summaryrefslogtreecommitdiffstats
path: root/builtin/help.c
blob: dc1fbe2b9862df507dc1e077258d3c44048eebef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
/*
 * Builtin help command
 */
#include "builtin.h"
#include "config.h"
#include "exec-cmd.h"
#include "gettext.h"
#include "pager.h"
#include "parse-options.h"
#include "path.h"
#include "run-command.h"
#include "config-list.h"
#include "help.h"
#include "alias.h"
#include "setup.h"

#ifndef DEFAULT_HELP_FORMAT
#define DEFAULT_HELP_FORMAT "man"
#endif

static struct man_viewer_list {
	struct man_viewer_list *next;
	char name[FLEX_ARRAY];
} *man_viewer_list;

static struct man_viewer_info_list {
	struct man_viewer_info_list *next;
	const char *info;
	char name[FLEX_ARRAY];
} *man_viewer_info_list;

enum help_format {
	HELP_FORMAT_NONE,
	HELP_FORMAT_MAN,
	HELP_FORMAT_INFO,
	HELP_FORMAT_WEB
};

enum show_config_type {
	SHOW_CONFIG_HUMAN,
	SHOW_CONFIG_VARS,
	SHOW_CONFIG_SECTIONS,
};

static enum help_action {
	HELP_ACTION_ALL = 1,
	HELP_ACTION_GUIDES,
	HELP_ACTION_CONFIG,
	HELP_ACTION_USER_INTERFACES,
	HELP_ACTION_DEVELOPER_INTERFACES,
	HELP_ACTION_CONFIG_FOR_COMPLETION,
	HELP_ACTION_CONFIG_SECTIONS_FOR_COMPLETION,
} cmd_mode;

static const char *html_path;
static int verbose = 1;
static enum help_format help_format = HELP_FORMAT_NONE;
static int exclude_guides;
static int show_external_commands = -1;
static int show_aliases = -1;
static struct option builtin_help_options[] = {
	OPT_CMDMODE('a', "all", &cmd_mode, N_("print all available commands"),
		    HELP_ACTION_ALL),
	OPT_BOOL(0, "external-commands", &show_external_commands,
		 N_("show external commands in --all")),
	OPT_BOOL(0, "aliases", &show_aliases, N_("show aliases in --all")),
	OPT_HIDDEN_BOOL(0, "exclude-guides", &exclude_guides, N_("exclude guides")),
	OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
	OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
			HELP_FORMAT_WEB),
	OPT_SET_INT('i', "info", &help_format, N_("show info page"),
			HELP_FORMAT_INFO),
	OPT__VERBOSE(&verbose, N_("print command description")),

	OPT_CMDMODE('g', "guides", &cmd_mode, N_("print list of useful guides"),
		    HELP_ACTION_GUIDES),
	OPT_CMDMODE(0, "user-interfaces", &cmd_mode,
		    N_("print list of user-facing repository, command and file interfaces"),
		    HELP_ACTION_USER_INTERFACES),
	OPT_CMDMODE(0, "developer-interfaces", &cmd_mode,
		    N_("print list of file formats, protocols and other developer interfaces"),
		    HELP_ACTION_DEVELOPER_INTERFACES),
	OPT_CMDMODE('c', "config", &cmd_mode, N_("print all configuration variable names"),
		    HELP_ACTION_CONFIG),
	OPT_CMDMODE_F(0, "config-for-completion", &cmd_mode, "",
		    HELP_ACTION_CONFIG_FOR_COMPLETION, PARSE_OPT_HIDDEN),
	OPT_CMDMODE_F(0, "config-sections-for-completion", &cmd_mode, "",
		    HELP_ACTION_CONFIG_SECTIONS_FOR_COMPLETION, PARSE_OPT_HIDDEN),

	OPT_END(),
};

static const char * const builtin_help_usage[] = {
	"git help [-a|--all] [--[no-]verbose] [--[no-]external-commands] [--[no-]aliases]",
	N_("git help [[-i|--info] [-m|--man] [-w|--web]] [<command>|<doc>]"),
	"git help [-g|--guides]",
	"git help [-c|--config]",
	"git help [--user-interfaces]",
	"git help [--developer-interfaces]",
	NULL
};

struct slot_expansion {
	const char *prefix;
	const char *placeholder;
	void (*fn)(struct string_list *list, const char *prefix);
	int found;
};

