archive.c - pub/scm/git/git - Git at Google

 #include "cache.h"
 #include "commit.h"
 #include "tree-walk.h"
 #include "attr.h"
 #include "archive.h"
 #include "parse-options.h"
 #include "unpack-trees.h"

 static char const * const archive_usage[] = {
 	"git archive [options] <tree-ish> [<path>...]",
 	"git archive --list",
 	"git archive --remote <repo> [--exec <cmd>] [options] <tree-ish> [<path>...]",
 	"git archive --remote <repo> [--exec <cmd>] --list",
 	NULL
 };

 #define USES_ZLIB_COMPRESSION 1

 static const struct archiver {
 	const char *name;
 	write_archive_fn_t write_archive;
 	unsigned int flags;
 } archivers[] = {
 	{ "tar", write_tar_archive },
 	{ "zip", write_zip_archive, USES_ZLIB_COMPRESSION },
 };

 static void format_subst(const struct commit *commit,
                          const char *src, size_t len,
                          struct strbuf *buf)
 {
 	char *to_free = NULL;
 	struct strbuf fmt = STRBUF_INIT;
 	struct pretty_print_context ctx = {0};
 	ctx.date_mode = DATE_NORMAL;
 	ctx.abbrev = DEFAULT_ABBREV;

 	if (src == buf->buf)
 		to_free = strbuf_detach(buf, NULL);
 	for (;;) {
 		const char *b, *c;

 		b = memmem(src, len, "$Format:", 8);
 		if (!b)
 			break;
 		c = memchr(b + 8, '$', (src + len) - b - 8);
 		if (!c)
 			break;

 		strbuf_reset(&fmt);
 		strbuf_add(&fmt, b + 8, c - b - 8);

 		strbuf_add(buf, src, b - src);
 		format_commit_message(commit, fmt.buf, buf, &ctx);
 		len -= c + 1 - src;
 		src  = c + 1;
 	}
 	strbuf_add(buf, src, len);
 	strbuf_release(&fmt);
 	free(to_free);
 }

 static void *sha1_file_to_archive(const char *path, const unsigned char *sha1,
 		unsigned int mode, enum object_type *type,
 		unsigned long *sizep, const struct commit *commit)
 {
 	void *buffer;

 	buffer = read_sha1_file(sha1, type, sizep);
 	if (buffer && S_ISREG(mode)) {
 		struct strbuf buf = STRBUF_INIT;
 		size_t size = 0;

 		strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
 		convert_to_working_tree(path, buf.buf, buf.len, &buf);
 		if (commit)
 			format_subst(commit, buf.buf, buf.len, &buf);
 		buffer = strbuf_detach(&buf, &size);
 		*sizep = size;
 	}

 	return buffer;
 }

 static void setup_archive_check(struct git_attr_check *check)
 {
 	static struct git_attr *attr_export_ignore;
 	static struct git_attr *attr_export_subst;

 	if (!attr_export_ignore) {
 		attr_export_ignore = git_attr("export-ignore");
 		attr_export_subst = git_attr("export-subst");
 	}
 	check[0].attr = attr_export_ignore;
 	check[1].attr = attr_export_subst;
 }

 struct archiver_context {
 	struct archiver_args *args;
 	write_archive_entry_fn_t write_entry;
 };

 static int write_archive_entry(const unsigned char *sha1, const char *base,
 		int baselen, const char *filename, unsigned mode, int stage,
 		void *context)
 {
 	static struct strbuf path = STRBUF_INIT;
 	struct archiver_context *c = context;
 	struct archiver_args *args = c->args;
 	write_archive_entry_fn_t write_entry = c->write_entry;
 	struct git_attr_check check[2];
 	const char *path_without_prefix;
 	int convert = 0;
 	int err;
 	enum object_type type;
 	unsigned long size;
 	void *buffer;

 	strbuf_reset(&path);
 	strbuf_grow(&path, PATH_MAX);
 	strbuf_add(&path, args->base, args->baselen);
 	strbuf_add(&path, base, baselen);
 	strbuf_addstr(&path, filename);
 	path_without_prefix = path.buf + args->baselen;

 	setup_archive_check(check);
 	if (!git_checkattr(path_without_prefix, ARRAY_SIZE(check), check)) {
 		if (ATTR_TRUE(check[0].value))
 			return 0;
 		convert = ATTR_TRUE(check[1].value);
 	}

