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 <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
  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         version = atoi(buffer.buf + strlen("emacsclient"));
  90
  91         if (version < 22) {
  92                 fprintf(stderr,
  93                         "emacsclient version '%d' too old (< 22).\n",
  94                         version);
  95                 strbuf_release(&buffer);
  96                 return -1;
  97         }
  98
  99         strbuf_release(&buffer);
 100         return 0;
 101 }
 102
 103 static void exec_woman_emacs(const char *path, const char *page)
 104 {
 105         char sbuf[STRERR_BUFSIZE];
 106
 107         if (!check_emacsclient_version()) {
 108                 /* This works only with emacsclient version >= 22. */
 109                 char *man_page;
 110
 111                 if (!path)
 112                         path = "emacsclient";
 113                 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
 114                         execlp(path, "emacsclient", "-e", man_page, NULL);
 115                         free(man_page);
 116                 }
 117                 warning("failed to exec '%s': %s", path,
 118                         strerror_r(errno, sbuf, sizeof(sbuf)));
 119         }
 120 }
 121
 122 static void exec_man_konqueror(const char *path, const char *page)
 123 {
 124         const char *display = getenv("DISPLAY");
 125
 126         if (display && *display) {
 127                 char *man_page;
 128                 const char *filename = "kfmclient";
 129                 char sbuf[STRERR_BUFSIZE];
 130
 131                 /* It's simpler to launch konqueror using kfmclient. */
 132                 if (path) {
 133                         const char *file = strrchr(path, '/');
 134                         if (file && !strcmp(file + 1, "konqueror")) {
 135                                 char *new = strdup(path);
 136                                 char *dest = strrchr(new, '/');
 137
 138                                 /* strlen("konqueror") == strlen("kfmclient") */
 139                                 strcpy(dest + 1, "kfmclient");
 140                                 path = new;
 141                         }
 142                         if (file)
 143                                 filename = file;
 144                 } else
 145                         path = "kfmclient";
 146                 if (asprintf(&man_page, "man:%s(1)", page) > 0) {
 147                         execlp(path, filename, "newTab", man_page, NULL);
 148                         free(man_page);
 149                 }
 150                 warning("failed to exec '%s': %s", path,
 151                         strerror_r(errno, sbuf, sizeof(sbuf)));
 152         }
 153 }
 154
 155 static void exec_man_man(const char *path, const char *page)
 156 {
 157         char sbuf[STRERR_BUFSIZE];
 158
 159         if (!path)
 160                 path = "man";
 161         execlp(path, "man", page, NULL);
 162         warning("failed to exec '%s': %s", path,
 163                 strerror_r(errno, sbuf, sizeof(sbuf)));
 164 }
 165
 166 static void exec_man_cmd(const char *cmd, const char *page)
 167 {
 168         char sbuf[STRERR_BUFSIZE];
 169         char *shell_cmd;
 170
 171         if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
 172                 execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
 173                 free(shell_cmd);
 174         }
 175         warning("failed to exec '%s': %s", cmd,
 176                 strerror_r(errno, sbuf, sizeof(sbuf)));
 177 }
 178
 179 static void add_man_viewer(const char *name)
 180 {
 181         struct man_viewer_list **p = &man_viewer_list;
 182         size_t len = strlen(name);
 183
 184         while (*p)
 185                 p = &((*p)->next);
 186         *p = zalloc(sizeof(**p) + len + 1);
 187         strncpy((*p)->name, name, len);
 188 }
 189
 190 static int supported_man_viewer(const char *name, size_t len)
 191 {
 192         return (!strncasecmp("man", name, len) ||
 193                 !strncasecmp("woman", name, len) ||
 194                 !strncasecmp("konqueror", name, len));
 195 }
 196
 197 static void do_add_man_viewer_info(const char *name,
 198                                    size_t len,
 199                                    const char *value)
 200 {
 201         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 202
 203         strncpy(new->name, name, len);
 204         new->info = strdup(value);
 205         new->next = man_viewer_info_list;
 206         man_viewer_info_list = new;
 207 }
 208
 209 static int add_man_viewer_path(const char *name,
 210                                size_t len,
 211                                const char *value)
 212 {
 213         if (supported_man_viewer(name, len))
 214                 do_add_man_viewer_info(name, len, value);
 215         else
 216                 warning("'%s': path for unsupported man viewer.\n"
 217                         "Please consider using 'man.<tool>.cmd' instead.",
 218                         name);
 219
 220         return 0;
 221 }
 222
 223 static int add_man_viewer_cmd(const char *name,
 224                               size_t len,
 225                               const char *value)
 226 {
 227         if (supported_man_viewer(name, len))
 228                 warning("'%s': cmd for supported man viewer.\n"
 229                         "Please consider using 'man.<tool>.path' instead.",
