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 <limits.h> 23 #include <stdio.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <sys/types.h> 27 #include <sys/stat.h> 28 #include <unistd.h> 29 30 static struct man_viewer_list { 31 struct man_viewer_list *next; 32 char name[0]; 33 } *man_viewer_list; 34 35 static struct man_viewer_info_list { 36 struct man_viewer_info_list *next; 37 const char *info; 38 char name[0]; 39 } *man_viewer_info_list; 40 41 enum help_format { 42 HELP_FORMAT_NONE, 43 HELP_FORMAT_MAN, 44 HELP_FORMAT_INFO, 45 HELP_FORMAT_WEB, 46 }; 47 48 static enum help_format parse_help_format(const char *format) 49 { 50 if (!strcmp(format, "man")) 51 return HELP_FORMAT_MAN; 52 if (!strcmp(format, "info")) 53 return HELP_FORMAT_INFO; 54 if (!strcmp(format, "web") || !strcmp(format, "html")) 55 return HELP_FORMAT_WEB; 56 57 pr_err("unrecognized help format '%s'", format); 58 return HELP_FORMAT_NONE; 59 } 60 61 static const char *get_man_viewer_info(const char *name) 62 { 63 struct man_viewer_info_list *viewer; 64 65 for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) { 66 if (!strcasecmp(name, viewer->name)) 67 return viewer->info; 68 } 69 return NULL; 70 } 71 72 static int check_emacsclient_version(void) 73 { 74 struct strbuf buffer = STRBUF_INIT; 75 struct child_process ec_process; 76 const char *argv_ec[] = { "emacsclient", "--version", NULL }; 77 int version; 78 int ret = -1; 79 80 /* emacsclient prints its version number on stderr */ 81 memset(&ec_process, 0, sizeof(ec_process)); 82 ec_process.argv = argv_ec; 83 ec_process.err = -1; 84 ec_process.stdout_to_stderr = 1; 85 if (start_command(&ec_process)) { 86 fprintf(stderr, "Failed to start emacsclient.\n"); 87 return -1; 88 } 89 if (strbuf_read(&buffer, ec_process.err, 20) < 0) { 90 fprintf(stderr, "Failed to read emacsclient version\n"); 91 goto out; 92 } 93 close(ec_process.err); 94 95 /* 96 * Don't bother checking return value, because "emacsclient --version" 97 * seems to always exits with code 1. 98 */ 99 finish_command(&ec_process); 100 101 if (!strstarts(buffer.buf, "emacsclient")) { 102 fprintf(stderr, "Failed to parse emacsclient version.\n"); 103 goto out; 104 } 105 106 version = atoi(buffer.buf + strlen("emacsclient")); 107 108 if (version < 22) { 109 fprintf(stderr, 110 "emacsclient version '%d' too old (< 22).\n", 111 version); 112 } else 113 ret = 0; 114 out: 115 strbuf_release(&buffer); 116 return ret; 117 } 118 119 static void exec_failed(const char *cmd) 120 { 121 char sbuf[STRERR_BUFSIZE]; 122 pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf))); 123 } 124 125 static void exec_woman_emacs(const char *path, const char *page) 126 { 127 if (!check_emacsclient_version()) { 128 /* This works only with emacsclient version >= 22. */ 129 char *man_page; 130 131 if (!path) 132 path = "emacsclient"; 133 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) { 134 execlp(path, "emacsclient", "-e", man_page, NULL); 135 free(man_page); 136 } 137 exec_failed(path); 138 } 139 } 140 141 static void exec_man_konqueror(const char *path, const char *page) 142 { 143 const char *display = getenv("DISPLAY"); 144 145 if (display && *display) { 146 char *man_page; 147 const char *filename = "kfmclient"; 148 149 /* It's simpler to launch konqueror using kfmclient. */ 150 if (path) { 151 const char *file = strrchr(path, '/'); 152 if (file && !strcmp(file + 1, "konqueror")) { 153 char *new = strdup(path); 154 char *dest = strrchr(new, '/'); 155 156 /* strlen("konqueror") == strlen("kfmclient") */ 157 strcpy(dest + 1, "kfmclient"); 158 path = new; 159 } 160 if (file) 161 filename = file; 162 } else 163 path = "kfmclient"; 164 if (asprintf(&man_page, "man:%s(1)", page) > 0) { 165 execlp(path, filename, "newTab", man_page, NULL); 166 free(man_page); 167 } 168 exec_failed(path); 169 } 170 } 171 172 static void exec_man_man(const char *path, const char *page) 173 { 174 if (!path) 175 path = "man"; 176 execlp(path, "man", page, NULL); 177 exec_failed(path); 178 } 179 180 static void exec_man_cmd(const char *cmd, const char *page) 181 { 182 char *shell_cmd; 183 184 if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) { 185 execl("/bin/sh", "sh", "-c", shell_cmd, NULL); 186 free(shell_cmd); 187 } 188 