Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit conditional markdown preprocessing (c8b1cd9)
   1/*
   2 * Builtin help command
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "builtin.h"
   7#include "exec-cmd.h"
   8#include "parse-options.h"
   9#include "run-command.h"
  10#include "column.h"
  11#include "help.h"
  12#include "alias.h"
  13
  14#ifndef DEFAULT_HELP_FORMAT
  15#define DEFAULT_HELP_FORMAT "man"
  16#endif
  17
  18static struct man_viewer_list {
  19        struct man_viewer_list *next;
  20        char name[FLEX_ARRAY];
  21} *man_viewer_list;
  22
  23static struct man_viewer_info_list {
  24        struct man_viewer_info_list *next;
  25        const char *info;
  26        char name[FLEX_ARRAY];
  27} *man_viewer_info_list;
  28
  29enum help_format {
  30        HELP_FORMAT_NONE,
  31        HELP_FORMAT_MAN,
  32        HELP_FORMAT_INFO,
  33        HELP_FORMAT_WEB
  34};
  35
  36static const char *html_path;
  37
  38static int show_all = 0;
  39static int show_guides = 0;
  40static int show_config;
  41static int verbose = 1;
  42static unsigned int colopts;
  43static enum help_format help_format = HELP_FORMAT_NONE;
  44static int exclude_guides;
  45static struct option builtin_help_options[] = {
  46        OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
  47        OPT_HIDDEN_BOOL(0, "exclude-guides", &exclude_guides, N_("exclude guides")),
  48        OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
  49        OPT_BOOL('c', "config", &show_config, N_("print all configuration variable names")),
  50        OPT_SET_INT_F(0, "config-for-completion", &show_config, "", 2, PARSE_OPT_HIDDEN),
  51        OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
  52        OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
  53                        HELP_FORMAT_WEB),
  54        OPT_SET_INT('i', "info", &help_format, N_("show info page"),
  55                        HELP_FORMAT_INFO),
  56        OPT__VERBOSE(&verbose, N_("print command description")),
  57        OPT_END(),
  58};
  59
  60static const char * const builtin_help_usage[] = {
  61        N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
  62        NULL
  63};
  64
  65static enum help_format parse_help_format(const char *format)
  66{
  67        if (!strcmp(format, "man"))
  68                return HELP_FORMAT_MAN;
  69        if (!strcmp(format, "info"))
  70                return HELP_FORMAT_INFO;
  71        if (!strcmp(format, "web") || !strcmp(format, "html"))
  72                return HELP_FORMAT_WEB;
  73        /*
  74         * Please update _git_config() in git-completion.bash when you
  75         * add new help formats.
  76         */
  77        die(_("unrecognized help format '%s'"), format);
  78}
  79
  80static const char *get_man_viewer_info(const char *name)
  81{
  82        struct man_viewer_info_list *viewer;
  83
  84        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  85        {
  86                if (!strcasecmp(name, viewer->name))
  87                        return viewer->info;
  88        }
  89        return NULL;
  90}
  91
  92static int check_emacsclient_version(void)
  93{
  94        struct strbuf buffer = STRBUF_INIT;
  95        struct child_process ec_process = CHILD_PROCESS_INIT;
  96        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  97        int version;
  98
  99        /* emacsclient prints its version number on stderr */
 100        ec_process.argv = argv_ec;
 101        ec_process.err = -1;
 102        ec_process.stdout_to_stderr = 1;
 103        if (start_command(&ec_process))
 104                return error(_("Failed to start emacsclient."));
 105
 106        strbuf_read(&buffer, ec_process.err, 20);
 107        close(ec_process.err);
 108
 109        /*
 110         * Don't bother checking return value, because "emacsclient --version"
 111         * seems to always exits with code 1.
