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