summaryrefslogtreecommitdiff
path: root/help.c
blob: ee15955b0bdf665681c3e7762eae4b925bec64eb (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
/*
 * builtin-help.c
 *
 * Builtin help-related commands (help, usage, version)
 */
#include "cache.h"
#include "builtin.h"
#include "exec_cmd.h"
#include "common-cmds.h"
#include "parse-options.h"
#include "run-command.h"

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_MAN,
	HELP_FORMAT_INFO,
	HELP_FORMAT_WEB,
};

static int show_all = 0;
static enum help_format help_format = HELP_FORMAT_MAN;
static struct option builtin_help_options[] = {
	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
	OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
	OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
			HELP_FORMAT_WEB),
	OPT_SET_INT('i', "info", &help_format, "show info page",
			HELP_FORMAT_INFO),
	OPT_END(),
};

static const char * const builtin_help_usage[] = {
	"git help [--all] [--man|--web|--info] [command]",
	NULL
};

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;
	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;
	const char *argv_ec[] = { "emacsclient", "--version", NULL };
	int version;

	/* emacsclient prints its version number on stderr */
	memset(&ec_process, 0, sizeof(ec_process));
	ec_process.argv = argv_ec;
	ec_process.err = -1;
	ec_process.stdout_to_stderr = 1;
	if (start_command(&ec_process)) {
		fprintf(stderr, "Failed to start emacsclient.\n");
		return -1;
	}
	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 (prefixcmp(buffer.buf, "emacsclient")) {
		fprintf(stderr, "Failed to parse emacsclient version.\n");
		strbuf_release(&buffer);
		return -1;
	}

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

	if (version < 22) {
		fprintf(stderr,
			"emacsclient version '%d' too old (< 22).\n",
			version);
		strbuf_release(&buffer);
		return -1;
	}

	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, NULL);
		warning("failed to exec '%s': %s", path, strerror(errno));
	}
}

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) {
			const char *file = strrchr(path, '/');
			if (file && !strcmp(file + 1, "konqueror")) {
				char *new = xstrdup(path);
				char *dest = strrchr(new, '/');

				/* strlen("konqueror") == strlen("kfmclient") */
				strcpy(dest + 1, "kfmclient");
				path = new;
			}
			if (file)
				filename = file;
		} else
			path = "kfmclient";
		strbuf_addf(&man_page, "man:%s(1)", page);
		execlp(path, filename, "newTab", man_page.buf, NULL);
		warning("failed to exec '%s': %s", path, strerror(errno));
	}
}

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

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("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
	warning("failed to exec '%s': %s", cmd, strerror(errno));
}

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

	while (*p)
		p = &((*p)->next);
	*p = xcalloc(1, (sizeof(**p) + len + 1));
	strncpy((*p)->name, name, len);
}

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 = xcalloc(1, sizeof(*new) + len + 1);

	strncpy(new->name, name, len);
	new->info = xstrdup(value);
	new->next = man_viewer_info_list;
	man_viewer_info_list = new;
}

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 = var + 4;
	const char *subkey = strrchr(name, '.');

	if (!subkey)
		return error("Config with no key for man viewer: %s", name);

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

	warning("'%s': unsupported man viewer sub key.", subkey);
	return 0;
}

static int git_help_config(const char *var, const char *value, 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, "man.viewer")) {
		if (!value)
			return config_error_nonbool(var);
		add_man_viewer(value);
		return 0;
	}
	if (!prefixcmp(var, "man."))
		return add_man_viewer_info(var, value);

	return git_default_config(var, value, cb);
}

/* most GUI terminals set COLUMNS (although some don't export it) */
static int term_columns(void)
{
	char *col_string = getenv("COLUMNS");
	int n_cols;

	if (col_string && (n_cols = atoi(col_string)) > 0)
		return n_cols;

#ifdef TIOCGWINSZ
	{
		struct winsize ws;
		if (!ioctl(1, TIOCGWINSZ, &ws)) {
			if (ws.ws_col)
				return ws.ws_col;
		}
	}
#endif

	return 80;
}

static inline void mput_char(char c, unsigned int num)
{
	while(num--)
		putchar(c);
}

static struct cmdnames {
	int alloc;
	int cnt;
	struct cmdname {
		size_t len;
		char name[1];
	} **names;
} main_cmds, other_cmds;

static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
{
	struct cmdname *ent = xmalloc(sizeof(*ent) + len);

	ent->len = len;
	memcpy(ent->name, name, len);
	ent->name[len] = 0;

	ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
	cmds->names[cmds->cnt++] = ent;
}

static int cmdname_compare(const void *a_, const void *b_)
{
	struct cmdname *a = *(struct cmdname **)a_;
	struct cmdname *b = *(struct cmdname **)b_;
	return strcmp(a->name, b->name);
}

static void uniq(struct cmdnames *cmds)
{
	int i, j;

	if (!cmds->cnt)
		return;

	for (i = j = 1; i < cmds->cnt; i++)
		if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
			cmds->names[j++] = cmds->names[i];

	cmds->cnt = j;
}

static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
{
	int ci, cj, ei;
	int cmp;

	ci = cj = ei = 0;
	while (ci < cmds->cnt && ei < excludes->cnt) {
		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
		if (cmp < 0)
			cmds->names[cj++] = cmds->names[ci++];
		else if (cmp == 0)
			ci++, ei++;
		else if (cmp > 0)
			ei++;
	}

	while (ci < cmds->cnt)
		cmds->names[cj++] = cmds->names[ci++];

	cmds->cnt = cj;
}

static void pretty_print_string_list(struct cmdnames *cmds, int longest)
{
	int cols = 1, rows;
	int space = longest + 1; /* min 1 SP between words */
	int max_cols = term_columns() - 1; /* don't print *on* the edge */
	int i, j;

	if (space < max_cols)
		cols = max_cols / space;
	rows = (cmds->cnt + cols - 1) / cols;

	for (i = 0; i < rows; i++) {
		printf("  ");

		for (j = 0; j < cols; j++) {
			int n = j * rows + i;
			int size = space;
			if (n >= cmds->cnt)
				break;
			if (j == cols-1 || n + rows >= cmds->cnt)
				size = 1;
			printf("%-*s", size, cmds->names[n]->name);
		}
		putchar('\n');
	}
}

static int is_executable(const char *name)
{
	struct stat st;

	if (stat(name, &st) || /* stat, not lstat */
	    !S_ISREG(st.st_mode))
		return 0;

#ifdef __MINGW32__
	/* cannot trust the executable bit, peek into the file instead */
	char buf[3] = { 0 };
	int n;
	int fd = open(name, O_RDONLY);
	st.st_mode &= ~S_IXUSR;
	if (fd >= 0) {
		n = read(fd, buf, 2);
		if (n == 2)
			/* DOS executables start with "MZ" */
			if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
				st.st_mode |= S_IXUSR;
		close(fd);
	}
#endif
	return st.st_mode & S_IXUSR;
}

static unsigned int list_commands_in_dir(struct cmdnames *cmds,
					 const char *path)
{
	unsigned int longest = 0;
	const char *prefix = "git-";
	int prefix_len = strlen(prefix);
	DIR *dir = opendir(path);
	struct dirent *de;

	if (!dir || chdir(path))
		return 0;

	while ((de = readdir(dir)) != NULL) {
		int entlen;

		if (prefixcmp(de->d_name, prefix))
			continue;

		if (!is_executable(de->d_name))
			continue;

		entlen = strlen(de->d_name) - prefix_len;
		if (has_extension(de->d_name, ".exe"))
			entlen -= 4;

		if (longest < entlen)
			longest = entlen;

		add_cmdname(cmds, de->d_name + prefix_len, entlen);
	}
	closedir(dir);

	return longest;
}

static unsigned int load_command_list(void)
{
	unsigned int longest = 0;
	unsigned int len;
	const char *env_path = getenv("PATH");
	char *paths, *path, *colon;
	const char *exec_path = git_exec_path();

	if (exec_path)
		longest = list_commands_in_dir(&main_cmds, exec_path);

	if (!env_path) {
		fprintf(stderr, "PATH not set\n");
		exit(1);
	}

	path = paths = xstrdup(env_path);
	while (1) {
		if ((colon = strchr(path, PATH_SEP)))
			*colon = 0;

