, 0);
	copy_le16(trailer.directory_start_disk, 0);
	copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
	copy_le16(trailer.entries, zip_dir_entries);
	copy_le32(trailer.size, zip_dir_offset);
	copy_le32(trailer.offset, zip_offset);
	copy_le16(trailer.comment_length, sha1 ? 40 : 0);

	write_or_die(1, zip_dir, zip_dir_offset);
	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
	if (sha1)
		write_or_die(1, sha1_to_hex(sha1), 40);
}

static void dos_time(time_t *time, int *dos_date, int *dos_time)
{
	struct tm *t = localtime(time);

	*dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
	            (t->tm_year + 1900 - 1980) * 512;
	*dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
}

int write_zip_archive(struct archiver_args *args)
{
	int plen = strlen(args->base);

	dos_time(&args->time, &zip_date, &zip_time);

	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
	verbose = args->verbose;

	if (args->base && plen > 0 && args->base[plen - 1] == '/') {
		char *base = xstrdup(args->base);
		int baselen = strlen(base);

		while (baselen > 0 && base[baselen - 1] == '/')
			base[--baselen] = '\0';
		write_zip_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
		free(base);
	}
	read_tree_recursive(args->tree, args->base, plen, 0,
			    args->pathspec, write_zip_entry);
	write_zip_trailer(args->commit_sha1);

	free(zip_dir);

	return 0;
}

void *parse_extra_zip_args(int argc, const char **argv)
{
	for (; argc > 0; argc--, argv++) {
		const char *arg = argv[0];

