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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * builtin-help.c
4 *
5 * Builtin help command
6 */
7#include "util/cache.h"
8#include "util/config.h"
9#include "util/strbuf.h"
10#include "builtin.h"
11#include <subcmd/exec-cmd.h>
12#include "common-cmds.h"
13#include <subcmd/parse-options.h>
14#include <subcmd/run-command.h>
15#include <subcmd/help.h>
16#include "util/debug.h"
17#include <linux/kernel.h>
18#include <linux/string.h>
19#include <linux/zalloc.h>
20#include <errno.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <sys/types.h>
25#include <sys/stat.h>
26#include <unistd.h>
27
28static struct man_viewer_list {
29 struct man_viewer_list *next;
30 char name[0];
31} *man_viewer_list;
32
33static struct man_viewer_info_list {
34 struct man_viewer_info_list *next;
35 const char *info;
36 char name[0];
37} *man_viewer_info_list;
38
39enum help_format {
40 HELP_FORMAT_NONE,
41 HELP_FORMAT_MAN,
42 HELP_FORMAT_INFO,
43 HELP_FORMAT_WEB,
44};
45
46static enum help_format parse_help_format(const char *format)
47{
48 if (!strcmp(format, "man"))
49 return HELP_FORMAT_MAN;
50 if (!strcmp(format, "info"))
51 return HELP_FORMAT_INFO;
52 if (!strcmp(format, "web") || !strcmp(format, "html"))
53 return HELP_FORMAT_WEB;
54
55 pr_err("unrecognized help format '%s'", format);
56 return HELP_FORMAT_NONE;
57}
58
59static const char *get_man_viewer_info(const char *name)
60{
61 struct man_viewer_info_list *viewer;
62
63 for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
64 if (!strcasecmp(name, viewer->name))
65 return viewer->info;
66 }
67 return NULL;
68}
69
70static int check_emacsclient_version(void)
71{
72 struct strbuf buffer = STRBUF_INIT;
73 struct child_process ec_process;
74 const char *argv_ec[] = { "emacsclient", "--version", NULL };
75 int version;
76 int ret = -1;
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 if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
88 fprintf(stderr, "Failed to read emacsclient version\n");
89 goto out;
90 }
91 close(ec_process.err);
92
93 /*
94 * Don't bother checking return value, because "emacsclient --version"
95 * seems to always exits with code 1.
96 */
97 finish_command(&ec_process);
98
99 if (!strstarts(buffer.buf, "emacsclient")) {
100 fprintf(stderr, "Failed to parse emacsclient version.\n");
101 goto out;
102 }
103
104 version = atoi(buffer.buf + strlen("emacsclient"));
105
106 if (version < 22) {
107 fprintf(stderr,
108 "emacsclient version '%d' too old (< 22).\n",
109 version);
110 } else
111 ret = 0;
112out:
113 strbuf_release(&buffer);
114 return ret;
115}
116
117static void exec_failed(const char *cmd)
118{
119 char sbuf[STRERR_BUFSIZE];
120 pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
121}
122
123static void exec_woman_emacs(const char *path, const char *page)
124{
125 if (!check_emacsclient_version()) {
126 /* This works only with emacsclient version >= 22. */
127 char *man_page;
128
129 if (!path)
130 path = "emacsclient";
131 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
132 execlp(path, "emacsclient", "-e", man_page, NULL);
133 free(man_page);
134 }
135 exec_failed(path);
136 }
137}
138
139static void exec_man_konqueror(const char *path, const char *page)
140{
141 const char *display = getenv("DISPLAY");
142
143 if (display && *display) {
144 char *man_page;
145 const char *filename = "kfmclient";
146
147 /* It's simpler to launch konqueror using kfmclient. */
148 if (path) {
149 const char *file = strrchr(path, '/');
150 if (file && !strcmp(file + 1, "konqueror")) {
