Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit commit: add short-circuit to paint_down_to_common() (d7c1ec3)
   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
  13#ifndef DEFAULT_HELP_FORMAT
  14#define DEFAULT_HELP_FORMAT "man"
  15#endif
  16
  17static struct man_viewer_list {
  18        struct man_viewer_list *next;
  19        char name[FLEX_ARRAY];
  20} *man_viewer_list;
  21
  22static struct man_viewer_info_list {
  23        struct man_viewer_info_list *next;
  24        const char *info;
  25        char name[FLEX_ARRAY];
  26} *man_viewer_info_list;
  27
  28enum help_format {
  29        HELP_FORMAT_NONE,
  30        HELP_FORMAT_MAN,
  31        HELP_FORMAT_INFO,
  32        HELP_FORMAT_WEB
  33};
  34
  35static const char *html_path;
  36
  37static int show_all = 0;
  38static int show_guides = 0;
  39static unsigned int colopts;
  40static enum help_format help_format = HELP_FORMAT_NONE;
  41static int exclude_guides;
  42static struct option builtin_help_options[] = {
  43        OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
  44        OPT_HIDDEN_BOOL(0, "exclude-guides", &exclude_guides, N_("exclude guides")),
  45        OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
  46        OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
  47        OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
  48                        HELP_FORMAT_WEB),
  49        OPT_SET_INT('i', "info", &help_format, N_("show info page"),
  50                        HELP_FORMAT_INFO),
  51        OPT_END(),
  52};
  53
  54static const char * const builtin_help_usage[] = {
  55        N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
  56        NULL
  57};
  58
  59static enum help_format parse_help_format(const char *format)
  60{
  61        if (!strcmp(format, "man"))
  62                return HELP_FORMAT_MAN;
  63        if (!strcmp(format, "info"))
  64                return HELP_FORMAT_INFO;
  65        if (!strcmp(format, "web") || !strcmp(format, "html"))
  66                return HELP_FORMAT_WEB;
  67        die(_("unrecognized help format '%s'"), format);
  68}
  69
  70static const char *get_man_viewer_info(const char *name)
  71{
  72        struct man_viewer_info_list *viewer;
  73
  74        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  75        {
  76                if (!strcasecmp(name, viewer->name))
  77                        return viewer->info;
  78        }
  79        return NULL;
  80}
  81
  82static int check_emacsclient_version(void)
  83{
  84        struct strbuf buffer = STRBUF_INIT;
  85        struct child_process ec_process = CHILD_PROCESS_INIT;
  86        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  87        int version;
  88
  89        /* emacsclient prints its version number on stderr */
  90        ec_process.argv = argv_ec;
  91        ec_process.err = -1;
  92        ec_process.stdout_to_stderr = 1;
  93        if (start_command(&ec_process))
  94                return error(_("Failed to start emacsclient."));
  95
  96        strbuf_read(&buffer, ec_process.err, 20);
  97        close(ec_process.err);
  98
  99        /*
 100         * Don't bother checking return value, because "emacsclient --version"
 101         * seems to always exits with code 1.
