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 unsigned int colopts;
  40 static enum help_format help_format = HELP_FORMAT_NONE;
  41 static int exclude_guides;
  42 static 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
  54 static const char * const builtin_help_usage[] = {
  55         N_("git help [--all] [--guides] [--man | --web | --info] [<command>]"),
  56         NULL
  57 };
  58
  59 static 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
  70 static 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
  82 static 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
 123 static 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
 137 static 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                 strbuf_release(&man_page);
 156         }
 157 }
 158
 159 static void exec_man_man(const char *path, const char *page)
 160 {
 161         if (!path)
 162                 path = "man";
 163         execlp(path, "man", page, (char *)NULL);
 164         warning_errno(_("failed to exec '%s'"), path);
 165 }
 166
 167 static void exec_man_cmd(const char *cmd, const char *page)
 168 {
 169         struct strbuf shell_cmd = STRBUF_INIT;
 170         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 171         execl(SHELL_PATH, SHELL_PATH, "-c", shell_cmd.buf, (char *)NULL);
 172         warning(_("failed to exec '%s'"), cmd);
 173 }
 174
 175 static void add_man_viewer(const char *name)
 176 {
 177         struct man_viewer_list **p = &man_viewer_list;
 178
 179         while (*p)
 180                 p = &((*p)->next);
 181         FLEX_ALLOC_STR(*p, name, name);
 182 }
 183
 184 static int supported_man_viewer(const char *name, size_t len)
 185 {
 186         return (!strncasecmp("man", name, len) ||
 187                 !strncasecmp("woman", name, len) ||
 188                 !strncasecmp("konqueror", name, len));
 189 }
 190
 191 static void do_add_man_viewer_info(const char *name,
 192                                    size_t len,
 193                                    const char *value)
 194 {
 195         struct man_viewer_info_list *new;
 196         FLEX_ALLOC_MEM(new, name, name, len);
 197         new->info = xstrdup(value);
 198         new->next = man_viewer_info_list;
 199         man_viewer_info_list = new;
 200 }
 201
 202 static int add_man_viewer_path(const char *name,
 203                                size_t len,
 204                                const char *value)
 205 {
 206         if (supported_man_viewer(name, len))
 207                 do_add_man_viewer_info(name, len, value);
 208         else
 209                 warning(_("'%s': path for unsupported man viewer.\n"
 210                           "Please consider using 'man.<tool>.cmd' instead."),
 211                         name);
 212
 213         return 0;
 214 }
 215
 216 static int add_man_viewer_cmd(const char *name,
 217                               size_t len,
 218                               const char *value)
 219 {
 220         if (supported_man_viewer(name, len))
 221                 warning(_("'%s': cmd for supported man viewer.\n"
 222                           "Please consider using 'man.<tool>.path' instead."),
 223                         name);
 224         else
 225                 do_add_man_viewer_info(name, len, value);
 226
 227         return 0;
 228 }
 229
 230 static int add_man_viewer_info(const char *var, const char *value)
 231 {
 232         const char *name, *subkey;
 233         int namelen;
 234
 235         if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 236                 return 0;
 237
 238         if (!strcmp(subkey, "path")) {
 239                 if (!value)
 240                         return config_error_nonbool(var);
 241                 return add_man_viewer_path(name, namelen, value);
 242         }
 243         if (!strcmp(subkey, "cmd")) {
 244                 if (!value)
 245                         return config_error_nonbool(var);
 246                 return add_man_viewer_cmd(name, namelen, value);
 247         }
 248
 249         return 0;
 250 }
 251
 252 static int git_help_config(const char *var, const char *value, void *cb)
 253 {
 254         if (starts_with(var, "column."))
 255                 return git_column_config(var, value, "help", &colopts);
 256         if (!strcmp(var, "help.format")) {
 257                 if (!value)
 258                         return config_error_nonbool(var);
 259                 help_format = parse_help_format(value);
 260                 return 0;
 261         }
 262         if (!strcmp(var, "help.htmlpath")) {
 263                 if (!value)
 264                         return config_error_nonbool(var);
 265                 html_path = xstrdup(value);
 266                 return 0;
 267         }
 268         if (!strcmp(var, "man.viewer")) {
 269                 if (!value)
 270                         return config_error_nonbool(var);
 271                 add_man_viewer(value);
 272                 return 0;
 273         }
 274         if (starts_with(var, "man."))