 112         */
 113        finish_command(&ec_process);
 114
 115        if (!starts_with(buffer.buf, "emacsclient")) {
 116                strbuf_release(&buffer);
 117                return error(_("Failed to parse emacsclient version."));
 118        }
 119
 120        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 121        version = atoi(buffer.buf);
 122
 123        if (version < 22) {
 124                strbuf_release(&buffer);
 125                return error(_("emacsclient version '%d' too old (< 22)."),
 126                        version);
 127        }
 128
 129        strbuf_release(&buffer);
 130        return 0;
 131}
 132
 133static void exec_woman_emacs(const char *path, const char *page)
 134{
 135        if (!check_emacsclient_version()) {
 136                /* This works only with emacsclient version >= 22. */
 137                struct strbuf man_page = STRBUF_INIT;
 138
 139                if (!path)
 140                        path = "emacsclient";
 141                strbuf_addf(&man_page, "(woman \"%s\")", page);
 142                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 143                warning_errno(_("failed to exec '%s'"), path);
 144                strbuf_release(&man_page);
 145        }
 146}
 147
 148static void exec_man_konqueror(const char *path, const char *page)
 149{
 150        const char *display = getenv("DISPLAY");
 151        if (display && *display) {
 152                struct strbuf man_page = STRBUF_INIT;
 153                const char *filename = "kfmclient";
 154
 155                /* It's simpler to launch konqueror using kfmclient. */
 156                if (path) {
 157                        size_t len;
 158                        if (strip_suffix(path, "/konqueror", &len))
 159                                path = xstrfmt("%.*s/kfmclient", (int)len, path);
 160                        filename = basename((char *)path);
 161                } else
 162                        path = "kfmclient";
 163                strbuf_addf(&man_page, "man:%s(1)", page);
 164                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 165                warning_errno(_("failed to exec '%s'"), path);
 166                strbuf_release(&man_page);
 167        }
 168}
 169
 170static void exec_man_man(const char *path, const char *page)
 171{
 172        if (!path)
 173                path = "man";
 174        execlp(path, "man", page, (char *)NULL);
 175        warning_errno(_("failed to exec '%s'"), path);
 176}
 177
 178static void exec_man_cmd(const char *cmd, const char *page)
 179{
 180        struct strbuf shell_cmd = STRBUF_INIT;
 181        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 182        execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
 183        warning(_("failed to exec '%s'"), cmd);
 184        strbuf_release(&shell_cmd);
 185}
 186
 187static void add_man_viewer(const char *name)
 188{
 189        struct man_viewer_list **p = &man_viewer_list;
 190
 191        while (*p)
 192                p = &((*p)->next);
 193        FLEX_ALLOC_STR(*p, name, name);
 194}
 195
 196static int supported_man_viewer(const char *name, size_t len)
 197{
 198        return (!strncasecmp("man", name, len) ||
 199                !strncasecmp("woman", name, len) ||
 200                !strncasecmp("konqueror", name, len));
 201}
 202
 203static void do_add_man_viewer_info(const char *name,
 204                                   size_t len,
 205                                   const char *value)
 206{
 207        struct man_viewer_info_list *new_man_viewer;
 208        FLEX_ALLOC_MEM(new_man_viewer, name, name, len);
 209        new_man_viewer->info = xstrdup(value);
 210        new_man_viewer->next = man_viewer_info_list;
 211        man_viewer_info_list = new_man_viewer;
 212}
 213
 214static int add_man_viewer_path(const char *name,
 215                               size_t len,
 216                               const char *value)
 217{
 218        if (supported_man_viewer(name, len))
 219                do_add_man_viewer_info(name, len, value);
 220        else
 221                warning(_("'%s': path for unsupported man viewer.\n"
 222                          "Please consider using 'man.<tool>.cmd' instead."),
 223                        name);
 224
 225        return 0;
 226}
 227
 228static int add_man_viewer_cmd(const char *name,
 229                              size_t len,
 230                              const char *value)
 231{
 232        if (supported_man_viewer(name, len))
 233                warning(_("'%s': cmd for supported man viewer.\n"
 234                          "Please consider using 'man.<tool>.path' instead."),
 235                        name);
 236        else
 237                do_add_man_viewer_info(name, len, value);
 238
 239        return 0;
 240}
 241
 242static int add_man_viewer_info(const char *var, const char *value)
 243{
 244        const char *name, *subkey;
 245        int namelen;
 246
 247        if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 248                return 0;
 249
 250        if (!strcmp(subkey, "path")) {
 251                if (!value)
 252                        return config_error_nonbool(var);
 253                return add_man_viewer_path(name, namelen, value);
 254        }
 255        if (!strcmp(subkey, "cmd")) {
 256                if (!value)
 257                        return config_error_nonbool(var);
 258                return add_man_viewer_cmd(name, namelen, value);
 259        }
 260
 261        return 0;
 262}
 263
 264static int git_help_config(const char *var, const char *value, void *cb)
 265{
 266        if (starts_with(var, "column."))
