builtin-mailinfo.c: check error status from rewind and ftruncate
[git/spearce.git] / builtin-help.c
blobe1eba778a526f500b0a65a6b112e468f04a3f869
1 /*
2 * builtin-help.c
4 * Builtin help command
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 #include "help.h"
14 static struct man_viewer_list {
15 struct man_viewer_list *next;
16 char name[FLEX_ARRAY];
17 } *man_viewer_list;
19 static struct man_viewer_info_list {
20 struct man_viewer_info_list *next;
21 const char *info;
22 char name[FLEX_ARRAY];
23 } *man_viewer_info_list;
25 enum help_format {
26 HELP_FORMAT_MAN,
27 HELP_FORMAT_INFO,
28 HELP_FORMAT_WEB,
31 static int show_all = 0;
32 static enum help_format help_format = HELP_FORMAT_MAN;
33 static struct option builtin_help_options[] = {
34 OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
35 OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
36 OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
37 HELP_FORMAT_WEB),
38 OPT_SET_INT('i', "info", &help_format, "show info page",
39 HELP_FORMAT_INFO),
40 OPT_END(),
43 static const char * const builtin_help_usage[] = {
44 "git help [--all] [--man|--web|--info] [command]",
45 NULL
48 static enum help_format parse_help_format(const char *format)
50 if (!strcmp(format, "man"))
51 return HELP_FORMAT_MAN;
52 if (!strcmp(format, "info"))
53 return HELP_FORMAT_INFO;
54 if (!strcmp(format, "web") || !strcmp(format, "html"))
55 return HELP_FORMAT_WEB;
56 die("unrecognized help format '%s'", format);
59 static const char *get_man_viewer_info(const char *name)
61 struct man_viewer_info_list *viewer;
63 for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
65 if (!strcasecmp(name, viewer->name))
66 return viewer->info;
68 return NULL;
71 static int check_emacsclient_version(void)
73 struct strbuf buffer = STRBUF_INIT;
74 struct child_process ec_process;
75 const char *argv_ec[] = { "emacsclient", "--version", NULL };
76 int version;
78 /* emacsclient prints its version number on stderr */
79 memset(&ec_process, 0, sizeof(ec_process));
80 ec_process.argv = argv_ec;
81 ec_process.err = -1;
82 ec_process.stdout_to_stderr = 1;
83 if (start_command(&ec_process))
84 return error("Failed to start emacsclient.");
86 strbuf_read(&buffer, ec_process.err, 20);
87 close(ec_process.err);
90 * Don't bother checking return value, because "emacsclient --version"
91 * seems to always exits with code 1.
93 finish_command(&ec_process);
95 if (prefixcmp(buffer.buf, "emacsclient")) {
96 strbuf_release(&buffer);
97 return error("Failed to parse emacsclient version.");
100 strbuf_remove(&buffer, 0, strlen("emacsclient"));
101 version = atoi(buffer.buf);
103 if (version < 22) {
104 strbuf_release(&buffer);
105 return error("emacsclient version '%d' too old (< 22).",
106 version);
109 strbuf_release(&buffer);
110 return 0;
113 static void exec_woman_emacs(const char *path, const char *page)
115 if (!check_emacsclient_version()) {
116 /* This works only with emacsclient version >= 22. */
117 struct strbuf man_page = STRBUF_INIT;
119 if (!path)
120 path = "emacsclient";
121 strbuf_addf(&man_page, "(woman \"%s\")", page);
122 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
123 warning("failed to exec '%s': %s", path, strerror(errno));
127 static void exec_man_konqueror(const char *path, const char *page)
129 const char *display = getenv("DISPLAY");
130 if (display && *display) {
