tools/perf/builtin-help.c

   1 /*
   2  * builtin-help.c
   3  *
   4  * Builtin help command
   5  */
   6 #include "perf.h"
   7 #include "util/cache.h"
   8 #include "builtin.h"
   9 #include <subcmd/exec-cmd.h>
  10 #include "common-cmds.h"
  11 #include <subcmd/parse-options.h>
  12 #include <subcmd/run-command.h>
  13 #include <subcmd/help.h>
  14 #include "util/debug.h"
  15
  16 static struct man_viewer_list {
  17         struct man_viewer_list *next;
  18         char name[FLEX_ARRAY];
  19 } *man_viewer_list;
  20
  21 static struct man_viewer_info_list {
  22         struct man_viewer_info_list *next;
  23         const char *info;
  24         char name[FLEX_ARRAY];
  25 } *man_viewer_info_list;
  26
  27 enum help_format {
  28         HELP_FORMAT_NONE,
  29         HELP_FORMAT_MAN,
  30         HELP_FORMAT_INFO,
  31         HELP_FORMAT_WEB,
  32 };
  33
  34 static enum help_format parse_help_format(const char *format)
  35 {
  36         if (!strcmp(format, "man"))
  37                 return HELP_FORMAT_MAN;
  38         if (!strcmp(format, "info"))
  39                 return HELP_FORMAT_INFO;
  40         if (!strcmp(format, "web") || !strcmp(format, "html"))
  41                 return HELP_FORMAT_WEB;
  42
  43         pr_err("unrecognized help format '%s'", format);
  44         return HELP_FORMAT_NONE;
  45 }
  46
  47 static const char *get_man_viewer_info(const char *name)
  48 {
  49         struct man_viewer_info_list *viewer;
  50
  51         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
  52                 if (!strcasecmp(name, viewer->name))
  53                         return viewer->info;
  54         }
  55         return NULL;
  56 }
  57
  58 static int check_emacsclient_version(void)
  59 {
  60         struct strbuf buffer = STRBUF_INIT;
  61         struct child_process ec_process;
  62         const char *argv_ec[] = { "emacsclient", "--version", NULL };
  63         int version;
  64
  65         /* emacsclient prints its version number on stderr */
  66         memset(&ec_process, 0, sizeof(ec_process));
  67         ec_process.argv = argv_ec;
  68         ec_process.err = -1;
  69         ec_process.stdout_to_stderr = 1;
  70         if (start_command(&ec_process)) {
  71                 fprintf(stderr, "Failed to start emacsclient.\n");
  72                 return -1;
  73         }
  74         strbuf_read(&buffer, ec_process.err, 20);
  75         close(ec_process.err);
  76
  77         /*
  78          * Don't bother checking return value, because "emacsclient --version"
  79          * seems to always exits with code 1.
  80          */
  81         finish_command(&ec_process);
  82
  83         if (prefixcmp(buffer.buf, "emacsclient")) {
  84                 fprintf(stderr, "Failed to parse emacsclient version.\n");
  85                 strbuf_release(&buffer);
  86                 return -1;
  87         }
  88
  89         strbuf_remove(&buffer, 0, strlen("emacsclient"));
  90         version = atoi(buffer.buf);
  91
  92         if (version < 22) {
  93                 fprintf(stderr,
  94                         "emacsclient version '%d' too old (< 22).\n",
  95                         version);
  96                 strbuf_release(&buffer);
  97                 return -1;
  98         }
  99
 100         strbuf_release(&buffer);
 101         return 0;
 102 }
 103
 104 static void exec_woman_emacs(const char *path, const char *page)
 105 {
 106         char sbuf[STRERR_BUFSIZE];
 107
 108         if (!check_emacsclient_version()) {
 109                 /* This works only with emacsclient version >= 22. */
 110                 struct strbuf man_page = STRBUF_INIT;
 111
 112                 if (!path)
 113                         path = "emacsclient";
 114                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 115                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 116                 warning("failed to exec '%s': %s", path,
 117                         strerror_r(errno, sbuf, sizeof(sbuf)));
 118         }
 119 }
 120
 121 static void exec_man_konqueror(const char *path, const char *page)
 122 {
 123         const char *display = getenv("DISPLAY");
 124
 125         if (display && *display) {
 126                 struct strbuf man_page = STRBUF_INIT;
 127                 const char *filename = "kfmclient";
 128                 char sbuf[STRERR_BUFSIZE];
 129
 130                 /* It's simpler to launch konqueror using kfmclient. */
 131                 if (path) {
 132                         const char *file = strrchr(path, '/');
 133                         if (file && !strcmp(file + 1, "konqueror")) {
 134                                 char *new = strdup(path);
 135                                 char *dest = strrchr(new, '/');
 136
 137                                 /* strlen("konqueror") == strlen("kfmclient") */
 138                                 strcpy(dest + 1, "kfmclient");
