[deliverable/linux.git] / tools / perf / builtin-help.c

/*
 * builtin-help.c
 *
 * Builtin help command
 */
#include "perf.h"
#include "util/cache.h"
#include "builtin.h"
#include <subcmd/exec-cmd.h>
#include "common-cmds.h"
#include <subcmd/parse-options.h>
#include <subcmd/run-command.h>
#include <subcmd/help.h>
#include "util/debug.h"

static struct man_viewer_list {
	struct man_viewer_list *next;
	char name[FLEX_ARRAY];
} *man_viewer_list;

static struct man_viewer_info_list {
	struct man_viewer_info_list *next;
	const char *info;
	char name[FLEX_ARRAY];
} *man_viewer_info_list;

enum help_format {
	HELP_FORMAT_NONE,
	HELP_FORMAT_MAN,
	HELP_FORMAT_INFO,
	HELP_FORMAT_WEB,
};

static enum help_format parse_help_format(const char *format)
{
	if (!strcmp(format, "man"))
		return HELP_FORMAT_MAN;
	if (!strcmp(format, "info"))
		return HELP_FORMAT_INFO;
	if (!strcmp(format, "web") || !strcmp(format, "html"))
		return HELP_FORMAT_WEB;

	pr_err("unrecognized help format '%s'", format);
	return HELP_FORMAT_NONE;
}

static const char *get_man_viewer_info(const char *name)
{
	struct man_viewer_info_list *viewer;

	for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
		if (!strcasecmp(name, viewer->name))
			return viewer->info;
	}
	return NULL;
}

static int check_emacsclient_version(void)
{
	struct strbuf buffer = STRBUF_INIT;
	struct child_process ec_process;
	const char *argv_ec[] = { "emacsclient", "--version", NULL };
	int version;

	/* emacsclient prints its version number on stderr */
	memset(&ec_process, 0, sizeof(ec_process));
	ec_process.argv = argv_ec;
	ec_process.err = -1;
	ec_process.stdout_to_stderr = 1;
	if (start_command(&ec_process)) {
		fprintf(stderr, "Failed to start emacsclient.\n");
		return -1;
	}
	strbuf_read(&buffer, ec_process.err, 20);
	close(ec_process.err);

	/*
	 * Don't bother checking return value, because "emacsclient --version"
	 * seems to always exits with code 1.
	 */
	finish_command(&ec_process);

	if (prefixcmp(buffer.buf, "emacsclient")) {
		fprintf(stderr, "Failed to parse emacsclient version.\n");
		strbuf_release(&buffer);
		return -1;
	}

	version = atoi(buffer.buf + strlen("emacsclient"));

	if (version < 22) {
		fprintf(stderr,
			"emacsclient version '%d' too old (< 22).\n",
			version);
		strbuf_release(&buffer);
		return -1;
	}

	strbuf_release(&buffer);
	return 0;
}

static void exec_woman_emacs(const char *path, const char *page)
{
	char sbuf[STRERR_BUFSIZE];

	if (!check_emacsclient_version()) {
		/* This works only with emacsclient version >= 22. */
		char *man_page;

		if (!path)
			path = "emacsclient";
		if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
			execlp(path, "emacsclient", "-e", man_page, NULL);
			free(man_page);
		}
		warning("failed to exec '%s': %s", path,
			strerror_r(errno, sbuf, sizeof(sbuf)));
	}
}

static void exec_man_konqueror(const char *path, const char *page)
{
	const char *display = getenv("DISPLAY");

	if (display && *display) {
		char *man_page;
		const char *filename = "kfmclient";
		char sbuf[STRERR_BUFSIZE];

		/* It's simpler to launch konqueror using kfmclient. */
		if (path) {
			const char *file = strrchr(path, '/');
			if (file && !strcmp(file + 1, "konqueror")) {
				char *new = strdup(path);
				char *dest = strrchr(new, '/');

