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 "util/exec_cmd.h"
  10 #include "common-cmds.h"
  11 #include "util/parse-options.h"
  12 #include "util/run-command.h"
  13 #include "util/help.h"
  14
  15 static struct man_viewer_list {
  16         struct man_viewer_list *next;
  17         char name[FLEX_ARRAY];
  18 } *man_viewer_list;
  19
  20 static struct man_viewer_info_list {
  21         struct man_viewer_info_list *next;
  22         const char *info;
  23         char name[FLEX_ARRAY];
  24 } *man_viewer_info_list;
  25
  26 enum help_format {
  27         HELP_FORMAT_NONE,
  28         HELP_FORMAT_MAN,
  29         HELP_FORMAT_INFO,
  30         HELP_FORMAT_WEB,
  31 };
  32
  33 static enum help_format parse_help_format(const char *format)
  34 {
  35         if (!strcmp(format, "man"))
  36                 return HELP_FORMAT_MAN;
  37         if (!strcmp(format, "info"))
  38                 return HELP_FORMAT_INFO;
  39         if (!strcmp(format, "web") || !strcmp(format, "html"))
  40                 return HELP_FORMAT_WEB;
  41
  42         pr_err("unrecognized help format '%s'", format);
  43         return HELP_FORMAT_NONE;
  44 }
  45
  46 static const char *get_man_viewer_info(const char *name)
  47 {
  48         struct man_viewer_info_list *viewer;
  49
  50         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
  51                 if (!strcasecmp(name, viewer->name))
  52                         return viewer->info;
  53         }
  54         return NULL;
  55 }
  56
  57 static int check_emacsclient_version(void)
  58 {
  59         struct strbuf buffer = STRBUF_INIT;
  60         struct child_process ec_process;
  61         const char *argv_ec[] = { "emacsclient", "--version", NULL };
  62         int version;
  63
  64         /* emacsclient prints its version number on stderr */
  65         memset(&ec_process, 0, sizeof(ec_process));
  66         ec_process.argv = argv_ec;
  67         ec_process.err = -1;
  68         ec_process.stdout_to_stderr = 1;
  69         if (start_command(&ec_process)) {
  70                 fprintf(stderr, "Failed to start emacsclient.\n");
  71                 return -1;
  72         }
  73         strbuf_read(&buffer, ec_process.err, 20);
  74         close(ec_process.err);
  75
  76         /*
  77          * Don't bother checking return value, because "emacsclient --version"
  78          * seems to always exits with code 1.
  79          */
  80         finish_command(&ec_process);
  81
  82         if (prefixcmp(buffer.buf, "emacsclient")) {
  83                 fprintf(stderr, "Failed to parse emacsclient version.\n");
  84                 strbuf_release(&buffer);
  85                 return -1;
  86         }
  87
  88         strbuf_remove(&buffer, 0, strlen("emacsclient"));
  89         version = atoi(buffer.buf);
  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         if (!check_emacsclient_version()) {
 106                 /* This works only with emacsclient version >= 22. */
 107                 struct strbuf man_page = STRBUF_INIT;
 108
 109                 if (!path)
 110                         path = "emacsclient";
 111                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 112                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 113                 warning("failed to exec '%s': %s", path, strerror(errno));
 114         }
 115 }
 116
 117 static void exec_man_konqueror(const char *path, const char *page)
 118 {
 119         const char *display = getenv("DISPLAY");
 120         if (display && *display) {
 121                 struct strbuf man_page = STRBUF_INIT;
 122                 const char *filename = "kfmclient";
 123
 124                 /* It's simpler to launch konqueror using kfmclient. */
 125                 if (path) {
 126                         const char *file = strrchr(path, '/');
 127                         if (file && !strcmp(file + 1, "konqueror")) {
 128                                 char *new = strdup(path);
 129                                 char *dest = strrchr(new, '/');
 130
 131                                 /* strlen("konqueror") == strlen("kfmclient") */
 132                                 strcpy(dest + 1, "kfmclient");
 133                                 path = new;
 134                         }
 135                         if (file)
 136                                 filename = file;
 137                 } else
 138                         path = "kfmclient";
 139                 strbuf_addf(&man_page, "man:%s(1)", page);
 140                 execlp(path, filename, "newTab", man_page.buf, NULL);
 141                 warning("failed to exec '%s': %s", path, strerror(errno));
 142         }
 143 }
 144
 145 static void exec_man_man(const char *path, const char *page)
 146 {
 147         if (!path)
 148                 path = "man";
 149         execlp(path, "man", page, NULL);
 150         warning("failed to exec '%s': %s", path, strerror(errno));
 151 }
 152
 153 static void exec_man_cmd(const char *cmd, const char *page)
 154 {
 155         struct strbuf shell_cmd = STRBUF_INIT;
 156         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 157         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 158         warning("failed to exec '%s': %s", cmd, strerror(errno));
 159 }
 160
 161 static void add_man_viewer(const char *name)
 162 {
 163         struct man_viewer_list **p = &man_viewer_list;
 164         size_t len = strlen(name);
 165
 166         while (*p)
 167                 p = &((*p)->next);
