help.c

   1 /*
   2  * builtin-help.c
   3  *
   4  * Builtin help-related commands (help, usage, version)
   5  */
   6 #include "cache.h"
   7 #include "builtin.h"
   8 #include "exec_cmd.h"
   9 #include "common-cmds.h"
  10 #include "parse-options.h"
  11 #include "run-command.h"
  12 #include "dir.h"
  13
  14 static struct man_viewer_list {
  15         struct man_viewer_list *next;
  16         char name[FLEX_ARRAY];
  17 } *man_viewer_list;
  18
  19 static struct man_viewer_info_list {
  20         struct man_viewer_info_list *next;
  21         const char *info;
  22         char name[FLEX_ARRAY];
  23 } *man_viewer_info_list;
  24
  25 enum help_format {
  26         HELP_FORMAT_MAN,
  27         HELP_FORMAT_INFO,
  28         HELP_FORMAT_WEB,
  29 };
  30
  31 static int show_all = 0;
  32 #ifdef __MINGW32__
  33 static enum help_format help_format = HELP_FORMAT_WEB;
  34 #else
  35 static enum help_format help_format = HELP_FORMAT_MAN;
  36 #endif
  37 static struct option builtin_help_options[] = {
  38         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  39         OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  40         OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  41                         HELP_FORMAT_WEB),
  42         OPT_SET_INT('i', "info", &help_format, "show info page",
  43                         HELP_FORMAT_INFO),
  44         OPT_END(),
  45 };
  46
  47 static const char * const builtin_help_usage[] = {
  48         "git-help [--all] [--man|--web|--info] [command]",
  49         NULL
  50 };
  51
  52 static enum help_format parse_help_format(const char *format)
  53 {
  54         if (!strcmp(format, "man"))
  55                 return HELP_FORMAT_MAN;
  56         if (!strcmp(format, "info"))
  57                 return HELP_FORMAT_INFO;
  58         if (!strcmp(format, "web") || !strcmp(format, "html"))
  59                 return HELP_FORMAT_WEB;
  60         die("unrecognized help format '%s'", format);
  61 }
  62
  63 static const char *get_man_viewer_info(const char *name)
  64 {
  65         struct man_viewer_info_list *viewer;
  66
  67         for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  68         {
  69                 if (!strcasecmp(name, viewer->name))
  70                         return viewer->info;
  71         }
  72         return NULL;
  73 }
  74
  75 static int check_emacsclient_version(void)
  76 {
  77         struct strbuf buffer = STRBUF_INIT;
  78         struct child_process ec_process;
  79         const char *argv_ec[] = { "emacsclient", "--version", NULL };
  80         int version;
  81
  82         /* emacsclient prints its version number on stderr */
  83         memset(&ec_process, 0, sizeof(ec_process));
  84         ec_process.argv = argv_ec;
  85         ec_process.err = -1;
  86         ec_process.stdout_to_stderr = 1;
  87         if (start_command(&ec_process)) {
  88                 fprintf(stderr, "Failed to start emacsclient.\n");
  89                 return -1;
  90         }
  91         strbuf_read(&buffer, ec_process.err, 20);
  92         close(ec_process.err);
  93
  94         /*
  95          * Don't bother checking return value, because "emacsclient --version"
  96          * seems to always exits with code 1.