exec_failed(cmd); 189 } 190 191 static void add_man_viewer(const char *name) 192 { 193 struct man_viewer_list **p = &man_viewer_list; 194 size_t len = strlen(name); 195 196 while (*p) 197 p = &((*p)->next); 198 *p = zalloc(sizeof(**p) + len + 1); 199 strcpy((*p)->name, name); 200 } 201 202 static int supported_man_viewer(const char *name, size_t len) 203 { 204 return (!strncasecmp("man", name, len) || 205 !strncasecmp("woman", name, len) || 206 !strncasecmp("konqueror", name, len)); 207 } 208 209 static void do_add_man_viewer_info(const char *name, 210 size_t len, 211 const char *value) 212 { 213 struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1); 214 215 strncpy(new->name, name, len); 216 new->info = strdup(value); 217 new->next = man_viewer_info_list; 218 man_viewer_info_list = new; 219 } 220 221 static void unsupported_man_viewer(const char *name, const char *var) 222 { 223 pr_warning("'%s': path for unsupported man viewer.\n" 224 "Please consider using 'man.<tool>.%s' instead.", name, var); 225 } 226 227 static int add_man_viewer_path(const char *name, 228 size_t len, 229 const char *value) 230 { 231 if (supported_man_viewer(name, len)) 232 do_add_man_viewer_info(name, len, value); 233 else 234 unsupported_man_viewer(name, "cmd"); 235 236 return 0; 237 } 238 239 static int add_man_viewer_cmd(const char *name, 240 size_t len, 241 const char *value) 242 { 243 if (supported_man_viewer(name, len)) 244 unsupported_man_viewer(name, "path"); 245 else 246 do_add_man_viewer_info(name, len, value); 247 248 return 0; 249 } 250 251 static int add_man_viewer_info(const char *var, const char *value) 252 { 253 const char *name = var + 4; 254 const char *subkey = strrchr(name, '.'); 255 256 if (!subkey) { 257 pr_err("Config with no key for man viewer: %s", name); 258 return -1; 259 } 260 261 if (!strcmp(subkey, ".path")) { 262 if (!value) 263 return config_error_nonbool(var); 264 return add_man_viewer_path(name, subkey - name, value); 265 } 266 if (!strcmp(subkey, ".cmd")) { 267 if (!value) 268 return config_error_nonbool(var); 269 return add_man_viewer_cmd(name, subkey - name, value); 270 } 271 272 pr_warning("'%s': unsupported man viewer sub key.", subkey); 273 return 0; 274 } 275 276 static int perf_help_config(const char *var, const char *value, void *cb) 277 { 278 enum help_format *help_formatp = cb; 279 280 if (!strcmp(var, "help.format")) { 281 if (!value) 282 return config_error_nonbool(var); 283 *help_formatp = parse_help_format(value); 284 if (*help_formatp == HELP_FORMAT_NONE) 285 return -1; 286 return 0; 287 } 288 if (!strcmp(var, "man.viewer")) { 289 if (!value) 290 return config_error_nonbool(var); 291 add_man_viewer(value); 292 return 0; 293 } 294 if (strstarts(var, "man.")) 295 return add_man_viewer_info(var, value); 296 297 return 0; 298 } 299 300 static struct cmdnames main_cmds, other_cmds; 301 302 void list_common_cmds_help(void) 303 { 304 unsigned int i, longest = 0; 305 306 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) { 307 if (longest < strlen(common_cmds[i].name)) 308 longest = strlen(common_cmds[i].name); 309 } 310 311 puts(" The most commonly used perf commands are:"); 312 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) { 313 printf(" %-*s ", longest, common_cmds[i].name); 314 puts(common_cmds[i].help); 315 } 316 } 317 318 static const char *cmd_to_page(const char *perf_cmd) 319 { 320 char *s; 321 322 if (!perf_cmd) 323 return "perf"; 324 else if (strstarts(perf_cmd, "perf")) 325 return perf_cmd; 326 327 return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s; 328 } 329 330 static void setup_man_path(void) 331 { 332 char *new_path; 333 const char *old_path = getenv("MANPATH"); 334 335 /* We should always put ':' after our path. If there is no 336 * old_path, the ':' at the end will let 'man' to try 337 * system-wide paths after ours to find the manual page. If 338 * there is old_path, we need ':' as delimiter. */ 339 if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) { 340 setenv("MANPATH", new_path, 1); 341 free(new_path); 342 } else { 343 pr_err("Unable to setup man path"); 344 } 345 } 346 347 static void exec_viewer(const char *name, const char *page) 348 { 349 const char *info = get_man_viewer_info(name); 350 351 if (!strcasecmp(name, "man")) 