 267                return git_column_config(var, value, "help", &colopts);
 268        if (!strcmp(var, "help.format")) {
 269                if (!value)
 270                        return config_error_nonbool(var);
 271                help_format = parse_help_format(value);
 272                return 0;
 273        }
 274        if (!strcmp(var, "help.htmlpath")) {
 275                if (!value)
 276                        return config_error_nonbool(var);
 277                html_path = xstrdup(value);
 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 (starts_with(var, "man."))
 287                return add_man_viewer_info(var, value);
 288
 289        return git_default_config(var, value, cb);
 290}
 291
 292static struct cmdnames main_cmds, other_cmds;
 293
 294static int is_git_command(const char *s)
 295{
 296        if (is_builtin(s))
 297                return 1;
 298
 299        load_command_list("git-", &main_cmds, &other_cmds);
 300        return is_in_cmdlist(&main_cmds, s) ||
 301                is_in_cmdlist(&other_cmds, s);
 302}
 303
 304static const char *cmd_to_page(const char *git_cmd)
 305{
 306        if (!git_cmd)
 307                return "git";
 308        else if (starts_with(git_cmd, "git"))
 309                return git_cmd;
 310        else if (is_git_command(git_cmd))
 311                return xstrfmt("git-%s", git_cmd);
 312        else
 313                return xstrfmt("git%s", git_cmd);
 314}
 315
 316static void setup_man_path(void)
 317{
 318        struct strbuf new_path = STRBUF_INIT;
 319        const char *old_path = getenv("MANPATH");
 320        char *git_man_path = system_path(GIT_MAN_PATH);
 321
 322        /* We should always put ':' after our path. If there is no
 323         * old_path, the ':' at the end will let 'man' to try
 324         * system-wide paths after ours to find the manual page. If
 325         * there is old_path, we need ':' as delimiter. */
 326        strbuf_addstr(&new_path, git_man_path);
 327        strbuf_addch(&new_path, ':');
 328        if (old_path)
 329                strbuf_addstr(&new_path, old_path);
 330
 331        free(git_man_path);
 332        setenv("MANPATH", new_path.buf, 1);
 333
 334        strbuf_release(&new_path);
 335}
 336
 337static 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
 353static void show_man_page(const char *git_cmd)
 354{
 355        struct man_viewer_list *viewer;
 356        const char *page = cmd_to_page(git_cmd);
 357        const char *fallback = getenv("GIT_MAN_VIEWER");
 358
 359        setup_man_path();
 360        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 361        {
 362                exec_viewer(viewer->name, page); /* will return when unable */
 363        }
 364        if (fallback)
 365                exec_viewer(fallback, page);
 366        exec_viewer("man", page);
 367        die(_("no man viewer handled the request"));
 368}
 369
 370static void show_info_page(const char *git_cmd)
 371{
 372        const char *page = cmd_to_page(git_cmd);
 373        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 374        execlp("info", "info", "gitman", page, (char *)NULL);
 375        die(_("no info viewer handled the request"));
 376}
 377
 378static void get_html_page_path(struct strbuf *page_path, const char *page)
 379{
 380        struct stat st;
 381        char *to_free = NULL;
 382
 383        if (!html_path)
 384                html_path = to_free = system_path(GIT_HTML_PATH);
 385
 386        /* Check that we have a git documentation directory. */
 387        if (!strstr(html_path, "://")) {
 388                if (stat(mkpath("%s/git.html", html_path), &st)
 389                    || !S_ISREG(st.st_mode))
 390                        die("'%s': not a documentation directory.", html_path);
 391        }
 392
 393        strbuf_init(page_path, 0);
 394        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 395        free(to_free);
 396}
 397
 398static void open_html(const char *path)
 399{
 400        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 401}
 402
 403static void show_html_page(const char *git_cmd)
 404{
 405        const char *page = cmd_to_page(git_cmd);
 406        struct strbuf page_path; /* it leaks but we exec bellow */
 407
 408        get_html_page_path(&page_path, page);
 409
 410        open_html(page_path.buf);
 411}
 412
 413static const char *check_git_cmd(const char* cmd)
 414{
 415        char *alias;
 416
 417        if (is_git_command(cmd))
 418                return cmd;
 419
 420        alias = alias_lookup(cmd);
 421        if (alias) {
 422                const char **argv;
 423                int count;
 424
 425                /*
 426                 * handle_builtin() in git.c rewrites "git cmd --help"
 427                 * to "git help --exclude-guides cmd", so we can use
 428                 * exclude_guides to distinguish "git cmd --help" from
 429                 * "git help cmd". In the latter case, or if cmd is an
 430                 * alias for a shell command, just print the alias
 431                 * definition.