 275                 return add_man_viewer_info(var, value);
 276
 277         return git_default_config(var, value, cb);
 278 }
 279
 280 static struct cmdnames main_cmds, other_cmds;
 281
 282 static int is_git_command(const char *s)
 283 {
 284         if (is_builtin(s))
 285                 return 1;
 286
 287         load_command_list("git-", &main_cmds, &other_cmds);
 288         return is_in_cmdlist(&main_cmds, s) ||
 289                 is_in_cmdlist(&other_cmds, s);
 290 }
 291
 292 static const char *cmd_to_page(const char *git_cmd)
 293 {
 294         if (!git_cmd)
 295                 return "git";
 296         else if (starts_with(git_cmd, "git"))
 297                 return git_cmd;
 298         else if (is_git_command(git_cmd))
 299                 return xstrfmt("git-%s", git_cmd);
 300         else
 301                 return xstrfmt("git%s", git_cmd);
 302 }
 303
 304 static void setup_man_path(void)
 305 {
 306         struct strbuf new_path = STRBUF_INIT;
 307         const char *old_path = getenv("MANPATH");
 308         char *git_man_path = system_path(GIT_MAN_PATH);
 309
 310         /* We should always put ':' after our path. If there is no
 311          * old_path, the ':' at the end will let 'man' to try
 312          * system-wide paths after ours to find the manual page. If
 313          * there is old_path, we need ':' as delimiter. */
 314         strbuf_addstr(&new_path, git_man_path);
 315         strbuf_addch(&new_path, ':');
 316         if (old_path)
 317                 strbuf_addstr(&new_path, old_path);
 318
 319         free(git_man_path);
 320         setenv("MANPATH", new_path.buf, 1);
 321
 322         strbuf_release(&new_path);
 323 }
 324
 325 static void exec_viewer(const char *name, const char *page)
 326 {
 327         const char *info = get_man_viewer_info(name);
 328
 329         if (!strcasecmp(name, "man"))
 330                 exec_man_man(info, page);
 331         else if (!strcasecmp(name, "woman"))
 332                 exec_woman_emacs(info, page);
 333         else if (!strcasecmp(name, "konqueror"))
 334                 exec_man_konqueror(info, page);
 335         else if (info)
 336                 exec_man_cmd(info, page);
 337         else
 338                 warning(_("'%s': unknown man viewer."), name);
 339 }
 340
 341 static void show_man_page(const char *git_cmd)
 342 {
 343         struct man_viewer_list *viewer;
 344         const char *page = cmd_to_page(git_cmd);
 345         const char *fallback = getenv("GIT_MAN_VIEWER");
 346
 347         setup_man_path();
 348         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 349         {
 350                 exec_viewer(viewer->name, page); /* will return when unable */
 351         }
 352         if (fallback)
 353                 exec_viewer(fallback, page);
 354         exec_viewer("man", page);
 355         die(_("no man viewer handled the request"));
 356 }
 357
 358 static void show_info_page(const char *git_cmd)
 359 {
 360         const char *page = cmd_to_page(git_cmd);
 361         setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 362         execlp("info", "info", "gitman", page, (char *)NULL);
 363         die(_("no info viewer handled the request"));
 364 }
 365
 366 static void get_html_page_path(struct strbuf *page_path, const char *page)
 367 {
 368         struct stat st;
 369         char *to_free = NULL;
 370
 371         if (!html_path)
 372                 html_path = to_free = system_path(GIT_HTML_PATH);
 373
 374         /* Check that we have a git documentation directory. */
 375         if (!strstr(html_path, "://")) {
 376                 if (stat(mkpath("%s/git.html", html_path), &st)
 377                     || !S_ISREG(st.st_mode))
 378                         die("'%s': not a documentation directory.", html_path);
 379         }
 380
 381         strbuf_init(page_path, 0);
 382         strbuf_addf(page_path, "%s/%s.html", html_path, page);
 383         free(to_free);
 384 }
 385
 386 static void open_html(const char *path)
 387 {
 388         execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 389 }
 390
 391 static void show_html_page(const char *git_cmd)
 392 {
 393         const char *page = cmd_to_page(git_cmd);
