Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit Merge branches 'bw/ls-files-sans-the-index' and 'bw/config-h' into bw/repo-object (25bf951)
   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        }
 135}
 136
 137static void exec_man_konqueror(const char *path, const char *page)
 138{
 139        const char *display = getenv("DISPLAY");
 140        if (display && *display) {
 141                struct strbuf man_page = STRBUF_INIT;
 142                const char *filename = "kfmclient";
 143
 144                /* It's simpler to launch konqueror using kfmclient. */
 145                if (path) {
 146                        size_t len;
 147                        if (strip_suffix(path, "/konqueror", &len))
 148                                path = xstrfmt("%.*s/kfmclient", (int)len, path);
 149                        filename = basename((char *)path);
 150                } else
 151                        path = "kfmclient";
 152                strbuf_addf(&man_page, "man:%s(1)", page);
 153                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 154                warning_errno(_("failed to exec '%s'"), path);
 155        }
 156}
 157
 158static void exec_man_man(const char *path, const char *page)
 159{
 160        if (!path)
 161                path = "man";
 162        execlp(path, "man", page, (char *)NULL);
 163        warning_errno(_("failed to exec '%s'"), path);
 164}
 165
 166static void exec_man_cmd(const char *cmd, const char *page)
 167{
 168        struct strbuf shell_cmd = STRBUF_INIT;
 169        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 170        execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
 171        warning(_("failed to exec '%s'"), cmd);
 172}
 173
 174static void add_man_viewer(const char *name)
 175{
 176        struct man_viewer_list **p = &man_viewer_list;
 177
 178        while (*p)
 179                p = &((*p)->next);
 180        FLEX_ALLOC_STR(*p, name, name);
 181}
 182
 183static int supported_man_viewer(const char *name, size_t len)
 184{
 185        return (!strncasecmp("man", name, len) ||
 186                !strncasecmp("woman", name, len) ||
 187                !strncasecmp("konqueror", name, len));
 188}
 189
 190static void do_add_man_viewer_info(const char *name,
 191                                   size_t len,
 192                                   const char *value)
 193{
 194        struct man_viewer_info_list *new;
 195        FLEX_ALLOC_MEM(new, name, name, len);
 196        new->info = xstrdup(value);
 197        new->next = man_viewer_info_list;
 198        man_viewer_info_list = new;
 199}
 200
 201static int add_man_viewer_path(const char *name,
 202                               size_t len,
 203                               const char *value)
 204{
 205        if (supported_man_viewer(name, len))
 206                do_add_man_viewer_info(name, len, value);
 207        else
 208                warning(_("'%s': path for unsupported man viewer.\n"
 209                          "Please consider using 'man.<tool>.cmd' instead."),
 210                        name);
 211
 212        return 0;
 213}
 214
 215static int add_man_viewer_cmd(const char *name,
 216                              size_t len,
 217                              const char *value)
 218{
 219        if (supported_man_viewer(name, len))
 220                warning(_("'%s': cmd for supported man viewer.\n"
 221                          "Please consider using 'man.<tool>.path' instead."),
 222                        name);
 223        else
 224                do_add_man_viewer_info(name, len, value);
 225
 226        return 0;
 227}
 228
 229static int add_man_viewer_info(const char *var, const char *value)
 230{
 231        const char *name, *subkey;
 232        int namelen;
 233
 234        if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 235                return 0;
 236
 237        if (!strcmp(subkey, "path")) {
 238                if (!value)
 239                        return config_error_nonbool(var);
 240                return add_man_viewer_path(name, namelen, value);
 241        }
 242        if (!strcmp(subkey, "cmd")) {
 243                if (!value)
 244                        return config_error_nonbool(var);
 245                return add_man_viewer_cmd(name, namelen, value);
 246        }
 247
 248        return 0;
 249}
 250
 251static int git_help_config(const char *var, const char *value, void *cb)
 252{
 253        if (starts_with(var, "column."))
