Merge branch 'ms/non-ascii-ticks'
[git] / builtin / help.c
1 /*
2  * Builtin help command
3  */
4 #include "cache.h"
5 #include "config.h"
6 #include "builtin.h"
7 #include "exec_cmd.h"
8 #include "parse-options.h"
9 #include "run-command.h"
10 #include "column.h"
11 #include "help.h"
12
13 #ifndef DEFAULT_HELP_FORMAT
14 #define DEFAULT_HELP_FORMAT "man"
15 #endif
16
17 static struct man_viewer_list {
18         struct man_viewer_list *next;
19         char name[FLEX_ARRAY];
20 } *man_viewer_list;
21
22 static struct man_viewer_info_list {
23         struct man_viewer_info_list *next;
24         const char *info;
25         char name[FLEX_ARRAY];
26 } *man_viewer_info_list;
27
28 enum help_format {
29         HELP_FORMAT_NONE,
30         HELP_FORMAT_MAN,
31         HELP_FORMAT_INFO,
32         HELP_FORMAT_WEB
33 };
34
35 static const char *html_path;
36
37 static int show_all = 0;
38 static int show_guides = 0;
39 static unsigned int colopts;
40 static enum help_format help_format = HELP_FORMAT_NONE;
41 static int exclude_guides;
42 static struct option builtin_help_options[] = {
43         OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
44         OPT_HIDDEN_BOOL(0, "exclude-guides", &exclude_guides, N_("exclude guides")),
45         OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
46         OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
47         OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
48                         HELP_FORMAT_WEB),
49         OPT_SET_INT('i', "info", &help_format, N_("show info page"),
50                         HELP_FORMAT_INFO),
51         OPT_END(),
52 };
53
54 static const char * const builtin_help_usage[] = {
55         N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
56         NULL
57 };
58
59 static enum help_format parse_help_format(const char *format)
60 {
61         if (!strcmp(format, "man"))
62                 return HELP_FORMAT_MAN;
63         if (!strcmp(format, "info"))
64                 return HELP_FORMAT_INFO;
65         if (!strcmp(format, "web") || !strcmp(format, "html"))
66                 return HELP_FORMAT_WEB;
67         die(_("unrecognized help format '%s'"), format);
68 }
69
70 static const char *get_man_viewer_info(const char *name)
71 {
72         struct man_viewer_info_list *viewer;
73
74         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
75         {
76                 if (!strcasecmp(name, viewer->name))
77                         return viewer->info;
78         }
79         return NULL;
80 }
81
82 static int check_emacsclient_version(void)
83 {
84         struct strbuf buffer = STRBUF_INIT;
85         struct child_process ec_process = CHILD_PROCESS_INIT;
86         const char *argv_ec[] = { "emacsclient", "--version", NULL };
87         int version;
88
89         /* emacsclient prints its version number on stderr */
90         ec_process.argv = argv_ec;
91         ec_process.err = -1;
92         ec_process.stdout_to_stderr = 1;
93         if (start_command(&ec_process))
94                 return error(_("Failed to start emacsclient."));
95
96         strbuf_read(&buffer, ec_process.err, 20);
97         close(ec_process.err);
98
99         /*
100          * Don't bother checking return value, because "emacsclient --version"
101          * seems to always exits with code 1.
102          */
103         finish_command(&ec_process);
104
105         if (!starts_with(buffer.buf, "emacsclient")) {
106                 strbuf_release(&buffer);
107                 return error(_("Failed to parse emacsclient version."));
108         }
109
110         strbuf_remove(&buffer, 0, strlen("emacsclient"));
111         version = atoi(buffer.buf);
112
113         if (version < 22) {
114                 strbuf_release(&buffer);
115                 return error(_("emacsclient version '%d' too old (< 22)."),
116                         version);
117         }
118
119         strbuf_release(&buffer);
120         return 0;
121 }
122
123 static void exec_woman_emacs(const char *path, const char *page)
124 {
125         if (!check_emacsclient_version()) {
126                 /* This works only with emacsclient version >= 22. */
127                 struct strbuf man_page = STRBUF_INIT;
128
129                 if (!path)
130                         path = "emacsclient";
131                 strbuf_addf(&man_page, "(woman \"%s\")", page);
132                 execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
133                 warning_errno(_("failed to exec '%s'"), path);
134                 strbuf_release(&man_page);
135         }
136 }
137
138 static void exec_man_konqueror(const char *path, const char *page)
139 {
140         const char *display = getenv("DISPLAY");
141         if (display && *display) {
142                 struct strbuf man_page = STRBUF_INIT;
143                 const char *filename = "kfmclient";
144
145                 /* It's simpler to launch konqueror using kfmclient. */
146                 if (path) {
147                         size_t len;
148                         if (strip_suffix(path, "/konqueror", &len))
149                                 path = xstrfmt("%.*s/kfmclient", (int)len, path);
150                         filename = basename((char *)path);
151                 } else
152                         path = "kfmclient";
153                 strbuf_addf(&man_page, "man:%s(1)", page);
154                 execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
155                 warning_errno(_("failed to exec '%s'"), path);
156                 strbuf_release(&man_page);
