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 #include <linux/kernel.h>
  16 #include <errno.h>
  17 #include <stdio.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <unistd.h>
  21
  22 static struct man_viewer_list {
  23         struct man_viewer_list *next;
  24         char name[0];
  25 } *man_viewer_list;
  26
  27 static struct man_viewer_info_list {
  28         struct man_viewer_info_list *next;
  29         const char *info;
  30         char name[0];
  31 } *man_viewer_info_list;
  32
  33 enum help_format {
  34         HELP_FORMAT_NONE,
  35         HELP_FORMAT_MAN,
  36         HELP_FORMAT_INFO,
  37         HELP_FORMAT_WEB,
  38 };
  39
  40 static enum help_format parse_help_format(const char *format)
  41 {
  42         if (!strcmp(format, "man"))
  43                 return HELP_FORMAT_MAN;
  44         if (!strcmp(format, "info"))
  45                 return HELP_FORMAT_INFO;
  46         if (!strcmp(format, "web") || !strcmp(format, "html"))
  47                 return HELP_FORMAT_WEB;
  48
  49         pr_err("unrecognized help format '%s'", format);
  50         return HELP_FORMAT_NONE;
  51 }
  52
  53 static const char *get_man_viewer_info(const char *name)
  54 {
  55         struct man_viewer_info_list *viewer;
  56
  57         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
  58                 if (!strcasecmp(name, viewer->name))
  59                         return viewer->info;
  60         }
  61         return NULL;
  62 }
  63
  64 static int check_emacsclient_version(void)
  65 {
  66         struct strbuf buffer = STRBUF_INIT;
  67         struct child_process ec_process;
  68         const char *argv_ec[] = { "emacsclient", "--version", NULL };
  69         int version;
  70         int ret = -1;
  71
  72         /* emacsclient prints its version number on stderr */
  73         memset(&ec_process, 0, sizeof(ec_process));
  74         ec_process.argv = argv_ec;
  75         ec_process.err = -1;
  76         ec_process.stdout_to_stderr = 1;
  77         if (start_command(&ec_process)) {
  78                 fprintf(stderr, "Failed to start emacsclient.\n");
  79                 return -1;
  80         }
  81         if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
  82                 fprintf(stderr, "Failed to read emacsclient version\n");
  83                 goto out;
  84         }
  85         close(ec_process.err);
  86
  87         /*
  88          * Don't bother checking return value, because "emacsclient --version"
  89          * seems to always exits with code 1.
  90          */
  91         finish_command(&ec_process);
  92
  93         if (prefixcmp(buffer.buf, "emacsclient")) {
  94                 fprintf(stderr, "Failed to parse emacsclient version.\n");
  95                 goto out;
  96         }
  97
  98         version = atoi(buffer.buf + strlen("emacsclient"));
  99
 100         if (version < 22) {
 101                 fprintf(stderr,
 102                         "emacsclient version '%d' too old (< 22).\n",
 103                         version);
 104         } else
 105                 ret = 0;
 106 out:
 107         strbuf_release(&buffer);
 108         return ret;
 109 }
 110
 111 static void exec_failed(const char *cmd)
 112 {
 113         char sbuf[STRERR_BUFSIZE];
 114         pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
 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                 char *man_page;
 122
 123                 if (!path)
 124                         path = "emacsclient";
 125                 if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
 126                         execlp(path, "emacsclient", "-e", man_page, NULL);
 127                         free(man_page);
 128                 }
 129                 exec_failed(path);
 130         }
 131 }
 132
 133 static void exec_man_konqueror(const char *path, const char *page)
 134 {
 135         const char *display = getenv("DISPLAY");
 136
 137         if (display && *display) {
 138                 char *man_page;
 139                 const char *filename = "kfmclient";
 140
 141                 /* It's simpler to launch konqueror using kfmclient. */
 142                 if (path) {
 143                         const char *file = strrchr(path, '/');
 144                         if (file && !strcmp(file + 1, "konqueror")) {
 145                                 char *new = strdup(path);
 146                                 char *dest = strrchr(new, '/');
 147
 148                                 /* strlen("konqueror") == strlen("kfmclient") */
 149                                 strcpy(dest + 1, "kfmclient");
 150                                 path = new;
 151                         }
 152                         if (file)
 153                                 filename = file;
 154                 } else
 155                         path = "kfmclient";
 156                 if (asprintf(&man_page, "man:%s(1)", page) > 0) {
 157                         execlp(path, filename, "newTab", man_page, NULL);
 158                         free(man_page);
 159                 }
 160                 exec_failed(path);
 161         }
 162 }
 163
 164 static void exec_man_man(const char *path, const char *page)
 165 {
 166         if (!path)
 167                 path = "man";
 168         execlp(path, "man", page, NULL);
 169         exec_failed(path);
 170 }
 171
 172 static void exec_man_cmd(const char *cmd, const char *page)
 173 {
 174         char *shell_cmd;
 175
 176         if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
 177                 execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
 178                 free(shell_cmd);
 179         }
 180         exec_failed(cmd);
 181 }
 182
 183 static void add_man_viewer(const char *name)
 184 {
 185         struct man_viewer_list **p = &man_viewer_list;
 186         size_t len = strlen(name);
 187
 188         while (*p)
 189                 p = &((*p)->next);
 190         *p = zalloc(sizeof(**p) + len + 1);