				/* strlen("konqueror") == strlen("kfmclient") */
				strcpy(dest + 1, "kfmclient");
				path = new;
			}
			if (file)
				filename = file;
		} else
			path = "kfmclient";
		if (asprintf(&man_page, "man:%s(1)", page) > 0) {
			execlp(path, filename, "newTab", man_page, NULL);
			free(man_page);
		}
		warning("failed to exec '%s': %s", path,
			strerror_r(errno, sbuf, sizeof(sbuf)));
	}
}

static void exec_man_man(const char *path, const char *page)
{
	char sbuf[STRERR_BUFSIZE];

	if (!path)
		path = "man";
	execlp(path, "man", page, NULL);
	warning("failed to exec '%s': %s", path,
		strerror_r(errno, sbuf, sizeof(sbuf)));
}

static void exec_man_cmd(const char *cmd, const char *page)
{
	char sbuf[STRERR_BUFSIZE];
	char *shell_cmd;

	if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
		execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
		free(shell_cmd);
	}
	warning("failed to exec '%s': %s", cmd,
		strerror_r(errno, sbuf, sizeof(sbuf)));
}

static void add_man_viewer(const char *name)
{
	struct man_viewer_list **p = &man_viewer_list;
	size_t len = strlen(name);

	while (*p)
		p = &((*p)->next);
	*p = zalloc(sizeof(**p) + len + 1);
	strncpy((*p)->name, name, len);
}

static int supported_man_viewer(const char *name, size_t len)
{
	return (!strncasecmp("man", name, len) ||
		!strncasecmp("woman", name, len) ||
		!strncasecmp("konqueror", name, len));
}

static void do_add_man_viewer_info(const char *name,
				   size_t len,
				   const char *value)
{
	struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);

	strncpy(new->name, name, len);
	new->info = strdup(value);
	new->next = man_viewer_info_list;
	man_viewer_info_list = new;
}

static int add_man_viewer_path(const char *name,
			       size_t len,
			       const char *value)
{
	if (supported_man_viewer(name, len))
		do_add_man_viewer_info(name, len, value);
	else
		warning("'%s': path for unsupported man viewer.\n"
			"Please consider using 'man.<tool>.cmd' instead.",
			name);

	return 0;
}

static int add_man_viewer_cmd(const char *name,
			      size_t len,
			      const char *value)
{
	if (supported_man_viewer(name, len))
		warning("'%s': cmd for supported man viewer.\n"
			"Please consider using 'man.<tool>.path' instead.",
			name);
	else
		do_add_man_viewer_info(name, len, value);

	return 0;
}

static int add_man_viewer_info(const char *var, const char *value)
{
	const char *name = var + 4;
	const char *subkey = strrchr(name, '.');

	if (!subkey)
		return error("Config with no key for man viewer: %s", name);

	if (!strcmp(subkey, ".path")) {
		if (!value)
			return config_error_nonbool(var);
		return add_man_viewer_path(name, subkey - name, value);
	}
	if (!strcmp(subkey, ".cmd")) {
		if (!value)
			return config_error_nonbool(var);
		return add_man_viewer_cmd(name, subkey - name, value);
	}

	warning("'%s': unsupported man viewer sub key.", subkey);
	return 0;
}

static int perf_help_config(const char *var, const char *value, void *cb)
{
	enum help_format *help_formatp = cb;

	if (!strcmp(var, "help.format")) {
		if (!value)
			return config_error_nonbool(var);
		*help_formatp = parse_help_format(value);
		if (*help_formatp == HELP_FORMAT_NONE)
			return -1;
		return 0;
	}
	if (!strcmp(var, "man.viewer")) {
		if (!value)
			return config_error_nonbool(var);
		add_man_viewer(value);
		return 0;
	}
	if (!prefixcmp(var, "man."))
		return add_man_viewer_info(var, value);

	return 0;
}

static struct cmdnames main_cmds, other_cmds;

void list_common_cmds_help(void)
{
	unsigned int i, longest = 0;

