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_MAN,
  28         HELP_FORMAT_INFO,
  29         HELP_FORMAT_WEB,
  30 };
  31
  32 static int show_all = 0;
  33 static enum help_format help_format = HELP_FORMAT_MAN;
  34 static struct option builtin_help_options[] = {
  35         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  36         OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  37         OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  38                         HELP_FORMAT_WEB),
  39         OPT_SET_INT('i', "info", &help_format, "show info page",
  40                         HELP_FORMAT_INFO),
  41         OPT_END(),
  42 };
  43
  44 static const char * const builtin_help_usage[] = {
  45         "perf help [--all] [--man|--web|--info] [command]",
  46         NULL
  47 };
  48
  49 static enum help_format parse_help_format(const char *format)
  50 {
  51         if (!strcmp(format, "man"))
  52                 return HELP_FORMAT_MAN;
  53         if (!strcmp(format, "info"))
  54                 return HELP_FORMAT_INFO;
  55         if (!strcmp(format, "web") || !strcmp(format, "html"))
  56                 return HELP_FORMAT_WEB;
  57         die("unrecognized help format '%s'", format);
  58 }
  59
  60 static const char *get_man_viewer_info(const char *name)
  61 {
  62         struct man_viewer_info_list *viewer;
  63
  64         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  65         {
  66                 if (!strcasecmp(name, viewer->name))
  67                         return viewer->info;
  68         }
  69         return NULL;
  70 }
  71
  72 static 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
  79         /* emacsclient prints its version number on stderr */
  80         memset(&ec_process, 0, sizeof(ec_process));
  81         ec_process.argv = argv_ec;
  82         ec_process.err = -1;
  83         ec_process.stdout_to_stderr = 1;
  84         if (start_command(&ec_process)) {
  85                 fprintf(stderr, "Failed to start emacsclient.\n");
  86                 return -1;
  87         }
  88         strbuf_read(&buffer, ec_process.err, 20);
  89         close(ec_process.err);
  90
  91         /*
  92          * Don't bother checking return value, because "emacsclient --version"
  93          * seems to always exits with code 1.
  94          */
  95         finish_command(&ec_process);
  96
  97         if (prefixcmp(buffer.buf, "emacsclient")) {
  98                 fprintf(stderr, "Failed to parse emacsclient version.\n");
  99                 strbuf_release(&buffer);
 100                 return -1;
 101         }
 102
 103         strbuf_remove(&buffer, 0, strlen("emacsclient"));
 104         version = atoi(buffer.buf);
 105
 106         if (version < 22) {
 107                 fprintf(stderr,
 108                         "emacsclient version '%d' too old (< 22).\n",
 109                         version);
 110                 strbuf_release(&buffer);
 111                 return -1;
 112         }
 113
 114         strbuf_release(&buffer);
 115         return 0;
 116 }
 117
 118 static void exec_woman_emacs(const char* path, const char *page)
 119 {
 120         if (!check_emacsclient_version()) {
 121                 /* This works only with emacsclient version >= 22. */
 122                 struct strbuf man_page = STRBUF_INIT;
 123
 124                 if (!path)
 125                         path = "emacsclient";
 126                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 127                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 128                 warning("failed to exec '%s': %s", path, strerror(errno));
 129         }
 130 }
 131
 132 static void exec_man_konqueror(const char* path, const char *page)
 133 {
 134         const char *display = getenv("DISPLAY");
 135         if (display && *display) {
 136                 struct strbuf man_page = STRBUF_INIT;
 137                 const char *filename = "kfmclient";
 138
 139                 /* It's simpler to launch konqueror using kfmclient. */
 140                 if (path) {
 141                         const char *file = strrchr(path, '/');
 142                         if (file && !strcmp(file + 1, "konqueror")) {
 143                                 char *new = strdup(path);
 144                                 char *dest = strrchr(new, '/');
 145
 146                                 /* strlen("konqueror") == strlen("kfmclient") */
 147                                 strcpy(dest + 1, "kfmclient");
 148                                 path = new;
