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
15static struct man_viewer_list {
16	struct man_viewer_list *next;
17	char name[FLEX_ARRAY];
18} *man_viewer_list;
19
20static 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
26enum help_format {
27	HELP_FORMAT_MAN,
28	HELP_FORMAT_INFO,
29	HELP_FORMAT_WEB,
30};
31
32static bool show_all = false;
33static enum help_format help_format = HELP_FORMAT_MAN;
34static struct option builtin_help_options[] = {
35	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
36	OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
37	OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
38			HELP_FORMAT_WEB),
39	OPT_SET_UINT('i', "info", &help_format, "show info page",
40			HELP_FORMAT_INFO),
41	OPT_END(),
42};
43
44static const char * const builtin_help_usage[] = {
45	"perf help [--all] [--man|--web|--info] [command]",
46	NULL
47};
48
49static 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
60static 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
71static 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
117static 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
131static 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
159static 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
167static 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
175static 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
186static 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
193static 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
205static 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
219static 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
233static 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
256static 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
276static struct cmdnames main_cmds, other_cmds;
277
278void 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
294static 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
300static 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
310static 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
320static 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
339static 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
355static 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
371static 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
378static 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
398static void open_html(const char *path)
399{
400	execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
401}
402#endif
403
404static 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
414int 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}
460