 	if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 		strbuf_addch(&path, '/');
 		if (args->verbose)
 			fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
 		err = write_entry(args, sha1, path.buf, path.len, mode, NULL, 0);
 		if (err)
 			return err;
 		return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 	}

 	buffer = sha1_file_to_archive(path_without_prefix, sha1, mode,
 			&type, &size, convert ? args->commit : NULL);
 	if (!buffer)
 		return error("cannot read %s", sha1_to_hex(sha1));
 	if (args->verbose)
 		fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
 	err = write_entry(args, sha1, path.buf, path.len, mode, buffer, size);
 	free(buffer);
 	return err;
 }

 int write_archive_entries(struct archiver_args *args,
 		write_archive_entry_fn_t write_entry)
 {
 	struct archiver_context context;
 	struct unpack_trees_options opts;
 	struct tree_desc t;
 	struct pathspec pathspec;
 	int err;

 	if (args->baselen > 0 && args->base[args->baselen - 1] == '/') {
 		size_t len = args->baselen;

 		while (len > 1 && args->base[len - 2] == '/')
 			len--;
 		if (args->verbose)
 			fprintf(stderr, "%.*s\n", (int)len, args->base);
 		err = write_entry(args, args->tree->object.sha1, args->base,
 				len, 040777, NULL, 0);
 		if (err)
 			return err;
 	}

 	context.args = args;
 	context.write_entry = write_entry;

 	/*
 	 * Setup index and instruct attr to read index only
 	 */
 	if (!args->worktree_attributes) {
 		memset(&opts, 0, sizeof(opts));
 		opts.index_only = 1;
 		opts.head_idx = -1;
 		opts.src_index = &the_index;
 		opts.dst_index = &the_index;
 		opts.fn = oneway_merge;
 		init_tree_desc(&t, args->tree->buffer, args->tree->size);
 		if (unpack_trees(1, &t, &opts))
 			return -1;
 		git_attr_set_direction(GIT_ATTR_INDEX, &the_index);
 	}

 	init_pathspec(&pathspec, args->pathspec);
 	err = read_tree_recursive(args->tree, "", 0, 0, &pathspec,
 				  write_archive_entry, &context);
 	free_pathspec(&pathspec);
 	if (err == READ_TREE_RECURSIVE)
 		err = 0;
 	return err;
 }

 static const struct archiver *lookup_archiver(const char *name)
 {
 	int i;

 	if (!name)
 		return NULL;

 	for (i = 0; i < ARRAY_SIZE(archivers); i++) {
 		if (!strcmp(name, archivers[i].name))
 			return &archivers[i];
 	}
 	return NULL;
 }

 static int reject_entry(const unsigned char *sha1, const char *base,
 			int baselen, const char *filename, unsigned mode,
 			int stage, void *context)
 {
 	return -1;
 }

 static int path_exists(struct tree *tree, const char *path)
 {
 	const char *paths[] = { path, NULL };
 	struct pathspec pathspec;
 	int ret;

 	init_pathspec(&pathspec, paths);
 	ret = read_tree_recursive(tree, "", 0, 0, &pathspec, reject_entry, NULL);
 	free_pathspec(&pathspec);
 	return ret != 0;
 }

 static void parse_pathspec_arg(const char **pathspec,
 		struct archiver_args *ar_args)
 {
 	ar_args->pathspec = pathspec = get_pathspec("", pathspec);
 	if (pathspec) {
 		while (*pathspec) {
 			if (!path_exists(ar_args->tree, *pathspec))
 				die("path not found: %s", *pathspec);
 			pathspec++;
 		}
 	}
 }

 static void parse_treeish_arg(const char **argv,
 		struct archiver_args *ar_args, const char *prefix)
 {
 	const char *name = argv[0];
 	const unsigned char *commit_sha1;
 	time_t archive_time;
 	struct tree *tree;
 	const struct commit *commit;
 	unsigned char sha1[20];

 	if (get_sha1(name, sha1))
 		die("Not a valid object name");

 	commit = lookup_commit_reference_gently(sha1, 1);
 	if (commit) {
 		commit_sha1 = commit->object.sha1;
 		archive_time = commit->date;
 	} else {
 		commit_sha1 = NULL;
 		archive_time = time(NULL);
 	}

 	tree = parse_tree_indirect(sha1);
 	if (tree == NULL)
 		die("not a tree object");

 	if (prefix) {
 		unsigned char tree_sha1[20];
 		unsigned int mode;
 		int err;

 		err = get_tree_entry(tree->object.sha1, prefix,
 				     tree_sha1, &mode);
 		if (err || !S_ISDIR(mode))
 			die("current working directory is untracked");

 		tree = parse_tree_indirect(tree_sha1);
 	}
 	ar_args->tree = tree;
 	ar_args->commit_sha1 = commit_sha1;
 	ar_args->commit = commit;
 	ar_args->time = archive_time;
 }