static void list_config_help(enum show_config_type type)
{
	struct slot_expansion slot_expansions[] = {
		{ "advice", "*", list_config_advices },
		{ "color.branch", "<slot>", list_config_color_branch_slots },
		{ "color.decorate", "<slot>", list_config_color_decorate_slots },
		{ "color.diff", "<slot>", list_config_color_diff_slots },
		{ "color.grep", "<slot>", list_config_color_grep_slots },
		{ "color.interactive", "<slot>", list_config_color_interactive_slots },
		{ "color.remote", "<slot>", list_config_color_sideband_slots },
		{ "color.status", "<slot>", list_config_color_status_slots },
		{ "fsck", "<msg-id>", list_config_fsck_msg_ids },
		{ "receive.fsck", "<msg-id>", list_config_fsck_msg_ids },
		{ NULL, NULL, NULL }
	};
	const char **p;
	struct slot_expansion *e;
	struct string_list keys = STRING_LIST_INIT_DUP;
	struct string_list keys_uniq = STRING_LIST_INIT_DUP;
	struct string_list_item *item;
	int i;

	for (p = config_name_list; *p; p++) {
		const char *var = *p;
		struct strbuf sb = STRBUF_INIT;

		for (e = slot_expansions; e->prefix; e++) {

			strbuf_reset(&sb);
			strbuf_addf(&sb, "%s.%s", e->prefix, e->placeholder);
			if (!strcasecmp(var, sb.buf)) {
				e->fn(&keys, e->prefix);
				e->found++;
				break;
			}
		}
		strbuf_release(&sb);
		if (!e->prefix)
			string_list_append(&keys, var);
	}

	for (e = slot_expansions; e->prefix; e++)
		if (!e->found)
			BUG("slot_expansion %s.%s is not used",
			    e->prefix, e->placeholder);

	string_list_sort(&keys);
	for (i = 0; i < keys.nr; i++) {
		const char *var = keys.items[i].string;
		const char *wildcard, *tag, *cut;
		const char *dot = NULL;
		struct strbuf sb = STRBUF_INIT;

		switch (type) {
		case SHOW_CONFIG_HUMAN:
			puts(var);
			continue;
		case SHOW_CONFIG_SECTIONS:
			dot = strchr(var, '.');
			break;
		case SHOW_CONFIG_VARS:
			break;
		}
		wildcard = strchr(var, '*');
		tag = strchr(var, '<');

		if (!dot && !wildcard && !tag) {
			string_list_append(&keys_uniq, var);
			continue;
		}

		if (dot)
			cut = dot;
		else if (wildcard && !tag)
			cut = wildcard;
		else if (!wildcard && tag)
			cut = tag;
		else
			cut = wildcard < tag ? wildcard : tag;

		strbuf_add(&sb, var, cut - var);
		string_list_append(&keys_uniq, sb.buf);
		strbuf_release(&sb);

	}
	string_list_clear(&keys, 0);
	string_list_remove_duplicates(&keys_uniq, 0);
	for_each_string_list_item(item, &keys_uniq)
		puts(item->string);
	string_list_clear(&keys_uniq, 0);
}

static enum help_format parse_help_format(const char *format)
{
	if (!strcmp(format, "man"))
		return HELP_FORMAT_MAN;
	if (!strcmp(format, "info"))
		return HELP_FORMAT_INFO;
	if (!strcmp(format, "web") || !strcmp(format, "html"))
		return HELP_FORMAT_WEB;
	/*
	 * Please update _git_config() in git-completion.bash when you
	 * add new help formats.
	 */
	die(_("unrecognized help format '%s'"), format);
}

static const char *get_man_viewer_info(const char *name)
{
	struct man_viewer_info_list *viewer;

	for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
	{
		if (!strcasecmp(name, viewer->name))
			return viewer->info;
	}
	return NULL;
}

static int check_emacsclient_version(void)
{
	struct strbuf buffer = STRBUF_INIT;
	struct child_process ec_process = CHILD_PROCESS_INIT;
	int version;

	/* emacsclient prints its version number on stderr */
	strvec_pushl(&ec_process.args, "emacsclient", "--version", NULL);
	ec_process.err = -1;
	ec_process.stdout_to_stderr = 1;
	if (start_command(&ec_process))
		return error(_("Failed to start emacsclient."));

	strbuf_read(&buffer, ec_process.err, 20);
	close(ec_process.err);

