502 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * builtin-help.c4 *5 * Builtin help command6 */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 30static struct man_viewer_list {31 struct man_viewer_list *next;32 char name[0];33} *man_viewer_list;34 35static 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 41enum help_format {42 HELP_FORMAT_NONE,43 HELP_FORMAT_MAN,44 HELP_FORMAT_INFO,45 HELP_FORMAT_WEB,46};47 48static 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 61static 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 72static 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 } else113 ret = 0;114out:115 strbuf_release(&buffer);116 return ret;117}118 119static 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 125static 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 141static 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 } else163 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 172static 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 180static 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 191static 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 202static 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 209static 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 221static 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 227static 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 else234 unsupported_man_viewer(name, "cmd");235 236 return 0;237}238 239static 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 else246 do_add_man_viewer_info(name, len, value);247 248 return 0;249}250 251static 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 276static 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 300static struct cmdnames main_cmds, other_cmds;301 302void 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 318static 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 330static 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 no336 * old_path, the ':' at the end will let 'man' to try337 * system-wide paths after ours to find the manual page. If338 * 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 347static 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 else360 pr_warning("'%s': unknown man viewer.", name);361}362 363static 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 381static 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 389static 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 for407 * example compat/mingw.h), we use the script web--browse to display408 * HTML.409 */410#ifndef open_html411static void open_html(const char *path)412{413 execl_cmd("web--browse", "-c", "help.browser", path, NULL);414}415#endif416 417static 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 below */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 430int 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_SUPPORT448 "probe",449#endif450#if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)451 "trace",452#endif453 NULL };454 const char *builtin_help_usage[] = {455 "perf help [--all] [--man|--web|--info] [command]",456 NULL457 };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