 102         */
 103        finish_command(&ec_process);
 104
 105        if (!starts_with(buffer.buf, "emacsclient")) {
 106                strbuf_release(&buffer);
 107                return error(_("Failed to parse emacsclient version."));
 108        }
 109
 110        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 111        version = atoi(buffer.buf);
 112
 113        if (version < 22) {
 114                strbuf_release(&buffer);
 115                return error(_("emacsclient version '%d' too old (< 22)."),
 116                        version);
 117        }
 118
 119        strbuf_release(&buffer);
 120        return 0;
 121}
 122
 123static void exec_woman_emacs(const char *path, const char *page)
 124{
 125        if (!check_emacsclient_version()) {
 126                /* This works only with emacsclient version >= 22. */
 127                struct strbuf man_page = STRBUF_INIT;
 128
 129                if (!path)
 130                        path = "emacsclient";
 131                strbuf_addf(&man_page, "(woman \"%s\")", page);
 132                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 133                warning_errno(_("failed to exec '%s'"), path);
 134                strbuf_release(&man_page);
 135        }
 136}
 137
 138static void exec_man_konqueror(const char *path, const char *page)
 139{
 140        const char *display = getenv("DISPLAY");
 141        if (display && *display) {
 142                struct strbuf man_page = STRBUF_INIT;
 143                const char *filename = "kfmclient";
 144
 145                /* It's simpler to launch konqueror using kfmclient. */
 146                if (path) {
 147                        size_t len;
 148                        if (strip_suffix(path, "/konqueror", &len))
 149                                path = xstrfmt("%.*s/kfmclient", (int)len, path);
 150                        filename = basename((char *)path);
 151                } else
 152                        path = "kfmclient";
 153                strbuf_addf(&man_page, "man:%s(1)", page);
 154                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 155                warning_errno(_("failed to exec '%s'"), path);
 156                strbuf_release(&man_page);
 157        }
 158}
 159
 160static void exec_man_man(const char *path, const char *page)
 161{
 162        if (!path)
 163                path = "man";
 164        execlp(path, "man", page, (char *)NULL);
 165        warning_errno(_("failed to exec '%s'"), path);
 166}
 167
 168static void exec_man_cmd(const char *cmd, const char *page)
 169{
 170        struct strbuf shell_cmd = STRBUF_INIT;
 171        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 172        execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
 173        warning(_("failed to exec '%s'"), cmd);
 174        strbuf_release(&shell_cmd);
 175}
 176
 177static void add_man_viewer(const char *name)
 178{
 179        struct man_viewer_list **p = &man_viewer_list;
 180
 181        while (*p)
 182                p = &((*p)->next);
 183        FLEX_ALLOC_STR(*p, name, name);
 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_man_viewer;
 198        FLEX_ALLOC_MEM(new_man_viewer, name, name, len);
 199        new_man_viewer->info = xstrdup(value);
 200        new_man_viewer->next = man_viewer_info_list;
 201        man_viewer_info_list = new_man_viewer;
 202}
 203
 204static int add_man_viewer_path(const char *name,
 205                               size_t len,
 206                               const char *value)
 207{
 208        if (supported_man_viewer(name, len))
 209                do_add_man_viewer_info(name, len, value);
 210        else
 211                warning(_("'%s': path for unsupported man viewer.\n"
 212                          "Please consider using 'man.<tool>.cmd' instead."),
 213                        name);
 214
 215        return 0;
 216}
 217
 218static int add_man_viewer_cmd(const char *name,
 219                              size_t len,
 220                              const char *value)
 221{
 222        if (supported_man_viewer(name, len))
 223                warning(_("'%s': cmd for supported man viewer.\n"
 224                          "Please consider using 'man.<tool>.path' instead."),
 225                        name);
 226        else
 227                do_add_man_viewer_info(name, len, value);
 228
 229        return 0;
 230}
 231
 232static int add_man_viewer_info(const char *var, const char *value)
 233{
 234        const char *name, *subkey;
 235        int namelen;
 236
 237        if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 238                return 0;
 239
 240        if (!strcmp(subkey, "path")) {
 241                if (!value)
 242                        return config_error_nonbool(var);
 243                return add_man_viewer_path(name, namelen, value);
 244        }
 245        if (!strcmp(subkey, "cmd")) {
 246                if (!value)
 247                        return config_error_nonbool(var);
 248                return add_man_viewer_cmd(name, namelen, value);
 249        }
 250
 251        return 0;
 252}
 253
 254static int git_help_config(const char *var, const char *value, void *cb)
 255{
 256        if (starts_with(var, "column."))