352 exec_man_man(info, page); 353 else if (!strcasecmp(name, "woman")) 354 exec_woman_emacs(info, page); 355 else if (!strcasecmp(name, "konqueror")) 356 exec_man_konqueror(info, page); 357 else if (info) 358 exec_man_cmd(info, page); 359 else 360 pr_warning("'%s': unknown man viewer.", name); 361 } 362 363 static int show_man_page(const char *perf_cmd) 364 { 365 struct man_viewer_list *viewer; 366 const char *page = cmd_to_page(perf_cmd); 367 const char *fallback = getenv("PERF_MAN_VIEWER"); 368 369 setup_man_path(); 370 for (viewer = man_viewer_list; viewer; viewer = viewer->next) 371 exec_viewer(viewer->name, page); /* will return when unable */ 372 373 if (fallback) 374 exec_viewer(fallback, page); 375 exec_viewer("man", page); 376 377 pr_err("no man viewer handled the request"); 378 return -1; 379 } 380 381 static int show_info_page(const char *perf_cmd) 382 { 383 const char *page = cmd_to_page(perf_cmd); 384 setenv("INFOPATH", system_path(PERF_INFO_PATH), 1); 385 execlp("info", "info", "perfman", page, NULL); 386 return -1; 387 } 388 389 static int get_html_page_path(char **page_path, const char *page) 390 { 391 struct stat st; 392 const char *html_path = system_path(PERF_HTML_PATH); 393 char path[PATH_MAX]; 394 395 /* Check that we have a perf documentation directory. */ 396 if (stat(mkpath(path, sizeof(path), "%s/perf.html", html_path), &st) 397 || !S_ISREG(st.st_mode)) { 398 pr_err("'%s': not a documentation directory.", html_path); 399 return -1; 400 } 401 402 return asprintf(page_path, "%s/%s.html", html_path, page); 403 } 404 405 /* 406 * If open_html is not defined in a platform-specific way (see for 407 * example compat/mingw.h), we use the script web--browse to display 408 * HTML. 409 */ 410 #ifndef open_html 411 static void open_html(const char *path) 412 { 413 execl_cmd("web--browse", "-c", "help.browser", path, NULL); 414 } 415 #endif 416 417 static int show_html_page(const char *perf_cmd) 418 { 419 const char *page = cmd_to_page(perf_cmd); 420 char *page_path; /* it leaks but we exec bellow */ 421 422 if (get_html_page_path(&page_path, page) < 0) 423 return -1; 424 425 open_html(page_path); 426 427 return 0; 428 } 429 430 int cmd_help(int argc, const char **argv) 431 { 432 bool show_all = false; 433 enum help_format help_format = HELP_FORMAT_MAN; 434 struct option builtin_help_options[] = { 435 OPT_BOOLEAN('a', "all", &show_all, "print all available commands"), 436 OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN), 437 OPT_SET_UINT('w', "web", &help_format, "show manual in web browser", 438 HELP_FORMAT_WEB), 439 OPT_SET_UINT('i', "info", &help_format, "show info page", 440 HELP_FORMAT_INFO), 441 OPT_END(), 442 }; 443 const char * const builtin_help_subcommands[] = { 444 "buildid-cache", "buildid-list", "diff", "evlist", "help", "list", 445 "record", "report", "bench", "stat", "timechart", "top", "annotate", 446 "script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data", 447 #ifdef HAVE_LIBELF_SUPPORT 448 "probe", 449 #endif 450 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT) 451 "trace", 452 #endif 453 NULL }; 454 const char *builtin_help_usage[] = { 455 "perf help [--all] [--man|--web|--info] [command]", 456 NULL 457 }; 458 int rc; 459 460 load_command_list("perf-", &main_cmds, &other_cmds); 461 462 rc = perf_config(perf_help_config, &help_format); 463 if (rc) 464 return rc; 465 466 argc = parse_options_subcommand(argc, argv, builtin_help_options, 467 builtin_help_subcommands, builtin_help_usage, 0); 468 469 if (show_all) { 470 printf("\n Usage: %s\n\n", perf_usage_string); 471 list_commands("perf commands", &main_cmds, &other_cmds); 472 printf(" %s\n\n", perf_more_info_string); 473 return 0; 474 } 475 476 if (!argv[0]) { 477 printf("\n usage: %s\n\n", perf_usage_string); 478 list_common_cmds_help(); 479 printf("\n %s\n\n", perf_more_info_string); 480 return 0; 481 } 482 483 switch (help_format) { 484 case HELP_FORMAT_MAN: 485 rc = show_man_page(argv[0]); 486 break; 487 case HELP_FORMAT_INFO: 488 rc = show_info_page(argv[0]); 489 break; 490 case HELP_FORMAT_WEB: 491 rc = show_html_page(argv[0]); 492 break; 493 case HELP_FORMAT_NONE: 494 /* fall-through */ 495 default: 496 rc = -1; 497 break; 498 } 499 500 return rc; 501 } 502