  97          */
  98         finish_command(&ec_process);
  99
 100         if (prefixcmp(buffer.buf, "emacsclient")) {
 101                 fprintf(stderr, "Failed to parse emacsclient version.\n");
 102                 strbuf_release(&buffer);
 103                 return -1;
 104         }
 105
 106         strbuf_remove(&buffer, 0, strlen("emacsclient"));
 107         version = atoi(buffer.buf);
 108
 109         if (version < 22) {
 110                 fprintf(stderr,
 111                         "emacsclient version '%d' too old (< 22).\n",
 112                         version);
 113                 strbuf_release(&buffer);
 114                 return -1;
 115         }
 116
 117         strbuf_release(&buffer);
 118         return 0;
 119 }
 120
 121 static void exec_woman_emacs(const char* path, const char *page)
 122 {
 123         if (!check_emacsclient_version()) {
 124                 /* This works only with emacsclient version >= 22. */
 125                 struct strbuf man_page = STRBUF_INIT;
 126
 127                 if (!path)
 128                         path = "emacsclient";
 129                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 130                 execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 131                 warning("failed to exec '%s': %s", path, strerror(errno));
 132         }
 133 }
 134
 135 static void exec_man_konqueror(const char* path, const char *page)
 136 {
 137         const char *display = getenv("DISPLAY");
 138         if (display && *display) {
 139                 struct strbuf man_page = STRBUF_INIT;
 140                 const char *filename = "kfmclient";
 141
 142                 /* It's simpler to launch konqueror using kfmclient. */
 143                 if (path) {
 144                         const char *file = strrchr(path, '/');
 145                         if (file && !strcmp(file + 1, "konqueror")) {
 146                                 char *new = xstrdup(path);
 147                                 char *dest = strrchr(new, '/');
 148
 149                                 /* strlen("konqueror") == strlen("kfmclient") */
 150                                 strcpy(dest + 1, "kfmclient");
 151                                 path = new;
 152                         }
 153                         if (file)
 154                                 filename = file;
 155                 } else
 156                         path = "kfmclient";
 157                 strbuf_addf(&man_page, "man:%s(1)", page);
 158                 execlp(path, filename, "newTab", man_page.buf, NULL);
 159                 warning("failed to exec '%s': %s", path, strerror(errno));
 160         }
 161 }
 162
 163 static void exec_man_man(const char* path, const char *page)
 164 {
 165         if (!path)
 166                 path = "man";
 167         execlp(path, "man", page, NULL);
 168         warning("failed to exec '%s': %s", path, strerror(errno));
 169 }
 170
 171 static void exec_man_cmd(const char *cmd, const char *page)
 172 {
 173         struct strbuf shell_cmd = STRBUF_INIT;
 174         strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 175         execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 176         warning("failed to exec '%s': %s", cmd, strerror(errno));
 177 }
 178
 179 static void add_man_viewer(const char *name)
 180 {
 181         struct man_viewer_list **p = &man_viewer_list;
 182         size_t len = strlen(name);
 183
 184         while (*p)
 185                 p = &((*p)->next);
 186         *p = xcalloc(1, (sizeof(**p) + len + 1));
 187         strncpy((*p)->name, name, len);
 188 }
 189
 190 static int supported_man_viewer(const char *name, size_t len)
 191 {
 192         return (!strncasecmp("man", name, len) ||
 193                 !strncasecmp("woman", name, len) ||
 194                 !strncasecmp("konqueror", name, len));
 195 }
 196
 197 static void do_add_man_viewer_info(const char *name,
 198                                    size_t len,
 199                                    const char *value)
 200 {
 201         struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 202
 203         strncpy(new->name, name, len);
 204         new->info = xstrdup(value);
 205         new->next = man_viewer_info_list;
 206         man_viewer_info_list = new;
 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 = var + 4;
 240         const char *subkey = strrchr(name, '.');
 241
 242         if (!subkey)
 243                 return error("Config with no key for man viewer: %s", name);
 244
 245         if (!strcmp(subkey, ".path")) {
 246                 if (!value)
 247                         return config_error_nonbool(var);
 248                 return add_man_viewer_path(name, subkey - name, value);
 249         }
 250         if (!strcmp(subkey, ".cmd")) {
 251                 if (!value)
 252                         return config_error_nonbool(var);
 253                 return add_man_viewer_cmd(name, subkey - name, value);
 254         }
 255
 256         warning("'%s': unsupported man viewer sub key.", subkey);
 257         return 0;
 258 }
 259
 260 static int git_help_config(const char *var, const char *value)
 261 {
 262         if (!strcmp(var, "help.format")) {
 263                 if (!value)
 264                         return config_error_nonbool(var);
 265                 help_format = parse_help_format(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 (!prefixcmp(var, "man."))