	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
		if (longest < strlen(common_cmds[i].name))
			longest = strlen(common_cmds[i].name);
	}

	puts(" The most commonly used perf commands are:");
	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
		printf("   %-*s   ", longest, common_cmds[i].name);
		puts(common_cmds[i].help);
	}
}

static int is_perf_command(const char *s)
{
	return is_in_cmdlist(&main_cmds, s) ||
		is_in_cmdlist(&other_cmds, s);
}

static const char *cmd_to_page(const char *perf_cmd)
{
	char *s;

	if (!perf_cmd)
		return "perf";
	else if (!prefixcmp(perf_cmd, "perf"))
		return perf_cmd;

	return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
}

static void setup_man_path(void)
{
	char *new_path;
	const char *old_path = getenv("MANPATH");

	/* We should always put ':' after our path. If there is no
	 * old_path, the ':' at the end will let 'man' to try
	 * system-wide paths after ours to find the manual page. If
	 * there is old_path, we need ':' as delimiter. */
	if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
		setenv("MANPATH", new_path, 1);
		free(new_path);
	} else {
		error("Unable to setup man path");
	}
}

static void exec_viewer(const char *name, const char *page)
{
	const char *info = get_man_viewer_info(name);

	if (!strcasecmp(name, "man"))
		exec_man_man(info, page);
	else if (!strcasecmp(name, "woman"))
		exec_woman_emacs(info, page);
	else if (!strcasecmp(name, "konqueror"))
		exec_man_konqueror(info, page);
	else if (info)
		exec_man_cmd(info, page);
	else
		warning("'%s': unknown man viewer.", name);
}

static int show_man_page(const char *perf_cmd)
{
	struct man_viewer_list *viewer;
	const char *page = cmd_to_page(perf_cmd);
	const char *fallback = getenv("PERF_MAN_VIEWER");

	setup_man_path();
	for (viewer = man_viewer_list; viewer; viewer = viewer->next)
		exec_viewer(viewer->name, page); /* will return when unable */

	if (fallback)
		exec_viewer(fallback, page);
	exec_viewer("man", page);

	pr_err("no man viewer handled the request");
	return -1;
}

static int show_info_page(const char *perf_cmd)
{
	const char *page = cmd_to_page(perf_cmd);
	setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
	execlp("info", "info", "perfman", page, NULL);
	return -1;
}

static int get_html_page_path(char **page_path, const char *page)
{
	struct stat st;
	const char *html_path = system_path(PERF_HTML_PATH);

	/* Check that we have a perf documentation directory. */
	if (stat(mkpath("%s/perf.html", html_path), &st)
	    || !S_ISREG(st.st_mode)) {
		pr_err("'%s': not a documentation directory.", html_path);
		return -1;
	}

	return asprintf(page_path, "%s/%s.html", html_path, page);
}

/*
 * If open_html is not defined in a platform-specific way (see for
 * example compat/mingw.h), we use the script web--browse to display
 * HTML.
 */
#ifndef open_html
static void open_html(const char *path)
{
	execl_cmd("web--browse", "-c", "help.browser", path, NULL);
}
#endif

static int show_html_page(const char *perf_cmd)
{
	const char *page = cmd_to_page(perf_cmd);
	char *page_path; /* it leaks but we exec bellow */

	if (get_html_page_path(&page_path, page) < 0)
		return -1;

	open_html(page_path);

	return 0;
}

int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
{
	bool show_all = false;
	enum help_format help_format = HELP_FORMAT_MAN;
	struct option builtin_help_options[] = {
	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
	OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
	OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
			HELP_FORMAT_WEB),
	OPT_SET_UINT('i', "info", &help_format, "show info page",
			HELP_FORMAT_INFO),
	OPT_END(),
	};
	const char * const builtin_help_subcommands[] = {
		"buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
		"record", "report", "bench", "stat", "timechart", "top", "annotate",
		"script", "sched", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
#ifdef HAVE_LIBELF_SUPPORT
		"probe",
#endif
#ifdef HAVE_LIBAUDIT_SUPPORT
		"trace",
#endif
	NULL };
	const char *builtin_help_usage[] = {
		"perf help [--all] [--man|--web|--info] [command]",
		NULL
	};
	const char *alias;
	int rc = 0;

