Merge branch 'cc/help'
[git/git.git] / help.c
1 /*
2 * builtin-help.c
3 *
4 * Builtin help-related commands (help, usage, version)
5 */
6 #include "cache.h"
7 #include "builtin.h"
8 #include "exec_cmd.h"
9 #include "common-cmds.h"
10 #include "parse-options.h"
11 #include "run-command.h"
12
13 static struct man_viewer_list {
14 struct man_viewer_list *next;
15 char name[FLEX_ARRAY];
16 } *man_viewer_list;
17
18 static struct man_viewer_info_list {
19 struct man_viewer_info_list *next;
20 const char *info;
21 char name[FLEX_ARRAY];
22 } *man_viewer_info_list;
23
24 enum help_format {
25 HELP_FORMAT_MAN,
26 HELP_FORMAT_INFO,
27 HELP_FORMAT_WEB,
28 };
29
30 static int show_all = 0;
31 static enum help_format help_format = HELP_FORMAT_MAN;
32 static struct option builtin_help_options[] = {
33 OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
34 OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
35 OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
36 HELP_FORMAT_WEB),
37 OPT_SET_INT('i', "info", &help_format, "show info page",
38 HELP_FORMAT_INFO),
39 OPT_END(),
40 };
41
42 static const char * const builtin_help_usage[] = {
43 "git-help [--all] [--man|--web|--info] [command]",
44 NULL
45 };
46
47 static enum help_format parse_help_format(const char *format)
48 {
49 if (!strcmp(format, "man"))
50 return HELP_FORMAT_MAN;
51 if (!strcmp(format, "info"))
52 return HELP_FORMAT_INFO;
53 if (!strcmp(format, "web") || !strcmp(format, "html"))
54 return HELP_FORMAT_WEB;
55 die("unrecognized help format '%s'", format);
56 }
57
58 static const char *get_man_viewer_info(const char *name)
59 {
60 struct man_viewer_info_list *viewer;
61
62 for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
63 {
64 if (!strcasecmp(name, viewer->name))
65 return viewer->info;
66 }
67 return NULL;
68 }
69
70 static int check_emacsclient_version(void)
71 {
72 struct strbuf buffer = STRBUF_INIT;
73 struct child_process ec_process;
74 const char *argv_ec[] = { "emacsclient", "--version", NULL };
75 int version;
76
77 /* emacsclient prints its version number on stderr */
78 memset(&ec_process, 0, sizeof(ec_process));
79 ec_process.argv = argv_ec;
80 ec_process.err = -1;
81 ec_process.stdout_to_stderr = 1;
82 if (start_command(&ec_process)) {
83 fprintf(stderr, "Failed to start emacsclient.\n");
84 return -1;
85 }
86 strbuf_read(&buffer, ec_process.err, 20);
87 close(ec_process.err);
88
89 /*
90 * Don't bother checking return value, because "emacsclient --version"
91 * seems to always exits with code 1.