 432                 */
 433                if (!exclude_guides || alias[0] == '!') {
 434                        printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
 435                        free(alias);
 436                        exit(0);
 437                }
 438                /*
 439                 * Otherwise, we pretend that the command was "git
 440                 * word0 --help". We use split_cmdline() to get the
 441                 * first word of the alias, to ensure that we use the
 442                 * same rules as when the alias is actually
 443                 * used. split_cmdline() modifies alias in-place.
 444                 */
 445                fprintf_ln(stderr, _("'%s' is aliased to '%s'"), cmd, alias);
 446                count = split_cmdline(alias, &argv);
 447                if (count < 0)
 448                        die(_("bad alias.%s string: %s"), cmd,
 449                            split_cmdline_strerror(count));
 450                free(argv);
 451                UNLEAK(alias);
 452                return alias;
 453        }
 454
 455        if (exclude_guides)
 456                return help_unknown_cmd(cmd);
 457
 458        return cmd;
 459}
 460
 461int cmd_help(int argc, const char **argv, const char *prefix)
 462{
 463        int nongit;
 464        enum help_format parsed_help_format;
 465
 466        argc = parse_options(argc, argv, prefix, builtin_help_options,
 467                        builtin_help_usage, 0);
 468        parsed_help_format = help_format;
 469
 470        if (show_all) {
 471                git_config(git_help_config, NULL);
 472                if (verbose) {
 473                        setup_pager();
 474                        list_all_cmds_help();
 475                        return 0;
 476                }
 477                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 478                load_command_list("git-", &main_cmds, &other_cmds);
 479                list_commands(colopts, &main_cmds, &other_cmds);
 480        }
 481
 482        if (show_config) {
 483                int for_human = show_config == 1;
 484
 485                if (!for_human) {
 486                        list_config_help(for_human);
 487                        return 0;
 488                }
 489                setup_pager();
 490                list_config_help(for_human);
 491                printf("\n%s\n", _("'git help config' for more information"));
 492                return 0;
 493        }
 494
 495        if (show_guides)
 496                list_common_guides_help();
 497
 498        if (show_all || show_guides) {
 499                printf("%s\n", _(git_more_info_string));
 500                /*
 501                * We're done. Ignore any remaining args
 502                */
 503                return 0;
 504        }
 505
 506        if (!argv[0]) {
 507                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 508                list_common_cmds_help();
 509                printf("\n%s\n", _(git_more_info_string));
 510                return 0;
 511        }
 512
 513        setup_git_directory_gently(&nongit);
 514        git_config(git_help_config, NULL);
 515
 516        if (parsed_help_format != HELP_FORMAT_NONE)
 517                help_format = parsed_help_format;
 518        if (help_format == HELP_FORMAT_NONE)
 519                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 520
 521        argv[0] = check_git_cmd(argv[0]);
 522
 523        switch (help_format) {
 524        case HELP_FORMAT_NONE:
 525        case HELP_FORMAT_MAN:
 526                show_man_page(argv[0]);
 527                break;
 528        case HELP_FORMAT_INFO:
 529                show_info_page(argv[0]);
 530                break;
 531        case HELP_FORMAT_WEB:
 532                show_html_page(argv[0]);
 533                break;
 534        }
 535
 536        return 0;
 537}