Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit Merge branch 'jc/lock-report-on-error' (95713ff)
   1/*
   2 * Builtin help command
   3 */
   4#include "cache.h"
   5#include "builtin.h"
   6#include "exec_cmd.h"
   7#include "parse-options.h"
   8#include "run-command.h"
   9#include "column.h"
  10#include "help.h"
  11
  12#ifndef DEFAULT_HELP_FORMAT
  13#define DEFAULT_HELP_FORMAT "man"
  14#endif
  15
  16static struct man_viewer_list {
  17        struct man_viewer_list *next;
  18        char name[FLEX_ARRAY];
  19} *man_viewer_list;
  20
  21static 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
  27enum help_format {
  28        HELP_FORMAT_NONE,
  29        HELP_FORMAT_MAN,
  30        HELP_FORMAT_INFO,
  31        HELP_FORMAT_WEB
  32};
  33
  34static const char *html_path;
  35
  36static int show_all = 0;
  37static int show_guides = 0;
  38static unsigned int colopts;
  39static enum help_format help_format = HELP_FORMAT_NONE;
  40static int exclude_guides;
  41static struct option builtin_help_options[] = {
  42        OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
  43        OPT_HIDDEN_BOOL(0, "exclude-guides", &exclude_guides, N_("exclude guides")),
  44        OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
  45        OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
  46        OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
  47                        HELP_FORMAT_WEB),
  48        OPT_SET_INT('i', "info", &help_format, N_("show info page"),
  49                        HELP_FORMAT_INFO),
  50        OPT_END(),
  51};
  52
  53static const char * const builtin_help_usage[] = {
  54        N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
  55        NULL
  56};
  57
  58static enum help_format parse_help_format(const char *format)
  59{
  60        if (!strcmp(format, "man"))
  61                return HELP_FORMAT_MAN;
  62        if (!strcmp(format, "info"))
  63                return HELP_FORMAT_INFO;
  64        if (!strcmp(format, "web") || !strcmp(format, "html"))
  65                return HELP_FORMAT_WEB;
  66        die(_("unrecognized help format '%s'"), format);
  67}
  68
  69static const char *get_man_viewer_info(const char *name)
  70{
  71        struct man_viewer_info_list *viewer;
  72
  73        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  74        {
  75                if (!strcasecmp(name, viewer->name))
  76                        return viewer->info;
  77        }
  78        return NULL;
  79}
  80
  81static int check_emacsclient_version(void)
  82{
  83        struct strbuf buffer = STRBUF_INIT;
  84        struct child_process ec_process = CHILD_PROCESS_INIT;
  85        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  86        int version;
  87
  88        /* emacsclient prints its version number on stderr */
  89        ec_process.argv = argv_ec;
  90        ec_process.err = -1;
  91        ec_process.stdout_to_stderr = 1;
  92        if (start_command(&ec_process))
  93                return error(_("Failed to start emacsclient."));
  94
  95        strbuf_read(&buffer, ec_process.err, 20);
  96        close(ec_process.err);
  97
  98        /*
  99         * Don't bother checking return value, because "emacsclient --version"
 100         * seems to always exits with code 1.
