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 "util/util.h" 18 #include <linux/kernel.h> 19 #include <linux/string.h> 20 #include <linux/zalloc.h> 21 #include <errno.h> 22 #include <stdio.h> 23 #include <stdlib.h> 24 #include <string.h> 25 #include <sys/types.h> 26 #include <sys/stat.h> 27 #include <unistd.h> 28 29 static struct man_viewer_list { 30 struct man_viewer_list *next; 31 char name[0]; 32 } *man_viewer_list; 33 34 static struct man_viewer_info_list { 35 struct man_viewer_info_list *next; 36 const char *info; 37 char name[0]; 38 } *man_viewer_info_list; 39 40 enum help_format { 41 HELP_FORMAT_NONE, 42 HELP_FORMAT_MAN, 43 HELP_FORMAT_INFO, 44 HELP_FORMAT_WEB, 45 }; 46 47 static enum help_format parse_help_format(const char *format) 48 { 49 if (!strcmp(format, "man")) 50 return HELP_FORMAT_MAN; 51 if (!strcmp(format, "info")) 52 return HELP_FORMAT_INFO; 53 if (!strcmp(format, "web") || !strcmp(format, "html")) 54 return HELP_FORMAT_WEB; 55 56 pr_err("unrecognized help format '%s'", format); 57 return HELP_FORMAT_NONE; 58 } 59 60 static const char *get_man_viewer_info(const char *name) 61 { 62 struct man_viewer_info_list *viewer; 63 64 for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) { 65 if (!strcasecmp(name, viewer->name)) 66 return viewer->info; 67 } 68 return NULL; 69 } 70 71 static int check_emacsclient_version(void) 72 { 73 struct strbuf buffer = STRBUF_INIT; 74 struct child_process ec_process; 75 const char *argv_ec[] = { "emacsclient", "--version", NULL }; 76 int version; 77 int ret = -1; 78 79 /* emacsclient prints its version number on stderr */ 80 memset(&ec_process, 0, sizeof(ec_process)); 81 ec_process.argv = argv_ec; 82 ec_process.err = -1; 83 ec_process.stdout_to_stderr = 1; 84 if (start_command(&ec_process)) { 85 fprintf(stderr, "Failed to start emacsclient.\n"); 86 return -1; 87 } 88 if (strbuf_read(&buffer, ec_process.err, 20) < 0) { 89 fprintf(stderr, "Failed to read emacsclient version\n"); 90 goto out; 91 } 92 close(ec_process.err); 93 94 /* 95 * Don't bother checking return value, because "emacsclient --version" 96 * seems to always exits with code 1. 97 */ 98 finish_command(&ec_process); 99 100 if (!strstarts(buffer.buf, "emacsclient")) { 101 fprintf(stderr, "Failed to parse emacsclient version.\n"); 102 goto out; 103 } 104 105 version = atoi(buffer.buf + strlen("emacsclient")); 106 107 if (version < 22) { 108 fprintf(stderr, 109 "emacsclient version '%d' too old (< 22).\n", 110 version); 111 } else 112 ret = 0; 113 out: 114 strbuf_release(&buffer); 115 return ret; 116 } 117 118 static void exec_failed(const char *cmd) 119 { 120 char sbuf[STRERR_BUFSIZE]; 121 pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf))); 122 } 123 124 static void exec_woman_emacs(const char *path, const char *page) 125 { 126 if (!check_emacsclient_version()) { 127 /* This works only with emacsclient version >= 22. */ 128 char *man_page; 129 130 if (!path) 131 path = "emacsclient"; 132 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) { 133 execlp(path, "emacsclient", "-e", man_page, NULL); 134 free(man_page); 135 } 136 exec_failed(path); 137 } 138 } 139 140 static void exec_man_konqueror(const char *path, const char *page) 141 { 142 const char *display = getenv("DISPLAY"); 143 144 if (display && *display) { 145 char *man_page; 146 const char *filename = "kfmclient"; 147 148 /* It's simpler to launch konqueror using kfmclient. */ 149 if (path) { 150 const char *file = strrchr(path, '/'); 151 if (file && !strcmp(file + 1, "konqueror")) { 152 char *new = strdup(path); 153 char *dest = strrchr(new, '/'); 154 155 /* strlen("konqueror") == strlen("kfmclient") */ 156 strcpy(dest + 1, "kfmclient"); 157 path = new; 158 } 159 if (file) 160 filename = file; 161 } else 162 path = "kfmclient"; 163 if (asprintf(&man_page, "man:%s(1)", page) > 0) { 164 execlp(path, filename, "newTab", man_page, NULL); 165 free(man_page); 166 } 167 exec_failed(path); 168 } 169 } 170 171 static void exec_man_man(const char *path, const char *page) 172 { 173 if (!path) 174 path = "man"; 175 execlp(path, "man", page, NULL); 176 exec_failed(path); 177 } 178 179 static void exec_man_cmd(const char *cmd, const char *page) 180 { 181 char *shell_cmd; 182 183 if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) { 