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 bool show_all = false;
  34 static enum help_format help_format = HELP_FORMAT_NONE;
  35 static struct option builtin_help_options[] = {
  36         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  37         OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  38         OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
  39                         HELP_FORMAT_WEB),
  40         OPT_SET_UINT('i', "info", &help_format, "show info page",
  41                         HELP_FORMAT_INFO),
  42         OPT_END(),
  43 };
  44
  45 static const char * const builtin_help_usage[] = {
  46         "perf help [--all] [--man|--web|--info] [command]",
  47         NULL
  48 };
  49
  50 static enum help_format parse_help_format(const char *format)
  51 {
  52         if (!strcmp(format, "man"))
  53                 return HELP_FORMAT_MAN;
  54         if (!strcmp(format, "info"))
  55                 return HELP_FORMAT_INFO;
  56         if (!strcmp(format, "web") || !strcmp(format, "html"))
  57                 return HELP_FORMAT_WEB;
  58
  59         pr_err("unrecognized help format '%s'", format);
  60         return HELP_FORMAT_NONE;
  61 }
  62
  63 static const char *get_man_viewer_info(const char *name)
  64 {
  65         struct man_viewer_info_list *viewer;
  66
  67         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
  68                 if (!strcasecmp(name, viewer->name))
  69                         return viewer->info;
  70         }
  71         return NULL;
  72 }
  73
  74 static int check_emacsclient_version(void)
  75 {
  76         struct strbuf buffer = STRBUF_INIT;
  77         struct child_process ec_process;
  78         const char *argv_ec[] = { "emacsclient", "--version", NULL };
  79         int version;
  80
  81         /* emacsclient prints its version number on stderr */
  82         memset(&ec_process, 0, sizeof(ec_process));
  83         ec_process.argv = argv_ec;
  84         ec_process.err = -1;
  85         ec_process.stdout_to_stderr = 1;
  86         if (start_command(&ec_process)) {
  87                 fprintf(stderr, "Failed to start emacsclient.\n");
  88                 return -1;
  89         }
  90         strbuf_read(&buffer, ec_process.err, 20);
  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 (prefixcmp(buffer.buf, "emacsclient")) {
 100                 fprintf(stderr, "Failed to parse emacsclient version.\n");
 101                 strbuf_release(&buffer);
 102                 return -1;
 103         }
 104
 105         strbuf_remove(&buffer, 0, strlen("emacsclient"));
 106         version = atoi(buffer.buf);
 107
 108         if (version < 22) {
 109                 fprintf(stderr,
 110                         "emacsclient version '%d' too old (< 22).\n",
 111                         version);
 112                 strbuf_release(&buffer);
 113                 return -1;
 114         }
 115
 116         strbuf_release(&buffer);
 117         return 0;
 118 }
 119
 120 static void exec_woman_emacs(const char *path, const char *page)
 121 {
 122         if (!check_emacsclient_version()) {
 123                 /* This works only with emacsclient version >= 22. */
 124                 struct strbuf man_page = STRBUF_INIT;
 125
 126                 if (!path)
 127                         path = "emacsclient";
 128                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 129                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 130                 warning("failed to exec '%s': %s", path, strerror(errno));
 131         }
 132 }
 133
 134 static void exec_man_konqueror(const char *path, const char *page)
 135 {
 136         const char *display = getenv("DISPLAY");
 137         if (display && *display) {
 138                 struct strbuf man_page = STRBUF_INIT;
 139                 const char *filename = "kfmclient";
 140
 141                 /* It's simpler to launch konqueror using kfmclient. */
 142                 if (path) {
 143                         const char *file = strrchr(path, '/');
 144                         if (file && !strcmp(file + 1, "konqueror")) {
 145                                 char *new = strdup(path);
 146                                 char *dest = strrchr(new, '/');
 147
 148                                 /* strlen("konqueror") == strlen("kfmclient") */
 149                                 strcpy(dest + 1, "kfmclient");
 150                                 path = new;
 151                         }
 152                         if (file)