 101         */
 102        finish_command(&ec_process);
 103
 104        if (!starts_with(buffer.buf, "emacsclient")) {
 105                strbuf_release(&buffer);
 106                return error(_("Failed to parse emacsclient version."));
 107        }
 108
 109        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 110        version = atoi(buffer.buf);
 111
 112        if (version < 22) {
 113                strbuf_release(&buffer);
 114                return error(_("emacsclient version '%d' too old (< 22)."),
 115                        version);
 116        }
 117
 118        strbuf_release(&buffer);
 119        return 0;
 120}
 121
 122static void exec_woman_emacs(const char *path, const char *page)
 123{
 124        if (!check_emacsclient_version()) {
 125                /* This works only with emacsclient version >= 22. */
 126                struct strbuf man_page = STRBUF_INIT;
 127
 128                if (!path)
 129                        path = "emacsclient";
 130                strbuf_addf(&man_page, "(woman \"%s\")", page);
 131                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 132                warning_errno(_("failed to exec '%s'"), path);
 133        }
 134}
 135
 136static void exec_man_konqueror(const char *path, const char *page)
 137{
 138        const char *display = getenv("DISPLAY");
 139        if (display && *display) {
 140                struct strbuf man_page = STRBUF_INIT;
 141                const char *filename = "kfmclient";
 142
 143                /* It's simpler to launch konqueror using kfmclient. */
 144                if (path) {
 145                        size_t len;
 146                        if (strip_suffix(path, "/konqueror", &len))
 147                                path = xstrfmt("%.*s/kfmclient", (int)len, path);
 148                        filename = basename((char *)path);
 149                } else
 150                        path = "kfmclient";
 151                strbuf_addf(&man_page, "man:%s(1)", page);
 152                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 153                warning_errno(_("failed to exec '%s'"), path);
 154        }
 155}
 156
 157static void exec_man_man(const char *path, const char *page)
 158{
 159        if (!path)
 160                path = "man";
 161        execlp(path, "man", page, (char *)NULL);
 162        warning_errno(_("failed to exec '%s'"), path);
 163}
 164
 165static void exec_man_cmd(const char *cmd, const char *page)
 166{
 167        struct strbuf shell_cmd = STRBUF_INIT;
 168        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 169        execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
 170        warning(_("failed to exec '%s'"), cmd);
 171}
 172
 173static void add_man_viewer(const char *name)
 174{
 175        struct man_viewer_list **p = &man_viewer_list;
 176
 177        while (*p)
 178                p = &((*p)->next);
 179        FLEX_ALLOC_STR(*p, name, name);
 180}
 181
 182static int supported_man_viewer(const char *name, size_t len)
 183{
 184        return (!strncasecmp("man", name, len) ||
 185                !strncasecmp("woman", name, len) ||
 186                !strncasecmp("konqueror", name, len));
 187}
 188
 189static void do_add_man_viewer_info(const char *name,
 190                                   size_t len,
 191                                   const char *value)
 192{
 193        struct man_viewer_info_list *new;
 194        FLEX_ALLOC_MEM(new, name, name, len);
 195        new->info = xstrdup(value);
 196        new->next = man_viewer_info_list;
 197        man_viewer_info_list = new;
 198}
 199
 200static int add_man_viewer_path(const char *name,
 201                               size_t len,
 202                               const char *value)
 203{
 204        if (supported_man_viewer(name, len))
 205                do_add_man_viewer_info(name, len, value);
 206        else
 207                warning(_("'%s': path for unsupported man viewer.\n"
 208                          "Please consider using 'man.<tool>.cmd' instead."),
 209                        name);
 210
 211        return 0;
 212}
 213
 214static int add_man_viewer_cmd(const char *name,
 215                              size_t len,
 216                              const char *value)
 217{
 218        if (supported_man_viewer(name, len))
 219                warning(_("'%s': cmd for supported man viewer.\n"
 220                          "Please consider using 'man.<tool>.path' instead."),
 221                        name);
 222        else
 223                do_add_man_viewer_info(name, len, value);
 224
 225        return 0;
 226}
 227
 228static int add_man_viewer_info(const char *var, const char *value)
 229{
 230        const char *name, *subkey;
 231        int namelen;
 232
 233        if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 234                return 0;
 235
 236        if (!strcmp(subkey, "path")) {
 237                if (!value)
 238                        return config_error_nonbool(var);
 239                return add_man_viewer_path(name, namelen, value);
 240        }
 241        if (!strcmp(subkey, "cmd")) {
 242                if (!value)
 243                        return config_error_nonbool(var);
 244                return add_man_viewer_cmd(name, namelen, value);
 245        }
 246
 247        return 0;
 248}
 249
 250static int git_help_config(const char *var, const char *value, void *cb)
 251{
 252        if (starts_with(var, "column."))