 275                 return add_man_viewer_info(var, value);
 276
 277         return git_default_config(var, value);
 278 }
 279
 280 /* most GUI terminals set COLUMNS (although some don't export it) */
 281 static int term_columns(void)
 282 {
 283         char *col_string = getenv("COLUMNS");
 284         int n_cols;
 285
 286         if (col_string && (n_cols = atoi(col_string)) > 0)
 287                 return n_cols;
 288
 289 #ifdef TIOCGWINSZ
 290         {
 291                 struct winsize ws;
 292                 if (!ioctl(1, TIOCGWINSZ, &ws)) {
 293                         if (ws.ws_col)
 294                                 return ws.ws_col;
 295                 }
 296         }
 297 #endif
 298
 299         return 80;
 300 }
 301
 302 static inline void mput_char(char c, unsigned int num)
 303 {
 304         while(num--)
 305                 putchar(c);
 306 }
 307
 308 static struct cmdnames {
 309         int alloc;
 310         int cnt;
 311         struct cmdname {
 312                 size_t len;
 313                 char name[1];
 314         } **names;
 315 } main_cmds, other_cmds;
 316
 317 static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 318 {
 319         struct cmdname *ent = xmalloc(sizeof(*ent) + len);
 320
 321         ent->len = len;
 322         memcpy(ent->name, name, len);
 323         ent->name[len] = 0;
 324
 325         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 326         cmds->names[cmds->cnt++] = ent;
 327 }
 328
 329 static int cmdname_compare(const void *a_, const void *b_)
 330 {
 331         struct cmdname *a = *(struct cmdname **)a_;
 332         struct cmdname *b = *(struct cmdname **)b_;
 333         return strcmp(a->name, b->name);
 334 }
 335
 336 static void uniq(struct cmdnames *cmds)
 337 {
 338         int i, j;
 339
 340         if (!cmds->cnt)
 341                 return;
 342
 343         for (i = j = 1; i < cmds->cnt; i++)
 344                 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
 345                         cmds->names[j++] = cmds->names[i];
 346
 347         cmds->cnt = j;
 348 }
 349
 350 static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 351 {
 352         int ci, cj, ei;
 353         int cmp;
 354
 355         ci = cj = ei = 0;
 356         while (ci < cmds->cnt && ei < excludes->cnt) {
 357                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 358                 if (cmp < 0)
 359                         cmds->names[cj++] = cmds->names[ci++];
 360                 else if (cmp == 0)
 361                         ci++, ei++;
 362                 else if (cmp > 0)
 363                         ei++;
 364         }
 365
 366         while (ci < cmds->cnt)
 367                 cmds->names[cj++] = cmds->names[ci++];
 368
 369         cmds->cnt = cj;
 370 }
 371
 372 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 373 {
 374         int cols = 1, rows;
 375         int space = longest + 1; /* min 1 SP between words */
 376         int max_cols = term_columns() - 1; /* don't print *on* the edge */
 377         int i, j;
 378
 379         if (space < max_cols)
 380                 cols = max_cols / space;
 381         rows = (cmds->cnt + cols - 1) / cols;
 382
 383         for (i = 0; i < rows; i++) {
 384                 printf("  ");
 385
 386                 for (j = 0; j < cols; j++) {
 387                         int n = j * rows + i;
 388                         int size = space;
 389                         if (n >= cmds->cnt)
 390                                 break;
 391                         if (j == cols-1 || n + rows >= cmds->cnt)
 392                                 size = 1;
 393                         printf("%-*s", size, cmds->names[n]->name);
 394                 }
 395                 putchar('\n');
 396         }
 397 }
 398
 399 static int is_executable(const char *name)
 400 {
 401         struct stat st;
 402
 403         if (stat(name, &st) || /* stat, not lstat */
 404             !S_ISREG(st.st_mode))
 405                 return 0;
 406
 407 #ifdef __MINGW32__
 408         /* cannot trust the executable bit, peek into the file instead */
 409         char buf[3] = { 0 };
 410         int n;
 411         int fd = open(name, O_RDONLY);
 412         st.st_mode &= ~S_IXUSR;
 413         if (fd >= 0) {
 414                 n = read(fd, buf, 2);
 415                 if (n == 2)
 416                         /* DOS executables start with "MZ" */
 417                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 418                                 st.st_mode |= S_IXUSR;
 419                 close(fd);
 420         }
 421 #endif
 422         return st.st_mode & S_IXUSR;
 423 }
 424
 425 static unsigned int list_commands_in_dir(struct cmdnames *cmds,
 426                                          const char *path)
 427 {
 428         unsigned int longest = 0;
 429         const char *prefix = "git-";
 430         int prefix_len = strlen(prefix);
 431         DIR *dir = opendir(path);
 432         struct dirent *de;
 433
 434         if (!dir || chdir(path))
 435                 return 0;
 436
