Merge branch 'sc/fmt-merge-msg-doc-markup-fix' into maint
[git] / builtin / help.c
1 /*
2  * Builtin help command
3  */
4 #include "cache.h"
5 #include "builtin.h"
6 #include "exec_cmd.h"
7 #include "parse-options.h"
8 #include "run-command.h"
9 #include "column.h"
10 #include "help.h"
11
12 #ifndef DEFAULT_HELP_FORMAT
13 #define DEFAULT_HELP_FORMAT "man"
14 #endif
15
16 static struct man_viewer_list {
17         struct man_viewer_list *next;
18         char name[FLEX_ARRAY];
19 } *man_viewer_list;
20
21 static struct man_viewer_info_list {
22         struct man_viewer_info_list *next;
23         const char *info;
24         char name[FLEX_ARRAY];
25 } *man_viewer_info_list;
26
27 enum help_format {
28         HELP_FORMAT_NONE,
29         HELP_FORMAT_MAN,
30         HELP_FORMAT_INFO,
31         HELP_FORMAT_WEB
32 };
33
34 static const char *html_path;
35
36 static int show_all = 0;
37 static int show_guides = 0;
38 static unsigned int colopts;
39 static enum help_format help_format = HELP_FORMAT_NONE;
40 static struct option builtin_help_options[] = {
41         OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
42         OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
43         OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
44         OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
45                         HELP_FORMAT_WEB),
46         OPT_SET_INT('i', "info", &help_format, N_("show info page"),
47                         HELP_FORMAT_INFO),
48         OPT_END(),
49 };
50
51 static const char * const builtin_help_usage[] = {
52         N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
53         NULL
54 };
55
56 static enum help_format parse_help_format(const char *format)
57 {
58         if (!strcmp(format, "man"))
59                 return HELP_FORMAT_MAN;
60         if (!strcmp(format, "info"))
61                 return HELP_FORMAT_INFO;
62         if (!strcmp(format, "web") || !strcmp(format, "html"))
63                 return HELP_FORMAT_WEB;
64         die(_("unrecognized help format '%s'"), format);
65 }
66
67 static const char *get_man_viewer_info(const char *name)
68 {
69         struct man_viewer_info_list *viewer;
70
71         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
72         {
73                 if (!strcasecmp(name, viewer->name))
74                         return viewer->info;
75         }
76         return NULL;
77 }
78
79 static int check_emacsclient_version(void)
80 {
81         struct strbuf buffer = STRBUF_INIT;
82         struct child_process ec_process = CHILD_PROCESS_INIT;
83         const char *argv_ec[] = { "emacsclient", "--version", NULL };
84         int version;
85
86         /* emacsclient prints its version number on stderr */
87         ec_process.argv = argv_ec;
88         ec_process.err = -1;
89         ec_process.stdout_to_stderr = 1;
90         if (start_command(&ec_process))
91                 return error(_("Failed to start emacsclient."));
92
93         strbuf_read(&buffer, ec_process.err, 20);
94         close(ec_process.err);
95
96         /*
97          * Don't bother checking return value, because "emacsclient --version"
98          * seems to always exits with code 1.