	load_command_list("perf-", &main_cmds, &other_cmds);

	perf_config(perf_help_config, &help_format);

	argc = parse_options_subcommand(argc, argv, builtin_help_options,
			builtin_help_subcommands, builtin_help_usage, 0);

	if (show_all) {
		printf("\n Usage: %s\n\n", perf_usage_string);
		list_commands("perf commands", &main_cmds, &other_cmds);
		printf(" %s\n\n", perf_more_info_string);
		return 0;
	}

	if (!argv[0]) {
		printf("\n usage: %s\n\n", perf_usage_string);
		list_common_cmds_help();
		printf("\n %s\n\n", perf_more_info_string);
		return 0;
	}

	alias = alias_lookup(argv[0]);
	if (alias && !is_perf_command(argv[0])) {
		printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
		return 0;
	}

	switch (help_format) {
	case HELP_FORMAT_MAN:
		rc = show_man_page(argv[0]);
		break;
	case HELP_FORMAT_INFO:
		rc = show_info_page(argv[0]);
		break;
	case HELP_FORMAT_WEB:
		rc = show_html_page(argv[0]);
		break;
	case HELP_FORMAT_NONE:
		/* fall-through */
	default:
		rc = -1;
		break;
	}

	return rc;
}
Commit	Line	Data
07800601 IM	1	/*
	2	* builtin-help.c
	3	*
	4	* Builtin help command
	5	*/
f37a291c	6	#include "perf.h"
148be2c1	7	#include "util/cache.h"
07800601	8	#include "builtin.h"
4b6ab94e	9	#include <subcmd/exec-cmd.h>
07800601	10	#include "common-cmds.h"
4b6ab94e JP	11	#include <subcmd/parse-options.h>
	12	#include <subcmd/run-command.h>
	13	#include <subcmd/help.h>
84f5d36f	14	#include "util/debug.h"
07800601 IM	15
	16	static struct man_viewer_list {
	17	struct man_viewer_list *next;
	18	char name[FLEX_ARRAY];
	19	} *man_viewer_list;
	20
	21	static 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
	27	enum help_format {
cc584821	28	HELP_FORMAT_NONE,
07800601 IM	29	HELP_FORMAT_MAN,
	30	HELP_FORMAT_INFO,
	31	HELP_FORMAT_WEB,
	32	};
	33
07800601 IM	34	static 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;
cc584821 DA	42
	43	pr_err("unrecognized help format '%s'", format);
	44	return HELP_FORMAT_NONE;
07800601 IM	45	}
	46
	47	static const char get_man_viewer_info(const char name)
	48	{
	49	struct man_viewer_info_list *viewer;
	50
c1e53017	51	for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
07800601 IM	52	if (!strcasecmp(name, viewer->name))
	53	return viewer->info;
	54	}
	55	return NULL;
	56	}
	57
	58	static 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
d1130686	89	version = atoi(buffer.buf + strlen("emacsclient"));
07800601 IM	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
c1e53017	103	static void exec_woman_emacs(const char path, const char page)
07800601	104	{
ede395d2 MH	105	char sbuf[STRERR_BUFSIZE];
ede395d2 MH	106
07800601 IM	107	if (!check_emacsclient_version()) {
07800601 IM	108	/* This works only with emacsclient version >= 22. */
a610f5cb	109	char *man_page;
07800601 IM	110
	111	if (!path)
	112	path = "emacsclient";
a610f5cb ACM	113	if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
	114	execlp(path, "emacsclient", "-e", man_page, NULL);
	115	free(man_page);
	116	}
ede395d2 MH	117	warning("failed to exec '%s': %s", path,
ede395d2 MH	118	strerror_r(errno, sbuf, sizeof(sbuf)));
07800601 IM	119	}
	120	}
	121
c1e53017	122	static void exec_man_konqueror(const char path, const char page)
07800601 IM	123	{
07800601 IM	124	const char *display = getenv("DISPLAY");
ede395d2	125
07800601	126	if (display && *display) {
a610f5cb	127	char *man_page;
07800601	128	const char *filename = "kfmclient";
ede395d2	129	char sbuf[STRERR_BUFSIZE];
