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 28 static struct man_viewer_list { 29 struct man_viewer_list *next; 30 char name[0]; 31 } *man_viewer_list; 32 33 static 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 39 enum help_format { 40 HELP_FORMAT_NONE, 41 HELP_FORMAT_MAN, 42 HELP_FORMAT_INFO, 43 HELP_FORMAT_WEB, 44 }; 45 46 static 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 59 static 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 70 static 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; 112 out: 113 strbuf_release(&buffer); 114 return ret; 115 } 116 117 static 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 } 122 123 static 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 } 138 139 static 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 } 169 170 static 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 } 177 178 static 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 } 188 189 static 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 } 199 200 static 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 } 206 207 static 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 } 218 219 static 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 } 224 225 static 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 } 236 237 static 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 } 248 249 static 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 } 273 274 static 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 } 297 298 static struct cmdnames main_cmds, other_cmds; 299 300 void 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 } 315 316 static 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 } 327 328 static 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 } 344 345 static 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 } 360 361 static 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 } 378 379 static 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 } 386 387 static 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 408 static void open_html(const char *path) 409 { 410 execl_cmd("web--browse", "-c", "help.browser", path, NULL); 411 } 412 #endif 413 414 static 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 } 426 427 int 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 } 499