 394         struct strbuf page_path; /* it leaks but we exec bellow */
 395
 396         get_html_page_path(&page_path, page);
 397
 398         open_html(page_path.buf);
 399 }
 400
 401 static struct {
 402         const char *name;
 403         const char *help;
 404 } common_guides[] = {
 405         { "attributes", N_("Defining attributes per path") },
 406         { "everyday", N_("Everyday Git With 20 Commands Or So") },
 407         { "glossary", N_("A Git glossary") },
 408         { "ignore", N_("Specifies intentionally untracked files to ignore") },
 409         { "modules", N_("Defining submodule properties") },
 410         { "revisions", N_("Specifying revisions and ranges for Git") },
 411         { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 412         { "workflows", N_("An overview of recommended workflows with Git") },
 413 };
 414
 415 static void list_common_guides_help(void)
 416 {
 417         int i, longest = 0;
 418
 419         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 420                 if (longest < strlen(common_guides[i].name))
 421                         longest = strlen(common_guides[i].name);
 422         }
 423
 424         puts(_("The common Git guides are:\n"));
 425         for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 426                 printf("   %s   ", common_guides[i].name);
 427                 mput_char(' ', longest - strlen(common_guides[i].name));
 428                 puts(_(common_guides[i].help));
 429         }
 430         putchar('\n');
 431 }
 432
 433 static const char *check_git_cmd(const char* cmd)
 434 {
 435         char *alias;
 436
 437         if (is_git_command(cmd))
 438                 return cmd;
 439
 440         alias = alias_lookup(cmd);
 441         if (alias) {
 442                 printf_ln(_("`git %s' is aliased to `%s'"), cmd, alias);
 443                 free(alias);
 444                 exit(0);
 445         }
 446
 447         if (exclude_guides)
 448                 return help_unknown_cmd(cmd);
 449
 450         return cmd;
 451 }
 452
 453 int cmd_help(int argc, const char **argv, const char *prefix)
 454 {
 455         int nongit;
 456         enum help_format parsed_help_format;
 457
 458         argc = parse_options(argc, argv, prefix, builtin_help_options,
 459                         builtin_help_usage, 0);
 460         parsed_help_format = help_format;
 461
 462         if (show_all) {
 463                 git_config(git_help_config, NULL);
 464                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 465                 load_command_list("git-", &main_cmds, &other_cmds);
 466                 list_commands(colopts, &main_cmds, &other_cmds);
 467         }
 468
 469         if (show_guides)
 470                 list_common_guides_help();
 471
 472         if (show_all || show_guides) {
 473                 printf("%s\n", _(git_more_info_string));
 474                 /*
 475                 * We're done. Ignore any remaining args
 476                 */
 477                 return 0;
 478         }
 479
 480         if (!argv[0]) {
 481                 printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 482                 list_common_cmds_help();
 483                 printf("\n%s\n", _(git_more_info_string));
 484                 return 0;
 485         }
 486
 487         setup_git_directory_gently(&nongit);
 488         git_config(git_help_config, NULL);
 489
 490         if (parsed_help_format != HELP_FORMAT_NONE)
 491                 help_format = parsed_help_format;
 492         if (help_format == HELP_FORMAT_NONE)
 493                 help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 494
 495         argv[0] = check_git_cmd(argv[0]);
 496
 497         switch (help_format) {
 498         case HELP_FORMAT_NONE:
 499         case HELP_FORMAT_MAN:
 500                 show_man_page(argv[0]);
 501                 break;
 502         case HELP_FORMAT_INFO:
 503                 show_info_page(argv[0]);
 504                 break;
 505         case HELP_FORMAT_WEB:
 506                 show_html_page(argv[0]);
 507                 break;
 508         }
 509
 510         return 0;
 511 }