perf: Make cmd_to_page() function more compact
[linux-2.6.git] / tools / perf / builtin-help.c
1 /*
2  * builtin-help.c
3  *
4  * Builtin help command
5  */
6 #include "perf.h"
7 #include "util/cache.h"
8 #include "builtin.h"
9 #include "util/exec_cmd.h"
10 #include "common-cmds.h"
11 #include "util/parse-options.h"
12 #include "util/run-command.h"
13 #include "util/help.h"
14
15 static struct man_viewer_list {
16         struct man_viewer_list *next;
17         char name[FLEX_ARRAY];
18 } *man_viewer_list;
19
20 static struct man_viewer_info_list {
21         struct man_viewer_info_list *next;
22         const char *info;
23         char name[FLEX_ARRAY];
24 } *man_viewer_info_list;
25
26 enum help_format {
27         HELP_FORMAT_MAN,
28         HELP_FORMAT_INFO,
29         HELP_FORMAT_WEB,
30 };
31
32 static int show_all = 0;
33 static enum help_format help_format = HELP_FORMAT_MAN;
34 static struct option builtin_help_options[] = {
35         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
36         OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
37         OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
38                         HELP_FORMAT_WEB),
39         OPT_SET_INT('i', "info", &help_format, "show info page",
40                         HELP_FORMAT_INFO),
41         OPT_END(),
42 };
43
44 static const char * const builtin_help_usage[] = {
45         "perf help [--all] [--man|--web|--info] [command]",
46         NULL
47 };
48
49 static enum help_format parse_help_format(const char *format)
50 {
51         if (!strcmp(format, "man"))
52                 return HELP_FORMAT_MAN;
53         if (!strcmp(format, "info"))
54                 return HELP_FORMAT_INFO;
55         if (!strcmp(format, "web") || !strcmp(format, "html"))
56                 return HELP_FORMAT_WEB;
57         die("unrecognized help format '%s'", format);
58 }
59
60 static const char *get_man_viewer_info(const char *name)
61 {
62         struct man_viewer_info_list *viewer;
63
64         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
65                 if (!strcasecmp(name, viewer->name))
66                         return viewer->info;
67         }
68         return NULL;
69 }
70
71 static int check_emacsclient_version(void)
72 {
73         struct strbuf buffer = STRBUF_INIT;
74         struct child_process ec_process;
75         const char *argv_ec[] = { "emacsclient", "--version", NULL };
76         int version;
77
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                 fprintf(stderr, "Failed to start emacsclient.\n");
85                 return -1;
86         }
87         strbuf_read(&buffer, ec_process.err, 20);
88         close(ec_process.err);
89
90         /*
91          * Don't bother checking return value, because "emacsclient --version"
92          * seems to always exits with code 1.
93          */
94         finish_command(&ec_process);
95
96         if (prefixcmp(buffer.buf, "emacsclient")) {
97                 fprintf(stderr, "Failed to parse emacsclient version.\n");
98                 strbuf_release(&buffer);
99                 return -1;
100         }
101
102         strbuf_remove(&buffer, 0, strlen("emacsclient"));
103         version = atoi(buffer.buf);
104
105         if (version < 22) {
106                 fprintf(stderr,
107                         "emacsclient version '%d' too old (< 22).\n",
108                         version);
109                 strbuf_release(&buffer);
110                 return -1;
111         }
112
113         strbuf_release(&buffer);
114         return 0;
115 }
116
117 static void exec_woman_emacs(const char *path, const char *page)
118 {
119         if (!check_emacsclient_version()) {
120                 /* This works only with emacsclient version >= 22. */
121                 struct strbuf man_page = STRBUF_INIT;
122
123                 if (!path)
124                         path = "emacsclient";
125                 strbuf_addf(&man_page, "(woman \"%s\")", page);
126                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
127                 warning("failed to exec '%s': %s", path, strerror(errno));
128         }
129 }
130
131 static void exec_man_konqueror(const char *path, const char *page)
132 {
133         const char *display = getenv("DISPLAY");
134         if (display && *display) {
135                 struct strbuf man_page = STRBUF_INIT;
136                 const char *filename = "kfmclient";