151 char *new = strdup(path);
152 char *dest = strrchr(new, '/');
153
154 /* strlen("konqueror") == strlen("kfmclient") */
155 strcpy(dest + 1, "kfmclient");
156 path = new;
157 }
158 if (file)
159 filename = file;
160 } else
161 path = "kfmclient";
162 if (asprintf(&man_page, "man:%s(1)", page) > 0) {
163 execlp(path, filename, "newTab", man_page, NULL);
164 free(man_page);
165 }
166 exec_failed(path);
167 }
168}
169
170static void exec_man_man(const char *path, const char *page)
171{
172 if (!path)
173 path = "man";
174 execlp(path, "man", page, NULL);
175 exec_failed(path);
176}
177
178static void exec_man_cmd(const char *cmd, const char *page)
179{
180 char *shell_cmd;
181
182 if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
183 execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
184 free(shell_cmd);
185 }
186 exec_failed(cmd);
187}
188
189static void add_man_viewer(const char *name)
190{
191 struct man_viewer_list **p = &man_viewer_list;
192 size_t len = strlen(name);
193
194 while (*p)
195 p = &((*p)->next);
196 *p = zalloc(sizeof(**p) + len + 1);
197 strcpy((*p)->name, name);
198}
199
200static int supported_man_viewer(const char *name, size_t len)
201{
202 return (!strncasecmp("man", name, len) ||
203 !strncasecmp("woman", name, len) ||
204 !strncasecmp("konqueror", name, len));
205}
206
207static void do_add_man_viewer_info(const char *name,
208 size_t len,
209 const char *value)
210{
211 struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
212
213 strncpy(new->name, name, len);
214 new->info = strdup(value);
215 new->next = man_viewer_info_list;
216 man_viewer_info_list = new;
217}
218
219static void unsupported_man_viewer(const char *name, const char *var)
220{
221 pr_warning("'%s': path for unsupported man viewer.\n"
222 "Please consider using 'man.<tool>.%s' instead.", name, var);
223}
224
225static int add_man_viewer_path(const char *name,
226 size_t len,
227 const char *value)
228{
229 if (supported_man_viewer(name, len))
230 do_add_man_viewer_info(name, len, value);
231 else
232 unsupported_man_viewer(name, "cmd");
233
234 return 0;
235}
236
237static int add_man_viewer_cmd(const char *name,
238 size_t len,
239 const char *value)
240{
241 if (supported_man_viewer(name, len))
242 unsupported_man_viewer(name, "path");
243 else
244 do_add_man_viewer_info(name, len, value);
245
246 return 0;
247}
248
249static int add_man_viewer_info(const char *var, const char *value)
250{
251 const char *name = var + 4;
252 const char *subkey = strrchr(name, '.');
253
254 if (!subkey) {
255 pr_err("Config with no key for man viewer: %s", name);
256 return -1;
257 }
258
259 if (!strcmp(subkey, ".path")) {
260 if (!value)
261 return config_error_nonbool(var);
262 return add_man_viewer_path(name, subkey - name, value);
263 }
264 if (!strcmp(subkey, ".cmd")) {
265 if (!value)
266 return config_error_nonbool(var);
267 return add_man_viewer_cmd(name, subkey - name, value);
268 }
269
270 pr_warning("'%s': unsupported man viewer sub key.", subkey);
271 return 0;
272}
273
274static int perf_help_config(const char *var, const char *value, void *cb)
275{
276 enum help_format *help_formatp = cb;
277
278 if (!strcmp(var, "help.format")) {
279 if (!value)
280 return config_error_nonbool(var);
281 *help_formatp = parse_help_format(value);
282 if (*help_formatp == HELP_FORMAT_NONE)
283 return -1;
284 return 0;
285 }
286 if (!strcmp(var, "man.viewer")) {
287 if (!value)
288 return config_error_nonbool(var);
289 add_man_viewer(value);
290 return 0;
291 }
292 if (strstarts(var, "man."))