 437         while ((de = readdir(dir)) != NULL) {
 438                 int entlen;
 439
 440                 if (prefixcmp(de->d_name, prefix))
 441                         continue;
 442
 443                 if (!is_executable(de->d_name))
 444                         continue;
 445
 446                 entlen = strlen(de->d_name) - prefix_len;
 447                 if (has_extension(de->d_name, ".exe"))
 448                         entlen -= 4;
 449
 450                 if (longest < entlen)
 451                         longest = entlen;
 452
 453                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
 454         }
 455         closedir(dir);
 456
 457         return longest;
 458 }
 459
 460 static unsigned int load_command_list(void)
 461 {
 462         unsigned int longest = 0;
 463         unsigned int len;
 464         const char *env_path = getenv("PATH");
 465         char *paths, *path, *colon;
 466         const char *exec_path = git_exec_path();
 467
 468         if (exec_path)
 469                 longest = list_commands_in_dir(&main_cmds, exec_path);
 470
 471         if (!env_path) {
 472                 fprintf(stderr, "PATH not set\n");
 473                 exit(1);
 474         }
 475
 476         path = paths = xstrdup(env_path);
 477         while (1) {
 478                 if ((colon = strchr(path, PATH_SEP)))
 479                         *colon = 0;
 480
 481                 len = list_commands_in_dir(&other_cmds, path);
 482                 if (len > longest)
 483                         longest = len;
 484
 485                 if (!colon)
 486                         break;
 487                 path = colon + 1;
 488         }
 489         free(paths);
 490
 491         qsort(main_cmds.names, main_cmds.cnt,
 492               sizeof(*main_cmds.names), cmdname_compare);
 493         uniq(&main_cmds);
 494
 495         qsort(other_cmds.names, other_cmds.cnt,
 496               sizeof(*other_cmds.names), cmdname_compare);
 497         uniq(&other_cmds);
 498         exclude_cmds(&other_cmds, &main_cmds);
 499
 500         return longest;
 501 }
 502
 503 static void list_commands(void)
 504 {
 505         unsigned int longest = load_command_list();
 506         const char *exec_path = git_exec_path();
 507
 508         if (main_cmds.cnt) {
 509                 printf("available git commands in '%s'\n", exec_path);
 510                 printf("----------------------------");
 511                 mput_char('-', strlen(exec_path));
 512                 putchar('\n');
 513                 pretty_print_string_list(&main_cmds, longest);
 514                 putchar('\n');
 515         }
 516
 517         if (other_cmds.cnt) {
 518                 printf("git commands available from elsewhere on your $PATH\n");
 519                 printf("---------------------------------------------------\n");
 520                 pretty_print_string_list(&other_cmds, longest);
 521                 putchar('\n');
 522         }
 523 }
 524
 525 void list_common_cmds_help(void)
 526 {
 527         int i, longest = 0;
 528
 529         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 530                 if (longest < strlen(common_cmds[i].name))
 531                         longest = strlen(common_cmds[i].name);
 532         }
 533
 534         puts("The most commonly used git commands are:");
 535         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 536                 printf("   %s   ", common_cmds[i].name);
 537                 mput_char(' ', longest - strlen(common_cmds[i].name));
 538                 puts(common_cmds[i].help);
 539         }
 540 }
 541
 542 static int is_in_cmdlist(struct cmdnames *c, const char *s)
 543 {
 544         int i;
 545         for (i = 0; i < c->cnt; i++)
 546                 if (!strcmp(s, c->names[i]->name))
 547                         return 1;
 548         return 0;
 549 }
 550
 551 static int is_git_command(const char *s)
 552 {
 553         load_command_list();
 554         return is_in_cmdlist(&main_cmds, s) ||
 555                 is_in_cmdlist(&other_cmds, s);
 556 }
 557
 558 static const char *cmd_to_page(const char *git_cmd)
 559 {
 560         if (!git_cmd)
 561                 return "git";
 562         else if (!prefixcmp(git_cmd, "git"))
 563                 return git_cmd;
 564         else {
 565                 int page_len = strlen(git_cmd) + 4;
 566                 char *p = xmalloc(page_len + 1);
 567                 strcpy(p, "git-");
 568                 strcpy(p + 4, git_cmd);
 569                 p[page_len] = 0;
 570                 return p;
 571         }
 572 }
 573
 574 static void setup_man_path(void)
 575 {
 576         struct strbuf new_path;
 577         const char *old_path = getenv("MANPATH");
 578
 579         strbuf_init(&new_path, 0);
 580
 581         /* We should always put ':' after our path. If there is no
 582          * old_path, the ':' at the end will let 'man' to try
 583          * system-wide paths after ours to find the manual page. If
 584          * there is old_path, we need ':' as delimiter. */
 585         strbuf_addstr(&new_path, GIT_MAN_PATH);