 254                return git_column_config(var, value, "help", &colopts);
 255        if (!strcmp(var, "help.format")) {
 256                if (!value)
 257                        return config_error_nonbool(var);
 258                help_format = parse_help_format(value);
 259                return 0;
 260        }
 261        if (!strcmp(var, "help.htmlpath")) {
 262                if (!value)
 263                        return config_error_nonbool(var);
 264                html_path = xstrdup(value);
 265                return 0;
 266        }
 267        if (!strcmp(var, "man.viewer")) {
 268                if (!value)
 269                        return config_error_nonbool(var);
 270                add_man_viewer(value);
 271                return 0;
 272        }
 273        if (starts_with(var, "man."))
 274                return add_man_viewer_info(var, value);
 275
 276        return git_default_config(var, value, cb);
 277}
 278
 279static struct cmdnames main_cmds, other_cmds;
 280
 281static int is_git_command(const char *s)
 282{
 283        if (is_builtin(s))
 284                return 1;
 285
 286        load_command_list("git-", &main_cmds, &other_cmds);
 287        return is_in_cmdlist(&main_cmds, s) ||
 288                is_in_cmdlist(&other_cmds, s);
 289}
 290
 291static const char *cmd_to_page(const char *git_cmd)
 292{
 293        if (!git_cmd)
 294                return "git";
 295        else if (starts_with(git_cmd, "git"))
 296                return git_cmd;
 297        else if (is_git_command(git_cmd))
 298                return xstrfmt("git-%s", git_cmd);
 299        else
 300                return xstrfmt("git%s", git_cmd);
 301}
 302
 303static void setup_man_path(void)
 304{
 305        struct strbuf new_path = STRBUF_INIT;
 306        const char *old_path = getenv("MANPATH");
 307        char *git_man_path = system_path(GIT_MAN_PATH);
 308
 309        /* We should always put ':' after our path. If there is no
 310         * old_path, the ':' at the end will let 'man' to try
 311         * system-wide paths after ours to find the manual page. If
 312         * there is old_path, we need ':' as delimiter. */
 313        strbuf_addstr(&new_path, git_man_path);
 314        strbuf_addch(&new_path, ':');
 315        if (old_path)
 316                strbuf_addstr(&new_path, old_path);
 317
 318        free(git_man_path);
 319        setenv("MANPATH", new_path.buf, 1);
 320
 321        strbuf_release(&new_path);
 322}
 323
 324static void exec_viewer(const char *name, const char *page)
 325{
 326        const char *info = get_man_viewer_info(name);
 327
 328        if (!strcasecmp(name, "man"))
 329                exec_man_man(info, page);
 330        else if (!strcasecmp(name, "woman"))
 331                exec_woman_emacs(info, page);
 332        else if (!strcasecmp(name, "konqueror"))
 333                exec_man_konqueror(info, page);
 334        else if (info)
 335                exec_man_cmd(info, page);
 336        else
 337                warning(_("'%s': unknown man viewer."), name);
 338}
 339
 340static void show_man_page(const char *git_cmd)
 341{
 342        struct man_viewer_list *viewer;
 343        const char *page = cmd_to_page(git_cmd);
 344        const char *fallback = getenv("GIT_MAN_VIEWER");
 345
 346        setup_man_path();
 347        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 348        {
 349                exec_viewer(viewer->name, page); /* will return when unable */
 350        }
 351        if (fallback)
 352                exec_viewer(fallback, page);
 353        exec_viewer("man", page);
 354        die(_("no man viewer handled the request"));
 355}
 356
 357static void show_info_page(const char *git_cmd)
 358{
 359        const char *page = cmd_to_page(git_cmd);
 360        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 361        execlp("info", "info", "gitman", page, (char *)NULL);
 362        die(_("no info viewer handled the request"));
 363}
 364
 365static void get_html_page_path(struct strbuf *page_path, const char *page)
 366{
 367        struct stat st;
 368        char *to_free = NULL;
 369
 370        if (!html_path)
 371                html_path = to_free = system_path(GIT_HTML_PATH);
 372
 373        /* Check that we have a git documentation directory. */
 374        if (!strstr(html_path, "://")) {
 375                if (stat(mkpath("%s/git.html", html_path), &st)
 376                    || !S_ISREG(st.st_mode))
 377                        die("'%s': not a documentation directory.", html_path);