293 return add_man_viewer_info(var, value);
294
295 return 0;
296}
297
298static struct cmdnames main_cmds, other_cmds;
299
300void list_common_cmds_help(void)
301{
302 unsigned int i, longest = 0;
303
304 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
305 if (longest < strlen(common_cmds[i].name))
306 longest = strlen(common_cmds[i].name);
307 }
308
309 puts(" The most commonly used perf commands are:");
310 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
311 printf(" %-*s ", longest, common_cmds[i].name);
312 puts(common_cmds[i].help);
313 }
314}
315
316static const char *cmd_to_page(const char *perf_cmd)
317{
318 char *s;
319
320 if (!perf_cmd)
321 return "perf";
322 else if (strstarts(perf_cmd, "perf"))
323 return perf_cmd;
324
325 return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
326}
327
328static void setup_man_path(void)
329{
330 char *new_path;
331 const char *old_path = getenv("MANPATH");
332
333 /* We should always put ':' after our path. If there is no
334 * old_path, the ':' at the end will let 'man' to try
335 * system-wide paths after ours to find the manual page. If
336 * there is old_path, we need ':' as delimiter. */
337 if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
338 setenv("MANPATH", new_path, 1);
339 free(new_path);
340 } else {
341 pr_err("Unable to setup man path");
342 }
343}
344
345static void exec_viewer(const char *name, const char *page)
346{
347 const char *info = get_man_viewer_info(name);
348
349 if (!strcasecmp(name, "man"))
350 exec_man_man(info, page);
351 else if (!strcasecmp(name, "woman"))
352 exec_woman_emacs(info, page);
353 else if (!strcasecmp(name, "konqueror"))
354 exec_man_konqueror(info, page);
355 else if (info)
356 exec_man_cmd(info, page);
357 else
358 pr_warning("'%s': unknown man viewer.", name);
359}
360
361static int show_man_page(const char *perf_cmd)
362{
363 struct man_viewer_list *viewer;
364 const char *page = cmd_to_page(perf_cmd);
365 const char *fallback = getenv("PERF_MAN_VIEWER");
366
367 setup_man_path();
368 for (viewer = man_viewer_list; viewer; viewer = viewer->next)
369 exec_viewer(viewer->name, page); /* will return when unable */
370
371 if (fallback)
372 exec_viewer(fallback, page);
373 exec_viewer("man", page);
374
375 pr_err("no man viewer handled the request");
376 return -1;
377}
378
379static int show_info_page(const char *perf_cmd)
380{
381 const char *page = cmd_to_page(perf_cmd);
382 setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
383 execlp("info", "info", "perfman", page, NULL);
384 return -1;
385}
386
387static int get_html_page_path(char **page_path, const char *page)
388{
389 struct stat st;
390 const char *html_path = system_path(PERF_HTML_PATH);
391
392 /* Check that we have a perf documentation directory. */
393 if (stat(mkpath("%s/perf.html", html_path), &st)
394 || !S_ISREG(st.st_mode)) {
395 pr_err("'%s': not a documentation directory.", html_path);
396 return -1;
397 }
398
399 return asprintf(page_path, "%s/%s.html", html_path, page);
400}
401
402/*
403 * If open_html is not defined in a platform-specific way (see for
404 * example compat/mingw.h), we use the script web--browse to display
405 * HTML.
406 */
407#ifndef open_html
408static void open_html(const char *path)
409{
410 execl_cmd("web--browse", "-c", "help.browser", path, NULL);
411}
412#endif
413
414static int show_html_page(const char *perf_cmd)
415{
416 const char *page = cmd_to_page(perf_cmd);
417 char *page_path; /* it leaks but we exec bellow */
418
419 if (get_html_page_path(&page_path, page) < 0)
420 return -1;
421
422 open_html(page_path);
423
424 return 0;
425}
426
427int cmd_help(int argc, const char **argv)
428{
429 bool show_all = false;
430 enum help_format help_format = HELP_FORMAT_MAN;
431 struct option builtin_help_options[] = {