92 */
93 finish_command(&ec_process);
94
95 if (prefixcmp(buffer.buf, "emacsclient")) {
96 fprintf(stderr, "Failed to parse emacsclient version.\n");
97 strbuf_release(&buffer);
98 return -1;
99 }
100
101 strbuf_remove(&buffer, 0, strlen("emacsclient"));
102 version = atoi(buffer.buf);
103
104 if (version < 22) {
105 fprintf(stderr,
106 "emacsclient version '%d' too old (< 22).\n",
107 version);
108 strbuf_release(&buffer);
109 return -1;
110 }
111
112 strbuf_release(&buffer);
113 return 0;
114 }
115
116 static void exec_woman_emacs(const char* path, const char *page)
117 {
118 if (!check_emacsclient_version()) {
119 /* This works only with emacsclient version >= 22. */
120 struct strbuf man_page = STRBUF_INIT;
121
122 if (!path)
123 path = "emacsclient";
124 strbuf_addf(&man_page, "(woman \"%s\")", page);
125 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
126 warning("failed to exec '%s': %s", path, strerror(errno));
127 }
128 }
129
130 static void exec_man_konqueror(const char* path, const char *page)
131 {
132 const char *display = getenv("DISPLAY");
133 if (display && *display) {
134 struct strbuf man_page = STRBUF_INIT;
135 const char *filename = "kfmclient";
136
137 /* It's simpler to launch konqueror using kfmclient. */
138 if (path) {
139 const char *file = strrchr(path, '/');
140 if (file && !strcmp(file + 1, "konqueror")) {
141 char *new = xstrdup(path);
142 char *dest = strrchr(new, '/');
143
144 /* strlen("konqueror") == strlen("kfmclient") */
145 strcpy(dest + 1, "kfmclient");
146 path = new;
147 }
148 if (file)
149 filename = file;
150 } else
151 path = "kfmclient";
152 strbuf_addf(&man_page, "man:%s(1)", page);
153 execlp(path, filename, "newTab", man_page.buf, NULL);
154 warning("failed to exec '%s': %s", path, strerror(errno));
155 }
156 }
157
158 static void exec_man_man(const char* path, const char *page)
159 {
160 if (!path)
161 path = "man";
162 execlp(path, "man", page, NULL);
163 warning("failed to exec '%s': %s", path, strerror(errno));
164 }
165
166 static void exec_man_cmd(const char *cmd, const char *page)
167 {
168 struct strbuf shell_cmd = STRBUF_INIT;
169 strbuf_addf(&shell_cmd, "%s %s", cmd, page);
170 execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
171 warning("failed to exec '%s': %s", cmd, strerror(errno));
172 }
173
174 static void add_man_viewer(const char *name)
175 {
176 struct man_viewer_list **p = &man_viewer_list;
177 size_t len = strlen(name);
178
179 while (*p)
180 p = &((*p)->next);
181 *p = xcalloc(1, (sizeof(**p) + len + 1));
182 strncpy((*p)->name, name, len);
183 }
184
185 static int supported_man_viewer(const char *name, size_t len)
186 {
187 return (!strncasecmp("man", name, len) ||
188 !strncasecmp("woman", name, len) ||
189 !strncasecmp("konqueror", name, len));
190 }
191
192 static void do_add_man_viewer_info(const char *name,
193 size_t len,
194 const char *value)
195 {
196 struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
197
198 strncpy(new->name, name, len);
199 new->info = xstrdup(value);
200 new->next = man_viewer_info_list;
201 man_viewer_info_list = new;
202 }
203
204 static int add_man_viewer_path(const char *name,
205 size_t len,
206 const char *value)
207 {
208 if (supported_man_viewer(name, len))
209 do_add_man_viewer_info(name, len, value);
210 else
211 warning("'%s': path for unsupported man viewer.\n"
212 "Please consider using 'man.<tool>.cmd' instead.",
213 name);
214
215 return 0;
216 }
217
218 static int add_man_viewer_cmd(const char *name,
219 size_t len,
220 const char *value)
221 {
222 if (supported_man_viewer(name, len))
223 warning("'%s': cmd for supported man viewer.\n"
224 "Please consider using 'man.<tool>.path' instead.",
225 name);
226 else
227 do_add_man_viewer_info(name, len, value);
228
229 return 0;
230 }
231
232 static int add_man_viewer_info(const char *var, const char *value)
233 {
234 const char *name = var + 4;
235 const char *subkey = strrchr(name, '.');
236
237 if (!subkey)
238 return error("Config with no key for man viewer: %s", name);
239
240 if (!strcmp(subkey, ".path")) {
241 if (!value)
242 return config_error_nonbool(var);
243 return add_man_viewer_path(name, subkey - name, value);
244 }
245 if (!strcmp(subkey, ".cmd")) {
246 if (!value)
247 return config_error_nonbool(var);
248 return add_man_viewer_cmd(name, subkey - name, value);
249 }
250
251 warning("'%s': unsupported man viewer sub key.", subkey);
252 return 0;
253 }
254
255 static int git_help_config(const char *var, const char *value)
256 {
257 if (!strcmp(var, "help.format")) {
258 if (!value)
259 return config_error_nonbool(var);
260 help_format = parse_help_format(value);
261 return 0;
262 }
263 if (!strcmp(var, "man.viewer")) {
264 if (!value)
265 return config_error_nonbool(var);
266 add_man_viewer(value);
267 return 0;
268 }
269 if (!prefixcmp(var, "man."))