 149                         }
 150                         if (file)
 151                                 filename = file;
 152                 } else
 153                         path = "kfmclient";
 154                 strbuf_addf(&man_page, "man:%s(1)", page);
 155                 execlp(path, filename, "newTab", man_page.buf, NULL);
 156                 warning("failed to exec '%s': %s", path, strerror(errno));
 157         }
 158 }
 159
 160 static void exec_man_man(const char* path, const char *page)
 161 {
 162         if (!path)
 163                 path = "man";
 164         execlp(path, "man", page, NULL);
 165         warning("failed to exec '%s': %s", path, strerror(errno));
 166 }
 167
 168 static void exec_man_cmd(const char *cmd, const char *page)
 169 {
 170         struct strbuf shell_cmd = STRBUF_INIT;
 171         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 172         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 173         warning("failed to exec '%s': %s", cmd, strerror(errno));
 174 }
 175
 176 static void add_man_viewer(const char *name)
 177 {
 178         struct man_viewer_list **p = &man_viewer_list;
 179         size_t len = strlen(name);
 180
 181         while (*p)
 182                 p = &((*p)->next);
 183         *p = calloc(1, (sizeof(**p) + len + 1));
 184         strncpy((*p)->name, name, len);
 185 }
 186
 187 static int supported_man_viewer(const char *name, size_t len)
 188 {
 189         return (!strncasecmp("man", name, len) ||
 190                 !strncasecmp("woman", name, len) ||
 191                 !strncasecmp("konqueror", name, len));
 192 }
 193
 194 static void do_add_man_viewer_info(const char *name,
 195                                    size_t len,
 196                                    const char *value)
 197 {
 198         struct man_viewer_info_list *new = calloc(1, sizeof(*new) + len + 1);
 199
 200         strncpy(new->name, name, len);
 201         new->info = strdup(value);
 202         new->next = man_viewer_info_list;
 203         man_viewer_info_list = new;
 204 }
 205
 206 static int add_man_viewer_path(const char *name,
 207                                size_t len,
 208                                const char *value)
 209 {
 210         if (supported_man_viewer(name, len))
 211                 do_add_man_viewer_info(name, len, value);
 212         else
 213                 warning("'%s': path for unsupported man viewer.\n"
 214                         "Please consider using 'man.<tool>.cmd' instead.",
 215                         name);
 216
 217         return 0;
 218 }
 219
 220 static int add_man_viewer_cmd(const char *name,
 221                               size_t len,
 222                               const char *value)
 223 {
 224         if (supported_man_viewer(name, len))
 225                 warning("'%s': cmd for supported man viewer.\n"
 226                         "Please consider using 'man.<tool>.path' instead.",
 227                         name);
 228         else
 229                 do_add_man_viewer_info(name, len, value);
 230
 231         return 0;
 232 }
 233
 234 static int add_man_viewer_info(const char *var, const char *value)
 235 {
 236         const char *name = var + 4;
 237         const char *subkey = strrchr(name, '.');
 238
 239         if (!subkey)
 240                 return error("Config with no key for man viewer: %s", name);
 241
 242         if (!strcmp(subkey, ".path")) {
 243                 if (!value)
 244                         return config_error_nonbool(var);
 245                 return add_man_viewer_path(name, subkey - name, value);
 246         }
 247         if (!strcmp(subkey, ".cmd")) {
 248                 if (!value)
 249                         return config_error_nonbool(var);
 250                 return add_man_viewer_cmd(name, subkey - name, value);
 251         }
 252
 253         warning("'%s': unsupported man viewer sub key.", subkey);
 254         return 0;
 255 }
 256
 257 static int perf_help_config(const char *var, const char *value, void *cb)
 258 {
 259         if (!strcmp(var, "help.format")) {
 260                 if (!value)
 261                         return config_error_nonbool(var);
 262                 help_format = parse_help_format(value);
 263                 return 0;
 264         }
 265         if (!strcmp(var, "man.viewer")) {
 266                 if (!value)
 267                         return config_error_nonbool(var);
 268                 add_man_viewer(value);
 269                 return 0;
 270         }
 271         if (!prefixcmp(var, "man."))