		if (arg[0] == '-' && isdigit(arg[1]) && arg[2] == '\0')
			zlib_compression_level = arg[1] - '0';
		else
			die("Unknown argument for zip format: %s", arg);
	}
	return NULL;
}
Commit	Line	Data
e4fbbfe9 RS	1	/*
	2	* Copyright (c) 2006 Rene Scharfe
	3	*/
	4	#include <time.h>
	5	#include "cache.h"
	6	#include "commit.h"
	7	#include "blob.h"
	8	#include "tree.h"
	9	#include "quote.h"
	10	#include "builtin.h"
ec06bff5	11	#include "archive.h"
e4fbbfe9	12
e0ffb248	13	static int verbose;
e4fbbfe9 RS	14	static int zip_date;
	15	static int zip_time;
	16
	17	static unsigned char *zip_dir;
	18	static unsigned int zip_dir_size;
	19
	20	static unsigned int zip_offset;
	21	static unsigned int zip_dir_offset;
	22	static unsigned int zip_dir_entries;
	23
	24	#define ZIP_DIRECTORY_MIN_SIZE (1024 * 1024)
	25
	26	struct zip_local_header {
	27	unsigned char magic[4];
	28	unsigned char version[2];
	29	unsigned char flags[2];
	30	unsigned char compression_method[2];
	31	unsigned char mtime[2];
	32	unsigned char mdate[2];
	33	unsigned char crc32[4];
	34	unsigned char compressed_size[4];
	35	unsigned char size[4];
	36	unsigned char filename_length[2];
	37	unsigned char extra_length[2];
0ea865ce	38	unsigned char _end[1];
e4fbbfe9 RS	39	};
	40
	41	struct zip_dir_header {
	42	unsigned char magic[4];
	43	unsigned char creator_version[2];
	44	unsigned char version[2];
	45	unsigned char flags[2];
	46	unsigned char compression_method[2];
	47	unsigned char mtime[2];
	48	unsigned char mdate[2];
	49	unsigned char crc32[4];
	50	unsigned char compressed_size[4];
	51	unsigned char size[4];
	52	unsigned char filename_length[2];
	53	unsigned char extra_length[2];
	54	unsigned char comment_length[2];
	55	unsigned char disk[2];
	56	unsigned char attr1[2];
	57	unsigned char attr2[4];
	58	unsigned char offset[4];
0ea865ce	59	unsigned char _end[1];
e4fbbfe9 RS	60	};
	61
	62	struct zip_dir_trailer {
	63	unsigned char magic[4];
	64	unsigned char disk[2];
	65	unsigned char directory_start_disk[2];
	66	unsigned char entries_on_this_disk[2];
	67	unsigned char entries[2];
	68	unsigned char size[4];
	69	unsigned char offset[4];
	70	unsigned char comment_length[2];
0ea865ce	71	unsigned char _end[1];
e4fbbfe9 RS	72	};
e4fbbfe9 RS	73
0ea865ce RS	74	/*
	75	* On ARM, padding is added at the end of the struct, so a simple
	76	* sizeof(struct ...) reports two bytes more than the payload size
	77	* we're interested in.
	78	*/
	79	#define ZIP_LOCAL_HEADER_SIZE offsetof(struct zip_local_header, _end)
	80	#define ZIP_DIR_HEADER_SIZE offsetof(struct zip_dir_header, _end)
	81	#define ZIP_DIR_TRAILER_SIZE offsetof(struct zip_dir_trailer, _end)
	82
e4fbbfe9 RS	83	static void copy_le16(unsigned char *dest, unsigned int n)
	84	{
	85	dest[0] = 0xff & n;
	86	dest[1] = 0xff & (n >> 010);
	87	}
	88
	89	static void copy_le32(unsigned char *dest, unsigned int n)
	90	{
	91	dest[0] = 0xff & n;
	92	dest[1] = 0xff & (n >> 010);
	93	dest[2] = 0xff & (n >> 020);
	94	dest[3] = 0xff & (n >> 030);
	95	}
	96
	97	static void zlib_deflate(void data, unsigned long size,
	98	unsigned long *compressed_size)
	99	{
	100	z_stream stream;
	101	unsigned long maxsize;
	102	void *buffer;
	103	int result;
	104
	105	memset(&stream, 0, sizeof(stream));
	106	deflateInit(&stream, zlib_compression_level);
	107	maxsize = deflateBound(&stream, size);
	108	buffer = xmalloc(maxsize);
	109
	110	stream.next_in = data;
	111	stream.avail_in = size;
	112	stream.next_out = buffer;
	113	stream.avail_out = maxsize;
	114
	115	do {
	116	result = deflate(&stream, Z_FINISH);
	117	} while (result == Z_OK);
	118
	119	if (result != Z_STREAM_END) {
	120	free(buffer);
	121	return NULL;
