help.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "builtin.h"
   4 #include "exec-cmd.h"
   5 #include "run-command.h"
   6 #include "levenshtein.h"
   7 #include "help.h"
   8 #include "command-list.h"
   9 #include "string-list.h"
  10 #include "column.h"
  11 #include "version.h"
  12 #include "refs.h"
  13 #include "parse-options.h"
  14
  15 struct category_description {
  16         uint32_t category;
  17         const char *desc;
  18 };
  19 static uint32_t common_mask =
  20         CAT_init | CAT_worktree | CAT_info |
  21         CAT_history | CAT_remote;
  22 static struct category_description common_categories[] = {
  23         { CAT_init, N_("start a working area (see also: git help tutorial)") },
  24         { CAT_worktree, N_("work on the current change (see also: git help everyday)") },
  25         { CAT_info, N_("examine the history and state (see also: git help revisions)") },
  26         { CAT_history, N_("grow, mark and tweak your common history") },
  27         { CAT_remote, N_("collaborate (see also: git help workflows)") },
  28         { 0, NULL }
  29 };
  30 static struct category_description main_categories[] = {
  31         { CAT_mainporcelain, N_("Main Porcelain Commands") },
  32         { CAT_ancillarymanipulators, N_("Ancillary Commands / Manipulators") },
  33         { CAT_ancillaryinterrogators, N_("Ancillary Commands / Interrogators") },
  34         { CAT_foreignscminterface, N_("Interacting with Others") },
  35         { CAT_plumbingmanipulators, N_("Low-level Commands / Manipulators") },
  36         { CAT_plumbinginterrogators, N_("Low-level Commands / Interrogators") },
  37         { CAT_synchingrepositories, N_("Low-level Commands / Synching Repositories") },
  38         { CAT_purehelpers, N_("Low-level Commands / Internal Helpers") },
  39         { 0, NULL }
  40 };
  41
  42 static const char *drop_prefix(const char *name, uint32_t category)
  43 {
  44         const char *new_name;
  45
  46         if (skip_prefix(name, "git-", &new_name))
  47                 return new_name;
  48         if (category == CAT_guide && skip_prefix(name, "git", &new_name))
  49                 return new_name;
  50         return name;
  51
  52 }
  53
  54 static void extract_cmds(struct cmdname_help **p_cmds, uint32_t mask)
  55 {
  56         int i, nr = 0;
  57         struct cmdname_help *cmds;
  58
  59         if (ARRAY_SIZE(command_list) == 0)
  60                 BUG("empty command_list[] is a sign of broken generate-cmdlist.sh");
  61
  62         ALLOC_ARRAY(cmds, ARRAY_SIZE(command_list) + 1);
  63
  64         for (i = 0; i < ARRAY_SIZE(command_list); i++) {
  65                 const struct cmdname_help *cmd = command_list + i;
  66
  67                 if (!(cmd->category & mask))
  68                         continue;
  69
  70                 cmds[nr] = *cmd;
  71                 cmds[nr].name = drop_prefix(cmd->name, cmd->category);
  72
  73                 nr++;
  74         }
  75         cmds[nr].name = NULL;
  76         *p_cmds = cmds;
  77 }
  78
  79 static void print_command_list(const struct cmdname_help *cmds,
  80                                uint32_t mask, int longest)
  81 {
  82         int i;
  83
  84         for (i = 0; cmds[i].name; i++) {
  85                 if (cmds[i].category & mask) {
  86                         size_t len = strlen(cmds[i].name);
  87                         printf("   %s   ", cmds[i].name);
  88                         mput_char(' ', longest > len ? longest - len : 1);
  89                         puts(_(cmds[i].help));
  90                 }
  91         }
  92 }
  93
  94 static int cmd_name_cmp(const void *elem1, const void *elem2)
  95 {
  96         const struct cmdname_help *e1 = elem1;
  97         const struct cmdname_help *e2 = elem2;
  98
  99         return strcmp(e1->name, e2->name);
 100 }
 101
 102 static void print_cmd_by_category(const struct category_description *catdesc,
 103                                   int *longest_p)
 104 {
 105         struct cmdname_help *cmds;
 106         int longest = 0;
 107         int i, nr = 0;
 108         uint32_t mask = 0;
 109
 110         for (i = 0; catdesc[i].desc; i++)
 111                 mask |= catdesc[i].category;
 112
 113         extract_cmds(&cmds, mask);
 114
 115         for (i = 0; cmds[i].name; i++, nr++) {
 116                 if (longest < strlen(cmds[i].name))
 117                         longest = strlen(cmds[i].name);
 118         }
 119         QSORT(cmds, nr, cmd_name_cmp);