07800601 IM	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";
a610f5cb ACM	146	if (asprintf(&man_page, "man:%s(1)", page) > 0) {
	147	execlp(path, filename, "newTab", man_page, NULL);
	148	free(man_page);
	149	}
ede395d2 MH	150	warning("failed to exec '%s': %s", path,
ede395d2 MH	151	strerror_r(errno, sbuf, sizeof(sbuf)));
07800601 IM	152	}
	153	}
	154
c1e53017	155	static void exec_man_man(const char path, const char page)
07800601	156	{
ede395d2 MH	157	char sbuf[STRERR_BUFSIZE];
ede395d2 MH	158
07800601 IM	159	if (!path)
	160	path = "man";
	161	execlp(path, "man", page, NULL);
ede395d2 MH	162	warning("failed to exec '%s': %s", path,
ede395d2 MH	163	strerror_r(errno, sbuf, sizeof(sbuf)));
07800601 IM	164	}
	165
	166	static void exec_man_cmd(const char cmd, const char page)
	167	{
ede395d2	168	char sbuf[STRERR_BUFSIZE];
a610f5cb	169	char *shell_cmd;
ede395d2	170
a610f5cb ACM	171	if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
	172	execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
	173	free(shell_cmd);
	174	}
ede395d2 MH	175	warning("failed to exec '%s': %s", cmd,
ede395d2 MH	176	strerror_r(errno, sbuf, sizeof(sbuf)));
07800601 IM	177	}
	178
	179	static 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);
36479484	186	p = zalloc(sizeof(*p) + len + 1);
07800601 IM	187	strncpy((*p)->name, name, len);
	188	}
	189
	190	static 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
	197	static void do_add_man_viewer_info(const char *name,
	198	size_t len,
	199	const char *value)
	200	{
36479484	201	struct man_viewer_info_list new = zalloc(sizeof(new) + len + 1);
07800601 IM	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
	209	static 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
	223	static 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
	237	static 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
	260	static int perf_help_config(const char var, const char value, void *cb)
	261	{
2bae1d1b ACM	262	enum help_format *help_formatp = cb;
2bae1d1b ACM	263
07800601 IM	264	if (!strcmp(var, "help.format")) {
	265	if (!value)
	266	return config_error_nonbool(var);
2bae1d1b ACM	267	*help_formatp = parse_help_format(value);
2bae1d1b ACM	268	if (*help_formatp == HELP_FORMAT_NONE)
cc584821	269	return -1;
07800601 IM	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
b8cbb349	281	return 0;
07800601 IM	282	}
	283
	284	static struct cmdnames main_cmds, other_cmds;
	285
	286	void list_common_cmds_help(void)
	287	{
f37a291c	288	unsigned int i, longest = 0;
07800601 IM	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
502fc5c7	295	puts(" The most commonly used perf commands are:");
07800601	296	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
3912f2ab	297	printf(" %-*s ", longest, common_cmds[i].name);
07800601 IM	298	puts(common_cmds[i].help);
	299	}
	300	}
	301
	302	static 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
07800601 IM	308	static const char cmd_to_page(const char perf_cmd)
07800601 IM	309	{
a610f5cb ACM	310	char *s;
a610f5cb ACM	311
07800601 IM	312	if (!perf_cmd)
	313	return "perf";
	314	else if (!prefixcmp(perf_cmd, "perf"))
	315	return perf_cmd;
a610f5cb ACM	316
a610f5cb ACM	317	return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
07800601 IM	318	}
	319
	320	static void setup_man_path(void)
	321	{
a610f5cb	322	char *new_path;
07800601 IM	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. */
a610f5cb ACM	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	}
