tools/perf/builtin-help.c

   1 /*
   2  * builtin-help.c
   3  *
   4  * Builtin help command
   5  */
   6 #include "perf.h"
   7 #include "util/config.h"
   8 #include "builtin.h"
   9 #include <subcmd/exec-cmd.h>
  10 #include "common-cmds.h"
  11 #include <subcmd/parse-options.h>
  12 #include <subcmd/run-command.h>
  13 #include <subcmd/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         int ret = -1;
  65
  66         /* emacsclient prints its version number on stderr */
  67         memset(&ec_process, 0, sizeof(ec_process));
  68         ec_process.argv = argv_ec;
  69         ec_process.err = -1;
  70         ec_process.stdout_to_stderr = 1;
  71         if (start_command(&ec_process)) {
  72                 fprintf(stderr, "Failed to start emacsclient.\n");
  73                 return -1;
  74         }
  75         if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
  76                 fprintf(stderr, "Failed to read emacsclient version\n");
  77                 goto out;
  78         }
  79         close(ec_process.err);
  80
  81         /*
  82          * Don't bother checking return value, because "emacsclient --version"
  83          * seems to always exits with code 1.
  84          */
  85         finish_command(&ec_process);
  86
  87         if (prefixcmp(buffer.buf, "emacsclient")) {
  88                 fprintf(stderr, "Failed to parse emacsclient version.\n");
  89                 goto out;
  90         }
  91
  92         version = atoi(buffer.buf + strlen("emacsclient"));
  93
  94         if (version < 22) {
  95                 fprintf(stderr,
  96                         "emacsclient version '%d' too old (< 22).\n",
  97                         version);
  98         } else
  99                 ret = 0;
 100 out:
 101         strbuf_release(&buffer);
 102         return ret;
 103 }
 104
 105 static void exec_woman_emacs(const char *path, const char *page)
 106 {
 107         char sbuf[STRERR_BUFSIZE];
 108
 109         if (!check_emacsclient_version()) {
 110                 /* This works only with emacsclient version >= 22. */
 111                 char *man_page;
 112
 113                 if (!path)
 114                         path = "emacsclient";
 115                 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
 116                         execlp(path, "emacsclient", "-e", man_page, NULL);
 117                         free(man_page);
 118                 }
 119                 warning("failed to exec '%s': %s", path,
 120                         str_error_r(errno, sbuf, sizeof(sbuf)));
 121         }
 122 }
 123
 124 static void exec_man_konqueror(const char *path, const char *page)
 125 {
 126         const char *display = getenv("DISPLAY");
 127
 128         if (display && *display) {
 129                 char *man_page;
 130                 const char *filename = "kfmclient";
 131                 char sbuf[STRERR_BUFSIZE];
 132
 133                 /* It's simpler to launch konqueror using kfmclient. */
 134                 if (path) {
 135                         const char *file = strrchr(path, '/');
 136                         if (file && !strcmp(file + 1, "konqueror")) {
 137                                 char *new = strdup(path);
 138                                 char *dest = strrchr(new, '/');
 139
 140                                 /* strlen("konqueror") == strlen("kfmclient") */
 141                                 strcpy(dest + 1, "kfmclient");
 142                                 path = new;
 143                         }
 144                         if (file)
 145                                 filename = file;
 146                 } else
 147                         path = "kfmclient";
 148                 if (asprintf(&man_page, "man:%s(1)", page) > 0) {
 149                         execlp(path, filename, "newTab", man_page, NULL);
 150                         free(man_page);
 151                 }
 152                 warning("failed to exec '%s': %s", path,
 153                         str_error_r(errno, sbuf, sizeof(sbuf)));
 154         }
 155 }
 156
 157 static void exec_man_man(const char *path, const char *page)
 158 {
 159         char sbuf[STRERR_BUFSIZE];
 160
 161         if (!path)
 162                 path = "man";
 163         execlp(path, "man", page, NULL);