 139                                 path = new;
 140                         }
 141                         if (file)
 142                                 filename = file;
 143                 } else
 144                         path = "kfmclient";
 145                 strbuf_addf(&man_page, "man:%s(1)", page);
 146                 execlp(path, filename, "newTab", man_page.buf, NULL);
 147                 warning("failed to exec '%s': %s", path,
 148                         strerror_r(errno, sbuf, sizeof(sbuf)));
 149         }
 150 }
 151
 152 static void exec_man_man(const char *path, const char *page)
 153 {
 154         char sbuf[STRERR_BUFSIZE];
 155
 156         if (!path)
 157                 path = "man";
 158         execlp(path, "man", page, NULL);
 159         warning("failed to exec '%s': %s", path,
 160                 strerror_r(errno, sbuf, sizeof(sbuf)));
 161 }
 162
 163 static void exec_man_cmd(const char *cmd, const char *page)
 164 {
 165         struct strbuf shell_cmd = STRBUF_INIT;
 166         char sbuf[STRERR_BUFSIZE];
 167
 168         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 169         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 170         warning("failed to exec '%s': %s", cmd,
 171                 strerror_r(errno, sbuf, sizeof(sbuf)));
 172 }
 173
 174 static void add_man_viewer(const char *name)
 175 {
 176         struct man_viewer_list **p = &man_viewer_list;
 177         size_t len = strlen(name);
 178
 179         while (*p)
 180                 p = &((*p)->next);
 181         *p = zalloc(sizeof(**p) + len + 1);
 182         strncpy((*p)->name, name, len);
 183 }
 184
 185 static int supported_man_viewer(const char *name, size_t len)
 186 {
 187         return (!strncasecmp("man", name, len) ||
 188                 !strncasecmp("woman", name, len) ||
 189                 !strncasecmp("konqueror", name, len));
 190 }
 191
 192 static void do_add_man_viewer_info(const char *name,
 193                                    size_t len,
 194                                    const char *value)
 195 {
 196         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 197
 198         strncpy(new->name, name, len);
 199         new->info = strdup(value);
 200         new->next = man_viewer_info_list;
 201         man_viewer_info_list = new;
 202 }
 203
 204 static int add_man_viewer_path(const char *name,
 205                                size_t len,
 206                                const char *value)
 207 {
 208         if (supported_man_viewer(name, len))
 209                 do_add_man_viewer_info(name, len, value);
 210         else
 211                 warning("'%s': path for unsupported man viewer.\n"
 212                         "Please consider using 'man.<tool>.cmd' instead.",
 213                         name);
 214
 215         return 0;
 216 }
 217
 218 static int add_man_viewer_cmd(const char *name,
 219                               size_t len,
 220                               const char *value)
 221 {
 222         if (supported_man_viewer(name, len))
 223                 warning("'%s': cmd for supported man viewer.\n"
 224                         "Please consider using 'man.<tool>.path' instead.",
 225                         name);
 226         else
 227                 do_add_man_viewer_info(name, len, value);
 228
 229         return 0;
 230 }
 231
 232 static int add_man_viewer_info(const char *var, const char *value)
 233 {
 234         const char *name = var + 4;
 235         const char *subkey = strrchr(name, '.');
 236
 237         if (!subkey)
 238                 return error("Config with no key for man viewer: %s", name);
 239
 240         if (!strcmp(subkey, ".path")) {
 241                 if (!value)
 242                         return config_error_nonbool(var);
 243                 return add_man_viewer_path(name, subkey - name, value);
 244         }
 245         if (!strcmp(subkey, ".cmd")) {
 246                 if (!value)
 247                         return config_error_nonbool(var);
 248                 return add_man_viewer_cmd(name, subkey - name, value);
 249         }
 250
 251         warning("'%s': unsupported man viewer sub key.", subkey);
 252         return 0;
 253 }
 254
 255 static int perf_help_config(const char *var, const char *value, void *cb)
 256 {
 257         enum help_format *help_formatp = cb;
 258
 259         if (!strcmp(var, "help.format")) {
 260                 if (!value)
 261                         return config_error_nonbool(var);
 262                 *help_formatp = parse_help_format(value);
 263                 if (*help_formatp == HELP_FORMAT_NONE)
 264                         return -1;
 265                 return 0;
 266         }
 267         if (!strcmp(var, "man.viewer")) {
 268                 if (!value)
 269                         return config_error_nonbool(var);
 270                 add_man_viewer(value);
 271                 return 0;
 272         }
 273         if (!prefixcmp(var, "man."))