 191         strncpy((*p)->name, name, len);
 192 }
 193
 194 static int supported_man_viewer(const char *name, size_t len)
 195 {
 196         return (!strncasecmp("man", name, len) ||
 197                 !strncasecmp("woman", name, len) ||
 198                 !strncasecmp("konqueror", name, len));
 199 }
 200
 201 static void do_add_man_viewer_info(const char *name,
 202                                    size_t len,
 203                                    const char *value)
 204 {
 205         struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
 206
 207         strncpy(new->name, name, len);
 208         new->info = strdup(value);
 209         new->next = man_viewer_info_list;
 210         man_viewer_info_list = new;
 211 }
 212
 213 static void unsupported_man_viewer(const char *name, const char *var)
 214 {
 215         pr_warning("'%s': path for unsupported man viewer.\n"
 216                    "Please consider using 'man.<tool>.%s' instead.", name, var);
 217 }
 218
 219 static int add_man_viewer_path(const char *name,
 220                                size_t len,
 221                                const char *value)
 222 {
 223         if (supported_man_viewer(name, len))
 224                 do_add_man_viewer_info(name, len, value);
 225         else
 226                 unsupported_man_viewer(name, "cmd");
 227
 228         return 0;
 229 }
 230
 231 static int add_man_viewer_cmd(const char *name,
 232                               size_t len,
 233                               const char *value)
 234 {
 235         if (supported_man_viewer(name, len))
 236                 unsupported_man_viewer(name, "path");
 237         else
 238                 do_add_man_viewer_info(name, len, value);
 239
 240         return 0;
 241 }
 242
 243 static int add_man_viewer_info(const char *var, const char *value)
 244 {
 245         const char *name = var + 4;
 246         const char *subkey = strrchr(name, '.');
 247
 248         if (!subkey) {
 249                 pr_err("Config with no key for man viewer: %s", name);
 250                 return -1;
 251         }
 252
 253         if (!strcmp(subkey, ".path")) {
 254                 if (!value)
 255                         return config_error_nonbool(var);
 256                 return add_man_viewer_path(name, subkey - name, value);
 257         }
 258         if (!strcmp(subkey, ".cmd")) {
 259                 if (!value)
 260                         return config_error_nonbool(var);
 261                 return add_man_viewer_cmd(name, subkey - name, value);
 262         }
 263
 264         pr_warning("'%s': unsupported man viewer sub key.", subkey);
 265         return 0;
 266 }
 267
 268 static int perf_help_config(const char *var, const char *value, void *cb)
 269 {
 270         enum help_format *help_formatp = cb;
 271
 272         if (!strcmp(var, "help.format")) {
 273                 if (!value)
 274                         return config_error_nonbool(var);
 275                 *help_formatp = parse_help_format(value);
 276                 if (*help_formatp == HELP_FORMAT_NONE)
 277                         return -1;
 278                 return 0;
 279         }
 280         if (!strcmp(var, "man.viewer")) {
 281                 if (!value)
 282                         return config_error_nonbool(var);
 283                 add_man_viewer(value);
 284                 return 0;
 285         }
 286         if (!prefixcmp(var, "man."))
 287                 return add_man_viewer_info(var, value);
 288
 289         return 0;
 290 }
 291
 292 static struct cmdnames main_cmds, other_cmds;
 293
 294 void list_common_cmds_help(void)
 295 {
 296         unsigned int i, longest = 0;
 297
 298         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 299                 if (longest < strlen(common_cmds[i].name))
 300                         longest = strlen(common_cmds[i].name);
 301         }
 302
 303         puts(" The most commonly used perf commands are:");
 304         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 305                 printf("   %-*s   ", longest, common_cmds[i].name);
 306                 puts(common_cmds[i].help);
 307         }
 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                 pr_err("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                 pr_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)
 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", "kallsyms", "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         int rc;
 450
 451         load_command_list("perf-", &main_cmds, &other_cmds);
 452
 453         rc = perf_config(perf_help_config, &help_format);
 454         if (rc)
 455                 return rc;
 456
 457         argc = parse_options_subcommand(argc, argv, builtin_help_options,
 458                         builtin_help_subcommands, builtin_help_usage, 0);
 459
 460         if (show_all) {
 461                 printf("\n Usage: %s\n\n", perf_usage_string);
 462                 list_commands("perf commands", &main_cmds, &other_cmds);
 463                 printf(" %s\n\n", perf_more_info_string);
 464                 return 0;
 465         }
 466
 467         if (!argv[0]) {
 468                 printf("\n usage: %s\n\n", perf_usage_string);
 469                 list_common_cmds_help();
 470                 printf("\n %s\n\n", perf_more_info_string);
 471                 return 0;
 472         }
 473
 474         switch (help_format) {
 475         case HELP_FORMAT_MAN:
 476                 rc = show_man_page(argv[0]);
 477                 break;
 478         case HELP_FORMAT_INFO:
 479                 rc = show_info_page(argv[0]);
 480                 break;
 481         case HELP_FORMAT_WEB:
 482                 rc = show_html_page(argv[0]);
 483                 break;
 484         case HELP_FORMAT_NONE:
 485                 /* fall-through */
 486         default:
 487                 rc = -1;
 488                 break;
 489         }
 490
 491         return rc;
 492 }