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