432 OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
433 OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
434 OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
435 HELP_FORMAT_WEB),
436 OPT_SET_UINT('i', "info", &help_format, "show info page",
437 HELP_FORMAT_INFO),
438 OPT_END(),
439 };
440 const char * const builtin_help_subcommands[] = {
441 "buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
442 "record", "report", "bench", "stat", "timechart", "top", "annotate",
443 "script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
444#ifdef HAVE_LIBELF_SUPPORT
445 "probe",
446#endif
447#if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
448 "trace",
449#endif
450 NULL };
451 const char *builtin_help_usage[] = {
452 "perf help [--all] [--man|--web|--info] [command]",
453 NULL
454 };
455 int rc;
456
457 load_command_list("perf-", &main_cmds, &other_cmds);
458
459 rc = perf_config(perf_help_config, &help_format);
460 if (rc)
461 return rc;
462
463 argc = parse_options_subcommand(argc, argv, builtin_help_options,
464 builtin_help_subcommands, builtin_help_usage, 0);
465
466 if (show_all) {
467 printf("\n Usage: %s\n\n", perf_usage_string);
468 list_commands("perf commands", &main_cmds, &other_cmds);
469 printf(" %s\n\n", perf_more_info_string);
470 return 0;
471 }
472
473 if (!argv[0]) {
474 printf("\n usage: %s\n\n", perf_usage_string);
475 list_common_cmds_help();
476 printf("\n %s\n\n", perf_more_info_string);
477 return 0;
478 }
479
480 switch (help_format) {
481 case HELP_FORMAT_MAN:
482 rc = show_man_page(argv[0]);
483 break;
484 case HELP_FORMAT_INFO:
485 rc = show_info_page(argv[0]);
486 break;
487 case HELP_FORMAT_WEB:
488 rc = show_html_page(argv[0]);
489 break;
490 case HELP_FORMAT_NONE:
491 /* fall-through */
492 default:
493 rc = -1;
494 break;
495 }
496
497 return rc;
498}
1/*
2 * builtin-help.c
3 *
4 * Builtin help command
5 */
6#include "perf.h"
7#include "util/config.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 int ret = -1;
65
66 /* emacsclient prints its version number on stderr */
67 memset(&ec_process, 0, sizeof(ec_process));
68 ec_process.argv = argv_ec;
69 ec_process.err = -1;
70 ec_process.stdout_to_stderr = 1;
71 if (start_command(&ec_process)) {
72 fprintf(stderr, "Failed to start emacsclient.\n");
73 return -1;
74 }
75 if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
76 fprintf(stderr, "Failed to read emacsclient version\n");
77 goto out;
78 }
79 close(ec_process.err);
80
81 /*
82 * Don't bother checking return value, because "emacsclient --version"
83 * seems to always exits with code 1.
84 */
85 finish_command(&ec_process);
86
87 if (prefixcmp(buffer.buf, "emacsclient")) {
88 fprintf(stderr, "Failed to parse emacsclient version.\n");
89 goto out;
90 }
91
92 version = atoi(buffer.buf + strlen("emacsclient"));
93
94 if (version < 22) {
95 fprintf(stderr,
96 "emacsclient version '%d' too old (< 22).\n",
97 version);
98 } else
99 ret = 0;
100out:
101 strbuf_release(&buffer);
102 return ret;
103}
104
105static void exec_woman_emacs(const char *path, const char *page)
106{
107 char sbuf[STRERR_BUFSIZE];
108
109 if (!check_emacsclient_version()) {
110 /* This works only with emacsclient version >= 22. */
111 char *man_page;
112
113 if (!path)
114 path = "emacsclient";
115 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
116 execlp(path, "emacsclient", "-e", man_page, NULL);
117 free(man_page);
118 }
119 warning("failed to exec '%s': %s", path,
120 str_error_r(errno, sbuf, sizeof(sbuf)));
121 }
122}
123
124static void exec_man_konqueror(const char *path, const char *page)
125{
126 const char *display = getenv("DISPLAY");
127
128 if (display && *display) {
129 char *man_page;
130 const char *filename = "kfmclient";
131 char sbuf[STRERR_BUFSIZE];
132
133 /* It's simpler to launch konqueror using kfmclient. */
134 if (path) {
