Linux Audio

Check our new training course

Loading...
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * builtin-help.c
  4 *
  5 * Builtin help command
  6 */
  7#include "perf.h"
  8#include "util/config.h"
  9#include "builtin.h"
 10#include <subcmd/exec-cmd.h>
 11#include "common-cmds.h"
 12#include <subcmd/parse-options.h>
 13#include <subcmd/run-command.h>
 14#include <subcmd/help.h>
 15#include "util/debug.h"
 16#include <linux/kernel.h>
 17#include <errno.h>
 18#include <stdio.h>
 19#include <sys/types.h>
 20#include <sys/stat.h>
 21#include <unistd.h>
 22
 23static struct man_viewer_list {
 24	struct man_viewer_list *next;
 25	char name[0];
 26} *man_viewer_list;
 27
 28static struct man_viewer_info_list {
 29	struct man_viewer_info_list *next;
 30	const char *info;
 31	char name[0];
 32} *man_viewer_info_list;
 33
 34enum help_format {
 35	HELP_FORMAT_NONE,
 36	HELP_FORMAT_MAN,
 37	HELP_FORMAT_INFO,
 38	HELP_FORMAT_WEB,
 39};
 40
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 41static enum help_format parse_help_format(const char *format)
 42{
 43	if (!strcmp(format, "man"))
 44		return HELP_FORMAT_MAN;
 45	if (!strcmp(format, "info"))
 46		return HELP_FORMAT_INFO;
 47	if (!strcmp(format, "web") || !strcmp(format, "html"))
 48		return HELP_FORMAT_WEB;
 49
 50	pr_err("unrecognized help format '%s'", format);
 51	return HELP_FORMAT_NONE;
 52}
 53
 54static const char *get_man_viewer_info(const char *name)
 55{
 56	struct man_viewer_info_list *viewer;
 57
 58	for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
 59		if (!strcasecmp(name, viewer->name))
 60			return viewer->info;
 61	}
 62	return NULL;
 63}
 64
 65static int check_emacsclient_version(void)
 66{
 67	struct strbuf buffer = STRBUF_INIT;
 68	struct child_process ec_process;
 69	const char *argv_ec[] = { "emacsclient", "--version", NULL };
 70	int version;
 71	int ret = -1;
 72
 73	/* emacsclient prints its version number on stderr */
 74	memset(&ec_process, 0, sizeof(ec_process));
 75	ec_process.argv = argv_ec;
 76	ec_process.err = -1;
 77	ec_process.stdout_to_stderr = 1;
 78	if (start_command(&ec_process)) {
 79		fprintf(stderr, "Failed to start emacsclient.\n");
 80		return -1;
 81	}
 82	if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
 83		fprintf(stderr, "Failed to read emacsclient version\n");
 84		goto out;
 85	}
 86	close(ec_process.err);
 87
 88	/*
 89	 * Don't bother checking return value, because "emacsclient --version"
 90	 * seems to always exits with code 1.
 91	 */
 92	finish_command(&ec_process);
 93
 94	if (!strstarts(buffer.buf, "emacsclient")) {
 95		fprintf(stderr, "Failed to parse emacsclient version.\n");
 96		goto out;
 
 97	}
 98
 99	version = atoi(buffer.buf + strlen("emacsclient"));
 