 274                 return add_man_viewer_info(var, value);
 275
 276         return perf_default_config(var, value, cb);
 277 }
 278
 279 static struct cmdnames main_cmds, other_cmds;
 280
 281 void list_common_cmds_help(void)
 282 {
 283         unsigned int i, longest = 0;
 284
 285         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 286                 if (longest < strlen(common_cmds[i].name))
 287                         longest = strlen(common_cmds[i].name);
 288         }
 289
 290         puts(" The most commonly used perf commands are:");
 291         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 292                 printf("   %-*s   ", longest, common_cmds[i].name);
 293                 puts(common_cmds[i].help);
 294         }
 295 }
 296
 297 static int is_perf_command(const char *s)
 298 {
 299         return is_in_cmdlist(&main_cmds, s) ||
 300                 is_in_cmdlist(&other_cmds, s);
 301 }
 302
 303 static const char *prepend(const char *prefix, const char *cmd)
 304 {
 305         size_t pre_len = strlen(prefix);
 306         size_t cmd_len = strlen(cmd);
 307         char *p = malloc(pre_len + cmd_len + 1);
 308         memcpy(p, prefix, pre_len);
 309         strcpy(p + pre_len, cmd);
 310         return p;
 311 }
 312
 313 static const char *cmd_to_page(const char *perf_cmd)
 314 {
 315         if (!perf_cmd)
 316                 return "perf";
 317         else if (!prefixcmp(perf_cmd, "perf"))
 318                 return perf_cmd;
 319         else
 320                 return prepend("perf-", perf_cmd);
 321 }
 322
 323 static void setup_man_path(void)
 324 {
 325         struct strbuf new_path = STRBUF_INIT;
 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         strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
 333         strbuf_addch(&new_path, ':');
 334         if (old_path)
 335                 strbuf_addstr(&new_path, old_path);
 336
 337         setenv("MANPATH", new_path.buf, 1);
 338
 339         strbuf_release(&new_path);
 340 }
 341
 342 static void exec_viewer(const char *name, const char *page)
 343 {
 344         const char *info = get_man_viewer_info(name);
 345
 346         if (!strcasecmp(name, "man"))
 347                 exec_man_man(info, page);
 348         else if (!strcasecmp(name, "woman"))
 349                 exec_woman_emacs(info, page);
 350         else if (!strcasecmp(name, "konqueror"))
 351                 exec_man_konqueror(info, page);
 352         else if (info)
 353                 exec_man_cmd(info, page);
 354         else
 355                 warning("'%s': unknown man viewer.", name);
 356 }
 357
 358 static int show_man_page(const char *perf_cmd)
 359 {
 360         struct man_viewer_list *viewer;
 361         const char *page = cmd_to_page(perf_cmd);
 362         const char *fallback = getenv("PERF_MAN_VIEWER");
 363
 364         setup_man_path();
 365         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 366                 exec_viewer(viewer->name, page); /* will return when unable */
 367
 368         if (fallback)
 369                 exec_viewer(fallback, page);
 370         exec_viewer("man", page);
 371
 372         pr_err("no man viewer handled the request");
 373         return -1;
 374 }
 375
 376 static int show_info_page(const char *perf_cmd)
 377 {
 378         const char *page = cmd_to_page(perf_cmd);
 379         setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
 380         execlp("info", "info", "perfman", page, NULL);
 381         return -1;
 382 }
 383
 384 static int get_html_page_path(struct strbuf *page_path, const char *page)
 385 {
 386         struct stat st;
 387         const char *html_path = system_path(PERF_HTML_PATH);
 388
 389         /* Check that we have a perf documentation directory. */
 390         if (stat(mkpath("%s/perf.html", html_path), &st)
 391             || !S_ISREG(st.st_mode)) {
 392                 pr_err("'%s': not a documentation directory.", html_path);
 393                 return -1;
 394         }
 395
 396         strbuf_init(page_path, 0);
 397         strbuf_addf(page_path, "%s/%s.html", html_path, page);
 398
 399         return 0;
 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         struct strbuf 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.buf);
 423
 424         return 0;
 425 }
 426
 427 int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
 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", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
 444 #ifdef HAVE_LIBELF_SUPPORT
 445                 "probe",
 446 #endif
 447 #ifdef HAVE_LIBAUDIT_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         const char *alias;
 456         int rc = 0;
 457
 458         load_command_list("perf-", &main_cmds, &other_cmds);
 459
 460         perf_config(perf_help_config, &help_format);
 461
 462         argc = parse_options_subcommand(argc, argv, builtin_help_options,
 463                         builtin_help_subcommands, builtin_help_usage, 0);
 464
 465         if (show_all) {
 466                 printf("\n Usage: %s\n\n", perf_usage_string);
 467                 list_commands("perf commands", &main_cmds, &other_cmds);
 468                 printf(" %s\n\n", perf_more_info_string);
 469                 return 0;
 470         }
 471
 472         if (!argv[0]) {
 473                 printf("\n usage: %s\n\n", perf_usage_string);
 474                 list_common_cmds_help();
 475                 printf("\n %s\n\n", perf_more_info_string);
 476                 return 0;
 477         }
 478
 479         alias = alias_lookup(argv[0]);
 480         if (alias && !is_perf_command(argv[0])) {
 481                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
 482                 return 0;
 483         }
 484
 485         switch (help_format) {
 486         case HELP_FORMAT_MAN:
 487                 rc = show_man_page(argv[0]);
 488                 break;
 489         case HELP_FORMAT_INFO:
 490                 rc = show_info_page(argv[0]);
 491                 break;
 492         case HELP_FORMAT_WEB:
 493                 rc = show_html_page(argv[0]);
 494                 break;
 495         case HELP_FORMAT_NONE:
 496                 /* fall-through */
 497         default:
 498                 rc = -1;
 499                 break;
 500         }
 501
 502         return rc;
 503 }