270 return add_man_viewer_info(var, value);
271
272 return git_default_config(var, value);
273 }
274
275 /* most GUI terminals set COLUMNS (although some don't export it) */
276 static int term_columns(void)
277 {
278 char *col_string = getenv("COLUMNS");
279 int n_cols;
280
281 if (col_string && (n_cols = atoi(col_string)) > 0)
282 return n_cols;
283
284 #ifdef TIOCGWINSZ
285 {
286 struct winsize ws;
287 if (!ioctl(1, TIOCGWINSZ, &ws)) {
288 if (ws.ws_col)
289 return ws.ws_col;
290 }
291 }
292 #endif
293
294 return 80;
295 }
296
297 static inline void mput_char(char c, unsigned int num)
298 {
299 while(num--)
300 putchar(c);
301 }
302
303 static struct cmdnames {
304 int alloc;
305 int cnt;
306 struct cmdname {
307 size_t len;
308 char name[1];
309 } **names;
310 } main_cmds, other_cmds;
311
312 static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
313 {
314 struct cmdname *ent = xmalloc(sizeof(*ent) + len);
315
316 ent->len = len;
317 memcpy(ent->name, name, len);
318 ent->name[len] = 0;
319
320 ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
321 cmds->names[cmds->cnt++] = ent;
322 }
323
324 static int cmdname_compare(const void *a_, const void *b_)
325 {
326 struct cmdname *a = *(struct cmdname **)a_;
327 struct cmdname *b = *(struct cmdname **)b_;
328 return strcmp(a->name, b->name);
329 }
330
331 static void uniq(struct cmdnames *cmds)
332 {
333 int i, j;
334
335 if (!cmds->cnt)
336 return;
337
338 for (i = j = 1; i < cmds->cnt; i++)
339 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
340 cmds->names[j++] = cmds->names[i];
341
342 cmds->cnt = j;
343 }
344
345 static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
346 {
347 int ci, cj, ei;
348 int cmp;
349
350 ci = cj = ei = 0;
351 while (ci < cmds->cnt && ei < excludes->cnt) {
352 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
353 if (cmp < 0)
354 cmds->names[cj++] = cmds->names[ci++];
355 else if (cmp == 0)
356 ci++, ei++;
357 else if (cmp > 0)
358 ei++;
359 }
360
361 while (ci < cmds->cnt)
362 cmds->names[cj++] = cmds->names[ci++];
363
364 cmds->cnt = cj;
365 }
366
367 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
368 {
369 int cols = 1, rows;
370 int space = longest + 1; /* min 1 SP between words */
371 int max_cols = term_columns() - 1; /* don't print *on* the edge */
372 int i, j;
373
374 if (space < max_cols)
375 cols = max_cols / space;
376 rows = (cmds->cnt + cols - 1) / cols;
377
378 for (i = 0; i < rows; i++) {
379 printf(" ");
380
381 for (j = 0; j < cols; j++) {
382 int n = j * rows + i;
383 int size = space;
384 if (n >= cmds->cnt)
385 break;
386 if (j == cols-1 || n + rows >= cmds->cnt)
387 size = 1;
388 printf("%-*s", size, cmds->names[n]->name);
389 }
390 putchar('\n');
391 }
392 }
393
394 static unsigned int list_commands_in_dir(struct cmdnames *cmds,
395 const char *path)
396 {
397 unsigned int longest = 0;
398 const char *prefix = "git-";
399 int prefix_len = strlen(prefix);
400 DIR *dir = opendir(path);
401 struct dirent *de;
402
403 if (!dir || chdir(path))
404 return 0;
405
406 while ((de = readdir(dir)) != NULL) {
407 struct stat st;
408 int entlen;
409
410 if (prefixcmp(de->d_name, prefix))
411 continue;
412
413 if (stat(de->d_name, &st) || /* stat, not lstat */
414 !S_ISREG(st.st_mode) ||
415 !(st.st_mode & S_IXUSR))
416 continue;
417
418 entlen = strlen(de->d_name) - prefix_len;