157         }
158 }
159
160 static void exec_man_man(const char *path, const char *page)
161 {
162         if (!path)
163                 path = "man";
164         execlp(path, "man", page, (char *)NULL);
165         warning_errno(_("failed to exec '%s'"), path);
166 }
167
168 static void exec_man_cmd(const char *cmd, const char *page)
169 {
170         struct strbuf shell_cmd = STRBUF_INIT;
171         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
172         execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
173         warning(_("failed to exec '%s'"), cmd);
174         strbuf_release(&shell_cmd);
175 }
176
177 static void add_man_viewer(const char *name)
178 {
179         struct man_viewer_list **p = &man_viewer_list;
180
181         while (*p)
182                 p = &((*p)->next);
183         FLEX_ALLOC_STR(*p, name, name);
184 }
185
186 static int supported_man_viewer(const char *name, size_t len)
187 {
188         return (!strncasecmp("man", name, len) ||
189                 !strncasecmp("woman", name, len) ||
190                 !strncasecmp("konqueror", name, len));
191 }
192
193 static void do_add_man_viewer_info(const char *name,
194                                    size_t len,
195                                    const char *value)
196 {
197         struct man_viewer_info_list *new;
198         FLEX_ALLOC_MEM(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, *subkey;
235         int namelen;
236
237         if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
238                 return 0;
239
240         if (!strcmp(subkey, "path")) {
241                 if (!value)
242                         return config_error_nonbool(var);
243                 return add_man_viewer_path(name, namelen, value);
244         }
245         if (!strcmp(subkey, "cmd")) {
246                 if (!value)
247                         return config_error_nonbool(var);
248                 return add_man_viewer_cmd(name, namelen, value);
249         }
250
251         return 0;
252 }
253
254 static int git_help_config(const char *var, const char *value, void *cb)
255 {
256         if (starts_with(var, "column."))
257                 return git_column_config(var, value, "help", &colopts);
258         if (!strcmp(var, "help.format")) {
259                 if (!value)
260                         return config_error_nonbool(var);
261                 help_format = parse_help_format(value);
262                 return 0;
263         }
264         if (!strcmp(var, "help.htmlpath")) {
265                 if (!value)
266                         return config_error_nonbool(var);
267                 html_path = xstrdup(value);
268                 return 0;
269         }
270         if (!strcmp(var, "man.viewer")) {
271                 if (!value)
272                         return config_error_nonbool(var);
273                 add_man_viewer(value);
274                 return 0;
275         }
276         if (starts_with(var, "man."))
277                 return add_man_viewer_info(var, value);
278
279         return git_default_config(var, value, cb);
280 }
281
282 static struct cmdnames main_cmds, other_cmds;
283
284 static int is_git_command(const char *s)
285 {
286         if (is_builtin(s))
287                 return 1;
288
289         load_command_list("git-", &main_cmds, &other_cmds);
290         return is_in_cmdlist(&main_cmds, s) ||
291                 is_in_cmdlist(&other_cmds, s);
292 }
293
294 static const char *cmd_to_page(const char *git_cmd)
295 {
296         if (!git_cmd)
297                 return "git";
298         else if (starts_with(git_cmd, "git"))
299                 return git_cmd;
300         else if (is_git_command(git_cmd))
301                 return xstrfmt("git-%s", git_cmd);
302         else
303                 return xstrfmt("git%s", git_cmd);
304 }
305
306 static void setup_man_path(void)
307 {
308         struct strbuf new_path = STRBUF_INIT;
309         const char *old_path = getenv("MANPATH");
310         char *git_man_path = system_path(GIT_MAN_PATH);
311
312         /* We should always put ':' after our path. If there is no
313          * old_path, the ':' at the end will let 'man' to try
314          * system-wide paths after ours to find the manual page. If
315          * there is old_path, we need ':' as delimiter. */
316         strbuf_addstr(&new_path, git_man_path);
317         strbuf_addch(&new_path, ':');
318         if (old_path)
319                 strbuf_addstr(&new_path, old_path);
320
321         free(git_man_path);
322         setenv("MANPATH", new_path.buf, 1);
323
324         strbuf_release(&new_path);
325 }
326
327 static void exec_viewer(const char *name, const char *page)
328 {
329         const char *info = get_man_viewer_info(name);
330
331         if (!strcasecmp(name, "man"))
332                 exec_man_man(info, page);
333         else if (!strcasecmp(name, "woman"))
334                 exec_woman_emacs(info, page);
335         else if (!strcasecmp(name, "konqueror"))
336                 exec_man_konqueror(info, page);
337         else if (info)
338                 exec_man_cmd(info, page);
339         else
340                 warning(_("'%s': unknown man viewer."), name);
341 }
342
343 static void show_man_page(const char *git_cmd)
344 {
345         struct man_viewer_list *viewer;
346         const char *page = cmd_to_page(git_cmd);
347         const char *fallback = getenv("GIT_MAN_VIEWER");
348
349         setup_man_path();
350         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
351         {