 253                return git_column_config(var, value, "help", &colopts);
 254        if (!strcmp(var, "help.format")) {
 255                if (!value)
 256                        return config_error_nonbool(var);
 257                help_format = parse_help_format(value);
 258                return 0;
 259        }
 260        if (!strcmp(var, "help.htmlpath")) {
 261                if (!value)
 262                        return config_error_nonbool(var);
 263                html_path = xstrdup(value);
 264                return 0;
 265        }
 266        if (!strcmp(var, "man.viewer")) {
 267                if (!value)
 268                        return config_error_nonbool(var);
 269                add_man_viewer(value);
 270                return 0;
 271        }
 272        if (starts_with(var, "man."))
 273                return add_man_viewer_info(var, value);
 274
 275        return git_default_config(var, value, cb);
 276}
 277
 278static struct cmdnames main_cmds, other_cmds;
 279
 280static int is_git_command(const char *s)
 281{
 282        if (is_builtin(s))
 283                return 1;
 284
 285        load_command_list("git-", &main_cmds, &other_cmds);
 286        return is_in_cmdlist(&main_cmds, s) ||
 287                is_in_cmdlist(&other_cmds, s);
 288}
 289
 290static const char *cmd_to_page(const char *git_cmd)
 291{
 292        if (!git_cmd)
 293                return "git";
 294        else if (starts_with(git_cmd, "git"))
 295                return git_cmd;
 296        else if (is_git_command(git_cmd))
 297                return xstrfmt("git-%s", git_cmd);
 298        else
 299                return xstrfmt("git%s", git_cmd);
 300}
 301
 302static void setup_man_path(void)
 303{
 304        struct strbuf new_path = STRBUF_INIT;
 305        const char *old_path = getenv("MANPATH");
 306        char *git_man_path = system_path(GIT_MAN_PATH);
 307
 308        /* We should always put ':' after our path. If there is no
 309         * old_path, the ':' at the end will let 'man' to try
 310         * system-wide paths after ours to find the manual page. If
 311         * there is old_path, we need ':' as delimiter. */
 312        strbuf_addstr(&new_path, git_man_path);
 313        strbuf_addch(&new_path, ':');
 314        if (old_path)
 315                strbuf_addstr(&new_path, old_path);
 316
 317        free(git_man_path);
 318        setenv("MANPATH", new_path.buf, 1);
 319
 320        strbuf_release(&new_path);
 321}
 322
 323static void exec_viewer(const char *name, const char *page)
 324{
 325        const char *info = get_man_viewer_info(name);
 326
 327        if (!strcasecmp(name, "man"))
 328                exec_man_man(info, page);
 329        else if (!strcasecmp(name, "woman"))
 330                exec_woman_emacs(info, page);
 331        else if (!strcasecmp(name, "konqueror"))
 332                exec_man_konqueror(info, page);
 333        else if (info)
 334                exec_man_cmd(info, page);
 335        else
 336                warning(_("'%s': unknown man viewer."), name);
 337}
 338
 339static void show_man_page(const char *git_cmd)
 340{
 341        struct man_viewer_list *viewer;
 342        const char *page = cmd_to_page(git_cmd);
 343        const char *fallback = getenv("GIT_MAN_VIEWER");
 344
 345        setup_man_path();
 346        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 347        {
 348                exec_viewer(viewer->name, page); /* will return when unable */
 349        }
 350        if (fallback)
 351                exec_viewer(fallback, page);
 352        exec_viewer("man", page);
 353        die(_("no man viewer handled the request"));
 354}
 355
 356static void show_info_page(const char *git_cmd)
 357{
 358        const char *page = cmd_to_page(git_cmd);
 359        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 360        execlp("info", "info", "gitman", page, (char *)NULL);
 361        die(_("no info viewer handled the request"));
 362}
 363
 364static void get_html_page_path(struct strbuf *page_path, const char *page)
 365{
 366        struct stat st;
 367        char *to_free = NULL;
 368
 369        if (!html_path)
 370                html_path = to_free = system_path(GIT_HTML_PATH);
 371
 372        /* Check that we have a git documentation directory. */
 373        if (!strstr(html_path, "://")) {
 374                if (stat(mkpath("%s/git.html", html_path), &st)
 375                    || !S_ISREG(st.st_mode))
 376                        die("'%s': not a documentation directory.", html_path);