135 const char *file = strrchr(path, '/');
136 if (file && !strcmp(file + 1, "konqueror")) {
137 char *new = strdup(path);
138 char *dest = strrchr(new, '/');
139
140 /* strlen("konqueror") == strlen("kfmclient") */
141 strcpy(dest + 1, "kfmclient");
142 path = new;
143 }
144 if (file)
145 filename = file;
146 } else
147 path = "kfmclient";
148 if (asprintf(&man_page, "man:%s(1)", page) > 0) {
149 execlp(path, filename, "newTab", man_page, NULL);
150 free(man_page);
151 }
152 warning("failed to exec '%s': %s", path,
153 str_error_r(errno, sbuf, sizeof(sbuf)));
154 }
155}
156
157static void exec_man_man(const char *path, const char *page)
158{
159 char sbuf[STRERR_BUFSIZE];
160
161 if (!path)
162 path = "man";
163 execlp(path, "man", page, NULL);
164 warning("failed to exec '%s': %s", path,
165 str_error_r(errno, sbuf, sizeof(sbuf)));
166}
167
168static void exec_man_cmd(const char *cmd, const char *page)
169{
170 char sbuf[STRERR_BUFSIZE];
171 char *shell_cmd;
172
173 if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
174 execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
175 free(shell_cmd);
176 }
177 warning("failed to exec '%s': %s", cmd,
178 str_error_r(errno, sbuf, sizeof(sbuf)));
179}
180
181static void add_man_viewer(const char *name)
182{
183 struct man_viewer_list **p = &man_viewer_list;
184 size_t len = strlen(name);
185
186 while (*p)
187 p = &((*p)->next);
188 *p = zalloc(sizeof(**p) + len + 1);
189 strncpy((*p)->name, name, len);
190}
191
192static int supported_man_viewer(const char *name, size_t len)
193{
194 return (!strncasecmp("man", name, len) ||
195 !strncasecmp("woman", name, len) ||
196 !strncasecmp("konqueror", name, len));
197}
198
199static void do_add_man_viewer_info(const char *name,
200 size_t len,
201 const char *value)
202{
203 struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
204
205 strncpy(new->name, name, len);
206 new->info = strdup(value);
207 new->next = man_viewer_info_list;
208 man_viewer_info_list = new;
209}
210
211static int add_man_viewer_path(const char *name,
212 size_t len,
213 const char *value)
214{
215 if (supported_man_viewer(name, len))
216 do_add_man_viewer_info(name, len, value);
217 else
218 warning("'%s': path for unsupported man viewer.\n"
219 "Please consider using 'man.<tool>.cmd' instead.",
220 name);
221
222 return 0;
223}
224
225static int add_man_viewer_cmd(const char *name,
226 size_t len,
227 const char *value)
228{
229 if (supported_man_viewer(name, len))
230 warning("'%s': cmd for supported man viewer.\n"
231 "Please consider using 'man.<tool>.path' instead.",
232 name);
233 else
234 do_add_man_viewer_info(name, len, value);
235
236 return 0;
237}
238
239static int add_man_viewer_info(const char *var, const char *value)
240{
241 const char *name = var + 4;
242 const char *subkey = strrchr(name, '.');
243
244 if (!subkey)
245 return error("Config with no key for man viewer: %s", name);
246
247 if (!strcmp(subkey, ".path")) {
248 if (!value)
249 return config_error_nonbool(var);
250 return add_man_viewer_path(name, subkey - name, value);
251 }
252 if (!strcmp(subkey, ".cmd")) {
253 if (!value)
254 return config_error_nonbool(var);
255 return add_man_viewer_cmd(name, subkey - name, value);
256 }
257
258 warning("'%s': unsupported man viewer sub key.", subkey);
259 return 0;
260}
261
262static int perf_help_config(const char *var, const char *value, void *cb)
263{
264 enum help_format *help_formatp = cb;
265
266 if (!strcmp(var, "help.format")) {
267 if (!value)
268 return config_error_nonbool(var);
269 *help_formatp = parse_help_format(value);
270 if (*help_formatp == HELP_FORMAT_NONE)
271 return -1;
272 return 0;
273 }
274 if (!strcmp(var, "man.viewer")) {
275 if (!value)
276 return config_error_nonbool(var);
277 add_man_viewer(value);
278 return 0;
279 }
280 if (!prefixcmp(var, "man."))