 257                return git_column_config(var, value, "help", &colopts);
 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, "help.htmlpath")) {
 265                if (!value)
 266                        return config_error_nonbool(var);
 267                html_path = xstrdup(value);
 268                return 0;
 269        }
 270        if (!strcmp(var, "man.viewer")) {
 271                if (!value)
 272                        return config_error_nonbool(var);
 273                add_man_viewer(value);
 274                return 0;
 275        }
 276        if (starts_with(var, "man."))
 277                return add_man_viewer_info(var, value);
 278
 279        return git_default_config(var, value, cb);
 280}
 281
 282static struct cmdnames main_cmds, other_cmds;
 283
 284static int is_git_command(const char *s)
 285{
 286        if (is_builtin(s))
 287                return 1;
 288
 289        load_command_list("git-", &main_cmds, &other_cmds);
 290        return is_in_cmdlist(&main_cmds, s) ||
 291                is_in_cmdlist(&other_cmds, s);
 292}
 293
 294static const char *cmd_to_page(const char *git_cmd)
 295{
 296        if (!git_cmd)
 297                return "git";
 298        else if (starts_with(git_cmd, "git"))
 299                return git_cmd;
 300        else if (is_git_command(git_cmd))
 301                return xstrfmt("git-%s", git_cmd);
 302        else
 303                return xstrfmt("git%s", git_cmd);
 304}
 305
 306static void setup_man_path(void)
 307{
 308        struct strbuf new_path = STRBUF_INIT;
 309        const char *old_path = getenv("MANPATH");
 310        char *git_man_path = system_path(GIT_MAN_PATH);
 311
 312        /* We should always put ':' after our path. If there is no
 313         * old_path, the ':' at the end will let 'man' to try
 314         * system-wide paths after ours to find the manual page. If
 315         * there is old_path, we need ':' as delimiter. */
 316        strbuf_addstr(&new_path, git_man_path);
 317        strbuf_addch(&new_path, ':');
 318        if (old_path)
 319                strbuf_addstr(&new_path, old_path);
 320
 321        free(git_man_path);
 322        setenv("MANPATH", new_path.buf, 1);
 323
 324        strbuf_release(&new_path);
 325}
 326
 327static void exec_viewer(const char *name, const char *page)
 328{
 329        const char *info = get_man_viewer_info(name);
 330
 331        if (!strcasecmp(name, "man"))
 332                exec_man_man(info, page);
 333        else if (!strcasecmp(name, "woman"))
 334                exec_woman_emacs(info, page);
 335        else if (!strcasecmp(name, "konqueror"))
 336                exec_man_konqueror(info, page);
 337        else if (info)
 338                exec_man_cmd(info, page);
 339        else
 340                warning(_("'%s': unknown man viewer."), name);
 341}
 342
 343static void show_man_page(const char *git_cmd)
 344{
 345        struct man_viewer_list *viewer;
 346        const char *page = cmd_to_page(git_cmd);
 347        const char *fallback = getenv("GIT_MAN_VIEWER");
 348
 349        setup_man_path();
 350        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 351        {
 352                exec_viewer(viewer->name, page); /* will return when unable */
 353        }
 354        if (fallback)
 355                exec_viewer(fallback, page);
 356        exec_viewer("man", page);
 357        die(_("no man viewer handled the request"));
 358}
 359
 360static void show_info_page(const char *git_cmd)
 361{
 362        const char *page = cmd_to_page(git_cmd);
 363        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 364        execlp("info", "info", "gitman", page, (char *)NULL);
 365        die(_("no info viewer handled the request"));
 366}
 367
 368static void get_html_page_path(struct strbuf *page_path, const char *page)
 369{
 370        struct stat st;
 371        char *to_free = NULL;
 372
 373        if (!html_path)
 374                html_path = to_free = system_path(GIT_HTML_PATH);
 375
 376        /* Check that we have a git documentation directory. */
 377        if (!strstr(html_path, "://")) {
 378                if (stat(mkpath("%s/git.html", html_path), &st)
 379                    || !S_ISREG(st.st_mode))
 380                        die("'%s': not a documentation directory.", html_path);
 381        }
 382
 383        strbuf_init(page_path, 0);
