linux/tools/perf/builtin-help.c
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   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
  15static struct man_viewer_list {
  16        struct man_viewer_list *next;
  17        char name[FLEX_ARRAY];
  18} *man_viewer_list;
  19
  20static 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
  26enum help_format {
  27        HELP_FORMAT_MAN,
  28        HELP_FORMAT_INFO,
  29        HELP_FORMAT_WEB,
  30};
  31
  32static bool show_all = false;
  33static enum help_format help_format = HELP_FORMAT_MAN;
  34static 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
  44static const char * const builtin_help_usage[] = {
  45        "perf help [--all] [--man|--web|--info] [command]",
  46        NULL
  47};
  48
  49static 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
  60static 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
  71static 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
 117static 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
 131static 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
 159static 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
 167static 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
 175static 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
 186static 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
 193static 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
 205static 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
 219static 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
 233static 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
 256static 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
 276static struct cmdnames main_cmds, other_cmds;
 277
 278void 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
 294static 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
 300static 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
 310static 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
 320static 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
 339static 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
 355static 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
 371static 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
 378static 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
 398static void open_html(const char *path)
 399{
 400        execl_perf_cmd("web--browse", "-c", "help.browser", path, NULL);
 401}
 402#endif
 403
 404static 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
 414int 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}
 460
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