git.oblomov.eu Git - git/blob - builtin/help.c

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