137
138                 /* It's simpler to launch konqueror using kfmclient. */
139                 if (path) {
140                         const char *file = strrchr(path, '/');
141                         if (file && !strcmp(file + 1, "konqueror")) {
142                                 char *new = strdup(path);
143                                 char *dest = strrchr(new, '/');
144
145                                 /* strlen("konqueror") == strlen("kfmclient") */
146                                 strcpy(dest + 1, "kfmclient");
147                                 path = new;
148                         }
149                         if (file)
150                                 filename = file;
151                 } else
152                         path = "kfmclient";
153                 strbuf_addf(&man_page, "man:%s(1)", page);
154                 execlp(path, filename, "newTab", man_page.buf, NULL);
155                 warning("failed to exec '%s': %s", path, strerror(errno));
156         }
157 }
158
159 static void exec_man_man(const char *path, const char *page)
160 {
161         if (!path)
162                 path = "man";
163         execlp(path, "man", page, NULL);
164         warning("failed to exec '%s': %s", path, strerror(errno));
165 }
166
167 static void exec_man_cmd(const char *cmd, const char *page)
168 {
169         struct strbuf shell_cmd = STRBUF_INIT;
170         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
171         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
172         warning("failed to exec '%s': %s", cmd, strerror(errno));
173 }
174
175 static void add_man_viewer(const char *name)
176 {
177         struct man_viewer_list **p = &man_viewer_list;
178         size_t len = strlen(name);
179
180         while (*p)
181                 p = &((*p)->next);
182         *p = zalloc(sizeof(**p) + len + 1);
183         strncpy((*p)->name, name, len);
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 = zalloc(sizeof(*new) + len + 1);
198
199         strncpy(new->name, name, len);
200         new->info = strdup(value);
201         new->next = man_viewer_info_list;
202         man_viewer_info_list = new;
203 }
204
205 static int add_man_viewer_path(const char *name,
206                                size_t len,
207                                const char *value)
208 {
209         if (supported_man_viewer(name, len))
210                 do_add_man_viewer_info(name, len, value);
211         else
212                 warning("'%s': path for unsupported man viewer.\n"
213                         "Please consider using 'man.<tool>.cmd' instead.",
214                         name);
215
216         return 0;
217 }
218
219 static int add_man_viewer_cmd(const char *name,
220                               size_t len,
221                               const char *value)
222 {
223         if (supported_man_viewer(name, len))
224                 warning("'%s': cmd for supported man viewer.\n"
225                         "Please consider using 'man.<tool>.path' instead.",
226                         name);
227         else
228                 do_add_man_viewer_info(name, len, value);
229
230         return 0;
231 }
232
233 static int add_man_viewer_info(const char *var, const char *value)
234 {
235         const char *name = var + 4;
236         const char *subkey = strrchr(name, '.');
237
238         if (!subkey)
239                 return error("Config with no key for man viewer: %s", name);
240
241         if (!strcmp(subkey, ".path")) {
242                 if (!value)
243                         return config_error_nonbool(var);
244                 return add_man_viewer_path(name, subkey - name, value);
245         }
246         if (!strcmp(subkey, ".cmd")) {
247                 if (!value)
248                         return config_error_nonbool(var);
249                 return add_man_viewer_cmd(name, subkey - name, value);
250         }
251
252         warning("'%s': unsupported man viewer sub key.", subkey);
253         return 0;
254 }
255
256 static int perf_help_config(const char *var, const char *value, void *cb)
257 {
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, "man.viewer")) {
265                 if (!value)
266                         return config_error_nonbool(var);
267                 add_man_viewer(value);
268                 return 0;
269         }
270         if (!prefixcmp(var, "man."))