 153                                 filename = file;
 154                 } else
 155                         path = "kfmclient";
 156                 strbuf_addf(&man_page, "man:%s(1)", page);
 157                 execlp(path, filename, "newTab", man_page.buf, NULL);
 158                 warning("failed to exec '%s': %s", path, strerror(errno));
 159         }
 160 }
 161
 162 static void exec_man_man(const char *path, const char *page)
 163 {
 164         if (!path)
 165                 path = "man";
 166         execlp(path, "man", page, NULL);
 167         warning("failed to exec '%s': %s", path, strerror(errno));
 168 }
 169
 170 static void exec_man_cmd(const char *cmd, const char *page)
 171 {
 172         struct strbuf shell_cmd = STRBUF_INIT;
 173         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 174         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 175         warning("failed to exec '%s': %s", cmd, strerror(errno));
 176 }
 177
 178 static void add_man_viewer(const char *name)
 179 {
 180         struct man_viewer_list **p = &man_viewer_list;
 181         size_t len = strlen(name);
 182
 183         while (*p)
 184                 p = &((*p)->next);
 185         *p = zalloc(sizeof(**p) + len + 1);
 186         strncpy((*p)->name, name, len);
 187 }
 188
 189 static int supported_man_viewer(const char *name, size_t len)
 190 {
 191         return (!strncasecmp("man", name, len) ||
 192                 !strncasecmp("woman", name, len) ||
 193                 !strncasecmp("konqueror", name, len));
 194 }
 195
 196 static void do_add_man_viewer_info(const char *name,
 197                                    size_t len,
 198                                    const char *value)
 199 {
 200         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 201
 202         strncpy(new->name, name, len);
 203         new->info = strdup(value);
 204         new->next = man_viewer_info_list;
 205         man_viewer_info_list = new;
 206 }
 207
 208 static int add_man_viewer_path(const char *name,
 209                                size_t len,
 210                                const char *value)
 211 {
 212         if (supported_man_viewer(name, len))
 213                 do_add_man_viewer_info(name, len, value);
 214         else
 215                 warning("'%s': path for unsupported man viewer.\n"
 216                         "Please consider using 'man.<tool>.cmd' instead.",
 217                         name);
 218
 219         return 0;
 220 }
 221
 222 static int add_man_viewer_cmd(const char *name,
 223                               size_t len,
 224                               const char *value)
 225 {
 226         if (supported_man_viewer(name, len))
 227                 warning("'%s': cmd for supported man viewer.\n"
 228                         "Please consider using 'man.<tool>.path' instead.",
 229                         name);
 230         else
 231                 do_add_man_viewer_info(name, len, value);
 232
 233         return 0;
 234 }
 235
 236 static int add_man_viewer_info(const char *var, const char *value)
 237 {
 238         const char *name = var + 4;
 239         const char *subkey = strrchr(name, '.');
 240
 241         if (!subkey)
 242                 return error("Config with no key for man viewer: %s", name);
 243
 244         if (!strcmp(subkey, ".path")) {
 245                 if (!value)
 246                         return config_error_nonbool(var);
 247                 return add_man_viewer_path(name, subkey - name, value);
 248         }
 249         if (!strcmp(subkey, ".cmd")) {
 250                 if (!value)
 251                         return config_error_nonbool(var);
 252                 return add_man_viewer_cmd(name, subkey - name, value);
 253         }
 254
 255         warning("'%s': unsupported man viewer sub key.", subkey);
 256         return 0;
 257 }
 258
 259 static int perf_help_config(const char *var, const char *value, void *cb)
 260 {
 261         if (!strcmp(var, "help.format")) {
 262                 if (!value)
 263                         return config_error_nonbool(var);
 264                 help_format = parse_help_format(value);
 265                 if (help_format == HELP_FORMAT_NONE)
 266                         return -1;
 267                 return 0;
 268         }
 269         if (!strcmp(var, "man.viewer")) {
 270                 if (!value)
 271                         return config_error_nonbool(var);
 272                 add_man_viewer(value);
 273                 return 0;
 274         }
 275         if (!prefixcmp(var, "man."))