 164         warning("failed to exec '%s': %s", path,
 165                 str_error_r(errno, sbuf, sizeof(sbuf)));
 166 }
 167
 168 static void exec_man_cmd(const char *cmd, const char *page)
 169 {
 170         char sbuf[STRERR_BUFSIZE];
 171         char *shell_cmd;
 172
 173         if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
 174                 execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
 175                 free(shell_cmd);
 176         }
 177         warning("failed to exec '%s': %s", cmd,
 178                 str_error_r(errno, sbuf, sizeof(sbuf)));
 179 }
 180
 181 static void add_man_viewer(const char *name)
 182 {
 183         struct man_viewer_list **p = &man_viewer_list;
 184         size_t len = strlen(name);
 185
 186         while (*p)
 187                 p = &((*p)->next);
 188         *p = zalloc(sizeof(**p) + len + 1);
 189         strncpy((*p)->name, name, len);
 190 }
 191
 192 static int supported_man_viewer(const char *name, size_t len)
 193 {
 194         return (!strncasecmp("man", name, len) ||
 195                 !strncasecmp("woman", name, len) ||
 196                 !strncasecmp("konqueror", name, len));
 197 }
 198
 199 static void do_add_man_viewer_info(const char *name,
 200                                    size_t len,
 201                                    const char *value)
 202 {
 203         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 204
 205         strncpy(new->name, name, len);
 206         new->info = strdup(value);
 207         new->next = man_viewer_info_list;
 208         man_viewer_info_list = new;
 209 }
 210
 211 static int add_man_viewer_path(const char *name,
 212                                size_t len,
 213                                const char *value)
 214 {
 215         if (supported_man_viewer(name, len))
 216                 do_add_man_viewer_info(name, len, value);
 217         else
 218                 warning("'%s': path for unsupported man viewer.\n"
 219                         "Please consider using 'man.<tool>.cmd' instead.",
 220                         name);
 221
 222         return 0;
 223 }
 224
 225 static int add_man_viewer_cmd(const char *name,
 226                               size_t len,
 227                               const char *value)
 228 {
 229         if (supported_man_viewer(name, len))
 230                 warning("'%s': cmd for supported man viewer.\n"
 231                         "Please consider using 'man.<tool>.path' instead.",
 232                         name);
 233         else
 234                 do_add_man_viewer_info(name, len, value);
 235
 236         return 0;
 237 }
 238
 239 static int add_man_viewer_info(const char *var, const char *value)
 240 {
 241         const char *name = var + 4;
 242         const char *subkey = strrchr(name, '.');
 243
 244         if (!subkey)
 245                 return error("Config with no key for man viewer: %s", name);
 246
 247         if (!strcmp(subkey, ".path")) {
 248                 if (!value)
 249                         return config_error_nonbool(var);
 250                 return add_man_viewer_path(name, subkey - name, value);
 251         }
 252         if (!strcmp(subkey, ".cmd")) {
 253                 if (!value)
 254                         return config_error_nonbool(var);
 255                 return add_man_viewer_cmd(name, subkey - name, value);
 256         }
 257
 258         warning("'%s': unsupported man viewer sub key.", subkey);
 259         return 0;
 260 }
 261
 262 static int perf_help_config(const char *var, const char *value, void *cb)
 263 {
 264         enum help_format *help_formatp = cb;
 265
 266         if (!strcmp(var, "help.format")) {
 267                 if (!value)
 268                         return config_error_nonbool(var);
 269                 *help_formatp = parse_help_format(value);
 270                 if (*help_formatp == HELP_FORMAT_NONE)
 271                         return -1;
 272                 return 0;
 273         }
 274         if (!strcmp(var, "man.viewer")) {
 275                 if (!value)
 276                         return config_error_nonbool(var);
 277                 add_man_viewer(value);
 278                 return 0;
 279         }
 280         if (!prefixcmp(var, "man."))