184 execl("/bin/sh", "sh", "-c", shell_cmd, NULL); 185 free(shell_cmd); 186 } 187 exec_failed(cmd); 188 } 189 190 static void add_man_viewer(const char *name) 191 { 192 struct man_viewer_list **p = &man_viewer_list; 193 size_t len = strlen(name); 194 195 while (*p) 196 p = &((*p)->next); 197 *p = zalloc(sizeof(**p) + len + 1); 198 strcpy((*p)->name, name); 199 } 200 201 static int supported_man_viewer(const char *name, size_t len) 202 { 203 return (!strncasecmp("man", name, len) || 204 !strncasecmp("woman", name, len) || 205 !strncasecmp("konqueror", name, len)); 206 } 207 208 static void do_add_man_viewer_info(const char *name, 209 size_t len, 210 const char *value) 211 { 212 struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1); 213 214 strncpy(new->name, name, len); 215 new->info = strdup(value); 216 new->next = man_viewer_info_list; 217 man_viewer_info_list = new; 218 } 219 220 static void unsupported_man_viewer(const char *name, const char *var) 221 { 222 pr_warning("'%s': path for unsupported man viewer.\n" 223 "Please consider using 'man.<tool>.%s' instead.", name, var); 224 } 225 226 static int add_man_viewer_path(const char *name, 227 size_t len, 228 const char *value) 229 { 230 if (supported_man_viewer(name, len)) 231 do_add_man_viewer_info(name, len, value); 232 else 233 unsupported_man_viewer(name, "cmd"); 234 235 return 0; 236 } 237 238 static int add_man_viewer_cmd(const char *name, 239 size_t len, 240 const char *value) 241 { 242 if (supported_man_viewer(name, len)) 243 unsupported_man_viewer(name, "path"); 244 else 245 do_add_man_viewer_info(name, len, value); 246 247 return 0; 248 } 249 250 static int add_man_viewer_info(const char *var, const char *value) 251 { 252 const char *name = var + 4; 253 const char *subkey = strrchr(name, '.'); 254 255 if (!subkey) { 256 pr_err("Config with no key for man viewer: %s", name); 257 return -1; 258 } 259 260 if (!strcmp(subkey, ".path")) { 261 if (!value) 262 return config_error_nonbool(var); 263 return add_man_viewer_path(name, subkey - name, value); 264 } 265 if (!strcmp(subkey, ".cmd")) { 266 if (!value) 267 return config_error_nonbool(var); 268 return add_man_viewer_cmd(name, subkey - name, value); 269 } 270 271 pr_warning("'%s': unsupported man viewer sub key.", subkey); 272 return 0; 273 } 274 275 static int perf_help_config(const char *var, const char *value, void *cb) 276 { 277 enum help_format *help_formatp = cb; 278 279 if (!strcmp(var, "help.format")) { 280 if (!value) 281 return config_error_nonbool(var); 282 *help_formatp = parse_help_format(value); 283 if (*help_formatp == HELP_FORMAT_NONE) 284 return -1; 285 return 0; 286 } 287 if (!strcmp(var, "man.viewer")) { 288 if (!value) 289 return config_error_nonbool(var); 290 add_man_viewer(value); 291 return 0; 292 } 293 if (strstarts(var, "man.")) 294 return add_man_viewer_info(var, value); 295 296 return 0; 297 } 298 299 static struct cmdnames main_cmds, other_cmds; 300 301 void list_common_cmds_help(void) 302 { 303 unsigned int i, longest = 0; 304 305 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) { 306 if (longest < strlen(common_cmds[i].name)) 307 longest = strlen(common_cmds[i].name); 308 } 309 310 puts(" The most commonly used perf commands are:"); 311 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) { 312 printf(" %-*s ", longest, common_cmds[i].name); 313 puts(common_cmds[i].help); 314 } 315 } 316 317 static const char *cmd_to_page(const char *perf_cmd) 318 { 319 char *s; 320 321 if (!perf_cmd) 322 return "perf"; 323 else if (strstarts(perf_cmd, "perf")) 324 return perf_cmd; 325 326 return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s; 327 } 328 329 static void setup_man_path(void) 330 { 331 char *new_path; 332 const char *old_path = getenv("MANPATH"); 333 334 /* We should always put ':' after our path. If there is no 335 * old_path, the ':' at the end will let 'man' to try 336 * system-wide paths after ours to find the manual page. If 337 * there is old_path, we need ':' as delimiter. */ 338 if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) { 339 setenv("MANPATH", new_path, 1); 340 free(new_path); 341 } else { 342 pr_err("Unable to setup man path"); 343 } 344 } 345 346 static void exec_viewer(const char *name, const char *page) 347 { 348 