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