		len = list_commands_in_dir(&other_cmds, path);
		if (len > longest)
			longest = len;

		if (!colon)
			break;
		path = colon + 1;
	}
	free(paths);

	qsort(main_cmds.names, main_cmds.cnt,
	      sizeof(*main_cmds.names), cmdname_compare);
	uniq(&main_cmds);

	qsort(other_cmds.names, other_cmds.cnt,
	      sizeof(*other_cmds.names), cmdname_compare);
	uniq(&other_cmds);
	exclude_cmds(&other_cmds, &main_cmds);

	return longest;
}

static void list_commands(void)
{
	unsigned int longest = load_command_list();
	const char *exec_path = git_exec_path();

	if (main_cmds.cnt) {
		printf("available git commands in '%s'\n", exec_path);
		printf("----------------------------");
		mput_char('-', strlen(exec_path));
		putchar('\n');
		pretty_print_string_list(&main_cmds, longest);
		putchar('\n');
	}

	if (other_cmds.cnt) {
		printf("git commands available from elsewhere on your $PATH\n");
		printf("---------------------------------------------------\n");
		pretty_print_string_list(&other_cmds, longest);
		putchar('\n');
	}
}

void list_common_cmds_help(void)
{
	int i, longest = 0;

	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
		if (longest < strlen(common_cmds[i].name))
			longest = strlen(common_cmds[i].name);
	}

	puts("The most commonly used git commands are:");
	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
		printf("   %s   ", common_cmds[i].name);
		mput_char(' ', longest - strlen(common_cmds[i].name));
		puts(common_cmds[i].help);
	}
}

static int is_in_cmdlist(struct cmdnames *c, const char *s)
{
	int i;
	for (i = 0; i < c->cnt; i++)
		if (!strcmp(s, c->names[i]->name))
			return 1;
	return 0;
}

static int is_git_command(const char *s)
{
	load_command_list();
	return is_in_cmdlist(&main_cmds, s) ||
		is_in_cmdlist(&other_cmds, s);
}

static const char *prepend(const char *prefix, const char *cmd)
{
	size_t pre_len = strlen(prefix);
	size_t cmd_len = strlen(cmd);
	char *p = xmalloc(pre_len + cmd_len + 1);
	memcpy(p, prefix, pre_len);
	strcpy(p + pre_len, cmd);
	return p;
}

static const char *cmd_to_page(const char *git_cmd)
{
	if (!git_cmd)
		return "git";
	else if (!prefixcmp(git_cmd, "git"))
		return git_cmd;
	else if (is_git_command(git_cmd))
		return prepend("git-", git_cmd);
	else
		return prepend("git", git_cmd);
}

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

	strbuf_init(&new_path, 0);

	/* 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);

	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 *git_cmd)
{
	struct man_viewer_list *viewer;
	const char *page = cmd_to_page(git_cmd);

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

static void show_info_page(const char *git_cmd)
{
	const char *page = cmd_to_page(git_cmd);
	setenv("INFOPATH", GIT_INFO_PATH, 1);
	execlp("info", "info", "gitman", page, NULL);
}

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

	/* Check that we have a git documentation directory. */
	if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
		die("'%s': not a documentation directory.", GIT_HTML_PATH);

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

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

	get_html_page_path(&page_path, page);

	execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
}

void help_unknown_cmd(const char *cmd)
{
	fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
	exit(1);
}

int cmd_version(int argc, const char **argv, const char *prefix)
{
	printf("git version %s\n", git_version_string);
	return 0;
}

int cmd_help(int argc, const char **argv, const char *prefix)
{
	int nongit;
	const char *alias;

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

	argc = parse_options(argc, argv, builtin_help_options,
			builtin_help_usage, 0);

	if (show_all) {
		printf("usage: %s\n\n", git_usage_string);
		list_commands();
		printf("%s\n", git_more_info_string);
		return 0;
	}

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

	alias = alias_lookup(argv[0]);
	if (alias && !is_git_command(argv[0])) {
		printf("`git %s' is aliased to `%s'\n", argv[0], alias);
		return 0;
	}

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

	return 0;
}