Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit Merge branch 'mk/blame-error-message' (23d58a0)
   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 struct option builtin_help_options[] = {
  41        OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
  42        OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
  43        OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
  44        OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
  45                        HELP_FORMAT_WEB),
  46        OPT_SET_INT('i', "info", &help_format, N_("show info page"),
  47                        HELP_FORMAT_INFO),
  48        OPT_END(),
  49};
  50
  51static const char * const builtin_help_usage[] = {
  52        N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
  53        NULL
  54};
  55
  56static enum help_format parse_help_format(const char *format)
  57{
  58        if (!strcmp(format, "man"))
  59                return HELP_FORMAT_MAN;
  60        if (!strcmp(format, "info"))
  61                return HELP_FORMAT_INFO;
  62        if (!strcmp(format, "web") || !strcmp(format, "html"))
  63                return HELP_FORMAT_WEB;
  64        die(_("unrecognized help format '%s'"), format);
  65}
  66
  67static const char *get_man_viewer_info(const char *name)
  68{
  69        struct man_viewer_info_list *viewer;
  70
  71        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  72        {
  73                if (!strcasecmp(name, viewer->name))
  74                        return viewer->info;
  75        }
  76        return NULL;
  77}
  78
  79static int check_emacsclient_version(void)
  80{
  81        struct strbuf buffer = STRBUF_INIT;
  82        struct child_process ec_process = CHILD_PROCESS_INIT;
  83        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  84        int version;
  85
  86        /* emacsclient prints its version number on stderr */
  87        ec_process.argv = argv_ec;
  88        ec_process.err = -1;
  89        ec_process.stdout_to_stderr = 1;
  90        if (start_command(&ec_process))
  91                return error(_("Failed to start emacsclient."));
  92
  93        strbuf_read(&buffer, ec_process.err, 20);
  94        close(ec_process.err);
  95
  96        /*
  97         * Don't bother checking return value, because "emacsclient --version"
  98         * seems to always exits with code 1.
  99         */
 100        finish_command(&ec_process);
 101
 102        if (!starts_with(buffer.buf, "emacsclient")) {
 103                strbuf_release(&buffer);
 104                return error(_("Failed to parse emacsclient version."));
 105        }
 106
 107        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 108        version = atoi(buffer.buf);
 109
 110        if (version < 22) {
 111                strbuf_release(&buffer);
 112                return error(_("emacsclient version '%d' too old (< 22)."),
 113                        version);
 114        }
 115
 116        strbuf_release(&buffer);
 117        return 0;
 118}
 119
 120static void exec_woman_emacs(const char *path, const char *page)
 121{
 122        if (!check_emacsclient_version()) {
 123                /* This works only with emacsclient version >= 22. */
 124                struct strbuf man_page = STRBUF_INIT;
 125
 126                if (!path)
 127                        path = "emacsclient";
 128                strbuf_addf(&man_page, "(woman \"%s\")", page);
 129                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 130                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 131        }
 132}
 133
 134static void exec_man_konqueror(const char *path, const char *page)
 135{
 136        const char *display = getenv("DISPLAY");
 137        if (display && *display) {
 138                struct strbuf man_page = STRBUF_INIT;
 139                const char *filename = "kfmclient";
 140
 141                /* It's simpler to launch konqueror using kfmclient. */
 142                if (path) {
 143                        size_t len;
 144                        if (strip_suffix(path, "/konqueror", &len))
 145                                path = xstrfmt("%.*s/kfmclient", (int)len, path);
 146                        filename = basename((char *)path);
 147                } else
 148                        path = "kfmclient";
 149                strbuf_addf(&man_page, "man:%s(1)", page);
 150                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 151                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 152        }
 153}
 154
 155static void exec_man_man(const char *path, const char *page)
 156{
 157        if (!path)
 158                path = "man";
 159        execlp(path, "man", page, (char *)NULL);
 160        warning(_("failed to exec '%s': %s"), path, strerror(errno));
 161}
 162
 163static void exec_man_cmd(const char *cmd, const char *page)
 164{
 165        struct strbuf shell_cmd = STRBUF_INIT;
 166        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 167        execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
 168        warning(_("failed to exec '%s': %s"), cmd, strerror(errno));
 169}
 170
 171static void add_man_viewer(const char *name)
 172{
 173        struct man_viewer_list **p = &man_viewer_list;
 174        size_t len = strlen(name);
 175
 176        while (*p)
 177                p = &((*p)->next);
 178        *p = xcalloc(1, (sizeof(**p) + len + 1));
 179        memcpy((*p)->name, name, len); /* NUL-terminated by xcalloc */
 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 = xcalloc(1, sizeof(*new) + len + 1);
 194
 195        memcpy(new->name, name, len); /* NUL-terminated by xcalloc */
 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
 385/*
 386 * If open_html is not defined in a platform-specific way (see for
 387 * example compat/mingw.h), we use the script web--browse to display
 388 * HTML.