 120
 121         for (i = 0; catdesc[i].desc; i++) {
 122                 uint32_t mask = catdesc[i].category;
 123                 const char *desc = catdesc[i].desc;
 124
 125                 printf("\n%s\n", _(desc));
 126                 print_command_list(cmds, mask, longest);
 127         }
 128         free(cmds);
 129         if (longest_p)
 130                 *longest_p = longest;
 131 }
 132
 133 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 134 {
 135         struct cmdname *ent;
 136         FLEX_ALLOC_MEM(ent, name, name, len);
 137         ent->len = len;
 138
 139         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 140         cmds->names[cmds->cnt++] = ent;
 141 }
 142
 143 static void clean_cmdnames(struct cmdnames *cmds)
 144 {
 145         int i;
 146         for (i = 0; i < cmds->cnt; ++i)
 147                 free(cmds->names[i]);
 148         free(cmds->names);
 149         cmds->cnt = 0;
 150         cmds->alloc = 0;
 151 }
 152
 153 static int cmdname_compare(const void *a_, const void *b_)
 154 {
 155         struct cmdname *a = *(struct cmdname **)a_;
 156         struct cmdname *b = *(struct cmdname **)b_;
 157         return strcmp(a->name, b->name);
 158 }
 159
 160 static void uniq(struct cmdnames *cmds)
 161 {
 162         int i, j;
 163
 164         if (!cmds->cnt)
 165                 return;
 166
 167         for (i = j = 1; i < cmds->cnt; i++) {
 168                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
 169                         free(cmds->names[i]);
 170                 else
 171                         cmds->names[j++] = cmds->names[i];
 172         }
 173
 174         cmds->cnt = j;
 175 }
 176
 177 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 178 {
 179         int ci, cj, ei;
 180         int cmp;
 181
 182         ci = cj = ei = 0;
 183         while (ci < cmds->cnt && ei < excludes->cnt) {
 184                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 185                 if (cmp < 0)
 186                         cmds->names[cj++] = cmds->names[ci++];
 187                 else if (cmp == 0) {
 188                         ei++;
 189                         free(cmds->names[ci++]);
 190                 } else if (cmp > 0)
 191                         ei++;
 192         }
 193
 194         while (ci < cmds->cnt)
 195                 cmds->names[cj++] = cmds->names[ci++];
 196
 197         cmds->cnt = cj;
 198 }
 199
 200 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
 201 {
 202         struct string_list list = STRING_LIST_INIT_NODUP;
 203         struct column_options copts;
 204         int i;
 205
 206         for (i = 0; i < cmds->cnt; i++)
 207                 string_list_append(&list, cmds->names[i]->name);
 208         /*
 209          * always enable column display, we only consult column.*
 210          * about layout strategy and stuff
 211          */
 212         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
 213         memset(&copts, 0, sizeof(copts));
 214         copts.indent = "  ";
 215         copts.padding = 2;
 216         print_columns(&list, colopts, &copts);
 217         string_list_clear(&list, 0);
 218 }
 219
 220 static void list_commands_in_dir(struct cmdnames *cmds,
 221                                          const char *path,
 222                                          const char *prefix)
 223 {
 224         DIR *dir = opendir(path);
 225         struct dirent *de;
 226         struct strbuf buf = STRBUF_INIT;
 227         int len;
 228
 229         if (!dir)
 230                 return;
 231         if (!prefix)
 232                 prefix = "git-";
 233
 234         strbuf_addf(&buf, "%s/", path);
 235         len = buf.len;
 236
 237         while ((de = readdir(dir)) != NULL) {
 238                 const char *ent;
 239                 size_t entlen;
 240
 241                 if (!skip_prefix(de->d_name, prefix, &ent))
 242                         continue;
 243
 244                 strbuf_setlen(&buf, len);
 245                 strbuf_addstr(&buf, de->d_name);
 246                 if (!is_executable(buf.buf))
 247                         continue;
 248
 249                 entlen = strlen(ent);
 250                 strip_suffix(ent, ".exe", &entlen);
 251
 252                 add_cmdname(cmds, ent, entlen);
 253         }
 254         closedir(dir);
 255         strbuf_release(&buf);
 256 }
 257
 258 void load_command_list(const char *prefix,
 259                 struct cmdnames *main_cmds,