352                 exec_viewer(viewer->name, page); /* will return when unable */
353         }
354         if (fallback)
355                 exec_viewer(fallback, page);
356         exec_viewer("man", page);
357         die(_("no man viewer handled the request"));
358 }
359
360 static void show_info_page(const char *git_cmd)
361 {
362         const char *page = cmd_to_page(git_cmd);
363         setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
364         execlp("info", "info", "gitman", page, (char *)NULL);
365         die(_("no info viewer handled the request"));
366 }
367
368 static void get_html_page_path(struct strbuf *page_path, const char *page)
369 {
370         struct stat st;
371         char *to_free = NULL;
372
373         if (!html_path)
374                 html_path = to_free = system_path(GIT_HTML_PATH);
375
376         /* Check that we have a git documentation directory. */
377         if (!strstr(html_path, "://")) {
378                 if (stat(mkpath("%s/git.html", html_path), &st)
379                     || !S_ISREG(st.st_mode))
380                         die("'%s': not a documentation directory.", html_path);
381         }
382
383         strbuf_init(page_path, 0);
384         strbuf_addf(page_path, "%s/%s.html", html_path, page);
385         free(to_free);
386 }
387
388 static void open_html(const char *path)
389 {
390         execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
391 }
392
393 static void show_html_page(const char *git_cmd)
394 {
395         const char *page = cmd_to_page(git_cmd);
396         struct strbuf page_path; /* it leaks but we exec bellow */
397
398         get_html_page_path(&page_path, page);
399
400         open_html(page_path.buf);
401 }
402
403 static struct {
404         const char *name;
405         const char *help;
406 } common_guides[] = {
407         { "attributes", N_("Defining attributes per path") },
408         { "everyday", N_("Everyday Git With 20 Commands Or So") },
409         { "glossary", N_("A Git glossary") },
410         { "ignore", N_("Specifies intentionally untracked files to ignore") },
411         { "modules", N_("Defining submodule properties") },
412         { "revisions", N_("Specifying revisions and ranges for Git") },
413         { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
414         { "workflows", N_("An overview of recommended workflows with Git") },
415 };
416
417 static void list_common_guides_help(void)
418 {
419         int i, longest = 0;
420
421         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
422                 if (longest < strlen(common_guides[i].name))
423                         longest = strlen(common_guides[i].name);
424         }
425
426         puts(_("The common Git guides are:\n"));
427         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
428                 printf("   %s   ", common_guides[i].name);
429                 mput_char(' ', longest - strlen(common_guides[i].name));
430                 puts(_(common_guides[i].help));
431         }
432         putchar('\n');
433 }
434
435 static const char *check_git_cmd(const char* cmd)
436 {
437         char *alias;
438
439         if (is_git_command(cmd))
440                 return cmd;
441
442         alias = alias_lookup(cmd);
443         if (alias) {
444                 printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
445                 free(alias);
446                 exit(0);
447         }
448
449         if (exclude_guides)
450                 return help_unknown_cmd(cmd);
451
452         return cmd;
453 }
454
455 int cmd_help(int argc, const char **argv, const char *prefix)
456 {
457         int nongit;
458         enum help_format parsed_help_format;
459
460         argc = parse_options(argc, argv, prefix, builtin_help_options,
461                         builtin_help_usage, 0);
462         parsed_help_format = help_format;
463
464         if (show_all) {
465                 git_config(git_help_config, NULL);
466                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
467                 load_command_list("git-", &main_cmds, &other_cmds);
468                 list_commands(colopts, &main_cmds, &other_cmds);
469         }
470
471         if (show_guides)
472                 list_common_guides_help();
473
474         if (show_all || show_guides) {
475                 printf("%s\n", _(git_more_info_string));
476                 /*
477                 * We're done. Ignore any remaining args
478                 */
479                 return 0;
480         }
481
482         if (!argv[0]) {
483                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
484                 list_common_cmds_help();
485                 printf("\n%s\n", _(git_more_info_string));
486                 return 0;
487         }
488
489         setup_git_directory_gently(&nongit);
490         git_config(git_help_config, NULL);
491
492         if (parsed_help_format != HELP_FORMAT_NONE)
493                 help_format = parsed_help_format;
494         if (help_format == HELP_FORMAT_NONE)
495                 help_format = parse_help_format(DEFAULT_HELP_FORMAT);
496
497         argv[0] = check_git_cmd(argv[0]);
498
499         switch (help_format) {
500         case HELP_FORMAT_NONE:
501         case HELP_FORMAT_MAN:
502                 show_man_page(argv[0]);
503                 break;
504         case HELP_FORMAT_INFO:
505                 show_info_page(argv[0]);
506                 break;
507         case HELP_FORMAT_WEB:
508                 show_html_page(argv[0]);
509                 break;
510         }
511
512         return 0;
513 }