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 bool show_all = false;
  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_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  37         OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
  38                         HELP_FORMAT_WEB),
  39         OPT_SET_UINT('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                 if (!strcasecmp(name, viewer->name))
  66                         return viewer->info;
  67         }
  68         return NULL;
  69 }
  70
  71 static int check_emacsclient_version(void)
  72 {
  73         struct strbuf buffer = STRBUF_INIT;
  74         struct child_process ec_process;
  75         const char *argv_ec[] = { "emacsclient", "--version", NULL };
  76         int version;
  77
  78         /* emacsclient prints its version number on stderr */
  79         memset(&ec_process, 0, sizeof(ec_process));
  80         ec_process.argv = argv_ec;
  81         ec_process.err = -1;
  82         ec_process.stdout_to_stderr = 1;
  83         if (start_command(&ec_process)) {
  84                 fprintf(stderr, "Failed to start emacsclient.\n");
  85                 return -1;
  86         }
  87         strbuf_read(&buffer, ec_process.err, 20);
  88         close(ec_process.err);
  89
  90         /*
  91          * Don't bother checking return value, because "emacsclient --version"
  92          * seems to always exits with code 1.
  93          */
  94         finish_command(&ec_process);
  95
  96         if (prefixcmp(buffer.buf, "emacsclient")) {
  97                 fprintf(stderr, "Failed to parse emacsclient version.\n");
  98                 strbuf_release(&buffer);
  99                 return -1;
 100         }
 101
 102         strbuf_remove(&buffer, 0, strlen("emacsclient"));
 103         version = atoi(buffer.buf);
 104
 105         if (version < 22) {
 106                 fprintf(stderr,
 107                         "emacsclient version '%d' too old (< 22).\n",
 108                         version);
 109                 strbuf_release(&buffer);
 110                 return -1;
 111         }
 112
 113         strbuf_release(&buffer);
 114         return 0;
 115 }
 116
 117 static void exec_woman_emacs(const char *path, const char *page)
 118 {
 119         if (!check_emacsclient_version()) {
 120                 /* This works only with emacsclient version >= 22. */
 121                 struct strbuf man_page = STRBUF_INIT;
 122
 123                 if (!path)
 124                         path = "emacsclient";
 125                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 126                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 127                 warning("failed to exec '%s': %s", path, strerror(errno));
 128         }
 129 }
 130
 131 static void exec_man_konqueror(const char *path, const char *page)
 132 {
 133         const char *display = getenv("DISPLAY");
 134         if (display && *display) {
 135                 struct strbuf man_page = STRBUF_INIT;
 136                 const char *filename = "kfmclient";
 137
 138                 /* It's simpler to launch konqueror using kfmclient. */
 139                 if (path) {
 140                         const char *file = strrchr(path, '/');
 141                         if (file && !strcmp(file + 1, "konqueror")) {
 142                                 char *new = strdup(path);
 143                                 char *dest = strrchr(new, '/');
 144
 145                                 /* strlen("konqueror") == strlen("kfmclient") */
 146                                 strcpy(dest + 1, "kfmclient");
 147                                 path = new;
 148                         }
 149                         if (file)
 150                                 filename = file;
 151                 } else
 152                         path = "kfmclient";
 153                 strbuf_addf(&man_page, "man:%s(1)", page);
 154                 execlp(path, filename, "newTab", man_page.buf, NULL);
 155                 warning("failed to exec '%s': %s", path, strerror(errno));
 156         }
 157 }
 158
 159 static void exec_man_man(const char *path, const char *page)
 160 {
 161         if (!path)
 162                 path = "man";
 163         execlp(path, "man", page, NULL);
 164         warning("failed to exec '%s': %s", path, strerror(errno));
 165 }
 166
 167 static void exec_man_cmd(const char *cmd, const char *page)
 168 {
 169         struct strbuf shell_cmd = STRBUF_INIT;
 170         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 171         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 172         warning("failed to exec '%s': %s", cmd, strerror(errno));
 173 }
 174
 175 static void add_man_viewer(const char *name)
 176 {
 177         struct man_viewer_list **p = &man_viewer_list;
 178         size_t len = strlen(name);
 179
 180         while (*p)