419 if (has_extension(de->d_name, ".exe"))
420 entlen -= 4;
421
422 if (longest < entlen)
423 longest = entlen;
424
425 add_cmdname(cmds, de->d_name + prefix_len, entlen);
426 }
427 closedir(dir);
428
429 return longest;
430 }
431
432 static unsigned int load_command_list(void)
433 {
434 unsigned int longest = 0;
435 unsigned int len;
436 const char *env_path = getenv("PATH");
437 char *paths, *path, *colon;
438 const char *exec_path = git_exec_path();
439
440 if (exec_path)
441 longest = list_commands_in_dir(&main_cmds, exec_path);
442
443 if (!env_path) {
444 fprintf(stderr, "PATH not set\n");
445 exit(1);
446 }
447
448 path = paths = xstrdup(env_path);
449 while (1) {
450 if ((colon = strchr(path, ':')))
451 *colon = 0;
452
453 len = list_commands_in_dir(&other_cmds, path);
454 if (len > longest)
455 longest = len;
456
457 if (!colon)
458 break;
459 path = colon + 1;
460 }
461 free(paths);
462
463 qsort(main_cmds.names, main_cmds.cnt,
464 sizeof(*main_cmds.names), cmdname_compare);
465 uniq(&main_cmds);
466
467 qsort(other_cmds.names, other_cmds.cnt,
468 sizeof(*other_cmds.names), cmdname_compare);
469 uniq(&other_cmds);
470 exclude_cmds(&other_cmds, &main_cmds);
471
472 return longest;
473 }
474
475 static void list_commands(void)
476 {
477 unsigned int longest = load_command_list();
478 const char *exec_path = git_exec_path();
479
480 if (main_cmds.cnt) {
481 printf("available git commands in '%s'\n", exec_path);
482 printf("----------------------------");
483 mput_char('-', strlen(exec_path));
484 putchar('\n');
485 pretty_print_string_list(&main_cmds, longest);
486 putchar('\n');
487 }
488
489 if (other_cmds.cnt) {
490 printf("git commands available from elsewhere on your $PATH\n");
491 printf("---------------------------------------------------\n");
492 pretty_print_string_list(&other_cmds, longest);
493 putchar('\n');
494 }
495 }
496
497 void list_common_cmds_help(void)
498 {
499 int i, longest = 0;
500
501 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
502 if (longest < strlen(common_cmds[i].name))
503 longest = strlen(common_cmds[i].name);
504 }
505
506 puts("The most commonly used git commands are:");
507 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
508 printf(" %s ", common_cmds[i].name);
509 mput_char(' ', longest - strlen(common_cmds[i].name));
510 puts(common_cmds[i].help);
511 }
512 }
513
514 static int is_in_cmdlist(struct cmdnames *c, const char *s)
515 {
516 int i;
517 for (i = 0; i < c->cnt; i++)
518 if (!strcmp(s, c->names[i]->name))
519 return 1;
520 return 0;
521 }
522
523 static int is_git_command(const char *s)
524 {
525 load_command_list();
526 return is_in_cmdlist(&main_cmds, s) ||
527 is_in_cmdlist(&other_cmds, s);
528 }
529
530 static const char *cmd_to_page(const char *git_cmd)
531 {
532 if (!git_cmd)
533 return "git";
534 else if (!prefixcmp(git_cmd, "git"))
535 return git_cmd;
536 else {
537 int page_len = strlen(git_cmd) + 4;
538 char *p = xmalloc(page_len + 1);
539 strcpy(p, "git-");
540 strcpy(p + 4, git_cmd);
541 p[page_len] = 0;
542 return p;
543 }
544 }
545
546 static void setup_man_path(void)
547 {
548 struct strbuf new_path;
549 const char *old_path = getenv("MANPATH");
550
551 strbuf_init(&new_path, 0);
552
553 /* We should always put ':' after our path. If there is no