99          */
100         finish_command(&ec_process);
101
102         if (!starts_with(buffer.buf, "emacsclient")) {
103                 strbuf_release(&buffer);
104                 return error(_("Failed to parse emacsclient version."));
105         }
106
107         strbuf_remove(&buffer, 0, strlen("emacsclient"));
108         version = atoi(buffer.buf);
109
110         if (version < 22) {
111                 strbuf_release(&buffer);
112                 return error(_("emacsclient version '%d' too old (< 22)."),
113                         version);
114         }
115
116         strbuf_release(&buffer);
117         return 0;
118 }
119
120 static void exec_woman_emacs(const char *path, const char *page)
121 {
122         if (!check_emacsclient_version()) {
123                 /* This works only with emacsclient version >= 22. */
124                 struct strbuf man_page = STRBUF_INIT;
125
126                 if (!path)
127                         path = "emacsclient";
128                 strbuf_addf(&man_page, "(woman \"%s\")", page);
129                 execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
130                 warning_errno(_("failed to exec '%s'"), path);
131         }
132 }
133
134 static void exec_man_konqueror(const char *path, const char *page)
135 {
136         const char *display = getenv("DISPLAY");
137         if (display && *display) {
138                 struct strbuf man_page = STRBUF_INIT;
139                 const char *filename = "kfmclient";
140
141                 /* It's simpler to launch konqueror using kfmclient. */
142                 if (path) {
143                         size_t len;
144                         if (strip_suffix(path, "/konqueror", &len))
145                                 path = xstrfmt("%.*s/kfmclient", (int)len, path);
146                         filename = basename((char *)path);
147                 } else
148                         path = "kfmclient";
149                 strbuf_addf(&man_page, "man:%s(1)", page);
150                 execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
151                 warning_errno(_("failed to exec '%s'"), path);
152         }
153 }
154
155 static void exec_man_man(const char *path, const char *page)
156 {
157         if (!path)
158                 path = "man";
159         execlp(path, "man", page, (char *)NULL);
160         warning_errno(_("failed to exec '%s'"), path);
161 }
162
163 static void exec_man_cmd(const char *cmd, const char *page)
164 {
165         struct strbuf shell_cmd = STRBUF_INIT;
166         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
167         execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
168         warning(_("failed to exec '%s'"), cmd);
169 }
170
171 static void add_man_viewer(const char *name)
172 {
173         struct man_viewer_list **p = &man_viewer_list;
174
175         while (*p)
176                 p = &((*p)->next);
177         FLEX_ALLOC_STR(*p, name, name);
178 }
179
180 static int supported_man_viewer(const char *name, size_t len)
181 {
182         return (!strncasecmp("man", name, len) ||
183                 !strncasecmp("woman", name, len) ||
184                 !strncasecmp("konqueror", name, len));
185 }
186
187 static void do_add_man_viewer_info(const char *name,
188                                    size_t len,
189                                    const char *value)
190 {
191         struct man_viewer_info_list *new;
192         FLEX_ALLOC_MEM(new, name, name, len);
193         new->info = xstrdup(value);
194         new->next = man_viewer_info_list;
195         man_viewer_info_list = new;
196 }
197
198 static int add_man_viewer_path(const char *name,
199                                size_t len,
200                                const char *value)
201 {
202         if (supported_man_viewer(name, len))
203                 do_add_man_viewer_info(name, len, value);
204         else
205                 warning(_("'%s': path for unsupported man viewer.\n"
206                           "Please consider using 'man.<tool>.cmd' instead."),
207                         name);
208
209         return 0;
210 }
211
212 static int add_man_viewer_cmd(const char *name,
213                               size_t len,
214                               const char *value)
215 {
216         if (supported_man_viewer(name, len))
217                 warning(_("'%s': cmd for supported man viewer.\n"
218                           "Please consider using 'man.<tool>.path' instead."),
219                         name);
220         else
221                 do_add_man_viewer_info(name, len, value);
222
223         return 0;
224 }
225
226 static int add_man_viewer_info(const char *var, const char *value)
227 {
228         const char *name, *subkey;
229         int namelen;
230
231         if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
232                 return 0;
233
234         if (!strcmp(subkey, "path")) {
235                 if (!value)
236                         return config_error_nonbool(var);
237                 return add_man_viewer_path(name, namelen, value);
238         }
239         if (!strcmp(subkey, "cmd")) {
240                 if (!value)
241                         return config_error_nonbool(var);
242                 return add_man_viewer_cmd(name, namelen, value);
243         }
244
245         return 0;
246 }
247
248 static int git_help_config(const char *var, const char *value, void *cb)
249 {
250         if (starts_with(var, "column."))