 230                         name);
 231         else
 232                 do_add_man_viewer_info(name, len, value);
 233
 234         return 0;
 235 }
 236
 237 static int add_man_viewer_info(const char *var, const char *value)
 238 {
 239         const char *name = var + 4;
 240         const char *subkey = strrchr(name, '.');
 241
 242         if (!subkey)
 243                 return error("Config with no key for man viewer: %s", name);
 244
 245         if (!strcmp(subkey, ".path")) {
 246                 if (!value)
 247                         return config_error_nonbool(var);
 248                 return add_man_viewer_path(name, subkey - name, value);
 249         }
 250         if (!strcmp(subkey, ".cmd")) {
 251                 if (!value)
 252                         return config_error_nonbool(var);
 253                 return add_man_viewer_cmd(name, subkey - name, value);
 254         }
 255
 256         warning("'%s': unsupported man viewer sub key.", subkey);
 257         return 0;
 258 }
 259
 260 static int perf_help_config(const char *var, const char *value, void *cb)
 261 {
 262         enum help_format *help_formatp = cb;
 263
 264         if (!strcmp(var, "help.format")) {
 265                 if (!value)
 266                         return config_error_nonbool(var);
 267                 *help_formatp = parse_help_format(value);
 268                 if (*help_formatp == HELP_FORMAT_NONE)
 269                         return -1;
 270                 return 0;
 271         }
 272         if (!strcmp(var, "man.viewer")) {
 273                 if (!value)
 274                         return config_error_nonbool(var);
 275                 add_man_viewer(value);
 276                 return 0;
 277         }
 278         if (!prefixcmp(var, "man."))
 279                 return add_man_viewer_info(var, value);
 280
 281         return 0;
 282 }
 283
 284 static struct cmdnames main_cmds, other_cmds;
 285
 286 void list_common_cmds_help(void)
 287 {
 288         unsigned int i, longest = 0;
 289
 290         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 291                 if (longest < strlen(common_cmds[i].name))
 292                         longest = strlen(common_cmds[i].name);
 293         }
 294
 295         puts(" The most commonly used perf commands are:");
 296         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 297                 printf("   %-*s   ", longest, common_cmds[i].name);
 298                 puts(common_cmds[i].help);
 299         }
 300 }
 301
 302 static int is_perf_command(const char *s)
 303 {
 304         return is_in_cmdlist(&main_cmds, s) ||
 305                 is_in_cmdlist(&other_cmds, s);
 306 }
 307
 308 static const char *cmd_to_page(const char *perf_cmd)
 309 {
 310         char *s;
 311
 312         if (!perf_cmd)
 313                 return "perf";
 314         else if (!prefixcmp(perf_cmd, "perf"))
 315                 return perf_cmd;
 316
 317         return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
 318 }
 319
 320 static void setup_man_path(void)
 321 {
 322         char *new_path;
 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         if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
 330                 setenv("MANPATH", new_path, 1);
 331                 free(new_path);
 332         } else {
 333                 error("Unable to setup man path");
 334         }
 335 }
 336
 337 static void exec_viewer(const char *name, const char *page)
 338 {
 339         const char *info = get_man_viewer_info(name);
 340
 341         if (!strcasecmp(name, "man"))
 342                 exec_man_man(info, page);
 343         else if (!strcasecmp(name, "woman"))
 344                 exec_woman_emacs(info, page);
 345         else if (!strcasecmp(name, "konqueror"))
 346                 exec_man_konqueror(info, page);
 347         else if (info)
 348                 exec_man_cmd(info, page);
 349         else
 350                 warning("'%s': unknown man viewer.", name);
 351 }
 352
 353 static int show_man_page(const char *perf_cmd)
 354 {
 355         struct man_viewer_list *viewer;
 356         const char *page = cmd_to_page(perf_cmd);
 357         const char *fallback = getenv("PERF_MAN_VIEWER");
 358
 359         setup_man_path();
 360         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 361                 exec_viewer(viewer->name, page); /* will return when unable */
 362
 363         if (fallback)
 364                 exec_viewer(fallback, page);
 365         exec_viewer("man", page);
 366
 367         pr_err("no man viewer handled the request");
 368         return -1;
 369 }
 370
 371 static int 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         return -1;
 377 }
 378
 379 static int get_html_page_path(char **page_path, const char *page)
 380 {
 381         struct stat st;
 382         const char *html_path = system_path(PERF_HTML_PATH);
 383
 384         /* Check that we have a perf documentation directory. */
 385         if (stat(mkpath("%s/perf.html", html_path), &st)
 386             || !S_ISREG(st.st_mode)) {
 387                 pr_err("'%s': not a documentation directory.", html_path);
 388                 return -1;
 389         }
 390
 391         return asprintf(page_path, "%s/%s.html", html_path, page);
 392 }
 393
 394 /*
 395  * If open_html is not defined in a platform-specific way (see for
 396  * example compat/mingw.h), we use the script web--browse to display
 397  * HTML.