	122	}
	123
	124	deflateEnd(&stream);
	125	*compressed_size = stream.total_out;
	126
	127	return buffer;
	128	}
	129
	130	static char construct_path(const char base, int baselen,
	131	const char filename, int isdir, int pathlen)
	132	{
	133	int filenamelen = strlen(filename);
	134	int len = baselen + filenamelen;
	135	char path, p;
	136
	137	if (isdir)
	138	len++;
	139	p = path = xmalloc(len + 1);
	140
	141	memcpy(p, base, baselen);
	142	p += baselen;
	143	memcpy(p, filename, filenamelen);
	144	p += filenamelen;
	145	if (isdir)
	146	*p++ = '/';
147	*p = '\0';
148
149	*pathlen = len;
150
151	return path;
152	}
153
154	static int write_zip_entry(const unsigned char *sha1,
155	const char *base, int baselen,
156	const char *filename, unsigned mode, int stage)
157	{
158	struct zip_local_header header;
159	struct zip_dir_header dirent;
62cdce17	160	unsigned long attr2;
e4fbbfe9 RS	161	unsigned long compressed_size;
	162	unsigned long uncompressed_size;
	163	unsigned long crc;
	164	unsigned long direntsize;
	165	unsigned long size;
	166	int method;
	167	int result = -1;
	168	int pathlen;
	169	unsigned char *out;
	170	char *path;
	171	char type[20];
	172	void *buffer = NULL;
	173	void *deflated = NULL;
	174
38f4d138	175	crc = crc32(0, NULL, 0);
e4fbbfe9 RS	176
e4fbbfe9 RS	177	path = construct_path(base, baselen, filename, S_ISDIR(mode), &pathlen);
e0ffb248 JH	178	if (verbose)
e0ffb248 JH	179	fprintf(stderr, "%s\n", path);
e4fbbfe9 RS	180	if (pathlen > 0xffff) {
	181	error("path too long (%d chars, SHA1: %s): %s", pathlen,
	182	sha1_to_hex(sha1), path);
	183	goto out;
	184	}
	185
	186	if (S_ISDIR(mode)) {
	187	method = 0;
62cdce17	188	attr2 = 16;
e4fbbfe9 RS	189	result = READ_TREE_RECURSIVE;
	190	out = NULL;
	191	uncompressed_size = 0;
	192	compressed_size = 0;
62cdce17 RS	193	} else if (S_ISREG(mode) \|\| S_ISLNK(mode)) {
	194	method = 0;
	195	attr2 = S_ISLNK(mode) ? ((mode \| 0777) << 16) : 0;
	196	if (S_ISREG(mode) && zlib_compression_level != 0)
	197	method = 8;
e4fbbfe9 RS	198	result = 0;
	199	buffer = read_sha1_file(sha1, type, &size);
	200	if (!buffer)
	201	die("cannot read %s", sha1_to_hex(sha1));
	202	crc = crc32(crc, buffer, size);
	203	out = buffer;
	204	uncompressed_size = size;
	205	compressed_size = size;
	206	} else {
	207	error("unsupported file mode: 0%o (SHA1: %s)", mode,
	208	sha1_to_hex(sha1));
	209	goto out;
	210	}
	211
	212	if (method == 8) {
	213	deflated = zlib_deflate(buffer, size, &compressed_size);
	214	if (deflated && compressed_size - 6 < size) {
	215	/* ZLIB --> raw compressed data (see RFC 1950) */
	216	/* CMF and FLG ... */
	217	out = (unsigned char *)deflated + 2;
	218	compressed_size -= 6; /* ... and ADLER32 */
	219	} else {
	220	method = 0;
	221	compressed_size = size;
	222	}
	223	}
	224
	225	/* make sure we have enough free space in the dictionary */
0ea865ce	226	direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
e4fbbfe9 RS	227	while (zip_dir_size < zip_dir_offset + direntsize) {
	228	zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
	229	zip_dir = xrealloc(zip_dir, zip_dir_size);
	230	}
	231
	232	copy_le32(dirent.magic, 0x02014b50);
62cdce17	233	copy_le16(dirent.creator_version, S_ISLNK(mode) ? 0x0317 : 0);
cf72fb07	234	copy_le16(dirent.version, 10);
e4fbbfe9 RS	235	copy_le16(dirent.flags, 0);
	236	copy_le16(dirent.compression_method, method);
	237	copy_le16(dirent.mtime, zip_time);
	238	copy_le16(dirent.mdate, zip_date);
	239	copy_le32(dirent.crc32, crc);
	240	copy_le32(dirent.compressed_size, compressed_size);
	241	copy_le32(dirent.size, uncompressed_size);
	242	copy_le16(dirent.filename_length, pathlen);
