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v4.6
 
  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 <subcmd/exec-cmd.h>
 10#include "common-cmds.h"
 11#include <subcmd/parse-options.h>
 12#include <subcmd/run-command.h>
 13#include <subcmd/help.h>
 14#include "util/debug.h"
 
 
 
 
 
 
 15
 16static struct man_viewer_list {
 17	struct man_viewer_list *next;
 18	char name[FLEX_ARRAY];
 19} *man_viewer_list;
 20
 21static 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
 27enum help_format {
 28	HELP_FORMAT_NONE,
 29	HELP_FORMAT_MAN,
 30	HELP_FORMAT_INFO,
 31	HELP_FORMAT_WEB,
 32};
 33
 34static enum help_format parse_help_format(const char *format)
 35{
 36	if (!strcmp(format, "man"))
 37		return HELP_FORMAT_MAN;
 38	if (!strcmp(format, "info"))
 39		return HELP_FORMAT_INFO;
 40	if (!strcmp(format, "web") || !strcmp(format, "html"))
 41		return HELP_FORMAT_WEB;
 42
 43	pr_err("unrecognized help format '%s'", format);
 44	return HELP_FORMAT_NONE;
 45}
 46
 47static const char *get_man_viewer_info(const char *name)
 48{
 49	struct man_viewer_info_list *viewer;
 50
 51	for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
 52		if (!strcasecmp(name, viewer->name))
 53			return viewer->info;
 54	}
 55	return NULL;
 56}
 57
 58static int check_emacsclient_version(void)
 59{
 60	struct strbuf buffer = STRBUF_INIT;
 61	struct child_process ec_process;
 62	const char *argv_ec[] = { "emacsclient", "--version", NULL };
 63	int version;
 
 64
 65	/* emacsclient prints its version number on stderr */
 66	memset(&ec_process, 0, sizeof(ec_process));
 67	ec_process.argv = argv_ec;
 68	ec_process.err = -1;
 69	ec_process.stdout_to_stderr = 1;
 70	if (start_command(&ec_process)) {
 71		fprintf(stderr, "Failed to start emacsclient.\n");
 72		return -1;
 73	}
 74	strbuf_read(&buffer, ec_process.err, 20);
 
 
 
 75	close(ec_process.err);
 76
 77	/*
 78	 * Don't bother checking return value, because "emacsclient --version"
 79	 * seems to always exits with code 1.
 80	 */
 81	finish_command(&ec_process);
 82
 83	if (prefixcmp(buffer.buf, "emacsclient")) {
 84		fprintf(stderr, "Failed to parse emacsclient version.\n");
 85		strbuf_release(&buffer);
 86		return -1;
 87	}
 88
 89	version = atoi(buffer.buf + strlen("emacsclient"));
 90
 91	if (version < 22) {
 92		fprintf(stderr,
 93			"emacsclient version '%d' too old (< 22).\n",
 94			version);
 95		strbuf_release(&buffer);
 96		return -1;
 97	}
 98
 99	strbuf_release(&buffer);
100	return 0;
101}
102
103static void exec_woman_emacs(const char *path, const char *page)
104{
105	char sbuf[STRERR_BUFSIZE];
 