 398  */
 399 #ifndef open_html
 400 static void open_html(const char *path)
 401 {
 402         execl_cmd("web--browse", "-c", "help.browser", path, NULL);
 403 }
 404 #endif
 405
 406 static int show_html_page(const char *perf_cmd)
 407 {
 408         const char *page = cmd_to_page(perf_cmd);
 409         char *page_path; /* it leaks but we exec bellow */
 410
 411         if (get_html_page_path(&page_path, page) < 0)
 412                 return -1;
 413
 414         open_html(page_path);
 415
 416         return 0;
 417 }
 418
 419 int cmd_help(int argc, const char **argv, const char *prefix __maybe_unused)
 420 {
 421         bool show_all = false;
 422         enum help_format help_format = HELP_FORMAT_MAN;
 423         struct option builtin_help_options[] = {
 424         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
 425         OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
 426         OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
 427                         HELP_FORMAT_WEB),
 428         OPT_SET_UINT('i', "info", &help_format, "show info page",
 429                         HELP_FORMAT_INFO),
 430         OPT_END(),
 431         };
 432         const char * const builtin_help_subcommands[] = {
 433                 "buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
 434                 "record", "report", "bench", "stat", "timechart", "top", "annotate",
 435                 "script", "sched", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
 436 #ifdef HAVE_LIBELF_SUPPORT
 437                 "probe",
 438 #endif
 439 #ifdef HAVE_LIBAUDIT_SUPPORT
 440                 "trace",
 441 #endif
 442         NULL };
 443         const char *builtin_help_usage[] = {
 444                 "perf help [--all] [--man|--web|--info] [command]",
 445                 NULL
 446         };
 447         const char *alias;
 448         int rc = 0;
 449
 450         load_command_list("perf-", &main_cmds, &other_cmds);
 451
 452         perf_config(perf_help_config, &help_format);
 453
 454         argc = parse_options_subcommand(argc, argv, builtin_help_options,
 455                         builtin_help_subcommands, builtin_help_usage, 0);
 456
 457         if (show_all) {
 458                 printf("\n Usage: %s\n\n", perf_usage_string);
 459                 list_commands("perf commands", &main_cmds, &other_cmds);
 460                 printf(" %s\n\n", perf_more_info_string);
 461                 return 0;
 462         }
 463
 464         if (!argv[0]) {
 465                 printf("\n usage: %s\n\n", perf_usage_string);
 466                 list_common_cmds_help();
 467                 printf("\n %s\n\n", perf_more_info_string);
 468                 return 0;
 469         }
 470
 471         alias = alias_lookup(argv[0]);
 472         if (alias && !is_perf_command(argv[0])) {
 473                 printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
 474                 return 0;
 475         }
 476
 477         switch (help_format) {
 478         case HELP_FORMAT_MAN:
 479                 rc = show_man_page(argv[0]);
 480                 break;
 481         case HELP_FORMAT_INFO:
 482                 rc = show_info_page(argv[0]);
 483                 break;
 484         case HELP_FORMAT_WEB:
 485                 rc = show_html_page(argv[0]);
 486                 break;
 487         case HELP_FORMAT_NONE:
 488                 /* fall-through */
 489         default:
 490                 rc = -1;
 491                 break;
 492         }
 493
 494         return rc;
 495 }