281 return add_man_viewer_info(var, value);
282
283 return 0;
284}
285
286static struct cmdnames main_cmds, other_cmds;
287
288void list_common_cmds_help(void)
289{
290 unsigned int i, longest = 0;
291
292 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
293 if (longest < strlen(common_cmds[i].name))
294 longest = strlen(common_cmds[i].name);
295 }
296
297 puts(" The most commonly used perf commands are:");
298 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
299 printf(" %-*s ", longest, common_cmds[i].name);
300 puts(common_cmds[i].help);
301 }
302}
303
304static int is_perf_command(const char *s)
305{
306 return is_in_cmdlist(&main_cmds, s) ||
307 is_in_cmdlist(&other_cmds, s);
308}
309
310static const char *cmd_to_page(const char *perf_cmd)
311{
312 char *s;
313
314 if (!perf_cmd)
315 return "perf";
316 else if (!prefixcmp(perf_cmd, "perf"))
317 return perf_cmd;
318
319 return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
320}
321
322static void setup_man_path(void)
323{
324 char *new_path;
325 const char *old_path = getenv("MANPATH");
326
327 /* We should always put ':' after our path. If there is no
328 * old_path, the ':' at the end will let 'man' to try
329 * system-wide paths after ours to find the manual page. If
330 * there is old_path, we need ':' as delimiter. */
331 if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
332 setenv("MANPATH", new_path, 1);
333 free(new_path);
334 } else {
335 error("Unable to setup man path");
336 }
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 int 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
369 pr_err("no man viewer handled the request");
370 return -1;
371}
372
373static int show_info_page(const char *perf_cmd)
374{
375 const char *page = cmd_to_page(perf_cmd);
376 setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
377 execlp("info", "info", "perfman", page, NULL);
378 return -1;
379}
380
381static int get_html_page_path(char **page_path, const char *page)
382{
383 struct stat st;
384 const char *html_path = system_path(PERF_HTML_PATH);
385
386 /* Check that we have a perf documentation directory. */
387 if (stat(mkpath("%s/perf.html", html_path), &st)
388 || !S_ISREG(st.st_mode)) {
389 pr_err("'%s': not a documentation directory.", html_path);
390 return -1;
391 }
392
393 return asprintf(page_path, "%s/%s.html", html_path, page);
394}
395
396/*
397 * If open_html is not defined in a platform-specific way (see for
398 * example compat/mingw.h), we use the script web--browse to display
399 * HTML.
400 */
401#ifndef open_html
402static void open_html(const char *path)
403{
404 execl_cmd("web--browse", "-c", "help.browser", path, NULL);
405}
406#endif
407
408static int show_html_page(const char *perf_cmd)
409{
410 const char *page = cmd_to_page(perf_cmd);
411 char *page_path; /* it leaks but we exec bellow */
412
413 if (get_html_page_path(&page_path, page) < 0)
414 return -1;
415
416 open_html(page_path);
417
418 return 0;
419}
420
421int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
422{
423 bool show_all = false;
424 enum help_format help_format = HELP_FORMAT_MAN;
425 struct option builtin_help_options[] = {
426 OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
427 OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
428 OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
429 HELP_FORMAT_WEB),
430 OPT_SET_UINT('i', "info", &help_format, "show info page",
431 HELP_FORMAT_INFO),
432 OPT_END(),
433 };
434 const char * const builtin_help_subcommands[] = {
435 "buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
436 "record", "report", "bench", "stat", "timechart", "top", "annotate",
437 "script", "sched", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
438#ifdef HAVE_LIBELF_SUPPORT
439 "probe",
440#endif
441#ifdef HAVE_LIBAUDIT_SUPPORT
442 "trace",
443#endif
444 NULL };
445 const char *builtin_help_usage[] = {
446 "perf help [--all] [--man|--web|--info] [command]",
447 NULL
448 };
449 const char *alias;
450 int rc = 0;
451
452 load_command_list("perf-", &main_cmds, &other_cmds);
453
454 perf_config(perf_help_config, &help_format);
455
456 argc = parse_options_subcommand(argc, argv, builtin_help_options,
457 builtin_help_subcommands, builtin_help_usage, 0);
458
459 if (show_all) {
460 printf("\n Usage: %s\n\n", perf_usage_string);
461 list_commands("perf commands", &main_cmds, &other_cmds);
462 printf(" %s\n\n", perf_more_info_string);
463 return 0;
464 }
465
466 if (!argv[0]) {
467 printf("\n usage: %s\n\n", perf_usage_string);
468 list_common_cmds_help();
469 printf("\n %s\n\n", perf_more_info_string);
470 return 0;
471 }
472
473 alias = alias_lookup(argv[0]);
474 if (alias && !is_perf_command(argv[0])) {
475 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
476 return 0;
477 }
478
479 switch (help_format) {
480 case HELP_FORMAT_MAN:
481 rc = show_man_page(argv[0]);
482 break;
483 case HELP_FORMAT_INFO:
484 rc = show_info_page(argv[0]);
485 break;
486 case HELP_FORMAT_WEB:
487 rc = show_html_page(argv[0]);
488 break;
489 case HELP_FORMAT_NONE:
490 /* fall-through */
491 default:
492 rc = -1;
493 break;
494 }
495
496 return rc;
497}