 276                 return add_man_viewer_info(var, value);
 277
 278         return perf_default_config(var, value, cb);
 279 }
 280
 281 static struct cmdnames main_cmds, other_cmds;
 282
 283 void list_common_cmds_help(void)
 284 {
 285         unsigned int i, longest = 0;
 286
 287         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 288                 if (longest < strlen(common_cmds[i].name))
 289                         longest = strlen(common_cmds[i].name);
 290         }
 291
 292         puts(" The most commonly used perf commands are:");
 293         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 294                 printf("   %-*s   ", longest, common_cmds[i].name);
 295                 puts(common_cmds[i].help);
 296         }
 297 }
 298
 299 static int is_perf_command(const char *s)
 300 {
 301         return is_in_cmdlist(&main_cmds, s) ||
 302                 is_in_cmdlist(&other_cmds, s);
 303 }
 304
 305 static const char *prepend(const char *prefix, const char *cmd)
 306 {
 307         size_t pre_len = strlen(prefix);
 308         size_t cmd_len = strlen(cmd);
 309         char *p = malloc(pre_len + cmd_len + 1);
 310         memcpy(p, prefix, pre_len);
 311         strcpy(p + pre_len, cmd);
 312         return p;
 313 }
 314
 315 static const char *cmd_to_page(const char *perf_cmd)
 316 {
 317         if (!perf_cmd)
 318                 return "perf";
 319         else if (!prefixcmp(perf_cmd, "perf"))
 320                 return perf_cmd;
 321         else
 322                 return prepend("perf-", perf_cmd);
 323 }
 324
 325 static void setup_man_path(void)
 326 {
 327         struct strbuf new_path = STRBUF_INIT;
 328         const char *old_path = getenv("MANPATH");
 329
 330         /* We should always put ':' after our path. If there is no
 331          * old_path, the ':' at the end will let 'man' to try
 332          * system-wide paths after ours to find the manual page. If
 333          * there is old_path, we need ':' as delimiter. */
 334         strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
 335         strbuf_addch(&new_path, ':');
 336         if (old_path)
 337                 strbuf_addstr(&new_path, old_path);
 338
 339         setenv("MANPATH", new_path.buf, 1);
 340
 341         strbuf_release(&new_path);
 342 }
 343
 344 static void exec_viewer(const char *name, const char *page)
 345 {
 346         const char *info = get_man_viewer_info(name);
 347
 348         if (!strcasecmp(name, "man"))
 349                 exec_man_man(info, page);
 350         else if (!strcasecmp(name, "woman"))
 351                 exec_woman_emacs(info, page);
 352         else if (!strcasecmp(name, "konqueror"))
 353                 exec_man_konqueror(info, page);
 354         else if (info)
 355                 exec_man_cmd(info, page);
 356         else
 357                 warning("'%s': unknown man viewer.", name);
 358 }
 359
 360 static int show_man_page(const char *perf_cmd)
 361 {
 362         struct man_viewer_list *viewer;
 363         const char *page = cmd_to_page(perf_cmd);
 364         const char *fallback = getenv("PERF_MAN_VIEWER");
 365
 366         setup_man_path();
 367         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 368                 exec_viewer(viewer->name, page); /* will return when unable */
 369
 370         if (fallback)
 371                 exec_viewer(fallback, page);
 372         exec_viewer("man", page);
 373
 374         pr_err("no man viewer handled the request");
 375         return -1;
 376 }
 377
 378 static int show_info_page(const char *perf_cmd)
 379 {
 380         const char *page = cmd_to_page(perf_cmd);
 381         setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
 382         execlp("info", "info", "perfman", page, NULL);
 383         return -1;
 384 }
 385
 386 static int get_html_page_path(struct strbuf *page_path, const char *page)
 387 {
 388         struct stat st;
 389         const char *html_path = system_path(PERF_HTML_PATH);
 390
 391         /* Check that we have a perf documentation directory. */
 392         if (stat(mkpath("%s/perf.html", html_path), &st)
 393             || !S_ISREG(st.st_mode)) {
 394                 pr_err("'%s': not a documentation directory.", html_path);
 395                 return -1;
 396         }
 397
 398         strbuf_init(page_path, 0);
 399         strbuf_addf(page_path, "%s/%s.html", html_path, page);
 400
 401         return 0;
 402 }
 403
 404 /*
 405  * If open_html is not defined in a platform-specific way (see for
 406  * example compat/mingw.h), we use the script web--browse to display
 407  * HTML.
 408  */
 409 #ifndef open_html
 410 static void open_html(const char *path)
 411 {
 412         execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
 413 }
 414 #endif
 415
 416 static int show_html_page(const char *perf_cmd)
 417 {
 418         const char *page = cmd_to_page(perf_cmd);
 419         struct strbuf page_path; /* it leaks but we exec bellow */
 420
 421         if (get_html_page_path(&page_path, page) != 0)
 422                 return -1;
 423
 424         open_html(page_path.buf);
 425
 426         return 0;
 427 }
 428
 429 int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
 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, NULL);
 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 }