07800601 IM	335	}
	336
	337	static 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
cc584821	353	static int show_man_page(const char *perf_cmd)
07800601 IM	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)
07800601	361	exec_viewer(viewer->name, page); /* will return when unable */
c1e53017	362
07800601 IM	363	if (fallback)
	364	exec_viewer(fallback, page);
	365	exec_viewer("man", page);
cc584821 DA	366
	367	pr_err("no man viewer handled the request");
	368	return -1;
07800601 IM	369	}
07800601 IM	370
cc584821	371	static int show_info_page(const char *perf_cmd)
07800601 IM	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);
cc584821	376	return -1;
07800601 IM	377	}
07800601 IM	378
a610f5cb	379	static int get_html_page_path(char *page_path, const char page)
07800601 IM	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)
cc584821 DA	386	\|\| !S_ISREG(st.st_mode)) {
	387	pr_err("'%s': not a documentation directory.", html_path);
	388	return -1;
	389	}
07800601	390
a610f5cb	391	return asprintf(page_path, "%s/%s.html", html_path, page);
07800601 IM	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
16f762a2	400	static void open_html(const char *path)
07800601	401	{
46113a54	402	execl_cmd("web--browse", "-c", "help.browser", path, NULL);
07800601 IM	403	}
	404	#endif
	405
cc584821	406	static int show_html_page(const char *perf_cmd)
07800601 IM	407	{
07800601 IM	408	const char *page = cmd_to_page(perf_cmd);
a610f5cb	409	char page_path; / it leaks but we exec bellow */
07800601	410
a610f5cb	411	if (get_html_page_path(&page_path, page) < 0)
cc584821	412	return -1;
07800601	413
a610f5cb	414	open_html(page_path);
cc584821 DA	415
cc584821 DA	416	return 0;
07800601 IM	417	}
07800601 IM	418
1d037ca1	419	int cmd_help(int argc, const char *argv, const char prefix __maybe_unused)
07800601	420	{
2bae1d1b	421	bool show_all = false;
670ab5d2	422	enum help_format help_format = HELP_FORMAT_MAN;
2bae1d1b ACM	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	};
e24a1108 YS	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[] = {
2bae1d1b ACM	444	"perf help [--all] [--man\|--web\|--info] [command]",
	445	NULL
	446	};
07800601	447	const char *alias;
cc584821	448	int rc = 0;
f37a291c	449
07800601 IM	450	load_command_list("perf-", &main_cmds, &other_cmds);
07800601 IM	451
2bae1d1b	452	perf_config(perf_help_config, &help_format);
07800601	453
e24a1108 YS	454	argc = parse_options_subcommand(argc, argv, builtin_help_options,
e24a1108 YS	455	builtin_help_subcommands, builtin_help_usage, 0);
07800601 IM	456
07800601 IM	457	if (show_all) {
3a134ae9	458	printf("\n Usage: %s\n\n", perf_usage_string);
07800601	459	list_commands("perf commands", &main_cmds, &other_cmds);
502fc5c7	460	printf(" %s\n\n", perf_more_info_string);
07800601 IM	461	return 0;
	462	}
	463
	464	if (!argv[0]) {
502fc5c7	465	printf("\n usage: %s\n\n", perf_usage_string);
07800601	466	list_common_cmds_help();
502fc5c7	467	printf("\n %s\n\n", perf_more_info_string);
07800601 IM	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:
cc584821	479	rc = show_man_page(argv[0]);
07800601 IM	480	break;
07800601 IM	481	case HELP_FORMAT_INFO:
cc584821	482	rc = show_info_page(argv[0]);
07800601 IM	483	break;
07800601 IM	484	case HELP_FORMAT_WEB:
cc584821 DA	485	rc = show_html_page(argv[0]);
	486	break;
	487	case HELP_FORMAT_NONE:
	488	/* fall-through */
83a0944f	489	default:
cc584821	490	rc = -1;
07800601 IM	491	break;
	492	}
	493
cc584821	494	return rc;
07800601	495	}