251                 return git_column_config(var, value, "help", &colopts);
252         if (!strcmp(var, "help.format")) {
253                 if (!value)
254                         return config_error_nonbool(var);
255                 help_format = parse_help_format(value);
256                 return 0;
257         }
258         if (!strcmp(var, "help.htmlpath")) {
259                 if (!value)
260                         return config_error_nonbool(var);
261                 html_path = xstrdup(value);
262                 return 0;
263         }
264         if (!strcmp(var, "man.viewer")) {
265                 if (!value)
266                         return config_error_nonbool(var);
267                 add_man_viewer(value);
268                 return 0;
269         }
270         if (starts_with(var, "man."))
271                 return add_man_viewer_info(var, value);
272
273         return git_default_config(var, value, cb);
274 }
275
276 static struct cmdnames main_cmds, other_cmds;
277
278 static int is_git_command(const char *s)
279 {
280         if (is_builtin(s))
281                 return 1;
282
283         load_command_list("git-", &main_cmds, &other_cmds);
284         return is_in_cmdlist(&main_cmds, s) ||
285                 is_in_cmdlist(&other_cmds, s);
286 }
287
288 static const char *cmd_to_page(const char *git_cmd)
289 {
290         if (!git_cmd)
291                 return "git";
292         else if (starts_with(git_cmd, "git"))
293                 return git_cmd;
294         else if (is_git_command(git_cmd))
295                 return xstrfmt("git-%s", git_cmd);
296         else
297                 return xstrfmt("git%s", git_cmd);
298 }
299
300 static void setup_man_path(void)
301 {
302         struct strbuf new_path = STRBUF_INIT;
303         const char *old_path = getenv("MANPATH");
304         char *git_man_path = system_path(GIT_MAN_PATH);
305
306         /* We should always put ':' after our path. If there is no
307          * old_path, the ':' at the end will let 'man' to try
308          * system-wide paths after ours to find the manual page. If
309          * there is old_path, we need ':' as delimiter. */
310         strbuf_addstr(&new_path, git_man_path);
311         strbuf_addch(&new_path, ':');
312         if (old_path)
313                 strbuf_addstr(&new_path, old_path);
314
315         free(git_man_path);
316         setenv("MANPATH", new_path.buf, 1);
317
318         strbuf_release(&new_path);
319 }
320
321 static void exec_viewer(const char *name, const char *page)
322 {
323         const char *info = get_man_viewer_info(name);
324
325         if (!strcasecmp(name, "man"))
326                 exec_man_man(info, page);
327         else if (!strcasecmp(name, "woman"))
328                 exec_woman_emacs(info, page);
329         else if (!strcasecmp(name, "konqueror"))
330                 exec_man_konqueror(info, page);
331         else if (info)
332                 exec_man_cmd(info, page);
333         else
334                 warning(_("'%s': unknown man viewer."), name);
335 }
336
337 static void show_man_page(const char *git_cmd)
338 {
339         struct man_viewer_list *viewer;
340         const char *page = cmd_to_page(git_cmd);
341         const char *fallback = getenv("GIT_MAN_VIEWER");
342
343         setup_man_path();
344         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
345         {
346                 exec_viewer(viewer->name, page); /* will return when unable */
347         }
348         if (fallback)
349                 exec_viewer(fallback, page);
350         exec_viewer("man", page);
351         die(_("no man viewer handled the request"));
352 }
353
354 static void show_info_page(const char *git_cmd)
355 {
356         const char *page = cmd_to_page(git_cmd);
357         setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
358         execlp("info", "info", "gitman", page, (char *)NULL);
359         die(_("no info viewer handled the request"));
360 }
361
362 static void get_html_page_path(struct strbuf *page_path, const char *page)
363 {
364         struct stat st;
365         char *to_free = NULL;
366
367         if (!html_path)
368                 html_path = to_free = system_path(GIT_HTML_PATH);
369
370         /* Check that we have a git documentation directory. */
371         if (!strstr(html_path, "://")) {