554 * old_path, the ':' at the end will let 'man' to try
555 * system-wide paths after ours to find the manual page. If
556 * there is old_path, we need ':' as delimiter. */
557 strbuf_addstr(&new_path, GIT_MAN_PATH);
558 strbuf_addch(&new_path, ':');
559 if (old_path)
560 strbuf_addstr(&new_path, old_path);
561
562 setenv("MANPATH", new_path.buf, 1);
563
564 strbuf_release(&new_path);
565 }
566
567 static void exec_viewer(const char *name, const char *page)
568 {
569 const char *info = get_man_viewer_info(name);
570
571 if (!strcasecmp(name, "man"))
572 exec_man_man(info, page);
573 else if (!strcasecmp(name, "woman"))
574 exec_woman_emacs(info, page);
575 else if (!strcasecmp(name, "konqueror"))
576 exec_man_konqueror(info, page);
577 else if (info)
578 exec_man_cmd(info, page);
579 else
580 warning("'%s': unknown man viewer.", name);
581 }
582
583 static void show_man_page(const char *git_cmd)
584 {
585 struct man_viewer_list *viewer;
586 const char *page = cmd_to_page(git_cmd);
587
588 setup_man_path();
589 for (viewer = man_viewer_list; viewer; viewer = viewer->next)
590 {
591 exec_viewer(viewer->name, page); /* will return when unable */
592 }
593 exec_viewer("man", page);
594 die("no man viewer handled the request");
595 }
596
597 static void show_info_page(const char *git_cmd)
598 {
599 const char *page = cmd_to_page(git_cmd);
600 setenv("INFOPATH", GIT_INFO_PATH, 1);
601 execlp("info", "info", "gitman", page, NULL);
602 }
603
604 static void get_html_page_path(struct strbuf *page_path, const char *page)
605 {
606 struct stat st;
607
608 /* Check that we have a git documentation directory. */
609 if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
610 die("'%s': not a documentation directory.", GIT_HTML_PATH);
611
612 strbuf_init(page_path, 0);
613 strbuf_addf(page_path, GIT_HTML_PATH "/%s.html", page);
614 }
615
616 static void show_html_page(const char *git_cmd)
617 {
618 const char *page = cmd_to_page(git_cmd);
619 struct strbuf page_path; /* it leaks but we exec bellow */
620
621 get_html_page_path(&page_path, page);
622
623 execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
624 }
625
626 void help_unknown_cmd(const char *cmd)
627 {
628 fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
629 exit(1);
630 }
631
632 int cmd_version(int argc, const char **argv, const char *prefix)
633 {
634 printf("git version %s\n", git_version_string);
635 return 0;
636 }
637
638 int cmd_help(int argc, const char **argv, const char *prefix)
639 {
640 int nongit;
641 const char *alias;
642
643 setup_git_directory_gently(&nongit);
644 git_config(git_help_config);
645
646 argc = parse_options(argc, argv, builtin_help_options,
647 builtin_help_usage, 0);
648
649 if (show_all) {
650 printf("usage: %s\n\n", git_usage_string);
651 list_commands();
652 return 0;
653 }
654
655 if (!argv[0]) {
656 printf("usage: %s\n\n", git_usage_string);
657 list_common_cmds_help();
658 return 0;
659 }
660
661 alias = alias_lookup(argv[0]);
662 if (alias && !is_git_command(argv[0])) {
663 printf("`git %s' is aliased to `%s'\n", argv[0], alias);
664 return 0;
665 }
666
667 switch (help_format) {
668 case HELP_FORMAT_MAN:
669 show_man_page(argv[0]);
670 break;
671 case HELP_FORMAT_INFO:
672 show_info_page(argv[0]);
673 break;
674 case HELP_FORMAT_WEB:
675 show_html_page(argv[0]);
676 break;
677 }
678
679 return 0;
680 }