 260                 struct cmdnames *other_cmds)
 261 {
 262         const char *env_path = getenv("PATH");
 263         const char *exec_path = git_exec_path();
 264
 265         if (exec_path) {
 266                 list_commands_in_dir(main_cmds, exec_path, prefix);
 267                 QSORT(main_cmds->names, main_cmds->cnt, cmdname_compare);
 268                 uniq(main_cmds);
 269         }
 270
 271         if (env_path) {
 272                 char *paths, *path, *colon;
 273                 path = paths = xstrdup(env_path);
 274                 while (1) {
 275                         if ((colon = strchr(path, PATH_SEP)))
 276                                 *colon = 0;
 277                         if (!exec_path || strcmp(path, exec_path))
 278                                 list_commands_in_dir(other_cmds, path, prefix);
 279
 280                         if (!colon)
 281                                 break;
 282                         path = colon + 1;
 283                 }
 284                 free(paths);
 285
 286                 QSORT(other_cmds->names, other_cmds->cnt, cmdname_compare);
 287                 uniq(other_cmds);
 288         }
 289         exclude_cmds(other_cmds, main_cmds);
 290 }
 291
 292 void list_commands(unsigned int colopts,
 293                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 294 {
 295         if (main_cmds->cnt) {
 296                 const char *exec_path = git_exec_path();
 297                 printf_ln(_("available git commands in '%s'"), exec_path);
 298                 putchar('\n');
 299                 pretty_print_cmdnames(main_cmds, colopts);
 300                 putchar('\n');
 301         }
 302
 303         if (other_cmds->cnt) {
 304                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 305                 putchar('\n');
 306                 pretty_print_cmdnames(other_cmds, colopts);
 307                 putchar('\n');
 308         }
 309 }
 310
 311 void list_common_cmds_help(void)
 312 {
 313         puts(_("These are common Git commands used in various situations:"));
 314         print_cmd_by_category(common_categories, NULL);
 315 }
 316
 317 void list_all_main_cmds(struct string_list *list)
 318 {
 319         struct cmdnames main_cmds, other_cmds;
 320         int i;
 321
 322         memset(&main_cmds, 0, sizeof(main_cmds));
 323         memset(&other_cmds, 0, sizeof(other_cmds));
 324         load_command_list("git-", &main_cmds, &other_cmds);
 325
 326         for (i = 0; i < main_cmds.cnt; i++)
 327                 string_list_append(list, main_cmds.names[i]->name);
 328
 329         clean_cmdnames(&main_cmds);
 330         clean_cmdnames(&other_cmds);
 331 }
 332
 333 void list_all_other_cmds(struct string_list *list)
 334 {
 335         struct cmdnames main_cmds, other_cmds;
 336         int i;
 337
 338         memset(&main_cmds, 0, sizeof(main_cmds));
 339         memset(&other_cmds, 0, sizeof(other_cmds));
 340         load_command_list("git-", &main_cmds, &other_cmds);
 341
 342         for (i = 0; i < other_cmds.cnt; i++)
 343                 string_list_append(list, other_cmds.names[i]->name);
 344
 345         clean_cmdnames(&main_cmds);
 346         clean_cmdnames(&other_cmds);
 347 }
 348
 349 void list_cmds_by_category(struct string_list *list,
 350                            const char *cat)
 351 {
 352         int i, n = ARRAY_SIZE(command_list);
 353         uint32_t cat_id = 0;
 354
 355         for (i = 0; category_names[i]; i++) {
 356                 if (!strcmp(cat, category_names[i])) {
 357                         cat_id = 1UL << i;
 358                         break;
 359                 }
 360         }
 361         if (!cat_id)
 362                 die(_("unsupported command listing type '%s'"), cat);
 363
 364         for (i = 0; i < n; i++) {
 365                 struct cmdname_help *cmd = command_list + i;
 366
 367                 if (!(cmd->category & cat_id))
 368                         continue;
 369                 string_list_append(list, drop_prefix(cmd->name, cmd->category));
 370         }
 371 }
 372
 373 void list_cmds_by_config(struct string_list *list)
 374 {
 375         const char *cmd_list;
 376
 377         /*
 378          * There's no actual repository setup at this point (and even
 379          * if there is, we don't really care; only global config
 380          * matters). If we accidentally set up a repository, it's ok
 381          * too since the caller (git --list-cmds=) should exit shortly
 382          * anyway.