100
101	if (version < 22) {
102		fprintf(stderr,
103			"emacsclient version '%d' too old (< 22).\n",
104			version);
105	} else
106		ret = 0;
107out:
108	strbuf_release(&buffer);
109	return ret;
110}
111
112static void exec_failed(const char *cmd)
113{
114	char sbuf[STRERR_BUFSIZE];
115	pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
116}
117
118static void exec_woman_emacs(const char *path, const char *page)
119{
120	if (!check_emacsclient_version()) {
121		/* This works only with emacsclient version >= 22. */
122		char *man_page;
123
124		if (!path)
125			path = "emacsclient";
126		if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
127			execlp(path, "emacsclient", "-e", man_page, NULL);
128			free(man_page);
129		}
130		exec_failed(path);
131	}
132}
133
134static void exec_man_konqueror(const char *path, const char *page)
135{
136	const char *display = getenv("DISPLAY");
137
138	if (display && *display) {
139		char *man_page;
140		const char *filename = "kfmclient";
141
142		/* It's simpler to launch konqueror using kfmclient. */
143		if (path) {
144			const char *file = strrchr(path, '/');
145			if (file && !strcmp(file + 1, "konqueror")) {
146				char *new = strdup(path);
147				char *dest = strrchr(new, '/');
148
149				/* strlen("konqueror") == strlen("kfmclient") */
150				strcpy(dest + 1, "kfmclient");
151				path = new;
152			}
153			if (file)
154				filename = file;
155		} else
156			path = "kfmclient";
157		if (asprintf(&man_page, "man:%s(1)", page) > 0) {
158			execlp(path, filename, "newTab", man_page, NULL);
159			free(man_page);
160		}
161		exec_failed(path);
162	}
163}
164
165static void exec_man_man(const char *path, const char *page)
166{
167	if (!path)
168		path = "man";
169	execlp(path, "man", page, NULL);
170	exec_failed(path);
171}
172
173static void exec_man_cmd(const char *cmd, const char *page)
174{
175	char *shell_cmd;
176
177	if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
178		execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
179		free(shell_cmd);
180	}
181	exec_failed(cmd);
182}
183
184static void add_man_viewer(const char *name)
185{
186	struct man_viewer_list **p = &man_viewer_list;
187	size_t len = strlen(name);
188
189	while (*p)
190		p = &((*p)->next);
191	*p = zalloc(sizeof(**p) + len + 1);
192	strncpy((*p)->name, name, len);
193}
194
195static int supported_man_viewer(const char *name, size_t len)
196{
197	return (!strncasecmp("man", name, len) ||
198		!strncasecmp("woman", name, len) ||
199		!strncasecmp("konqueror", name, len));
200}
201
202static void do_add_man_viewer_info(const char *name,
203				   size_t len,
204				   const char *value)
205{
206	struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
207
208	strncpy(new->name, name, len);
209	new->info = strdup(value);
210	new->next = man_viewer_info_list;
211	man_viewer_info_list = new;
212}
213
214static void unsupported_man_viewer(const char *name, const char *var)
215{
216	pr_warning("'%s': path for unsupported man viewer.\n"
217		   "Please consider using 'man.<tool>.%s' instead.", name, var);
218}
219
220static int add_man_viewer_path(const char *name,
221			       size_t len,
222			       const char *value)
223{
224	if (supported_man_viewer(name, len))
225		do_add_man_viewer_info(name, len, value);
226	else
227		unsupported_man_viewer(name, "cmd");
 
 
228
229	return 0;
230}
231
232static int add_man_viewer_cmd(const char *name,
233			      size_t len,
234			      const char *value)
235{
236	if (supported_man_viewer(name, len))
237		unsupported_man_viewer(name, "path");
 
 
238	else
239		do_add_man_viewer_info(name, len, value);
240
241	return 0;
242}
243
244static int add_man_viewer_info(const char *var, const char *value)
245{
246	const char *name = var + 4;
247	const char *subkey = strrchr(name, '.');
248
249	if (!subkey) {
250		pr_err("Config with no key for man viewer: %s", name);
251		return -1;
252	}
253
254	if (!strcmp(subkey, ".path")) {
255		if (!value)
256			return config_error_nonbool(var);
257		return add_man_viewer_path(name, subkey - name, value);
258	}
259	if (!strcmp(subkey, ".cmd")) {
260		if (!value)
261			return config_error_nonbool(var);
262		return add_man_viewer_cmd(name, subkey - name, value);
263	}
264
265	pr_warning("'%s': unsupported man viewer sub key.", subkey);
266	return 0;
267}
268
269static int perf_help_config(const char *var, const char *value, void *cb)
270{
271	enum help_format *help_formatp = cb;
272
273	if (!strcmp(var, "help.format")) {
274		if (!value)
275			return config_error_nonbool(var);
276		*help_formatp = parse_help_format(value);
277		if (*help_formatp == HELP_FORMAT_NONE)
278			return -1;
279		return 0;
280	}
281	if (!strcmp(var, "man.viewer")) {
282		if (!value)
283			return config_error_nonbool(var);
284		add_man_viewer(value);
285		return 0;
286	}
287	if (strstarts(var, "man."))
288		return add_man_viewer_info(var, value);
289
290	return 0;
291}
292
293static struct cmdnames main_cmds, other_cmds;
294
295void list_common_cmds_help(void)
296{
297	unsigned int i, longest = 0;
298
299	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
300		if (longest < strlen(common_cmds[i].name))
301			longest = strlen(common_cmds[i].name);
302	}
303
304	puts(" The most commonly used perf commands are:");
305	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
306		printf("   %-*s   ", longest, common_cmds[i].name);
307		puts(common_cmds[i].help);
308	}
309}
310
311static const char *cmd_to_page(const char *perf_cmd)
312{
313	char *s;
 
 
 
 
 
 
 
 
 
 
 
 
314
 
 
315	if (!perf_cmd)
316		return "perf";
317	else if (strstarts(perf_cmd, "perf"))
318		return perf_cmd;
319
320	return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
321}
322
323static void setup_man_path(void)
324{
325	char *new_path;
326	const char *old_path = getenv("MANPATH");
327
328	/* We should always put ':' after our path. If there is no
329	 * old_path, the ':' at the end will let 'man' to try
330	 * system-wide paths after ours to find the manual page. If
331	 * there is old_path, we need ':' as delimiter. */
332	if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
333		setenv("MANPATH", new_path, 1);
334		free(new_path);
335	} else {
336		pr_err("Unable to setup man path");
337	}
 