 #define OPT__COMPR(s, v, h, p) \
 	{ OPTION_SET_INT, (s), NULL, (v), NULL, (h), \
 	  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, (p) }
 #define OPT__COMPR_HIDDEN(s, v, p) \
 	{ OPTION_SET_INT, (s), NULL, (v), NULL, "", \
 	  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_HIDDEN, NULL, (p) }

 static int parse_archive_args(int argc, const char **argv,
 		const struct archiver **ar, struct archiver_args *args)
 {
 	const char *format = "tar";
 	const char *base = NULL;
 	const char *remote = NULL;
 	const char *exec = NULL;
 	const char *output = NULL;
 	int compression_level = -1;
 	int verbose = 0;
 	int i;
 	int list = 0;
 	int worktree_attributes = 0;
 	struct option opts[] = {
 		OPT_GROUP(""),
 		OPT_STRING(0, "format", &format, "fmt", "archive format"),
 		OPT_STRING(0, "prefix", &base, "prefix",
 			"prepend prefix to each pathname in the archive"),
 		OPT_STRING('o', "output", &output, "file",
 			"write the archive to this file"),
 		OPT_BOOLEAN(0, "worktree-attributes", &worktree_attributes,
 			"read .gitattributes in working directory"),
 		OPT__VERBOSE(&verbose, "report archived files on stderr"),
 		OPT__COMPR('0', &compression_level, "store only", 0),
 		OPT__COMPR('1', &compression_level, "compress faster", 1),
 		OPT__COMPR_HIDDEN('2', &compression_level, 2),
 		OPT__COMPR_HIDDEN('3', &compression_level, 3),
 		OPT__COMPR_HIDDEN('4', &compression_level, 4),
 		OPT__COMPR_HIDDEN('5', &compression_level, 5),
 		OPT__COMPR_HIDDEN('6', &compression_level, 6),
 		OPT__COMPR_HIDDEN('7', &compression_level, 7),
 		OPT__COMPR_HIDDEN('8', &compression_level, 8),
 		OPT__COMPR('9', &compression_level, "compress better", 9),
 		OPT_GROUP(""),
 		OPT_BOOLEAN('l', "list", &list,
 			"list supported archive formats"),
 		OPT_GROUP(""),
 		OPT_STRING(0, "remote", &remote, "repo",
 			"retrieve the archive from remote repository <repo>"),
 		OPT_STRING(0, "exec", &exec, "cmd",
 			"path to the remote git-upload-archive command"),
 		OPT_END()
 	};

 	argc = parse_options(argc, argv, NULL, opts, archive_usage, 0);

 	if (remote)
 		die("Unexpected option --remote");
 	if (exec)
 		die("Option --exec can only be used together with --remote");
 	if (output)
 		die("Unexpected option --output");

 	if (!base)
 		base = "";

 	if (list) {
 		for (i = 0; i < ARRAY_SIZE(archivers); i++)
 			printf("%s\n", archivers[i].name);
 		exit(0);
 	}

 	/* We need at least one parameter -- tree-ish */
 	if (argc < 1)
 		usage_with_options(archive_usage, opts);
 	*ar = lookup_archiver(format);
 	if (!*ar)
 		die("Unknown archive format '%s'", format);

 	args->compression_level = Z_DEFAULT_COMPRESSION;
 	if (compression_level != -1) {
 		if ((*ar)->flags & USES_ZLIB_COMPRESSION)
 			args->compression_level = compression_level;
 		else {
 			die("Argument not supported for format '%s': -%d",
 					format, compression_level);
 		}
 	}
 	args->verbose = verbose;
 	args->base = base;
 	args->baselen = strlen(base);
 	args->worktree_attributes = worktree_attributes;

 	return argc;
 }

 int write_archive(int argc, const char **argv, const char *prefix,
 		int setup_prefix)
 {
 	const struct archiver *ar = NULL;
 	struct archiver_args args;