 377        }
 378
 379        strbuf_init(page_path, 0);
 380        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 381        free(to_free);
 382}
 383
 384static void open_html(const char *path)
 385{
 386        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 387}
 388
 389static void show_html_page(const char *git_cmd)
 390{
 391        const char *page = cmd_to_page(git_cmd);
 392        struct strbuf page_path; /* it leaks but we exec bellow */
 393
 394        get_html_page_path(&page_path, page);
 395
 396        open_html(page_path.buf);
 397}
 398
 399static struct {
 400        const char *name;
 401        const char *help;
 402} common_guides[] = {
 403        { "attributes", N_("Defining attributes per path") },
 404        { "everyday", N_("Everyday Git With 20 Commands Or So") },
 405        { "glossary", N_("A Git glossary") },
 406        { "ignore", N_("Specifies intentionally untracked files to ignore") },
 407        { "modules", N_("Defining submodule properties") },
 408        { "revisions", N_("Specifying revisions and ranges for Git") },
 409        { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 410        { "workflows", N_("An overview of recommended workflows with Git") },
 411};
 412
 413static void list_common_guides_help(void)
 414{
 415        int i, longest = 0;
 416
 417        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 418                if (longest < strlen(common_guides[i].name))
 419                        longest = strlen(common_guides[i].name);
 420        }
 421
 422        puts(_("The common Git guides are:\n"));
 423        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 424                printf("   %s   ", common_guides[i].name);
 425                mput_char(' ', longest - strlen(common_guides[i].name));
 426                puts(_(common_guides[i].help));
 427        }
 428        putchar('\n');
 429}
 430
 431static const char *check_git_cmd(const char* cmd)
 432{
 433        char *alias;
 434
 435        if (is_git_command(cmd))
 436                return cmd;
 437
 438        alias = alias_lookup(cmd);
 439        if (alias) {
 440                printf_ln(_("`git %s' is aliased to `%s'"), cmd, alias);
 441                free(alias);
 442                exit(0);
 443        }
 444
 445        if (exclude_guides)
 446                return help_unknown_cmd(cmd);
 447
 448        return cmd;
 449}
 450
 451int cmd_help(int argc, const char **argv, const char *prefix)
 452{
 453        int nongit;
 454        enum help_format parsed_help_format;
 455
 456        argc = parse_options(argc, argv, prefix, builtin_help_options,
 457                        builtin_help_usage, 0);
 458        parsed_help_format = help_format;
 459
 460        if (show_all) {
 461                git_config(git_help_config, NULL);
 462                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 463                load_command_list("git-", &main_cmds, &other_cmds);
 464                list_commands(colopts, &main_cmds, &other_cmds);
 465        }
 466
 467        if (show_guides)
 468                list_common_guides_help();
 469
 470        if (show_all || show_guides) {
 471                printf("%s\n", _(git_more_info_string));
 472                /*
 473                * We're done. Ignore any remaining args
 474                */
 475                return 0;
 476        }
 477
 478        if (!argv[0]) {
 479                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 480                list_common_cmds_help();
 481                printf("\n%s\n", _(git_more_info_string));
 482                return 0;
 483        }
 484
 485        setup_git_directory_gently(&nongit);
 486        git_config(git_help_config, NULL);
 487
 488        if (parsed_help_format != HELP_FORMAT_NONE)
 489                help_format = parsed_help_format;
 490        if (help_format == HELP_FORMAT_NONE)
 491                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 492
 493        argv[0] = check_git_cmd(argv[0]);
 494
 495        switch (help_format) {
 496        case HELP_FORMAT_NONE:
 497        case HELP_FORMAT_MAN:
 498                show_man_page(argv[0]);
 499                break;
 500        case HELP_FORMAT_INFO:
 501                show_info_page(argv[0]);
 502                break;
 503        case HELP_FORMAT_WEB:
 504                show_html_page(argv[0]);
 505                break;
 506        }
 507
 508        return 0;
 509}