 586         strbuf_addch(&new_path, ':');
 587         if (old_path)
 588                 strbuf_addstr(&new_path, old_path);
 589
 590         setenv("MANPATH", new_path.buf, 1);
 591
 592         strbuf_release(&new_path);
 593 }
 594
 595 static void exec_viewer(const char *name, const char *page)
 596 {
 597         const char *info = get_man_viewer_info(name);
 598
 599         if (!strcasecmp(name, "man"))
 600                 exec_man_man(info, page);
 601         else if (!strcasecmp(name, "woman"))
 602                 exec_woman_emacs(info, page);
 603         else if (!strcasecmp(name, "konqueror"))
 604                 exec_man_konqueror(info, page);
 605         else if (info)
 606                 exec_man_cmd(info, page);
 607         else
 608                 warning("'%s': unknown man viewer.", name);
 609 }
 610
 611 static void show_man_page(const char *git_cmd)
 612 {
 613         struct man_viewer_list *viewer;
 614         const char *page = cmd_to_page(git_cmd);
 615
 616         setup_man_path();
 617         for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 618         {
 619                 exec_viewer(viewer->name, page); /* will return when unable */
 620         }
 621         exec_viewer("man", page);
 622         die("no man viewer handled the request");
 623 }
 624
 625 static void show_info_page(const char *git_cmd)
 626 {
 627         const char *page = cmd_to_page(git_cmd);
 628         setenv("INFOPATH", GIT_INFO_PATH, 1);
 629         execlp("info", "info", "gitman", page, NULL);
 630 }
 631
 632 static void get_html_page_path(struct strbuf *page_path, const char *page)
 633 {
 634         struct stat st;
 635
 636         /* Check that we have a git documentation directory. */
 637         if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
 638                 die("'%s': not a documentation directory.", GIT_HTML_PATH);
 639
 640         strbuf_init(page_path, 0);
 641         strbuf_addf(page_path, GIT_HTML_PATH "/%s.html", page);
 642 }
 643
 644 static void show_html_page(const char *git_cmd)
 645 {
 646 #ifdef __MINGW32__
 647         const char* exec_path = git_exec_path();
 648         char *htmlpath = make_native_separator(
 649                            mkpath("%s/../doc/git/html/%s.html"
 650                                   , exec_path
 651                                   , git_cmd)
 652                          );
 653         if (!file_exists(htmlpath)) {
 654                 htmlpath = make_native_separator(
 655                               mkpath("%s/../doc/git/html/git-%s.html"
 656                                      , exec_path
 657                                      , git_cmd)
 658                            );
 659                 if (!file_exists(htmlpath)) {
 660                         fprintf(stderr, "Can't find HTML help for '%s'.\n"
 661                                 , git_cmd);
 662                         exit(1);
 663                 }
 664         }
 665         printf("Launching default browser to display HTML help ...\n");
 666         ShellExecute(NULL, "open", htmlpath, NULL, "\\", 0);
 667 #else
 668         const char *page = cmd_to_page(git_cmd);
 669         struct strbuf page_path; /* it leaks but we exec bellow */
 670
 671         get_html_page_path(&page_path, page);
 672
 673         execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
 674 #endif
 675 }
 676
 677 void help_unknown_cmd(const char *cmd)
 678 {
 679         fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
 680         exit(1);
 681 }
 682
 683 int cmd_version(int argc, const char **argv, const char *prefix)
 684 {
 685         printf("git version %s\n", git_version_string);
 686         return 0;
 687 }
 688
 689 int cmd_help(int argc, const char **argv, const char *prefix)
 690 {
 691         int nongit;
 692         const char *alias;
 693
 694         setup_git_directory_gently(&nongit);
 695         git_config(git_help_config);
 696
 697         argc = parse_options(argc, argv, builtin_help_options,
 698                         builtin_help_usage, 0);
 699
 700         if (show_all) {
 701                 printf("usage: %s\n\n", git_usage_string);
 702                 list_commands();
 703                 return 0;
 704         }
 705
 706         if (!argv[0]) {
 707                 printf("usage: %s\n\n", git_usage_string);
 708                 list_common_cmds_help();
 709                 return 0;
 710         }
 711
 712         alias = alias_lookup(argv[0]);
 713         if (alias && !is_git_command(argv[0])) {
 714                 printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 715                 return 0;
 716         }
 717
 718         switch (help_format) {
 719         case HELP_FORMAT_MAN:
 720                 show_man_page(argv[0]);
 721                 break;
 722         case HELP_FORMAT_INFO:
 723                 show_info_page(argv[0]);
 724                 break;
 725         case HELP_FORMAT_WEB:
 726                 show_html_page(argv[0]);
 727                 break;
 728         }
 729
 730         return 0;
 731 }