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 23 static struct man_viewer_list { 24 struct man_viewer_list *next; 25 char name[0]; 26 } *man_viewer_list; 27 28 static 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 34 enum help_format { 35 HELP_FORMAT_NONE, 36 HELP_FORMAT_MAN, 37 HELP_FORMAT_INFO, 38 HELP_FORMAT_WEB, 39 }; 40 41 static 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 54 static 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 65 static 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; 107 out: 108 strbuf_release(&buffer); 109 return ret; 110 } 111 112 static 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 } 117 118 static 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 } 133 134 static 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 } 164 165 static 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 } 172 173 static 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 } 183 184 static 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 strcpy((*p)->name, name); 193 } 194 195 static 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 } 201 202 static 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 } 213 214 static 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 } 219 220 static 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 } 231 232 static 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 } 243 244 static 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 } 268 269 static 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 } 292 293 static struct cmdnames main_cmds, other_cmds; 294 295 void 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 } 310 311 static 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 } 322 323 static 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 } 339 340 static 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 } 355 356 static 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 } 373 374 static 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 } 381 382 static 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 403 static void open_html(const char *path) 404 { 405 execl_cmd("web--browse", "-c", "help.browser", path, NULL); 406 } 407 #endif 408 409 static 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 } 421 422 int 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 } 494