 181                 p = &((*p)->next);
 182         *p = zalloc(sizeof(**p) + len + 1);
 183         strncpy((*p)->name, name, len);
 184 }
 185
 186 static int supported_man_viewer(const char *name, size_t len)
 187 {
 188         return (!strncasecmp("man", name, len) ||
 189                 !strncasecmp("woman", name, len) ||
 190                 !strncasecmp("konqueror", name, len));
 191 }
 192
 193 static void do_add_man_viewer_info(const char *name,
 194                                    size_t len,
 195                                    const char *value)
 196 {
 197         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 198
 199         strncpy(new->name, name, len);
 200         new->info = strdup(value);
 201         new->next = man_viewer_info_list;
 202         man_viewer_info_list = new;
 203 }
 204
 205 static int add_man_viewer_path(const char *name,
 206                                size_t len,
 207                                const char *value)
 208 {
 209         if (supported_man_viewer(name, len))
 210                 do_add_man_viewer_info(name, len, value);
 211         else
 212                 warning("'%s': path for unsupported man viewer.\n"
 213                         "Please consider using 'man.<tool>.cmd' instead.",
 214                         name);
 215
 216         return 0;
 217 }
 218
 219 static int add_man_viewer_cmd(const char *name,
 220                               size_t len,
 221                               const char *value)
 222 {
 223         if (supported_man_viewer(name, len))
 224                 warning("'%s': cmd for supported man viewer.\n"
 225                         "Please consider using 'man.<tool>.path' instead.",
 226                         name);
 227         else
 228                 do_add_man_viewer_info(name, len, value);
 229
 230         return 0;
 231 }
 232
 233 static int add_man_viewer_info(const char *var, const char *value)
 234 {
 235         const char *name = var + 4;
 236         const char *subkey = strrchr(name, '.');
 237
 238         if (!subkey)
 239                 return error("Config with no key for man viewer: %s", name);
 240
 241         if (!strcmp(subkey, ".path")) {
 242                 if (!value)
 243                         return config_error_nonbool(var);
 244                 return add_man_viewer_path(name, subkey - name, value);
 245         }
 246         if (!strcmp(subkey, ".cmd")) {
 247                 if (!value)
 248                         return config_error_nonbool(var);
 249                 return add_man_viewer_cmd(name, subkey - name, value);
 250         }
 251
 252         warning("'%s': unsupported man viewer sub key.", subkey);
 253         return 0;
 254 }
 255
 256 static int perf_help_config(const char *var, const char *value, void *cb)
 257 {
 258         if (!strcmp(var, "help.format")) {
 259                 if (!value)
 260                         return config_error_nonbool(var);
 261                 help_format = parse_help_format(value);
 262                 return 0;
 263         }
 264         if (!strcmp(var, "man.viewer")) {
 265                 if (!value)
 266                         return config_error_nonbool(var);
 267                 add_man_viewer(value);
 268                 return 0;
 269         }
 270         if (!prefixcmp(var, "man."))
 271                 return add_man_viewer_info(var, value);
 272
 273         return perf_default_config(var, value, cb);
 274 }
 275
 276 static struct cmdnames main_cmds, other_cmds;
 277
 278 void list_common_cmds_help(void)
 279 {
 280         unsigned int i, longest = 0;
 281
 282         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 283                 if (longest < strlen(common_cmds[i].name))
 284                         longest = strlen(common_cmds[i].name);
 285         }
 286
 287         puts(" The most commonly used perf commands are:");
 288         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 289                 printf("   %-*s   ", longest, common_cmds[i].name);
 290                 puts(common_cmds[i].help);
 291         }
 292 }
 293
 294 static int is_perf_command(const char *s)
 295 {
 296         return is_in_cmdlist(&main_cmds, s) ||
 297                 is_in_cmdlist(&other_cmds, s);
 298 }
 299
 300 static const char *prepend(const char *prefix, const char *cmd)
 301 {
 302         size_t pre_len = strlen(prefix);
 303         size_t cmd_len = strlen(cmd);
 304         char *p = malloc(pre_len + cmd_len + 1);
 305         memcpy(p, prefix, pre_len);
 306         strcpy(p + pre_len, cmd);
 307         return p;
 308 }
 309
 310 static const char *cmd_to_page(const char *perf_cmd)
 311 {
 312         if (!perf_cmd)
 313                 return "perf";
 314         else if (!prefixcmp(perf_cmd, "perf"))
 315                 return perf_cmd;
 316         else
 317                 return prepend("perf-", perf_cmd);
 318 }
 319
 320 static void setup_man_path(void)