 168         *p = zalloc(sizeof(**p) + len + 1);
 169         strncpy((*p)->name, name, len);
 170 }
 171
 172 static int supported_man_viewer(const char *name, size_t len)
 173 {
 174         return (!strncasecmp("man", name, len) ||
 175                 !strncasecmp("woman", name, len) ||
 176                 !strncasecmp("konqueror", name, len));
 177 }
 178
 179 static void do_add_man_viewer_info(const char *name,
 180                                    size_t len,
 181                                    const char *value)
 182 {
 183         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 184
 185         strncpy(new->name, name, len);
 186         new->info = strdup(value);
 187         new->next = man_viewer_info_list;
 188         man_viewer_info_list = new;
 189 }
 190
 191 static int add_man_viewer_path(const char *name,
 192                                size_t len,
 193                                const char *value)
 194 {
 195         if (supported_man_viewer(name, len))
 196                 do_add_man_viewer_info(name, len, value);
 197         else
 198                 warning("'%s': path for unsupported man viewer.\n"
 199                         "Please consider using 'man.<tool>.cmd' instead.",
 200                         name);
 201
 202         return 0;
 203 }
 204
 205 static int add_man_viewer_cmd(const char *name,
 206                               size_t len,
 207                               const char *value)
 208 {
 209         if (supported_man_viewer(name, len))
 210                 warning("'%s': cmd for supported man viewer.\n"
 211                         "Please consider using 'man.<tool>.path' instead.",
 212                         name);
 213         else
 214                 do_add_man_viewer_info(name, len, value);
 215
 216         return 0;
 217 }
 218
 219 static int add_man_viewer_info(const char *var, const char *value)
 220 {
 221         const char *name = var + 4;
 222         const char *subkey = strrchr(name, '.');
 223
 224         if (!subkey)
 225                 return error("Config with no key for man viewer: %s", name);
 226
 227         if (!strcmp(subkey, ".path")) {
 228                 if (!value)
 229                         return config_error_nonbool(var);
 230                 return add_man_viewer_path(name, subkey - name, value);
 231         }
 232         if (!strcmp(subkey, ".cmd")) {
 233                 if (!value)
 234                         return config_error_nonbool(var);
 235                 return add_man_viewer_cmd(name, subkey - name, value);
 236         }
 237
 238         warning("'%s': unsupported man viewer sub key.", subkey);
 239         return 0;
 240 }
 241
 242 static int perf_help_config(const char *var, const char *value, void *cb)
 243 {
 244         enum help_format *help_formatp = cb;
 245
 246         if (!strcmp(var, "help.format")) {
 247                 if (!value)
 248                         return config_error_nonbool(var);
 249                 *help_formatp = parse_help_format(value);
 250                 if (*help_formatp == HELP_FORMAT_NONE)
 251                         return -1;
 252                 return 0;
 253         }
 254         if (!strcmp(var, "man.viewer")) {
 255                 if (!value)
 256                         return config_error_nonbool(var);
 257                 add_man_viewer(value);
 258                 return 0;
 259         }
 260         if (!prefixcmp(var, "man."))
 261                 return add_man_viewer_info(var, value);
 262
 263         return perf_default_config(var, value, cb);
 264 }
 265
 266 static struct cmdnames main_cmds, other_cmds;
 267
 268 void list_common_cmds_help(void)
 269 {
 270         unsigned int i, longest = 0;
 271
 272         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 273                 if (longest < strlen(common_cmds[i].name))
 274                         longest = strlen(common_cmds[i].name);
 275         }
 276
 277         puts(" The most commonly used perf commands are:");
 278         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 279                 printf("   %-*s   ", longest, common_cmds[i].name);
 280                 puts(common_cmds[i].help);
 281         }
 282 }
 283
 284 static int is_perf_command(const char *s)
 285 {
 286         return is_in_cmdlist(&main_cmds, s) ||
 287                 is_in_cmdlist(&other_cmds, s);
 288 }
 289
 290 static const char *prepend(const char *prefix, const char *cmd)
 291 {
 292         size_t pre_len = strlen(prefix);
 293         size_t cmd_len = strlen(cmd);
 294         char *p = malloc(pre_len + cmd_len + 1);
 295         memcpy(p, prefix, pre_len);
 296         strcpy(p + pre_len, cmd);
 297         return p;
 298 }
 299
 300 static const char *cmd_to_page(const char *perf_cmd)
 301 {
 302         if (!perf_cmd)
 303                 return "perf";
 304         else if (!prefixcmp(perf_cmd, "perf"))
 305                 return perf_cmd;
 306         else
 307                 return prepend("perf-", perf_cmd);
 308 }
 309
 310 static void setup_man_path(void)
 311 {
 312         struct strbuf new_path = STRBUF_INIT;
 313         const char *old_path = getenv("MANPATH");
 314
 315         /* We should always put ':' after our path. If there is no
 316          * old_path, the ':' at the end will let 'man' to try
 317          * system-wide paths after ours to find the manual page. If
 318          * there is old_path, we need ':' as delimiter. */
 319         strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