372                 if (stat(mkpath("%s/git.html", html_path), &st)
373                     || !S_ISREG(st.st_mode))
374                         die("'%s': not a documentation directory.", html_path);
375         }
376
377         strbuf_init(page_path, 0);
378         strbuf_addf(page_path, "%s/%s.html", html_path, page);
379         free(to_free);
380 }
381
382 static void open_html(const char *path)
383 {
384         execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
385 }
386
387 static void show_html_page(const char *git_cmd)
388 {
389         const char *page = cmd_to_page(git_cmd);
390         struct strbuf page_path; /* it leaks but we exec bellow */
391
392         get_html_page_path(&page_path, page);
393
394         open_html(page_path.buf);
395 }
396
397 static struct {
398         const char *name;
399         const char *help;
400 } common_guides[] = {
401         { "attributes", N_("Defining attributes per path") },
402         { "everyday", N_("Everyday Git With 20 Commands Or So") },
403         { "glossary", N_("A Git glossary") },
404         { "ignore", N_("Specifies intentionally untracked files to ignore") },
405         { "modules", N_("Defining submodule properties") },
406         { "revisions", N_("Specifying revisions and ranges for Git") },
407         { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
408         { "workflows", N_("An overview of recommended workflows with Git") },
409 };
410
411 static void list_common_guides_help(void)
412 {
413         int i, longest = 0;
414
415         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
416                 if (longest < strlen(common_guides[i].name))
417                         longest = strlen(common_guides[i].name);
418         }
419
420         puts(_("The common Git guides are:\n"));
421         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
422                 printf("   %s   ", common_guides[i].name);
423                 mput_char(' ', longest - strlen(common_guides[i].name));
424                 puts(_(common_guides[i].help));
425         }
426         putchar('\n');
427 }
428
429 int cmd_help(int argc, const char **argv, const char *prefix)
430 {
431         int nongit;
432         char *alias;
433         enum help_format parsed_help_format;
434
435         argc = parse_options(argc, argv, prefix, builtin_help_options,
436                         builtin_help_usage, 0);
437         parsed_help_format = help_format;
438
439         if (show_all) {
440                 git_config(git_help_config, NULL);
441                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
442                 load_command_list("git-", &main_cmds, &other_cmds);
443                 list_commands(colopts, &main_cmds, &other_cmds);
444         }
445
446         if (show_guides)
447                 list_common_guides_help();
448
449         if (show_all || show_guides) {
450                 printf("%s\n", _(git_more_info_string));
451                 /*
452                 * We're done. Ignore any remaining args
453                 */
454                 return 0;
455         }
456
457         if (!argv[0]) {
458                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
459                 list_common_cmds_help();
460                 printf("\n%s\n", _(git_more_info_string));
461                 return 0;
462         }
463
464         setup_git_directory_gently(&nongit);
465         git_config(git_help_config, NULL);
466
467         if (parsed_help_format != HELP_FORMAT_NONE)
468                 help_format = parsed_help_format;
469         if (help_format == HELP_FORMAT_NONE)
470                 help_format = parse_help_format(DEFAULT_HELP_FORMAT);
471
472         alias = alias_lookup(argv[0]);
473         if (alias && !is_git_command(argv[0])) {
474                 printf_ln(_("`git %s' is aliased to `%s'"), argv[0], alias);
475                 free(alias);
476                 return 0;
477         }
478
479         switch (help_format) {
480         case HELP_FORMAT_NONE:
481         case HELP_FORMAT_MAN:
482                 show_man_page(argv[0]);
483                 break;
484         case HELP_FORMAT_INFO:
485                 show_info_page(argv[0]);
486                 break;
487         case HELP_FORMAT_WEB:
488                 show_html_page(argv[0]);
489                 break;
490         }
491
492         return 0;
493 }