	/*
	 * Don't bother checking return value, because "emacsclient --version"
	 * seems to always exits with code 1.
	 */
	finish_command(&ec_process);

	if (!starts_with(buffer.buf, "emacsclient")) {
		strbuf_release(&buffer);
		return error(_("Failed to parse emacsclient version."));
	}

	strbuf_remove(&buffer, 0, strlen("emacsclient"));
	version = atoi(buffer.buf);

	if (version < 22) {
		strbuf_release(&buffer);
		return error(_("emacsclient version '%d' too old (< 22)."),
			version);
	}

	strbuf_release(&buffer);
	return 0;
}

static void exec_woman_emacs(const char *path, const char *page)
{
	if (!check_emacsclient_version()) {
		/* This works only with emacsclient version >= 22. */
		struct strbuf man_page = STRBUF_INIT;

		if (!path)
			path = "emacsclient";
		strbuf_addf(&man_page, "(woman \"%s\")", page);
		execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
		warning_errno(_("failed to exec '%s'"), path);
		strbuf_release(&man_page);
	}
}

static void exec_man_konqueror(const char *path, const char *page)
{
	const char *display = getenv("DISPLAY");
	if (display && *display) {
		struct strbuf man_page = STRBUF_INIT;
		const char *filename = "kfmclient";

		/* It's simpler to launch konqueror using kfmclient. */
		if (path) {
			size_t len;
			if (strip_suffix(path, "/konqueror", &len))
				path = xstrfmt("%.*s/kfmclient", (int)len, path);
			filename = basename((char *)path);
		} else
			path = "kfmclient";
		strbuf_addf(&man_page, "man:%s(1)", page);
		execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
		warning_errno(_("failed to exec '%s'"), path);
		strbuf_release(&man_page);
	}
}

static void exec_man_man(const char *path, const char *page)
{
	if (!path)
		path = "man";
	execlp(path, "man", page, (char *)NULL);
	warning_errno(_("failed to exec '%s'"), path);
}

static void exec_man_cmd(const char *cmd, const char *page)
{
	struct strbuf shell_cmd = STRBUF_INIT;
	strbuf_addf(&shell_cmd, "%s %s", cmd, page);
	execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
	warning(_("failed to exec '%s'"), cmd);
	strbuf_release(&shell_cmd);
}

static void add_man_viewer(const char *name)
{
	struct man_viewer_list **p = &man_viewer_list;

	while (*p)
		p = &((*p)->next);
	FLEX_ALLOC_STR(*p, name, name);
}

static int supported_man_viewer(const char *name, size_t len)
{
	return (!strncasecmp("man", name, len) ||
		!strncasecmp("woman", name, len) ||
		!strncasecmp("konqueror", name, len));
}

static void do_add_man_viewer_info(const char *name,
				   size_t len,
				   const char *value)
{
	struct man_viewer_info_list *new_man_viewer;
	FLEX_ALLOC_MEM(new_man_viewer, name, name, len);
	new_man_viewer->info = xstrdup(value);
	new_man_viewer->next = man_viewer_info_list;
	man_viewer_info_list = new_man_viewer;
}

static int add_man_viewer_path(const char *name,
			       size_t len,
			       const char *value)
{
	if (supported_man_viewer(name, len))
		do_add_man_viewer_info(name, len, value);
	else
		warning(_("'%s': path for unsupported man viewer.\n"
			  "Please consider using 'man.<tool>.cmd' instead."),
			name);

	return 0;
}

static int add_man_viewer_cmd(const char *name,
			      size_t len,
			      const char *value)
{
	if (supported_man_viewer(name, len))
		warning(_("'%s': cmd for supported man viewer.\n"
			  "Please consider using 'man.<tool>.path' instead."),
			name);
	else
		do_add_man_viewer_info(name, len, value);

	return 0;
}

static int add_man_viewer_info(const char *var, const char *value)
{
	const char *name, *subkey;
	size_t namelen;

	if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
		return 0;

	if (!strcmp(subkey, "path")) {
		if (!value)
			return config_error_nonbool(var);
		return add_man_viewer_path(name, namelen, value);
	}
	if (!strcmp(subkey, "cmd")) {
		if (!value)
			return config_error_nonbool(var);
		return add_man_viewer_cmd(name, namelen, value);
	}

	return 0;
}

static int git_help_config(const char *var, const char *value,
			   const struct config_context *ctx, void *cb)
{
	if (!strcmp(var, "help.format")) {
		if (!value)
			return config_error_nonbool(var);
		help_format = parse_help_format(value);
		return 0;
	}
	if (!strcmp(var, "help.htmlpath")) {
		if (!value)
			return config_error_nonbool(var);
		html_path = xstrdup(value);
		return 0;
	}
	if (!strcmp(var, "man.viewer")) {
		if (!value)
			return config_error_nonbool(var);
		add_man_viewer(value);
		return 0;
	}
	if (starts_with(var, "man."))
		return add_man_viewer_info(var, value);