 321 {
 322         struct strbuf new_path = STRBUF_INIT;
 323         const char *old_path = getenv("MANPATH");
 324
 325         /* We should always put ':' after our path. If there is no
 326          * old_path, the ':' at the end will let 'man' to try
 327          * system-wide paths after ours to find the manual page. If
 328          * there is old_path, we need ':' as delimiter. */
 329         strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
 330         strbuf_addch(&new_path, ':');
 331         if (old_path)
 332                 strbuf_addstr(&new_path, old_path);
 333
 334         setenv("MANPATH", new_path.buf, 1);
 335
 336         strbuf_release(&new_path);
 337 }
 338
 339 static void exec_viewer(const char *name, const char *page)
 340 {
 341         const char *info = get_man_viewer_info(name);
 342
 343         if (!strcasecmp(name, "man"))
 344                 exec_man_man(info, page);
 345         else if (!strcasecmp(name, "woman"))
 346                 exec_woman_emacs(info, page);
 347         else if (!strcasecmp(name, "konqueror"))
 348                 exec_man_konqueror(info, page);
 349         else if (info)
 350                 exec_man_cmd(info, page);
 351         else
 352                 warning("'%s': unknown man viewer.", name);
 353 }
 354
 355 static void show_man_page(const char *perf_cmd)
 356 {
 357         struct man_viewer_list *viewer;
 358         const char *page = cmd_to_page(perf_cmd);
 359         const char *fallback = getenv("PERF_MAN_VIEWER");
 360
 361         setup_man_path();
 362         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 363                 exec_viewer(viewer->name, page); /* will return when unable */
 364
 365         if (fallback)
 366                 exec_viewer(fallback, page);
 367         exec_viewer("man", page);
 368         die("no man viewer handled the request");
 369 }
 370
 371 static void show_info_page(const char *perf_cmd)
 372 {
 373         const char *page = cmd_to_page(perf_cmd);
 374         setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
 375         execlp("info", "info", "perfman", page, NULL);
 376 }
 377
 378 static void get_html_page_path(struct strbuf *page_path, const char *page)
 379 {
 380         struct stat st;
 381         const char *html_path = system_path(PERF_HTML_PATH);
 382
 383         /* Check that we have a perf documentation directory. */
 384         if (stat(mkpath("%s/perf.html", html_path), &st)
 385             || !S_ISREG(st.st_mode))
 386                 die("'%s': not a documentation directory.", html_path);
 387
 388         strbuf_init(page_path, 0);
 389         strbuf_addf(page_path, "%s/%s.html", html_path, page);
 390 }
 391
 392 /*
 393  * If open_html is not defined in a platform-specific way (see for
 394  * example compat/mingw.h), we use the script web--browse to display
 395  * HTML.
 396  */
 397 #ifndef open_html
 398 static void open_html(const char *path)
 399 {
 400         execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
 401 }
 402 #endif
 403
 404 static void show_html_page(const char *perf_cmd)
 405 {
 406         const char *page = cmd_to_page(perf_cmd);
 407         struct strbuf page_path; /* it leaks but we exec bellow */
 408
 409         get_html_page_path(&page_path, page);
 410
 411         open_html(page_path.buf);
 412 }
 413
 414 int cmd_help(int argc, const char **argv, const char *prefix __used)
 415 {
 416         const char *alias;
 417
 418         load_command_list("perf-", &main_cmds, &other_cmds);
 419
 420         perf_config(perf_help_config, NULL);
 421
 422         argc = parse_options(argc, argv, builtin_help_options,
 423                         builtin_help_usage, 0);
 424
 425         if (show_all) {
 426                 printf("\n usage: %s\n\n", perf_usage_string);
 427                 list_commands("perf commands", &main_cmds, &other_cmds);
 428                 printf(" %s\n\n", perf_more_info_string);
 429                 return 0;
 430         }
 431
 432         if (!argv[0]) {
 433                 printf("\n usage: %s\n\n", perf_usage_string);
 434                 list_common_cmds_help();
 435                 printf("\n %s\n\n", perf_more_info_string);
 436                 return 0;
 437         }
 438
 439         alias = alias_lookup(argv[0]);
 440         if (alias && !is_perf_command(argv[0])) {
 441                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
 442                 return 0;
 443         }
 444
 445         switch (help_format) {
 446         case HELP_FORMAT_MAN:
 447                 show_man_page(argv[0]);
 448                 break;
 449         case HELP_FORMAT_INFO:
 450                 show_info_page(argv[0]);
 451                 break;
 452         case HELP_FORMAT_WEB:
 453                 show_html_page(argv[0]);
 454         default:
 455                 break;
 456         }
 457
 458         return 0;
 459 }