path.c: and an option to call real_path() in expand_user_path()
[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 int exclude_guides;
41 static struct option builtin_help_options[] = {
42         OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
43         OPT_HIDDEN_BOOL(0, "exclude-guides", &exclude_guides, N_("exclude guides")),
44         OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
45         OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
46         OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
47                         HELP_FORMAT_WEB),
48         OPT_SET_INT('i', "info", &help_format, N_("show info page"),
49                         HELP_FORMAT_INFO),
50         OPT_END(),
51 };
52
53 static const char * const builtin_help_usage[] = {
54         N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
55         NULL
56 };
57
58 static enum help_format parse_help_format(const char *format)
59 {
60         if (!strcmp(format, "man"))
61                 return HELP_FORMAT_MAN;
62         if (!strcmp(format, "info"))
63                 return HELP_FORMAT_INFO;
64         if (!strcmp(format, "web") || !strcmp(format, "html"))
65                 return HELP_FORMAT_WEB;
66         die(_("unrecognized help format '%s'"), format);
67 }
68
69 static const char *get_man_viewer_info(const char *name)
70 {
71         struct man_viewer_info_list *viewer;
72
73         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
74         {
75                 if (!strcasecmp(name, viewer->name))
76                         return viewer->info;
77         }
78         return NULL;
79 }
80
81 static int check_emacsclient_version(void)
82 {
83         struct strbuf buffer = STRBUF_INIT;
84         struct child_process ec_process = CHILD_PROCESS_INIT;
85         const char *argv_ec[] = { "emacsclient", "--version", NULL };
86         int version;
87
88         /* emacsclient prints its version number on stderr */
89         ec_process.argv = argv_ec;
90         ec_process.err = -1;
91         ec_process.stdout_to_stderr = 1;
92         if (start_command(&ec_process))
93                 return error(_("Failed to start emacsclient."));
94
95         strbuf_read(&buffer, ec_process.err, 20);
96         close(ec_process.err);
97
98         /*
99          * Don't bother checking return value, because "emacsclient --version"
100          * seems to always exits with code 1.
101          */
102         finish_command(&ec_process);
103
104         if (!starts_with(buffer.buf, "emacsclient")) {
105                 strbuf_release(&buffer);
106                 return error(_("Failed to parse emacsclient version."));
107         }
108
109         strbuf_remove(&buffer, 0, strlen("emacsclient"));
110         version = atoi(buffer.buf);
111
112         if (version < 22) {
113                 strbuf_release(&buffer);
114                 return error(_("emacsclient version '%d' too old (< 22)."),
115                         version);
116         }
117
118         strbuf_release(&buffer);
119         return 0;
120 }
121
122 static void exec_woman_emacs(const char *path, const char *page)
123 {
124         if (!check_emacsclient_version()) {
125                 /* This works only with emacsclient version >= 22. */
126                 struct strbuf man_page = STRBUF_INIT;
127
128                 if (!path)
129                         path = "emacsclient";
130                 strbuf_addf(&man_page, "(woman \"%s\")", page);
131                 execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
132                 warning_errno(_("failed to exec '%s'"), path);
133         }
134 }
135
136 static void exec_man_konqueror(const char *path, const char *page)
137 {
138         const char *display = getenv("DISPLAY");
139         if (display && *display) {
140                 struct strbuf man_page = STRBUF_INIT;
141                 const char *filename = "kfmclient";
142
143                 /* It's simpler to launch konqueror using kfmclient. */
144                 if (path) {
145                         size_t len;
146                         if (strip_suffix(path, "/konqueror", &len))
147                                 path = xstrfmt("%.*s/kfmclient", (int)len, path);
148                         filename = basename((char *)path);
149                 } else
150                         path = "kfmclient";
151                 strbuf_addf(&man_page, "man:%s(1)", page);
152                 execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
153                 warning_errno(_("failed to exec '%s'"), path);
154         }
155 }
156
157 static void exec_man_man(const char *path, const char *page)
158 {
159         if (!path)
160                 path = "man";
161         execlp(path, "man", page, (char *)NULL);
162         warning_errno(_("failed to exec '%s'"), path);
163 }
164
165 static void exec_man_cmd(const char *cmd, const char *page)
166 {
167         struct strbuf shell_cmd = STRBUF_INIT;
168         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
169         execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
170         warning(_("failed to exec '%s'"), cmd);
171 }
172
173 static void add_man_viewer(const char *name)
174 {
175         struct man_viewer_list **p = &man_viewer_list;
176
177         while (*p)
178                 p = &((*p)->next);
179         FLEX_ALLOC_STR(*p, name, name);
180 }
181
182 static int supported_man_viewer(const char *name, size_t len)
183 {
184         return (!strncasecmp("man", name, len) ||
185                 !strncasecmp("woman", name, len) ||
186                 !strncasecmp("konqueror", name, len));
187 }