131 struct strbuf man_page = STRBUF_INIT;
132 const char *filename = "kfmclient";
134 /* It's simpler to launch konqueror using kfmclient. */
135 if (path) {
136 const char *file = strrchr(path, '/');
137 if (file && !strcmp(file + 1, "konqueror")) {
138 char *new = xstrdup(path);
139 char *dest = strrchr(new, '/');
141 /* strlen("konqueror") == strlen("kfmclient") */
142 strcpy(dest + 1, "kfmclient");
143 path = new;
145 if (file)
146 filename = file;
147 } else
148 path = "kfmclient";
149 strbuf_addf(&man_page, "man:%s(1)", page);
150 execlp(path, filename, "newTab", man_page.buf, NULL);
151 warning("failed to exec '%s': %s", path, strerror(errno));
155 static void exec_man_man(const char *path, const char *page)
157 if (!path)
158 path = "man";
159 execlp(path, "man", page, NULL);
160 warning("failed to exec '%s': %s", path, strerror(errno));
163 static void exec_man_cmd(const char *cmd, const char *page)
165 struct strbuf shell_cmd = STRBUF_INIT;
166 strbuf_addf(&shell_cmd, "%s %s", cmd, page);
167 execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
168 warning("failed to exec '%s': %s", cmd, strerror(errno));
171 static void add_man_viewer(const char *name)
173 struct man_viewer_list **p = &man_viewer_list;
174 size_t len = strlen(name);
176 while (*p)
177 p = &((*p)->next);
178 *p = xcalloc(1, (sizeof(**p) + len + 1));
179 strncpy((*p)->name, name, len);
182 static int supported_man_viewer(const char *name, size_t len)
184 return (!strncasecmp("man", name, len) ||
185 !strncasecmp("woman", name, len) ||
186 !strncasecmp("konqueror", name, len));
189 static void do_add_man_viewer_info(const char *name,
190 size_t len,
191 const char *value)
193 struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
195 strncpy(new->name, name, len);
196 new->info = xstrdup(value);
197 new->next = man_viewer_info_list;
198 man_viewer_info_list = new;
201 static int add_man_viewer_path(const char *name,
202 size_t len,
203 const char *value)
205 if (supported_man_viewer(name, len))
206 do_add_man_viewer_info(name, len, value);
207 else
208 warning("'%s': path for unsupported man viewer.\n"
209 "Please consider using 'man.<tool>.cmd' instead.",
210 name);
212 return 0;
215 static int add_man_viewer_cmd(const char *name,
216 size_t len,
217 const char *value)
219 if (supported_man_viewer(name, len))
220 warning("'%s': cmd for supported man viewer.\n"
221 "Please consider using 'man.<tool>.path' instead.",
222 name);
223 else
224 do_add_man_viewer_info(name, len, value);
226 return 0;
229 static int add_man_viewer_info(const char *var, const char *value)
231 const char *name = var + 4;
232 const char *subkey = strrchr(name, '.');
234 if (!subkey)
235 return 0;
237 if (!strcmp(subkey, ".path")) {
238 if (!value)
239 return config_error_nonbool(var);
240 return add_man_viewer_path(name, subkey - name, value);
242 if (!strcmp(subkey, ".cmd")) {
243 if (!value)
244 return config_error_nonbool(var);
245 return add_man_viewer_cmd(name, subkey - name, value);
248 return 0;
251 static int git_help_config(const char *var, const char *value, void *cb)
253 if (!strcmp(var, "help.format")) {
254 if (!value)
255 return config_error_nonbool(var);
256 help_format = parse_help_format(value);
257 return 0;
259 if (!strcmp(var, "man.viewer")) {
260 if (!value)
261 return config_error_nonbool(var);
262 add_man_viewer(value);
263 return 0;
265 if (!prefixcmp(var, "man."))