 281                 return add_man_viewer_info(var, value);
 282
 283         return 0;
 284 }
 285
 286 static struct cmdnames main_cmds, other_cmds;
 287
 288 void list_common_cmds_help(void)
 289 {
 290         unsigned int i, longest = 0;
 291
 292         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 293                 if (longest < strlen(common_cmds[i].name))
 294                         longest = strlen(common_cmds[i].name);
 295         }
 296
 297         puts(" The most commonly used perf commands are:");
 298         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 299                 printf("   %-*s   ", longest, common_cmds[i].name);
 300                 puts(common_cmds[i].help);
 301         }
 302 }
 303
 304 static int is_perf_command(const char *s)
 305 {
 306         return is_in_cmdlist(&main_cmds, s) ||
 307                 is_in_cmdlist(&other_cmds, s);
 308 }
 309
 310 static const char *cmd_to_page(const char *perf_cmd)
 311 {
 312         char *s;
 313
 314         if (!perf_cmd)
 315                 return "perf";
 316         else if (!prefixcmp(perf_cmd, "perf"))
 317                 return perf_cmd;
 318
 319         return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
 320 }
 321
 322 static void setup_man_path(void)
 323 {
 324         char *new_path;
 325         const char *old_path = getenv("MANPATH");
 326
 327         /* We should always put ':' after our path. If there is no
 328          * old_path, the ':' at the end will let 'man' to try
 329          * system-wide paths after ours to find the manual page. If
 330          * there is old_path, we need ':' as delimiter. */
 331         if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
 332                 setenv("MANPATH", new_path, 1);
 333                 free(new_path);
 334         } else {
 335                 error("Unable to setup man path");
 336         }
 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 int 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
 369         pr_err("no man viewer handled the request");
 370         return -1;
 371 }
 372
 373 static int show_info_page(const char *perf_cmd)
 374 {
 375         const char *page = cmd_to_page(perf_cmd);
 376         setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
 377         execlp("info", "info", "perfman", page, NULL);
 378         return -1;
 379 }
 380
 381 static int get_html_page_path(char **page_path, const char *page)
 382 {
 383         struct stat st;
 384         const char *html_path = system_path(PERF_HTML_PATH);
 385
 386         /* Check that we have a perf documentation directory. */
 387         if (stat(mkpath("%s/perf.html", html_path), &st)
 388             || !S_ISREG(st.st_mode)) {
 389                 pr_err("'%s': not a documentation directory.", html_path);
 390                 return -1;
 391         }
 392
 393         return asprintf(page_path, "%s/%s.html", html_path, page);
 394 }
 395
 396 /*
 397  * If open_html is not defined in a platform-specific way (see for
 398  * example compat/mingw.h), we use the script web--browse to display
 399  * HTML.
 400  */
 401 #ifndef open_html
 402 static void open_html(const char *path)
 403 {
 404         execl_cmd("web--browse", "-c", "help.browser", path, NULL);
 405 }
 406 #endif
 407
 408 static int show_html_page(const char *perf_cmd)
 409 {
 410         const char *page = cmd_to_page(perf_cmd);
 411         char *page_path; /* it leaks but we exec bellow */
 412
 413         if (get_html_page_path(&page_path, page) < 0)
 414                 return -1;
 415
 416         open_html(page_path);
 417
 418         return 0;
 419 }
 420
 421 int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
 422 {
 423         bool show_all = false;
 424         enum help_format help_format = HELP_FORMAT_MAN;
 425         struct option builtin_help_options[] = {
 426         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
 427         OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
 428         OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
 429                         HELP_FORMAT_WEB),
 430         OPT_SET_UINT('i', "info", &help_format, "show info page",
 431                         HELP_FORMAT_INFO),
 432         OPT_END(),
 433         };
 434         const char * const builtin_help_subcommands[] = {
 435                 "buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
 436                 "record", "report", "bench", "stat", "timechart", "top", "annotate",
 437                 "script", "sched", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
 438 #ifdef HAVE_LIBELF_SUPPORT
 439                 "probe",
 440 #endif
 441 #ifdef HAVE_LIBAUDIT_SUPPORT
 442                 "trace",
 443 #endif
 444         NULL };
 445         const char *builtin_help_usage[] = {
 446                 "perf help [--all] [--man|--web|--info] [command]",
 447                 NULL
 448         };
 449         const char *alias;
 450         int rc = 0;
 451
 452         load_command_list("perf-", &main_cmds, &other_cmds);
 453
 454         perf_config(perf_help_config, &help_format);
 455
 456         argc = parse_options_subcommand(argc, argv, builtin_help_options,
 457                         builtin_help_subcommands, builtin_help_usage, 0);
 458
 459         if (show_all) {
 460                 printf("\n Usage: %s\n\n", perf_usage_string);
 461                 list_commands("perf commands", &main_cmds, &other_cmds);
 462                 printf(" %s\n\n", perf_more_info_string);
 463                 return 0;
 464         }
 465
 466         if (!argv[0]) {
 467                 printf("\n usage: %s\n\n", perf_usage_string);
 468                 list_common_cmds_help();
 469                 printf("\n %s\n\n", perf_more_info_string);
 470                 return 0;
 471         }
 472
 473         alias = alias_lookup(argv[0]);
 474         if (alias && !is_perf_command(argv[0])) {
 475                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
 476                 return 0;
 477         }
 478
 479         switch (help_format) {
 480         case HELP_FORMAT_MAN:
 481                 rc = show_man_page(argv[0]);
 482                 break;
 483         case HELP_FORMAT_INFO:
 484                 rc = show_info_page(argv[0]);
 485                 break;
 486         case HELP_FORMAT_WEB:
 487                 rc = show_html_page(argv[0]);
 488                 break;
 489         case HELP_FORMAT_NONE:
 490                 /* fall-through */
 491         default:
 492                 rc = -1;
 493                 break;
 494         }
 495
 496         return rc;
 497 }