188
189 static void do_add_man_viewer_info(const char *name,
190                                    size_t len,
191                                    const char *value)
192 {
193         struct man_viewer_info_list *new;
194         FLEX_ALLOC_MEM(new, name, name, len);
195         new->info = xstrdup(value);
196         new->next = man_viewer_info_list;
197         man_viewer_info_list = new;
198 }
199
200 static int add_man_viewer_path(const char *name,
201                                size_t len,
202                                const char *value)
203 {
204         if (supported_man_viewer(name, len))
205                 do_add_man_viewer_info(name, len, value);
206         else
207                 warning(_("'%s': path for unsupported man viewer.\n"
208                           "Please consider using 'man.<tool>.cmd' instead."),
209                         name);
210
211         return 0;
212 }
213
214 static int add_man_viewer_cmd(const char *name,
215                               size_t len,
216                               const char *value)
217 {
218         if (supported_man_viewer(name, len))
219                 warning(_("'%s': cmd for supported man viewer.\n"
220                           "Please consider using 'man.<tool>.path' instead."),
221                         name);
222         else
223                 do_add_man_viewer_info(name, len, value);
224
225         return 0;
226 }
227
228 static int add_man_viewer_info(const char *var, const char *value)
229 {
230         const char *name, *subkey;
231         int namelen;
232
233         if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
234                 return 0;
235
236         if (!strcmp(subkey, "path")) {
237                 if (!value)
238                         return config_error_nonbool(var);
239                 return add_man_viewer_path(name, namelen, value);
240         }
241         if (!strcmp(subkey, "cmd")) {
242                 if (!value)
243                         return config_error_nonbool(var);
244                 return add_man_viewer_cmd(name, namelen, value);
245         }
246
247         return 0;
248 }
249
250 static int git_help_config(const char *var, const char *value, void *cb)
251 {
252         if (starts_with(var, "column."))
253                 return git_column_config(var, value, "help", &colopts);
254         if (!strcmp(var, "help.format")) {
255                 if (!value)
256                         return config_error_nonbool(var);
257                 help_format = parse_help_format(value);
258                 return 0;
259         }
260         if (!strcmp(var, "help.htmlpath")) {
261                 if (!value)
262                         return config_error_nonbool(var);
263                 html_path = xstrdup(value);
264                 return 0;
265         }
266         if (!strcmp(var, "man.viewer")) {
267                 if (!value)
268                         return config_error_nonbool(var);
269                 add_man_viewer(value);
270                 return 0;
271         }
272         if (starts_with(var, "man."))
273                 return add_man_viewer_info(var, value);
274
275         return git_default_config(var, value, cb);
276 }
277
278 static struct cmdnames main_cmds, other_cmds;
279
280 static int is_git_command(const char *s)
281 {
282         if (is_builtin(s))
283                 return 1;
284
285         load_command_list("git-", &main_cmds, &other_cmds);
286         return is_in_cmdlist(&main_cmds, s) ||
287                 is_in_cmdlist(&other_cmds, s);
288 }
289
290 static const char *cmd_to_page(const char *git_cmd)
291 {
292         if (!git_cmd)
293                 return "git";
294         else if (starts_with(git_cmd, "git"))
295                 return git_cmd;
296         else if (is_git_command(git_cmd))
297                 return xstrfmt("git-%s", git_cmd);
298         else
299                 return xstrfmt("git%s", git_cmd);
300 }
301
302 static void setup_man_path(void)
303 {
304         struct strbuf new_path = STRBUF_INIT;
305         const char *old_path = getenv("MANPATH");
306         char *git_man_path = system_path(GIT_MAN_PATH);
307
308         /* We should always put ':' after our path. If there is no
309          * old_path, the ':' at the end will let 'man' to try
310          * system-wide paths after ours to find the manual page. If
311          * there is old_path, we need ':' as delimiter. */
312         strbuf_addstr(&new_path, git_man_path);
313         strbuf_addch(&new_path, ':');
314         if (old_path)
315                 strbuf_addstr(&new_path, old_path);
316
317         free(git_man_path);
318         setenv("MANPATH", new_path.buf, 1);
319
320         strbuf_release(&new_path);
321 }
322
323 static void exec_viewer(const char *name, const char *page)
324 {
325         const char *info = get_man_viewer_info(name);
326
327         if (!strcasecmp(name, "man"))
328                 exec_man_man(info, page);
329         else if (!strcasecmp(name, "woman"))
330                 exec_woman_emacs(info, page);
331         else if (!strcasecmp(name, "konqueror"))
332                 exec_man_konqueror(info, page);
333         else if (info)
334                 exec_man_cmd(info, page);
335         else
336                 warning(_("'%s': unknown man viewer."), name);
337 }
338
339 static void show_man_page(const char *git_cmd)
340 {
341         struct man_viewer_list *viewer;
342         const char *page = cmd_to_page(git_cmd);
343         const char *fallback = getenv("GIT_MAN_VIEWER");
344
345         setup_man_path();
346         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