 384        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 385        free(to_free);
 386}
 387
 388static void open_html(const char *path)
 389{
 390        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 391}
 392
 393static void show_html_page(const char *git_cmd)
 394{
 395        const char *page = cmd_to_page(git_cmd);
 396        struct strbuf page_path; /* it leaks but we exec bellow */
 397
 398        get_html_page_path(&page_path, page);
 399
 400        open_html(page_path.buf);
 401}
 402
 403static struct {
 404        const char *name;
 405        const char *help;
 406} common_guides[] = {
 407        { "attributes", N_("Defining attributes per path") },
 408        { "everyday", N_("Everyday Git With 20 Commands Or So") },
 409        { "glossary", N_("A Git glossary") },
 410        { "ignore", N_("Specifies intentionally untracked files to ignore") },
 411        { "modules", N_("Defining submodule properties") },
 412        { "revisions", N_("Specifying revisions and ranges for Git") },
 413        { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 414        { "workflows", N_("An overview of recommended workflows with Git") },
 415};
 416
 417static void list_common_guides_help(void)
 418{
 419        int i, longest = 0;
 420
 421        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 422                if (longest < strlen(common_guides[i].name))
 423                        longest = strlen(common_guides[i].name);
 424        }
 425
 426        puts(_("The common Git guides are:\n"));
 427        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 428                printf("   %s   ", common_guides[i].name);
 429                mput_char(' ', longest - strlen(common_guides[i].name));
 430                puts(_(common_guides[i].help));
 431        }
 432        putchar('\n');
 433}
 434
 435static const char *check_git_cmd(const char* cmd)
 436{
 437        char *alias;
 438
 439        if (is_git_command(cmd))
 440                return cmd;
 441
 442        alias = alias_lookup(cmd);
 443        if (alias) {
 444                printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
 445                free(alias);
 446                exit(0);
 447        }
 448
 449        if (exclude_guides)
 450                return help_unknown_cmd(cmd);
 451
 452        return cmd;
 453}
 454
 455int cmd_help(int argc, const char **argv, const char *prefix)
 456{
 457        int nongit;
 458        enum help_format parsed_help_format;
 459
 460        argc = parse_options(argc, argv, prefix, builtin_help_options,
 461                        builtin_help_usage, 0);
 462        parsed_help_format = help_format;
 463
 464        if (show_all) {
 465                git_config(git_help_config, NULL);
 466                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 467                load_command_list("git-", &main_cmds, &other_cmds);
 468                list_commands(colopts, &main_cmds, &other_cmds);
 469        }
 470
 471        if (show_guides)
 472                list_common_guides_help();
 473
 474        if (show_all || show_guides) {
 475                printf("%s\n", _(git_more_info_string));
 476                /*
 477                * We're done. Ignore any remaining args
 478                */
 479                return 0;
 480        }
 481
 482        if (!argv[0]) {
 483                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 484                list_common_cmds_help();
 485                printf("\n%s\n", _(git_more_info_string));
 486                return 0;
 487        }
 488
 489        setup_git_directory_gently(&nongit);
 490        git_config(git_help_config, NULL);
 491
 492        if (parsed_help_format != HELP_FORMAT_NONE)
 493                help_format = parsed_help_format;
 494        if (help_format == HELP_FORMAT_NONE)
 495                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 496
 497        argv[0] = check_git_cmd(argv[0]);
 498
 499        switch (help_format) {
 500        case HELP_FORMAT_NONE:
 501        case HELP_FORMAT_MAN:
 502                show_man_page(argv[0]);
 503                break;
 504        case HELP_FORMAT_INFO:
 505                show_info_page(argv[0]);
 506                break;
 507        case HELP_FORMAT_WEB:
 508                show_html_page(argv[0]);
 509                break;
 510        }
 511
 512        return 0;
 513}