266 return add_man_viewer_info(var, value);
268 return git_default_config(var, value, cb);
271 static struct cmdnames main_cmds, other_cmds;
273 void list_common_cmds_help(void)
275 int i, longest = 0;
277 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
278 if (longest < strlen(common_cmds[i].name))
279 longest = strlen(common_cmds[i].name);
282 puts("The most commonly used git commands are:");
283 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
284 printf(" %s ", common_cmds[i].name);
285 mput_char(' ', longest - strlen(common_cmds[i].name));
286 puts(common_cmds[i].help);
290 static int is_git_command(const char *s)
292 return is_in_cmdlist(&main_cmds, s) ||
293 is_in_cmdlist(&other_cmds, s);
296 static const char *prepend(const char *prefix, const char *cmd)
298 size_t pre_len = strlen(prefix);
299 size_t cmd_len = strlen(cmd);
300 char *p = xmalloc(pre_len + cmd_len + 1);
301 memcpy(p, prefix, pre_len);
302 strcpy(p + pre_len, cmd);
303 return p;
306 static const char *cmd_to_page(const char *git_cmd)
308 if (!git_cmd)
309 return "git";
310 else if (!prefixcmp(git_cmd, "git"))
311 return git_cmd;
312 else if (is_git_command(git_cmd))
313 return prepend("git-", git_cmd);
314 else
315 return prepend("git", git_cmd);
318 static void setup_man_path(void)
320 struct strbuf new_path = STRBUF_INIT;
321 const char *old_path = getenv("MANPATH");
323 /* We should always put ':' after our path. If there is no
324 * old_path, the ':' at the end will let 'man' to try
325 * system-wide paths after ours to find the manual page. If
326 * there is old_path, we need ':' as delimiter. */
327 strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
328 strbuf_addch(&new_path, ':');
329 if (old_path)
330 strbuf_addstr(&new_path, old_path);
332 setenv("MANPATH", new_path.buf, 1);
334 strbuf_release(&new_path);
337 static void exec_viewer(const char *name, const char *page)
339 const char *info = get_man_viewer_info(name);
341 if (!strcasecmp(name, "man"))
342 exec_man_man(info, page);
343 else if (!strcasecmp(name, "woman"))
344 exec_woman_emacs(info, page);
345 else if (!strcasecmp(name, "konqueror"))
346 exec_man_konqueror(info, page);
347 else if (info)
348 exec_man_cmd(info, page);
349 else
350 warning("'%s': unknown man viewer.", name);
353 static void show_man_page(const char *git_cmd)
355 struct man_viewer_list *viewer;
356 const char *page = cmd_to_page(git_cmd);
357 const char *fallback = getenv("GIT_MAN_VIEWER");
359 setup_man_path();
360 for (viewer = man_viewer_list; viewer; viewer = viewer->next)
362 exec_viewer(viewer->name, page); /* will return when unable */
364 if (fallback)
365 exec_viewer(fallback, page);
366 exec_viewer("man", page);
367 die("no man viewer handled the request");
370 static void show_info_page(const char *git_cmd)
372 const char *page = cmd_to_page(git_cmd);
373 setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
374 execlp("info", "info", "gitman", page, NULL);
377 static void get_html_page_path(struct strbuf *page_path, const char *page)
379 struct stat st;
380 const char *html_path = system_path(GIT_HTML_PATH);
382 /* Check that we have a git documentation directory. */
383 if (stat(mkpath("%s/git.html", html_path), &st)
384 || !S_ISREG(st.st_mode))
385 die("'%s': not a documentation directory.", html_path);
387 strbuf_init(page_path, 0);
388 strbuf_addf(page_path, "%s/%s.html", html_path, page);
392 * If open_html is not defined in a platform-specific way (see for
393 * example compat/mingw.h), we use the script web--browse to display
394 * HTML.
396 #ifndef open_html
397 static void open_html(const char *path)
399 execl_git_cmd("web--browse", "-c", "help.browser", path, NULL);
401 #endif
403 static void show_html_page(const char *git_cmd)
405 const char *page = cmd_to_page(git_cmd);
406 struct strbuf page_path; /* it leaks but we exec bellow */
408 get_html_page_path(&page_path, page);
410 open_html(page_path.buf);
413 int cmd_help(int argc, const char **argv, const char *prefix)
415 int nongit;
416 const char *alias;
417 load_command_list("git-", &main_cmds, &other_cmds);
419 setup_git_directory_gently(&nongit);
420 git_config(git_help_config, NULL);
422 argc = parse_options(argc, argv, prefix, builtin_help_options,
423 builtin_help_usage, 0);
425 if (show_all) {
426 printf("usage: %s\n\n", git_usage_string);
427 list_commands("git commands", &main_cmds, &other_cmds);
428 printf("%s\n", git_more_info_string);
429 return 0;
432 if (!argv[0]) {
433 printf("usage: %s\n\n", git_usage_string);
434 list_common_cmds_help();
435 printf("\n%s\n", git_more_info_string);
436 return 0;
439 alias = alias_lookup(argv[0]);
440 if (alias && !is_git_command(argv[0])) {
441 printf("`git %s' is aliased to `%s'\n", argv[0], alias);
442 return 0;
445 switch (help_format) {
446 case HELP_FORMAT_MAN:
447 show_man_page(argv[0]);
448 break;
449 case HELP_FORMAT_INFO:
450 show_info_page(argv[0]);
451 break;
452 case HELP_FORMAT_WEB:
453 show_html_page(argv[0]);
454 break;
457 return 0;