 	argc = parse_archive_args(argc, argv, &ar, &args);
 	if (setup_prefix && prefix == NULL)
 		prefix = setup_git_directory();

 	parse_treeish_arg(argv, &args, prefix);
 	parse_pathspec_arg(argv + 1, &args);

 	git_config(git_default_config, NULL);

 	return ar->write_archive(&args);
 }
	#include "cache.h"
	#include "commit.h"
	#include "tree-walk.h"
	#include "attr.h"
	#include "archive.h"
	#include "parse-options.h"
	#include "unpack-trees.h"

	static char const * const archive_usage[] = {
	"git archive [options] <tree-ish> [<path>...]",
	"git archive --list",
	"git archive --remote <repo> [--exec <cmd>] [options] <tree-ish> [<path>...]",
	"git archive --remote <repo> [--exec <cmd>] --list",
	NULL
	};

	#define USES_ZLIB_COMPRESSION 1

	static const struct archiver {
	const char *name;
	write_archive_fn_t write_archive;
	unsigned int flags;
	} archivers[] = {
	{ "tar", write_tar_archive },
	{ "zip", write_zip_archive, USES_ZLIB_COMPRESSION },
	};

	static void format_subst(const struct commit *commit,
	const char *src, size_t len,
	struct strbuf *buf)
	{
	char *to_free = NULL;
	struct strbuf fmt = STRBUF_INIT;
	struct pretty_print_context ctx = {0};
	ctx.date_mode = DATE_NORMAL;
	ctx.abbrev = DEFAULT_ABBREV;

	if (src == buf->buf)
	to_free = strbuf_detach(buf, NULL);
	for (;;) {
	const char b, c;

	b = memmem(src, len, "$Format:", 8);
	if (!b)
	break;
	c = memchr(b + 8, '$', (src + len) - b - 8);
	if (!c)
	break;

	strbuf_reset(&fmt);
	strbuf_add(&fmt, b + 8, c - b - 8);

	strbuf_add(buf, src, b - src);
	format_commit_message(commit, fmt.buf, buf, &ctx);
	len -= c + 1 - src;
	src = c + 1;
	}
	strbuf_add(buf, src, len);
	strbuf_release(&fmt);
	free(to_free);
	}

	static void sha1_file_to_archive(const char path, const unsigned char *sha1,
	unsigned int mode, enum object_type *type,
	unsigned long sizep, const struct commit commit)
	{
	void *buffer;

	buffer = read_sha1_file(sha1, type, sizep);
	if (buffer && S_ISREG(mode)) {
	struct strbuf buf = STRBUF_INIT;
	size_t size = 0;

	strbuf_attach(&buf, buffer, sizep, sizep + 1);
	convert_to_working_tree(path, buf.buf, buf.len, &buf);
	if (commit)
	format_subst(commit, buf.buf, buf.len, &buf);
	buffer = strbuf_detach(&buf, &size);
	*sizep = size;
	}

	return buffer;
	}

	static void setup_archive_check(struct git_attr_check *check)
	{
	static struct git_attr *attr_export_ignore;
	static struct git_attr *attr_export_subst;

	if (!attr_export_ignore) {
	attr_export_ignore = git_attr("export-ignore");
	attr_export_subst = git_attr("export-subst");
	}
	check[0].attr = attr_export_ignore;
	check[1].attr = attr_export_subst;
	}

	struct archiver_context {
	struct archiver_args *args;
	write_archive_entry_fn_t write_entry;
	};

	static int write_archive_entry(const unsigned char sha1, const char base,
	int baselen, const char *filename, unsigned mode, int stage,
	void *context)
	{
	static struct strbuf path = STRBUF_INIT;
	struct archiver_context *c = context;
	struct archiver_args *args = c->args;
	write_archive_entry_fn_t write_entry = c->write_entry;
	struct git_attr_check check[2];
	const char *path_without_prefix;
	int convert = 0;
	int err;
	enum object_type type;
	unsigned long size;
	void *buffer;

	strbuf_reset(&path);
	strbuf_grow(&path, PATH_MAX);
	strbuf_add(&path, args->base, args->baselen);
	strbuf_add(&path, base, baselen);
	strbuf_addstr(&path, filename);
	path_without_prefix = path.buf + args->baselen;

	setup_archive_check(check);
	if (!git_checkattr(path_without_prefix, ARRAY_SIZE(check), check)) {
	if (ATTR_TRUE(check[0].value))
	return 0;
	convert = ATTR_TRUE(check[1].value);
	}