 378        }
 379
 380        strbuf_init(page_path, 0);
 381        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 382        free(to_free);
 383}
 384
 385static void open_html(const char *path)
 386{
 387        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 388}
 389
 390static void show_html_page(const char *git_cmd)
 391{
 392        const char *page = cmd_to_page(git_cmd);
 393        struct strbuf page_path; /* it leaks but we exec bellow */
 394
 395        get_html_page_path(&page_path, page);
 396
 397        open_html(page_path.buf);
 398}
 399
 400static struct {
 401        const char *name;
 402        const char *help;
 403} common_guides[] = {
 404        { "attributes", N_("Defining attributes per path") },
 405        { "everyday", N_("Everyday Git With 20 Commands Or So") },
 406        { "glossary", N_("A Git glossary") },
 407        { "ignore", N_("Specifies intentionally untracked files to ignore") },
 408        { "modules", N_("Defining submodule properties") },
 409        { "revisions", N_("Specifying revisions and ranges for Git") },
 410        { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 411        { "workflows", N_("An overview of recommended workflows with Git") },
 412};
 413
 414static void list_common_guides_help(void)
 415{
 416        int i, longest = 0;
 417
 418        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 419                if (longest < strlen(common_guides[i].name))
 420                        longest = strlen(common_guides[i].name);
 421        }
 422
 423        puts(_("The common Git guides are:\n"));
 424        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 425                printf("   %s   ", common_guides[i].name);
 426                mput_char(' ', longest - strlen(common_guides[i].name));
 427                puts(_(common_guides[i].help));
 428        }
 429        putchar('\n');
 430}
 431
 432static const char *check_git_cmd(const char* cmd)
 433{
 434        char *alias;
 435
 436        if (is_git_command(cmd))
 437                return cmd;
 438
 439        alias = alias_lookup(cmd);
 440        if (alias) {
 441                printf_ln(_("`git %s' is aliased to `%s'"), cmd, alias);
 442                free(alias);
 443                exit(0);
 444        }
 445
 446        if (exclude_guides)
 447                return help_unknown_cmd(cmd);
 448
 449        return cmd;
 450}
 451
 452int cmd_help(int argc, const char **argv, const char *prefix)
 453{
 454        int nongit;
 455        enum help_format parsed_help_format;
 456
 457        argc = parse_options(argc, argv, prefix, builtin_help_options,
 458                        builtin_help_usage, 0);
 459        parsed_help_format = help_format;
 460
 461        if (show_all) {
 462                git_config(git_help_config, NULL);
 463                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 464                load_command_list("git-", &main_cmds, &other_cmds);
 465                list_commands(colopts, &main_cmds, &other_cmds);
 466        }
 467
 468        if (show_guides)
 469                list_common_guides_help();
 470
 471        if (show_all || show_guides) {
 472                printf("%s\n", _(git_more_info_string));
 473                /*
 474                * We're done. Ignore any remaining args
 475                */
 476                return 0;
 477        }
 478
 479        if (!argv[0]) {
 480                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 481                list_common_cmds_help();
 482                printf("\n%s\n", _(git_more_info_string));
 483                return 0;
 484        }
 485
 486        setup_git_directory_gently(&nongit);
 487        git_config(git_help_config, NULL);
 488
 489        if (parsed_help_format != HELP_FORMAT_NONE)
 490                help_format = parsed_help_format;
 491        if (help_format == HELP_FORMAT_NONE)
 492                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 493
 494        argv[0] = check_git_cmd(argv[0]);
 495
 496        switch (help_format) {
 497        case HELP_FORMAT_NONE:
 498        case HELP_FORMAT_MAN:
 499                show_man_page(argv[0]);
 500                break;
 501        case HELP_FORMAT_INFO:
 502                show_info_page(argv[0]);
 503                break;
 504        case HELP_FORMAT_WEB:
 505                show_html_page(argv[0]);
 506                break;
 507        }
 508
 509        return 0;
 510}