 
106
 
 
107	if (!check_emacsclient_version()) {
108		/* This works only with emacsclient version >= 22. */
109		char *man_page;
110
111		if (!path)
112			path = "emacsclient";
113		if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
114			execlp(path, "emacsclient", "-e", man_page, NULL);
115			free(man_page);
116		}
117		warning("failed to exec '%s': %s", path,
118			strerror_r(errno, sbuf, sizeof(sbuf)));
119	}
120}
121
122static void exec_man_konqueror(const char *path, const char *page)
123{
124	const char *display = getenv("DISPLAY");
125
126	if (display && *display) {
127		char *man_page;
128		const char *filename = "kfmclient";
129		char sbuf[STRERR_BUFSIZE];
130
131		/* It's simpler to launch konqueror using kfmclient. */
132		if (path) {
133			const char *file = strrchr(path, '/');
134			if (file && !strcmp(file + 1, "konqueror")) {
135				char *new = strdup(path);
136				char *dest = strrchr(new, '/');
137
138				/* strlen("konqueror") == strlen("kfmclient") */
139				strcpy(dest + 1, "kfmclient");
140				path = new;
141			}
142			if (file)
143				filename = file;
144		} else
145			path = "kfmclient";
146		if (asprintf(&man_page, "man:%s(1)", page) > 0) {
147			execlp(path, filename, "newTab", man_page, NULL);
148			free(man_page);
149		}
150		warning("failed to exec '%s': %s", path,
151			strerror_r(errno, sbuf, sizeof(sbuf)));
152	}
153}
154
155static void exec_man_man(const char *path, const char *page)
156{
157	char sbuf[STRERR_BUFSIZE];
158
159	if (!path)
160		path = "man";
161	execlp(path, "man", page, NULL);
162	warning("failed to exec '%s': %s", path,
163		strerror_r(errno, sbuf, sizeof(sbuf)));
164}
165
166static void exec_man_cmd(const char *cmd, const char *page)
167{
168	char sbuf[STRERR_BUFSIZE];
169	char *shell_cmd;
170
171	if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
172		execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
173		free(shell_cmd);
174	}
175	warning("failed to exec '%s': %s", cmd,
176		strerror_r(errno, sbuf, sizeof(sbuf)));
177}
178
179static void add_man_viewer(const char *name)
180{
181	struct man_viewer_list **p = &man_viewer_list;
182	size_t len = strlen(name);
183
184	while (*p)
185		p = &((*p)->next);
186	*p = zalloc(sizeof(**p) + len + 1);
187	strncpy((*p)->name, name, len);
188}
189
190static int supported_man_viewer(const char *name, size_t len)
191{
192	return (!strncasecmp("man", name, len) ||
193		!strncasecmp("woman", name, len) ||
194		!strncasecmp("konqueror", name, len));
195}
196
197static void do_add_man_viewer_info(const char *name,
198				   size_t len,
199				   const char *value)
200{
201	struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
202
203	strncpy(new->name, name, len);
204	new->info = strdup(value);
205	new->next = man_viewer_info_list;
206	man_viewer_info_list = new;
207}
208
 
 
 
 
 
 
209static int add_man_viewer_path(const char *name,
210			       size_t len,
211			       const char *value)
212{
213	if (supported_man_viewer(name, len))
214		do_add_man_viewer_info(name, len, value);
215	else
216		warning("'%s': path for unsupported man viewer.\n"
217			"Please consider using 'man.<tool>.cmd' instead.",
218			name);
219
220	return 0;
221}
222
223static int add_man_viewer_cmd(const char *name,
224			      size_t len,
225			      const char *value)
226{
227	if (supported_man_viewer(name, len))
228		warning("'%s': cmd for supported man viewer.\n"
229			"Please consider using 'man.<tool>.path' instead.",
230			name);
231	else
232		do_add_man_viewer_info(name, len, value);
233
234	return 0;
235}
236
237static int add_man_viewer_info(const char *var, const char *value)
238{
239	const char *name = var + 4;
240	const char *subkey = strrchr(name, '.');
241
242	if (!subkey)
243		return error("Config with no key for man viewer: %s", name);
 