	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
	strbuf_addch(&path, '/');
	if (args->verbose)
	fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
	err = write_entry(args, sha1, path.buf, path.len, mode, NULL, 0);
	if (err)
	return err;
	return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
	}

	buffer = sha1_file_to_archive(path_without_prefix, sha1, mode,
	&type, &size, convert ? args->commit : NULL);
	if (!buffer)
	return error("cannot read %s", sha1_to_hex(sha1));
	if (args->verbose)
	fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
	err = write_entry(args, sha1, path.buf, path.len, mode, buffer, size);
	free(buffer);
	return err;
	}

	int write_archive_entries(struct archiver_args *args,
	write_archive_entry_fn_t write_entry)
	{
	struct archiver_context context;
	struct unpack_trees_options opts;
	struct tree_desc t;
	struct pathspec pathspec;
	int err;

	if (args->baselen > 0 && args->base[args->baselen - 1] == '/') {
	size_t len = args->baselen;

	while (len > 1 && args->base[len - 2] == '/')
	len--;
	if (args->verbose)
	fprintf(stderr, "%.*s\n", (int)len, args->base);
	err = write_entry(args, args->tree->object.sha1, args->base,
	len, 040777, NULL, 0);
	if (err)
	return err;
	}

	context.args = args;
	context.write_entry = write_entry;

	/*
	* Setup index and instruct attr to read index only
	*/
	if (!args->worktree_attributes) {
	memset(&opts, 0, sizeof(opts));
	opts.index_only = 1;
	opts.head_idx = -1;
	opts.src_index = &the_index;
	opts.dst_index = &the_index;
	opts.fn = oneway_merge;
	init_tree_desc(&t, args->tree->buffer, args->tree->size);
	if (unpack_trees(1, &t, &opts))
	return -1;
	git_attr_set_direction(GIT_ATTR_INDEX, &the_index);
	}

	init_pathspec(&pathspec, args->pathspec);
	err = read_tree_recursive(args->tree, "", 0, 0, &pathspec,
	write_archive_entry, &context);
	free_pathspec(&pathspec);
	if (err == READ_TREE_RECURSIVE)
	err = 0;
	return err;
	}

	static const struct archiver lookup_archiver(const char name)
	{
	int i;

	if (!name)
	return NULL;

	for (i = 0; i < ARRAY_SIZE(archivers); i++) {
	if (!strcmp(name, archivers[i].name))
	return &archivers[i];
	}
	return NULL;
	}

	static int reject_entry(const unsigned char sha1, const char base,
	int baselen, const char *filename, unsigned mode,
	int stage, void *context)
	{
	return -1;
	}

	static int path_exists(struct tree tree, const char path)
	{
	const char *paths[] = { path, NULL };
	struct pathspec pathspec;
	int ret;

	init_pathspec(&pathspec, paths);
	ret = read_tree_recursive(tree, "", 0, 0, &pathspec, reject_entry, NULL);
	free_pathspec(&pathspec);
	return ret != 0;
	}

	static void parse_pathspec_arg(const char **pathspec,
	struct archiver_args *ar_args)
	{
	ar_args->pathspec = pathspec = get_pathspec("", pathspec);
	if (pathspec) {
	while (*pathspec) {
	if (!path_exists(ar_args->tree, *pathspec))
	die("path not found: %s", *pathspec);
	pathspec++;
	}
	}
	}

	static void parse_treeish_arg(const char **argv,
	struct archiver_args ar_args, const char prefix)
	{
	const char *name = argv[0];
	const unsigned char *commit_sha1;
	time_t archive_time;
	struct tree *tree;
	const struct commit *commit;
	unsigned char sha1[20];

	if (get_sha1(name, sha1))
	die("Not a valid object name");

	commit = lookup_commit_reference_gently(sha1, 1);
	if (commit) {
	commit_sha1 = commit->object.sha1;
	archive_time = commit->date;
	} else {
	commit_sha1 = NULL;
	archive_time = time(NULL);
	}

	tree = parse_tree_indirect(sha1);
	if (tree == NULL)
	die("not a tree object");

	if (prefix) {
	unsigned char tree_sha1[20];
	unsigned int mode;
	int err;

	err = get_tree_entry(tree->object.sha1, prefix,
	tree_sha1, &mode);
	if (err \|\| !S_ISDIR(mode))
	die("current working directory is untracked");

	tree = parse_tree_indirect(tree_sha1);
	}
	ar_args->tree = tree;
	ar_args->commit_sha1 = commit_sha1;
	ar_args->commit = commit;
	ar_args->time = archive_time;
	}