347         {
348                 exec_viewer(viewer->name, page); /* will return when unable */
349         }
350         if (fallback)
351                 exec_viewer(fallback, page);
352         exec_viewer("man", page);
353         die(_("no man viewer handled the request"));
354 }
355
356 static void show_info_page(const char *git_cmd)
357 {
358         const char *page = cmd_to_page(git_cmd);
359         setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
360         execlp("info", "info", "gitman", page, (char *)NULL);
361         die(_("no info viewer handled the request"));
362 }
363
364 static void get_html_page_path(struct strbuf *page_path, const char *page)
365 {
366         struct stat st;
367         char *to_free = NULL;
368
369         if (!html_path)
370                 html_path = to_free = system_path(GIT_HTML_PATH);
371
372         /* Check that we have a git documentation directory. */
373         if (!strstr(html_path, "://")) {
374                 if (stat(mkpath("%s/git.html", html_path), &st)
375                     || !S_ISREG(st.st_mode))
376                         die("'%s': not a documentation directory.", html_path);
377         }
378
379         strbuf_init(page_path, 0);
380         strbuf_addf(page_path, "%s/%s.html", html_path, page);
381         free(to_free);
382 }
383
384 static void open_html(const char *path)
385 {
386         execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
387 }
388
389 static void show_html_page(const char *git_cmd)
390 {
391         const char *page = cmd_to_page(git_cmd);
392         struct strbuf page_path; /* it leaks but we exec bellow */
393
394         get_html_page_path(&page_path, page);
395
396         open_html(page_path.buf);
397 }
398
399 static struct {
400         const char *name;
401         const char *help;
402 } common_guides[] = {
403         { "attributes", N_("Defining attributes per path") },
404         { "everyday", N_("Everyday Git With 20 Commands Or So") },
405         { "glossary", N_("A Git glossary") },
406         { "ignore", N_("Specifies intentionally untracked files to ignore") },
407         { "modules", N_("Defining submodule properties") },
408         { "revisions", N_("Specifying revisions and ranges for Git") },
409         { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
410         { "workflows", N_("An overview of recommended workflows with Git") },
411 };
412
413 static void list_common_guides_help(void)
414 {
415         int i, longest = 0;
416
417         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
418                 if (longest < strlen(common_guides[i].name))
419                         longest = strlen(common_guides[i].name);
420         }
421
422         puts(_("The common Git guides are:\n"));
423         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
424                 printf("   %s   ", common_guides[i].name);
425                 mput_char(' ', longest - strlen(common_guides[i].name));
426                 puts(_(common_guides[i].help));
427         }
428         putchar('\n');
429 }
430
431 static const char *check_git_cmd(const char* cmd)
432 {
433         char *alias;
434
435         if (is_git_command(cmd))
436                 return cmd;
437
438         alias = alias_lookup(cmd);
439         if (alias) {
440                 printf_ln(_("`git %s' is aliased to `%s'"), cmd, alias);
441                 free(alias);
442                 exit(0);
443         }
444
445         if (exclude_guides)
446                 return help_unknown_cmd(cmd);
447
448         return cmd;
449 }
450
451 int cmd_help(int argc, const char **argv, const char *prefix)
452 {
453         int nongit;
454         enum help_format parsed_help_format;
455
456         argc = parse_options(argc, argv, prefix, builtin_help_options,
457                         builtin_help_usage, 0);
458         parsed_help_format = help_format;
459
460         if (show_all) {
461                 git_config(git_help_config, NULL);
462                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
463                 load_command_list("git-", &main_cmds, &other_cmds);
464                 list_commands(colopts, &main_cmds, &other_cmds);
465         }
466
467         if (show_guides)
468                 list_common_guides_help();
469
470         if (show_all || show_guides) {
471                 printf("%s\n", _(git_more_info_string));
472                 /*
473                 * We're done. Ignore any remaining args
474                 */
475                 return 0;
476         }
477
478         if (!argv[0]) {
479                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
480                 list_common_cmds_help();
481                 printf("\n%s\n", _(git_more_info_string));
482                 return 0;
483         }
484
485         setup_git_directory_gently(&nongit);
486         git_config(git_help_config, NULL);
487
488         if (parsed_help_format != HELP_FORMAT_NONE)
489                 help_format = parsed_help_format;
490         if (help_format == HELP_FORMAT_NONE)
491                 help_format = parse_help_format(DEFAULT_HELP_FORMAT);
492
493         argv[0] = check_git_cmd(argv[0]);
494
495         switch (help_format) {
496         case HELP_FORMAT_NONE:
497         case HELP_FORMAT_MAN:
498                 show_man_page(argv[0]);
499                 break;
500         case HELP_FORMAT_INFO:
501                 show_info_page(argv[0]);
502                 break;
503         case HELP_FORMAT_WEB:
504                 show_html_page(argv[0]);
505                 break;
506         }
507
508         return 0;
509 }