 320         strbuf_addch(&new_path, ':');
 321         if (old_path)
 322                 strbuf_addstr(&new_path, old_path);
 323
 324         setenv("MANPATH", new_path.buf, 1);
 325
 326         strbuf_release(&new_path);
 327 }
 328
 329 static void exec_viewer(const char *name, const char *page)
 330 {
 331         const char *info = get_man_viewer_info(name);
 332
 333         if (!strcasecmp(name, "man"))
 334                 exec_man_man(info, page);
 335         else if (!strcasecmp(name, "woman"))
 336                 exec_woman_emacs(info, page);
 337         else if (!strcasecmp(name, "konqueror"))
 338                 exec_man_konqueror(info, page);
 339         else if (info)
 340                 exec_man_cmd(info, page);
 341         else
 342                 warning("'%s': unknown man viewer.", name);
 343 }
 344
 345 static int show_man_page(const char *perf_cmd)
 346 {
 347         struct man_viewer_list *viewer;
 348         const char *page = cmd_to_page(perf_cmd);
 349         const char *fallback = getenv("PERF_MAN_VIEWER");
 350
 351         setup_man_path();
 352         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 353                 exec_viewer(viewer->name, page); /* will return when unable */
 354
 355         if (fallback)
 356                 exec_viewer(fallback, page);
 357         exec_viewer("man", page);
 358
 359         pr_err("no man viewer handled the request");
 360         return -1;
 361 }
 362
 363 static int show_info_page(const char *perf_cmd)
 364 {
 365         const char *page = cmd_to_page(perf_cmd);
 366         setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
 367         execlp("info", "info", "perfman", page, NULL);
 368         return -1;
 369 }
 370
 371 static int get_html_page_path(struct strbuf *page_path, const char *page)
 372 {
 373         struct stat st;
 374         const char *html_path = system_path(PERF_HTML_PATH);
 375
 376         /* Check that we have a perf documentation directory. */
 377         if (stat(mkpath("%s/perf.html", html_path), &st)
 378             || !S_ISREG(st.st_mode)) {
 379                 pr_err("'%s': not a documentation directory.", html_path);
 380                 return -1;
 381         }
 382
 383         strbuf_init(page_path, 0);
 384         strbuf_addf(page_path, "%s/%s.html", html_path, page);
 385
 386         return 0;
 387 }
 388
 389 /*
 390  * If open_html is not defined in a platform-specific way (see for
 391  * example compat/mingw.h), we use the script web--browse to display
 392  * HTML.
 393  */
 394 #ifndef open_html
 395 static void open_html(const char *path)
 396 {
 397         execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
 398 }
 399 #endif
 400
 401 static int show_html_page(const char *perf_cmd)
 402 {
 403         const char *page = cmd_to_page(perf_cmd);
 404         struct strbuf page_path; /* it leaks but we exec bellow */
 405
 406         if (get_html_page_path(&page_path, page) != 0)
 407                 return -1;
 408
 409         open_html(page_path.buf);
 410
 411         return 0;
 412 }
 413
 414 int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
 415 {
 416         bool show_all = false;
 417         enum help_format help_format = HELP_FORMAT_MAN;
 418         struct option builtin_help_options[] = {
 419         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
 420         OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
 421         OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
 422                         HELP_FORMAT_WEB),
 423         OPT_SET_UINT('i', "info", &help_format, "show info page",
 424                         HELP_FORMAT_INFO),
 425         OPT_END(),
 426         };
 427         const char * const builtin_help_usage[] = {
 428                 "perf help [--all] [--man|--web|--info] [command]",
 429                 NULL
 430         };
 431         const char *alias;
 432         int rc = 0;
 433
 434         load_command_list("perf-", &main_cmds, &other_cmds);
 435
 436         perf_config(perf_help_config, &help_format);
 437
 438         argc = parse_options(argc, argv, builtin_help_options,
 439                         builtin_help_usage, 0);
 440
 441         if (show_all) {
 442                 printf("\n usage: %s\n\n", perf_usage_string);
 443                 list_commands("perf commands", &main_cmds, &other_cmds);
 444                 printf(" %s\n\n", perf_more_info_string);
 445                 return 0;
 446         }
 447
 448         if (!argv[0]) {
 449                 printf("\n usage: %s\n\n", perf_usage_string);
 450                 list_common_cmds_help();
 451                 printf("\n %s\n\n", perf_more_info_string);
 452                 return 0;
 453         }
 454
 455         alias = alias_lookup(argv[0]);
 456         if (alias && !is_perf_command(argv[0])) {
 457                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
 458                 return 0;
 459         }
 460
 461         switch (help_format) {
 462         case HELP_FORMAT_MAN:
 463                 rc = show_man_page(argv[0]);
 464                 break;
 465         case HELP_FORMAT_INFO:
 466                 rc = show_info_page(argv[0]);
 467                 break;
 468         case HELP_FORMAT_WEB:
 469                 rc = show_html_page(argv[0]);
 470                 break;
 471         case HELP_FORMAT_NONE:
 472                 /* fall-through */
 473         default:
 474                 rc = -1;
 475                 break;
 476         }
 477
 478         return rc;
 479 }