	243	copy_le16(dirent.extra_length, 0);
	244	copy_le16(dirent.comment_length, 0);
	245	copy_le16(dirent.disk, 0);
	246	copy_le16(dirent.attr1, 0);
62cdce17	247	copy_le32(dirent.attr2, attr2);
e4fbbfe9	248	copy_le32(dirent.offset, zip_offset);
0ea865ce RS	249	memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
0ea865ce RS	250	zip_dir_offset += ZIP_DIR_HEADER_SIZE;
e4fbbfe9 RS	251	memcpy(zip_dir + zip_dir_offset, path, pathlen);
	252	zip_dir_offset += pathlen;
	253	zip_dir_entries++;
	254
	255	copy_le32(header.magic, 0x04034b50);
cf72fb07	256	copy_le16(header.version, 10);
e4fbbfe9 RS	257	copy_le16(header.flags, 0);
	258	copy_le16(header.compression_method, method);
	259	copy_le16(header.mtime, zip_time);
	260	copy_le16(header.mdate, zip_date);
	261	copy_le32(header.crc32, crc);
	262	copy_le32(header.compressed_size, compressed_size);
	263	copy_le32(header.size, uncompressed_size);
	264	copy_le16(header.filename_length, pathlen);
	265	copy_le16(header.extra_length, 0);
0ea865ce RS	266	write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
0ea865ce RS	267	zip_offset += ZIP_LOCAL_HEADER_SIZE;
e4fbbfe9 RS	268	write_or_die(1, path, pathlen);
	269	zip_offset += pathlen;
	270	if (compressed_size > 0) {
	271	write_or_die(1, out, compressed_size);
	272	zip_offset += compressed_size;
	273	}
	274
	275	out:
	276	free(buffer);
	277	free(deflated);
	278	free(path);
	279
	280	return result;
	281	}
	282
	283	static void write_zip_trailer(const unsigned char *sha1)
	284	{
	285	struct zip_dir_trailer trailer;
	286
	287	copy_le32(trailer.magic, 0x06054b50);
	288	copy_le16(trailer.disk, 0);
	289	copy_le16(trailer.directory_start_disk, 0);
	290	copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
	291	copy_le16(trailer.entries, zip_dir_entries);
	292	copy_le32(trailer.size, zip_dir_offset);
	293	copy_le32(trailer.offset, zip_offset);
	294	copy_le16(trailer.comment_length, sha1 ? 40 : 0);
	295
	296	write_or_die(1, zip_dir, zip_dir_offset);
0ea865ce	297	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
e4fbbfe9 RS	298	if (sha1)
	299	write_or_die(1, sha1_to_hex(sha1), 40);
	300	}
	301
	302	static void dos_time(time_t time, int dos_date, int *dos_time)
	303	{
	304	struct tm *t = localtime(time);
	305
	306	dos_date = t->tm_mday + (t->tm_mon + 1) 32 +
	307	(t->tm_year + 1900 - 1980) * 512;
	308	dos_time = t->tm_sec / 2 + t->tm_min 32 + t->tm_hour * 2048;
	309	}
	310
ec06bff5 FBH	311	int write_zip_archive(struct archiver_args *args)
	312	{
	313	int plen = strlen(args->base);
	314
	315	dos_time(&args->time, &zip_date, &zip_time);
	316
	317	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
	318	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
e0ffb248	319	verbose = args->verbose;
ec06bff5 FBH	320
ec06bff5 FBH	321	if (args->base && plen > 0 && args->base[plen - 1] == '/') {
326711c1	322	char *base = xstrdup(args->base);
ec06bff5 FBH	323	int baselen = strlen(base);
	324
	325	while (baselen > 0 && base[baselen - 1] == '/')
	326	base[--baselen] = '\0';
	327	write_zip_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
	328	free(base);
	329	}
	330	read_tree_recursive(args->tree, args->base, plen, 0,
	331	args->pathspec, write_zip_entry);
	332	write_zip_trailer(args->commit_sha1);
	333
	334	free(zip_dir);
	335
	336	return 0;
	337	}
854c4168 RS	338
	339	void parse_extra_zip_args(int argc, const char *argv)
	340	{
	341	for (; argc > 0; argc--, argv++) {
	342	const char *arg = argv[0];
	343
	344	if (arg[0] == '-' && isdigit(arg[1]) && arg[2] == '\0')
	345	zlib_compression_level = arg[1] - '0';
	346	else
	347	die("Unknown argument for zip format: %s", arg);
	348	}
	349	return NULL;
	350	}