 389 */
 390#ifndef open_html
 391static void open_html(const char *path)
 392{
 393        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 394}
 395#endif
 396
 397static void show_html_page(const char *git_cmd)
 398{
 399        const char *page = cmd_to_page(git_cmd);
 400        struct strbuf page_path; /* it leaks but we exec bellow */
 401
 402        get_html_page_path(&page_path, page);
 403
 404        open_html(page_path.buf);
 405}
 406
 407static struct {
 408        const char *name;
 409        const char *help;
 410} common_guides[] = {
 411        { "attributes", N_("Defining attributes per path") },
 412        { "everyday", N_("Everyday Git With 20 Commands Or So") },
 413        { "glossary", N_("A Git glossary") },
 414        { "ignore", N_("Specifies intentionally untracked files to ignore") },
 415        { "modules", N_("Defining submodule properties") },
 416        { "revisions", N_("Specifying revisions and ranges for Git") },
 417        { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 418        { "workflows", N_("An overview of recommended workflows with Git") },
 419};
 420
 421static void list_common_guides_help(void)
 422{
 423        int i, longest = 0;
 424
 425        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 426                if (longest < strlen(common_guides[i].name))
 427                        longest = strlen(common_guides[i].name);
 428        }
 429
 430        puts(_("The common Git guides are:\n"));
 431        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 432                printf("   %s   ", common_guides[i].name);
 433                mput_char(' ', longest - strlen(common_guides[i].name));
 434                puts(_(common_guides[i].help));
 435        }
 436        putchar('\n');
 437}
 438
 439int cmd_help(int argc, const char **argv, const char *prefix)
 440{
 441        int nongit;
 442        char *alias;
 443        enum help_format parsed_help_format;
 444
 445        argc = parse_options(argc, argv, prefix, builtin_help_options,
 446                        builtin_help_usage, 0);
 447        parsed_help_format = help_format;
 448
 449        if (show_all) {
 450                git_config(git_help_config, NULL);
 451                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 452                load_command_list("git-", &main_cmds, &other_cmds);
 453                list_commands(colopts, &main_cmds, &other_cmds);
 454        }
 455
 456        if (show_guides)
 457                list_common_guides_help();
 458
 459        if (show_all || show_guides) {
 460                printf("%s\n", _(git_more_info_string));
 461                /*
 462                * We're done. Ignore any remaining args
 463                */
 464                return 0;
 465        }
 466
 467        if (!argv[0]) {
 468                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 469                list_common_cmds_help();
 470                printf("\n%s\n", _(git_more_info_string));
 471                return 0;
 472        }
 473
 474        setup_git_directory_gently(&nongit);
 475        git_config(git_help_config, NULL);
 476
 477        if (parsed_help_format != HELP_FORMAT_NONE)
 478                help_format = parsed_help_format;
 479        if (help_format == HELP_FORMAT_NONE)
 480                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 481
 482        alias = alias_lookup(argv[0]);
 483        if (alias && !is_git_command(argv[0])) {
 484                printf_ln(_("`git %s' is aliased to `%s'"), argv[0], alias);
 485                free(alias);
 486                return 0;
 487        }
 488
 489        switch (help_format) {
 490        case HELP_FORMAT_NONE:
 491        case HELP_FORMAT_MAN:
 492                show_man_page(argv[0]);
 493                break;
 494        case HELP_FORMAT_INFO:
 495                show_info_page(argv[0]);
 496                break;
 497        case HELP_FORMAT_WEB:
 498                show_html_page(argv[0]);
 499                break;
 500        }
 501
 502        return 0;
 503}