const char *info = get_man_viewer_info(name); 349 350 if (!strcasecmp(name, "man")) 351 exec_man_man(info, page); 352 else if (!strcasecmp(name, "woman")) 353 exec_woman_emacs(info, page); 354 else if (!strcasecmp(name, "konqueror")) 355 exec_man_konqueror(info, page); 356 else if (info) 357 exec_man_cmd(info, page); 358 else 359 pr_warning("'%s': unknown man viewer.", name); 360 } 361 362 static int show_man_page(const char *perf_cmd) 363 { 364 struct man_viewer_list *viewer; 365 const char *page = cmd_to_page(perf_cmd); 366 const char *fallback = getenv("PERF_MAN_VIEWER"); 367 368 setup_man_path(); 369 for (viewer = man_viewer_list; viewer; viewer = viewer->next) 370 exec_viewer(viewer->name, page); /* will return when unable */ 371 372 if (fallback) 373 exec_viewer(fallback, page); 374 exec_viewer("man", page); 375 376 pr_err("no man viewer handled the request"); 377 return -1; 378 } 379 380 static int show_info_page(const char *perf_cmd) 381 { 382 const char *page = cmd_to_page(perf_cmd); 383 setenv("INFOPATH", system_path(PERF_INFO_PATH), 1); 384 execlp("info", "info", "perfman", page, NULL); 385 return -1; 386 } 387 388 static int get_html_page_path(char **page_path, const char *page) 389 { 390 struct stat st; 391 const char *html_path = system_path(PERF_HTML_PATH); 392 393 /* Check that we have a perf documentation directory. */ 394 if (stat(mkpath("%s/perf.html", html_path), &st) 395 || !S_ISREG(st.st_mode)) { 396 pr_err("'%s': not a documentation directory.", html_path); 397 return -1; 398 } 399 400 return asprintf(page_path, "%s/%s.html", html_path, page); 401 } 402 403 /* 404 * If open_html is not defined in a platform-specific way (see for 405 * example compat/mingw.h), we use the script web--browse to display 406 * HTML. 407 */ 408 #ifndef open_html 409 static void open_html(const char *path) 410 { 411 execl_cmd("web--browse", "-c", "help.browser", path, NULL); 412 } 413 #endif 414 415 static int show_html_page(const char *perf_cmd) 416 { 417 const char *page = cmd_to_page(perf_cmd); 418 char *page_path; /* it leaks but we exec bellow */ 419 420 if (get_html_page_path(&page_path, page) < 0) 421 return -1; 422 423 open_html(page_path); 424 425 return 0; 426 } 427 428 int cmd_help(int argc, const char **argv) 429 { 430 bool show_all = false; 431 enum help_format help_format = HELP_FORMAT_MAN; 432 struct option builtin_help_options[] = { 433 OPT_BOOLEAN('a', "all", &show_all, "print all available commands"), 434 OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN), 435 OPT_SET_UINT('w', "web", &help_format, "show manual in web browser", 436 HELP_FORMAT_WEB), 437 OPT_SET_UINT('i', "info", &help_format, "show info page", 438 HELP_FORMAT_INFO), 439 OPT_END(), 440 }; 441 const char * const builtin_help_subcommands[] = { 442 "buildid-cache", "buildid-list", "diff", "evlist", "help", "list", 443 "record", "report", "bench", "stat", "timechart", "top", "annotate", 444 "script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data", 445 #ifdef HAVE_LIBELF_SUPPORT 446 "probe", 447 #endif 448 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT) 449 "trace", 450 #endif 451 NULL }; 452 const char *builtin_help_usage[] = { 453 "perf help [--all] [--man|--web|--info] [command]", 454 NULL 455 }; 456 int rc; 457 458 load_command_list("perf-", &main_cmds, &other_cmds); 459 460 rc = perf_config(perf_help_config, &help_format); 461 if (rc) 462 return rc; 463 464 argc = parse_options_subcommand(argc, argv, builtin_help_options, 465 builtin_help_subcommands, builtin_help_usage, 0); 466 467 if (show_all) { 468 printf("\n Usage: %s\n\n", perf_usage_string); 469 list_commands("perf commands", &main_cmds, &other_cmds); 470 printf(" %s\n\n", perf_more_info_string); 471 return 0; 472 } 473 474 if (!argv[0]) { 475 printf("\n usage: %s\n\n", perf_usage_string); 476 list_common_cmds_help(); 477 printf("\n %s\n\n", perf_more_info_string); 478 return 0; 479 } 480 481 switch (help_format) { 482 case HELP_FORMAT_MAN: 483 rc = show_man_page(argv[0]); 484 break; 485 case HELP_FORMAT_INFO: 486 rc = show_info_page(argv[0]); 487 break; 488 case HELP_FORMAT_WEB: 489 rc = show_html_page(argv[0]); 490 break; 491 case HELP_FORMAT_NONE: 492 /* fall-through */ 493 default: 494 rc = -1; 495 break; 496 } 497 498 return rc; 499 } 500