	return git_default_config(var, value, ctx, cb);
}

static struct cmdnames main_cmds, other_cmds;

static int is_git_command(const char *s)
{
	if (is_builtin(s))
		return 1;

	load_command_list("git-", &main_cmds, &other_cmds);
	return is_in_cmdlist(&main_cmds, s) ||
		is_in_cmdlist(&other_cmds, s);
}

static const char *cmd_to_page(const char *git_cmd)
{
	if (!git_cmd)
		return "git";
	else if (starts_with(git_cmd, "git"))
		return git_cmd;
	else if (is_git_command(git_cmd))
		return xstrfmt("git-%s", git_cmd);
	else if (!strcmp("scalar", git_cmd))
		return xstrdup(git_cmd);
	else
		return xstrfmt("git%s", git_cmd);
}

static void setup_man_path(void)
{
	struct strbuf new_path = STRBUF_INIT;
	const char *old_path = getenv("MANPATH");
	char *git_man_path = system_path(GIT_MAN_PATH);

	/* We should always put ':' after our path. If there is no
	 * old_path, the ':' at the end will let 'man' to try
	 * system-wide paths after ours to find the manual page. If
	 * there is old_path, we need ':' as delimiter. */
	strbuf_addstr(&new_path, git_man_path);
	strbuf_addch(&new_path, ':');
	if (old_path)
		strbuf_addstr(&new_path, old_path);

	free(git_man_path);
	setenv("MANPATH", new_path.buf, 1);

	strbuf_release(&new_path);
}

static void exec_viewer(const char *name, const char *page)
{
	const char *info = get_man_viewer_info(name);

	if (!strcasecmp(name, "man"))
		exec_man_man(info, page);
	else if (!strcasecmp(name, "woman"))
		exec_woman_emacs(info, page);
	else if (!strcasecmp(name, "konqueror"))
		exec_man_konqueror(info, page);
	else if (info)
		exec_man_cmd(info, page);
	else
		warning(_("'%s': unknown man viewer."), name);
}

static void show_man_page(const char *page)
{
	struct man_viewer_list *viewer;
	const char *fallback = getenv("GIT_MAN_VIEWER");

	setup_man_path();
	for (viewer = man_viewer_list; viewer; viewer = viewer->next)
	{
		exec_viewer(viewer->name, page); /* will return when unable */
	}
	if (fallback)
		exec_viewer(fallback, page);
	exec_viewer("man", page);
	die(_("no man viewer handled the request"));
}

static void show_info_page(const char *page)
{
	setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
	execlp("info", "info", "gitman", page, (char *)NULL);
	die(_("no info viewer handled the request"));
}

static void get_html_page_path(struct strbuf *page_path, const char *page)
{
	struct stat st;
	char *to_free = NULL;

	if (!html_path)
		html_path = to_free = system_path(GIT_HTML_PATH);

	/*
	 * Check that the page we're looking for exists.
	 */
	if (!strstr(html_path, "://")) {
		if (stat(mkpath("%s/%s.html", html_path, page), &st)
		    || !S_ISREG(st.st_mode))
			die("'%s/%s.html': documentation file not found.",
				html_path, page);
	}

	strbuf_init(page_path, 0);
	strbuf_addf(page_path, "%s/%s.html", html_path, page);
	free(to_free);
}

static void open_html(const char *path)
{
	execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
}

static void show_html_page(const char *page)
{
	struct strbuf page_path; /* it leaks but we exec bellow */

	get_html_page_path(&page_path, page);

	open_html(page_path.buf);
}

static const char *check_git_cmd(const char* cmd)
{
	char *alias;

	if (is_git_command(cmd))
		return cmd;

	alias = alias_lookup(cmd);
	if (alias) {
		const char **argv;
		int count;

		/*
		 * handle_builtin() in git.c rewrites "git cmd --help"
		 * to "git help --exclude-guides cmd", so we can use
		 * exclude_guides to distinguish "git cmd --help" from
		 * "git help cmd". In the latter case, or if cmd is an
		 * alias for a shell command, just print the alias
		 * definition.
		 */
		if (!exclude_guides || alias[0] == '!') {
			printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
			free(alias);
			exit(0);
		}
		/*
		 * Otherwise, we pretend that the command was "git
		 * word0 --help". We use split_cmdline() to get the
		 * first word of the alias, to ensure that we use the
		 * same rules as when the alias is actually
		 * used. split_cmdline() modifies alias in-place.
		 */
		fprintf_ln(stderr, _("'%s' is aliased to '%s'"), cmd, alias);
		count = split_cmdline(alias, &argv);
		if (count < 0)
			die(_("bad alias.%s string: %s"), cmd,
			    split_cmdline_strerror(count));
		free(argv);
		UNLEAK(alias);
		return alias;
	}