 272                 return add_man_viewer_info(var, value);
 273
 274         return perf_default_config(var, value, cb);
 275 }
 276
 277 static struct cmdnames main_cmds, other_cmds;
 278
 279 void list_common_cmds_help(void)
 280 {
 281         unsigned int i, longest = 0;
 282
 283         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 284                 if (longest < strlen(common_cmds[i].name))
 285                         longest = strlen(common_cmds[i].name);
 286         }
 287
 288         puts(" The most commonly used perf commands are:");
 289         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 290                 printf("   %s   ", common_cmds[i].name);
 291                 mput_char(' ', longest - strlen(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 if (is_perf_command(perf_cmd))
 319                 return prepend("perf-", perf_cmd);
 320         else
 321                 return prepend("perf-", perf_cmd);
 322 }
 323
 324 static void setup_man_path(void)
 325 {
 326         struct strbuf new_path = STRBUF_INIT;
 327         const char *old_path = getenv("MANPATH");
 328
 329         /* We should always put ':' after our path. If there is no
 330          * old_path, the ':' at the end will let 'man' to try
 331          * system-wide paths after ours to find the manual page. If
 332          * there is old_path, we need ':' as delimiter. */
 333         strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
 334         strbuf_addch(&new_path, ':');
 335         if (old_path)
 336                 strbuf_addstr(&new_path, old_path);
 337
 338         setenv("MANPATH", new_path.buf, 1);
 339
 340         strbuf_release(&new_path);
 341 }
 342
 343 static void exec_viewer(const char *name, const char *page)
 344 {
 345         const char *info = get_man_viewer_info(name);
 346
 347         if (!strcasecmp(name, "man"))
 348                 exec_man_man(info, page);
 349         else if (!strcasecmp(name, "woman"))
 350                 exec_woman_emacs(info, page);
 351         else if (!strcasecmp(name, "konqueror"))
 352                 exec_man_konqueror(info, page);
 353         else if (info)
 354                 exec_man_cmd(info, page);
 355         else
 356                 warning("'%s': unknown man viewer.", name);
 357 }
 358
 359 static void show_man_page(const char *perf_cmd)
 360 {
 361         struct man_viewer_list *viewer;
 362         const char *page = cmd_to_page(perf_cmd);
 363         const char *fallback = getenv("PERF_MAN_VIEWER");
 364
 365         setup_man_path();
 366         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 367         {
 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         die("no man viewer handled the request");
 374 }
 375
 376 static void 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 }
 382
 383 static void 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                 die("'%s': not a documentation directory.", html_path);
 392
 393         strbuf_init(page_path, 0);
 394         strbuf_addf(page_path, "%s/%s.html", html_path, page);
 395 }
 396
 397 /*
 398  * If open_html is not defined in a platform-specific way (see for
 399  * example compat/mingw.h), we use the script web--browse to display
 400  * HTML.
 401  */
 402 #ifndef open_html
 403 static void open_html(const char *path)
 404 {
 405         execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
 406 }
 407 #endif
 408
 409 static void show_html_page(const char *perf_cmd)
 410 {
 411         const char *page = cmd_to_page(perf_cmd);
 412         struct strbuf page_path; /* it leaks but we exec bellow */
 413
 414         get_html_page_path(&page_path, page);
 415
 416         open_html(page_path.buf);
 417 }
 418
 419 int cmd_help(int argc, const char **argv, const char *prefix __used)
 420 {
 421         const char *alias;
 422
 423         load_command_list("perf-", &main_cmds, &other_cmds);
 424
 425         perf_config(perf_help_config, NULL);
 426
 427         argc = parse_options(argc, argv, builtin_help_options,
 428                         builtin_help_usage, 0);
 429
 430         if (show_all) {
 431                 printf("\n usage: %s\n\n", perf_usage_string);
 432                 list_commands("perf commands", &main_cmds, &other_cmds);
 433                 printf(" %s\n\n", perf_more_info_string);
 434                 return 0;
 435         }
 436
 437         if (!argv[0]) {
 438                 printf("\n usage: %s\n\n", perf_usage_string);
 439                 list_common_cmds_help();
 440                 printf("\n %s\n\n", perf_more_info_string);
 441                 return 0;
 442         }
 443
 444         alias = alias_lookup(argv[0]);
 445         if (alias && !is_perf_command(argv[0])) {
 446                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
 447                 return 0;
 448         }
 449
 450         switch (help_format) {
 451         case HELP_FORMAT_MAN:
 452                 show_man_page(argv[0]);
 453                 break;
 454         case HELP_FORMAT_INFO:
 455                 show_info_page(argv[0]);
 456                 break;
 457         case HELP_FORMAT_WEB:
 458                 show_html_page(argv[0]);
 459                 break;
 460         }
 461
 462         return 0;
 463 }