 
244
245	if (!strcmp(subkey, ".path")) {
246		if (!value)
247			return config_error_nonbool(var);
248		return add_man_viewer_path(name, subkey - name, value);
249	}
250	if (!strcmp(subkey, ".cmd")) {
251		if (!value)
252			return config_error_nonbool(var);
253		return add_man_viewer_cmd(name, subkey - name, value);
254	}
255
256	warning("'%s': unsupported man viewer sub key.", subkey);
257	return 0;
258}
259
260static int perf_help_config(const char *var, const char *value, void *cb)
261{
262	enum help_format *help_formatp = cb;
263
264	if (!strcmp(var, "help.format")) {
265		if (!value)
266			return config_error_nonbool(var);
267		*help_formatp = parse_help_format(value);
268		if (*help_formatp == HELP_FORMAT_NONE)
269			return -1;
270		return 0;
271	}
272	if (!strcmp(var, "man.viewer")) {
273		if (!value)
274			return config_error_nonbool(var);
275		add_man_viewer(value);
276		return 0;
277	}
278	if (!prefixcmp(var, "man."))
279		return add_man_viewer_info(var, value);
280
281	return 0;
282}
283
284static struct cmdnames main_cmds, other_cmds;
285
286void list_common_cmds_help(void)
287{
288	unsigned int i, longest = 0;
289
290	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
291		if (longest < strlen(common_cmds[i].name))
292			longest = strlen(common_cmds[i].name);
293	}
294
295	puts(" The most commonly used perf commands are:");
296	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
297		printf("   %-*s   ", longest, common_cmds[i].name);
298		puts(common_cmds[i].help);
299	}
300}
301
302static int is_perf_command(const char *s)
303{
304	return is_in_cmdlist(&main_cmds, s) ||
305		is_in_cmdlist(&other_cmds, s);
306}
307
308static const char *cmd_to_page(const char *perf_cmd)
309{
310	char *s;
311
312	if (!perf_cmd)
313		return "perf";
314	else if (!prefixcmp(perf_cmd, "perf"))
315		return perf_cmd;
316
317	return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
318}
319
320static void setup_man_path(void)
321{
322	char *new_path;
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	if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
330		setenv("MANPATH", new_path, 1);
331		free(new_path);
332	} else {
333		error("Unable to setup man path");
334	}
335}
336
337static void exec_viewer(const char *name, const char *page)
338{
339	const char *info = get_man_viewer_info(name);
340
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);
351}
352
353static int show_man_page(const char *perf_cmd)
354{
355	struct man_viewer_list *viewer;
356	const char *page = cmd_to_page(perf_cmd);
357	const char *fallback = getenv("PERF_MAN_VIEWER");
358
359	setup_man_path();
360	for (viewer = man_viewer_list; viewer; viewer = viewer->next)
361		exec_viewer(viewer->name, page); /* will return when unable */
362
363	if (fallback)
364		exec_viewer(fallback, page);
365	exec_viewer("man", page);
366
367	pr_err("no man viewer handled the request");
368	return -1;
369}
370
371static int 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	return -1;
377}
378
379static int get_html_page_path(char **page_path, const char *page)
380{
381	struct stat st;
382	const char *html_path = system_path(PERF_HTML_PATH);
383
384	/* Check that we have a perf documentation directory. */
385	if (stat(mkpath("%s/perf.html", html_path), &st)
386	    || !S_ISREG(st.st_mode)) {
387		pr_err("'%s': not a documentation directory.", html_path);
388		return -1;
389	}
390
391	return asprintf(page_path, "%s/%s.html", html_path, page);
392}
393
394/*
395 * If open_html is not defined in a platform-specific way (see for
396 * example compat/mingw.h), we use the script web--browse to display
397 * HTML.
398 */
399#ifndef open_html
400static void open_html(const char *path)
401{
402	execl_cmd("web--browse", "-c", "help.browser", path, NULL);
403}
404#endif
405
406static int show_html_page(const char *perf_cmd)
407{
408	const char *page = cmd_to_page(perf_cmd);
409	char *page_path; /* it leaks but we exec bellow */
410
411	if (get_html_page_path(&page_path, page) < 0)
412		return -1;
413
414	open_html(page_path);
415
416	return 0;
417}
418
419int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
420{
421	bool show_all = false;
422	enum help_format help_format = HELP_FORMAT_MAN;
423	struct option builtin_help_options[] = {
424	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
425	OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
426	OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
427			HELP_FORMAT_WEB),
428	OPT_SET_UINT('i', "info", &help_format, "show info page",
429			HELP_FORMAT_INFO),
430	OPT_END(),
431	};
432	const char * const builtin_help_subcommands[] = {
433		"buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
434		"record", "report", "bench", "stat", "timechart", "top", "annotate",
435		"script", "sched", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
436#ifdef HAVE_LIBELF_SUPPORT
437		"probe",
438#endif
439#ifdef HAVE_LIBAUDIT_SUPPORT
440		"trace",
441#endif
442	NULL };
443	const char *builtin_help_usage[] = {
444		"perf help [--all] [--man|--web|--info] [command]",
445		NULL
446	};
447	const char *alias;
448	int rc = 0;
449
450	load_command_list("perf-", &main_cmds, &other_cmds);
451
452	perf_config(perf_help_config, &help_format);
 
 
453
454	argc = parse_options_subcommand(argc, argv, builtin_help_options,
455			builtin_help_subcommands, builtin_help_usage, 0);
456
457	if (show_all) {
458		printf("\n Usage: %s\n\n", perf_usage_string);
459		list_commands("perf commands", &main_cmds, &other_cmds);
460		printf(" %s\n\n", perf_more_info_string);
461		return 0;
462	}
463
464	if (!argv[0]) {
465		printf("\n usage: %s\n\n", perf_usage_string);
466		list_common_cmds_help();
467		printf("\n %s\n\n", perf_more_info_string);
468		return 0;
469	}
470
471	alias = alias_lookup(argv[0]);
472	if (alias && !is_perf_command(argv[0])) {
473		printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
474		return 0;
475	}
476
477	switch (help_format) {
478	case HELP_FORMAT_MAN:
479		rc = show_man_page(argv[0]);
480		break;
481	case HELP_FORMAT_INFO:
482		rc = show_info_page(argv[0]);
483		break;
484	case HELP_FORMAT_WEB:
485		rc = show_html_page(argv[0]);
486		break;
487	case HELP_FORMAT_NONE:
488		/* fall-through */
489	default:
490		rc = -1;
491		break;
492	}
493
494	return rc;
495}
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}