271                 return add_man_viewer_info(var, value);
272
273         return perf_default_config(var, value, cb);
274 }
275
276 static struct cmdnames main_cmds, other_cmds;
277
278 void list_common_cmds_help(void)
279 {
280         unsigned int i, longest = 0;
281
282         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
283                 if (longest < strlen(common_cmds[i].name))
284                         longest = strlen(common_cmds[i].name);
285         }
286
287         puts(" The most commonly used perf commands are:");
288         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
289                 printf("   %-*s   ", longest, common_cmds[i].name);
290                 puts(common_cmds[i].help);
291         }
292 }
293
294 static int is_perf_command(const char *s)
295 {
296         return is_in_cmdlist(&main_cmds, s) ||
297                 is_in_cmdlist(&other_cmds, s);
298 }
299
300 static const char *prepend(const char *prefix, const char *cmd)
301 {
302         size_t pre_len = strlen(prefix);
303         size_t cmd_len = strlen(cmd);
304         char *p = malloc(pre_len + cmd_len + 1);
305         memcpy(p, prefix, pre_len);
306         strcpy(p + pre_len, cmd);
307         return p;
308 }
309
310 static const char *cmd_to_page(const char *perf_cmd)
311 {
312         if (!perf_cmd)
313                 return "perf";
314         else if (!prefixcmp(perf_cmd, "perf"))
315                 return perf_cmd;
316         else
317                 return prepend("perf-", perf_cmd);
318 }
319
320 static void setup_man_path(void)
321 {
322         struct strbuf new_path = STRBUF_INIT;
323         const char *old_path = getenv("MANPATH");
324
325         /* We should always put ':' after our path. If there is no
326          * old_path, the ':' at the end will let 'man' to try
327          * system-wide paths after ours to find the manual page. If
328          * there is old_path, we need ':' as delimiter. */
329         strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
330         strbuf_addch(&new_path, ':');
331         if (old_path)
332                 strbuf_addstr(&new_path, old_path);
333
334         setenv("MANPATH", new_path.buf, 1);
335
336         strbuf_release(&new_path);
337 }
338
339 static void exec_viewer(const char *name, const char *page)
340 {
341         const char *info = get_man_viewer_info(name);
342
343         if (!strcasecmp(name, "man"))
344                 exec_man_man(info, page);
345         else if (!strcasecmp(name, "woman"))
346                 exec_woman_emacs(info, page);
347         else if (!strcasecmp(name, "konqueror"))
348                 exec_man_konqueror(info, page);
349         else if (info)
350                 exec_man_cmd(info, page);
351         else
352                 warning("'%s': unknown man viewer.", name);
353 }
354
355 static void show_man_page(const char *perf_cmd)
356 {
357         struct man_viewer_list *viewer;
358         const char *page = cmd_to_page(perf_cmd);
359         const char *fallback = getenv("PERF_MAN_VIEWER");
360
361         setup_man_path();
362         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
363                 exec_viewer(viewer->name, page); /* will return when unable */
364
365         if (fallback)
366                 exec_viewer(fallback, page);
367         exec_viewer("man", page);
368         die("no man viewer handled the request");
369 }
370
371 static void show_info_page(const char *perf_cmd)
372 {
373         const char *page = cmd_to_page(perf_cmd);
374         setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
375         execlp("info", "info", "perfman", page, NULL);
376 }
377
378 static void get_html_page_path(struct strbuf *page_path, const char *page)
379 {
380         struct stat st;
381         const char *html_path = system_path(PERF_HTML_PATH);
382
383         /* Check that we have a perf documentation directory. */
384         if (stat(mkpath("%s/perf.html", html_path), &st)
385             || !S_ISREG(st.st_mode))
386                 die("'%s': not a documentation directory.", html_path);
387
388         strbuf_init(page_path, 0);
389         strbuf_addf(page_path, "%s/%s.html", html_path, page);
390 }
391
392 /*
393  * If open_html is not defined in a platform-specific way (see for
394  * example compat/mingw.h), we use the script web--browse to display
395  * HTML.
396  */
397 #ifndef open_html
398 static void open_html(const char *path)
399 {
400         execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
401 }
402 #endif
403
404 static void show_html_page(const char *perf_cmd)
405 {
406         const char *page = cmd_to_page(perf_cmd);
407         struct strbuf page_path; /* it leaks but we exec bellow */
408
409         get_html_page_path(&page_path, page);
410
411         open_html(page_path.buf);
412 }
413
414 int cmd_help(int argc, const char **argv, const char *prefix __used)
415 {
416         const char *alias;
417
418         load_command_list("perf-", &main_cmds, &other_cmds);
419
420         perf_config(perf_help_config, NULL);
421
422         argc = parse_options(argc, argv, builtin_help_options,
423                         builtin_help_usage, 0);
424
425         if (show_all) {
426                 printf("\n usage: %s\n\n", perf_usage_string);
427                 list_commands("perf commands", &main_cmds, &other_cmds);
428                 printf(" %s\n\n", perf_more_info_string);
429                 return 0;
430         }
431
432         if (!argv[0]) {
433                 printf("\n usage: %s\n\n", perf_usage_string);
434                 list_common_cmds_help();
435                 printf("\n %s\n\n", perf_more_info_string);
436                 return 0;
437         }
438
439         alias = alias_lookup(argv[0]);
440         if (alias && !is_perf_command(argv[0])) {
441                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
442                 return 0;
443         }
444
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         default:
455                 break;
456         }
457
458         return 0;
459 }