Merge branch 'pb/push'
[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 }