 
338}
339
340static void exec_viewer(const char *name, const char *page)
341{
342	const char *info = get_man_viewer_info(name);
343
344	if (!strcasecmp(name, "man"))
345		exec_man_man(info, page);
346	else if (!strcasecmp(name, "woman"))
347		exec_woman_emacs(info, page);
348	else if (!strcasecmp(name, "konqueror"))
349		exec_man_konqueror(info, page);
350	else if (info)
351		exec_man_cmd(info, page);
352	else
353		pr_warning("'%s': unknown man viewer.", name);
354}
355
356static int show_man_page(const char *perf_cmd)
357{
358	struct man_viewer_list *viewer;
359	const char *page = cmd_to_page(perf_cmd);
360	const char *fallback = getenv("PERF_MAN_VIEWER");
361
362	setup_man_path();
363	for (viewer = man_viewer_list; viewer; viewer = viewer->next)
364		exec_viewer(viewer->name, page); /* will return when unable */
365
366	if (fallback)
367		exec_viewer(fallback, page);
368	exec_viewer("man", page);
369
370	pr_err("no man viewer handled the request");
371	return -1;
372}
373
374static int show_info_page(const char *perf_cmd)
375{
376	const char *page = cmd_to_page(perf_cmd);
377	setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
378	execlp("info", "info", "perfman", page, NULL);
379	return -1;
380}
381
382static int get_html_page_path(char **page_path, const char *page)
383{
384	struct stat st;
385	const char *html_path = system_path(PERF_HTML_PATH);
386
387	/* Check that we have a perf documentation directory. */
388	if (stat(mkpath("%s/perf.html", html_path), &st)
389	    || !S_ISREG(st.st_mode)) {
390		pr_err("'%s': not a documentation directory.", html_path);
391		return -1;
392	}
393
394	return asprintf(page_path, "%s/%s.html", html_path, page);
 
395}
396
397/*
398 * If open_html is not defined in a platform-specific way (see for
399 * example compat/mingw.h), we use the script web--browse to display
400 * HTML.
401 */
402#ifndef open_html
403static void open_html(const char *path)
404{
405	execl_cmd("web--browse", "-c", "help.browser", path, NULL);
406}
407#endif
408
409static int show_html_page(const char *perf_cmd)
410{
411	const char *page = cmd_to_page(perf_cmd);
412	char *page_path; /* it leaks but we exec bellow */
413
414	if (get_html_page_path(&page_path, page) < 0)
415		return -1;
416
417	open_html(page_path);
418
419	return 0;
420}
421
422int cmd_help(int argc, const char **argv)
423{
424	bool show_all = false;
425	enum help_format help_format = HELP_FORMAT_MAN;
426	struct option builtin_help_options[] = {
427	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
428	OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
429	OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
430			HELP_FORMAT_WEB),
431	OPT_SET_UINT('i', "info", &help_format, "show info page",
432			HELP_FORMAT_INFO),
433	OPT_END(),
434	};
435	const char * const builtin_help_subcommands[] = {
436		"buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
437		"record", "report", "bench", "stat", "timechart", "top", "annotate",
438		"script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
439#ifdef HAVE_LIBELF_SUPPORT
440		"probe",
441#endif
442#if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
443		"trace",
444#endif
445	NULL };
446	const char *builtin_help_usage[] = {
447		"perf help [--all] [--man|--web|--info] [command]",
448		NULL
449	};
450	int rc;
451
452	load_command_list("perf-", &main_cmds, &other_cmds);
453
454	rc = perf_config(perf_help_config, &help_format);
455	if (rc)
456		return rc;
457
458	argc = parse_options_subcommand(argc, argv, builtin_help_options,
459			builtin_help_subcommands, builtin_help_usage, 0);
460
461	if (show_all) {
462		printf("\n Usage: %s\n\n", perf_usage_string);
463		list_commands("perf commands", &main_cmds, &other_cmds);
464		printf(" %s\n\n", perf_more_info_string);
465		return 0;
466	}
467
468	if (!argv[0]) {
469		printf("\n usage: %s\n\n", perf_usage_string);
470		list_common_cmds_help();
471		printf("\n %s\n\n", perf_more_info_string);
472		return 0;
473	}
474
 
 
 
 
 
 
475	switch (help_format) {
476	case HELP_FORMAT_MAN:
477		rc = show_man_page(argv[0]);
478		break;
479	case HELP_FORMAT_INFO:
480		rc = show_info_page(argv[0]);
481		break;
482	case HELP_FORMAT_WEB:
483		rc = show_html_page(argv[0]);
484		break;
485	case HELP_FORMAT_NONE:
486		/* fall-through */
487	default:
488		rc = -1;
489		break;
490	}
491
492	return rc;
493}
v3.1
 
  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}