	#define OPT__COMPR(s, v, h, p) \
	{ OPTION_SET_INT, (s), NULL, (v), NULL, (h), \
	PARSE_OPT_NOARG \| PARSE_OPT_NONEG, NULL, (p) }
	#define OPT__COMPR_HIDDEN(s, v, p) \
	{ OPTION_SET_INT, (s), NULL, (v), NULL, "", \
	PARSE_OPT_NOARG \| PARSE_OPT_NONEG \| PARSE_OPT_HIDDEN, NULL, (p) }

	static int parse_archive_args(int argc, const char **argv,
	const struct archiver *ar, struct archiver_args args)
	{
	const char *format = "tar";
	const char *base = NULL;
	const char *remote = NULL;
	const char *exec = NULL;
	const char *output = NULL;
	int compression_level = -1;
	int verbose = 0;
	int i;
	int list = 0;
	int worktree_attributes = 0;
	struct option opts[] = {
	OPT_GROUP(""),
	OPT_STRING(0, "format", &format, "fmt", "archive format"),
	OPT_STRING(0, "prefix", &base, "prefix",
	"prepend prefix to each pathname in the archive"),
	OPT_STRING('o', "output", &output, "file",
	"write the archive to this file"),
	OPT_BOOLEAN(0, "worktree-attributes", &worktree_attributes,
	"read .gitattributes in working directory"),
	OPT__VERBOSE(&verbose, "report archived files on stderr"),
	OPT__COMPR('0', &compression_level, "store only", 0),
	OPT__COMPR('1', &compression_level, "compress faster", 1),
	OPT__COMPR_HIDDEN('2', &compression_level, 2),
	OPT__COMPR_HIDDEN('3', &compression_level, 3),
	OPT__COMPR_HIDDEN('4', &compression_level, 4),
	OPT__COMPR_HIDDEN('5', &compression_level, 5),
	OPT__COMPR_HIDDEN('6', &compression_level, 6),
	OPT__COMPR_HIDDEN('7', &compression_level, 7),
	OPT__COMPR_HIDDEN('8', &compression_level, 8),
	OPT__COMPR('9', &compression_level, "compress better", 9),
	OPT_GROUP(""),
	OPT_BOOLEAN('l', "list", &list,
	"list supported archive formats"),
	OPT_GROUP(""),
	OPT_STRING(0, "remote", &remote, "repo",
	"retrieve the archive from remote repository <repo>"),
	OPT_STRING(0, "exec", &exec, "cmd",
	"path to the remote git-upload-archive command"),
	OPT_END()
	};

	argc = parse_options(argc, argv, NULL, opts, archive_usage, 0);

	if (remote)
	die("Unexpected option --remote");
	if (exec)
	die("Option --exec can only be used together with --remote");
	if (output)
	die("Unexpected option --output");

	if (!base)
	base = "";

	if (list) {
	for (i = 0; i < ARRAY_SIZE(archivers); i++)
	printf("%s\n", archivers[i].name);
	exit(0);
	}

	/* We need at least one parameter -- tree-ish */
	if (argc < 1)
	usage_with_options(archive_usage, opts);
	*ar = lookup_archiver(format);
	if (!*ar)
	die("Unknown archive format '%s'", format);

	args->compression_level = Z_DEFAULT_COMPRESSION;
	if (compression_level != -1) {
	if ((*ar)->flags & USES_ZLIB_COMPRESSION)
	args->compression_level = compression_level;
	else {
	die("Argument not supported for format '%s': -%d",
	format, compression_level);
	}
	}
	args->verbose = verbose;
	args->base = base;
	args->baselen = strlen(base);
	args->worktree_attributes = worktree_attributes;

	return argc;
	}

	int write_archive(int argc, const char *argv, const char prefix,
	int setup_prefix)
	{
	const struct archiver *ar = NULL;
	struct archiver_args args;

	argc = parse_archive_args(argc, argv, &ar, &args);
	if (setup_prefix && prefix == NULL)
	prefix = setup_git_directory();

	parse_treeish_arg(argv, &args, prefix);
	parse_pathspec_arg(argv + 1, &args);

	git_config(git_default_config, NULL);

	return ar->write_archive(&args);
	}