	if (exclude_guides)
		return help_unknown_cmd(cmd);

	return cmd;
}

static void no_help_format(const char *opt_mode, enum help_format fmt)
{
	const char *opt_fmt;

	switch (fmt) {
	case HELP_FORMAT_NONE:
		return;
	case HELP_FORMAT_MAN:
		opt_fmt = "--man";
		break;
	case HELP_FORMAT_INFO:
		opt_fmt = "--info";
		break;
	case HELP_FORMAT_WEB:
		opt_fmt = "--web";
		break;
	default:
		BUG("unreachable");
	}

	usage_msg_optf(_("options '%s' and '%s' cannot be used together"),
		       builtin_help_usage, builtin_help_options, opt_mode,
		       opt_fmt);
}

static void opt_mode_usage(int argc, const char *opt_mode,
			   enum help_format fmt)
{
	if (argc)
		usage_msg_optf(_("the '%s' option doesn't take any non-option arguments"),
			       builtin_help_usage, builtin_help_options,
			       opt_mode);

	no_help_format(opt_mode, fmt);
}

int cmd_help(int argc, const char **argv, const char *prefix)
{
	int nongit;
	enum help_format parsed_help_format;
	const char *page;

	argc = parse_options(argc, argv, prefix, builtin_help_options,
			builtin_help_usage, 0);
	parsed_help_format = help_format;

	if (cmd_mode != HELP_ACTION_ALL &&
	    (show_external_commands >= 0 ||
	     show_aliases >= 0))
		usage_msg_opt(_("the '--no-[external-commands|aliases]' options can only be used with '--all'"),
			      builtin_help_usage, builtin_help_options);

	switch (cmd_mode) {
	case HELP_ACTION_ALL:
		opt_mode_usage(argc, "--all", help_format);
		if (verbose) {
			setup_pager();
			list_all_cmds_help(show_external_commands,
					   show_aliases);
			return 0;
		}
		printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
		load_command_list("git-", &main_cmds, &other_cmds);
		list_commands(&main_cmds, &other_cmds);
		printf("%s\n", _(git_more_info_string));
		break;
	case HELP_ACTION_GUIDES:
		opt_mode_usage(argc, "--guides", help_format);
		list_guides_help();
		printf("%s\n", _(git_more_info_string));
		return 0;
	case HELP_ACTION_CONFIG_FOR_COMPLETION:
		opt_mode_usage(argc, "--config-for-completion", help_format);
		list_config_help(SHOW_CONFIG_VARS);
		return 0;
	case HELP_ACTION_USER_INTERFACES:
		opt_mode_usage(argc, "--user-interfaces", help_format);
		list_user_interfaces_help();
		return 0;
	case HELP_ACTION_DEVELOPER_INTERFACES:
		opt_mode_usage(argc, "--developer-interfaces", help_format);
		list_developer_interfaces_help();
		return 0;
	case HELP_ACTION_CONFIG_SECTIONS_FOR_COMPLETION:
		opt_mode_usage(argc, "--config-sections-for-completion",
			       help_format);
		list_config_help(SHOW_CONFIG_SECTIONS);
		return 0;
	case HELP_ACTION_CONFIG:
		opt_mode_usage(argc, "--config", help_format);
		setup_pager();
		list_config_help(SHOW_CONFIG_HUMAN);
		printf("\n%s\n", _("'git help config' for more information"));
		return 0;
	}

	if (!argv[0]) {
		printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
		list_common_cmds_help();
		printf("\n%s\n", _(git_more_info_string));
		return 0;
	}

	setup_git_directory_gently(&nongit);
	git_config(git_help_config, NULL);

	if (parsed_help_format != HELP_FORMAT_NONE)
		help_format = parsed_help_format;
	if (help_format == HELP_FORMAT_NONE)
		help_format = parse_help_format(DEFAULT_HELP_FORMAT);

	argv[0] = check_git_cmd(argv[0]);

	page = cmd_to_page(argv[0]);
	switch (help_format) {
	case HELP_FORMAT_NONE:
	case HELP_FORMAT_MAN:
		show_man_page(page);
		break;
	case HELP_FORMAT_INFO:
		show_info_page(page);
		break;
	case HELP_FORMAT_WEB:
		show_html_page(page);
		break;
	}

	return 0;
}