 383          */
 384         if (git_config_get_string_const("completion.commands", &cmd_list))
 385                 return;
 386
 387         string_list_sort(list);
 388         string_list_remove_duplicates(list, 0);
 389
 390         while (*cmd_list) {
 391                 struct strbuf sb = STRBUF_INIT;
 392                 const char *p = strchrnul(cmd_list, ' ');
 393
 394                 strbuf_add(&sb, cmd_list, p - cmd_list);
 395                 if (*cmd_list == '-')
 396                         string_list_remove(list, cmd_list + 1, 0);
 397                 else
 398                         string_list_insert(list, sb.buf);
 399                 strbuf_release(&sb);
 400                 while (*p == ' ')
 401                         p++;
 402                 cmd_list = p;
 403         }
 404 }
 405
 406 void list_common_guides_help(void)
 407 {
 408         struct category_description catdesc[] = {
 409                 { CAT_guide, N_("The common Git guides are:") },
 410                 { 0, NULL }
 411         };
 412         print_cmd_by_category(catdesc, NULL);
 413         putchar('\n');
 414 }
 415
 416 struct slot_expansion {
 417         const char *prefix;
 418         const char *placeholder;
 419         void (*fn)(struct string_list *list, const char *prefix);
 420         int found;
 421 };
 422
 423 void list_config_help(int for_human)
 424 {
 425         struct slot_expansion slot_expansions[] = {
 426                 { "advice", "*", list_config_advices },
 427                 { "color.branch", "<slot>", list_config_color_branch_slots },
 428                 { "color.decorate", "<slot>", list_config_color_decorate_slots },
 429                 { "color.diff", "<slot>", list_config_color_diff_slots },
 430                 { "color.grep", "<slot>", list_config_color_grep_slots },
 431                 { "color.interactive", "<slot>", list_config_color_interactive_slots },
 432                 { "color.remote", "<slot>", list_config_color_sideband_slots },
 433                 { "color.status", "<slot>", list_config_color_status_slots },
 434                 { "fsck", "<msg-id>", list_config_fsck_msg_ids },
 435                 { "receive.fsck", "<msg-id>", list_config_fsck_msg_ids },
 436                 { NULL, NULL, NULL }
 437         };
 438         const char **p;
 439         struct slot_expansion *e;
 440         struct string_list keys = STRING_LIST_INIT_DUP;
 441         int i;
 442
 443         for (p = config_name_list; *p; p++) {
 444                 const char *var = *p;
 445                 struct strbuf sb = STRBUF_INIT;
 446
 447                 for (e = slot_expansions; e->prefix; e++) {
 448
 449                         strbuf_reset(&sb);
 450                         strbuf_addf(&sb, "%s.%s", e->prefix, e->placeholder);
 451                         if (!strcasecmp(var, sb.buf)) {
 452                                 e->fn(&keys, e->prefix);
 453                                 e->found++;
 454                                 break;
 455                         }
 456                 }
 457                 strbuf_release(&sb);
 458                 if (!e->prefix)
 459                         string_list_append(&keys, var);
 460         }
 461
 462         for (e = slot_expansions; e->prefix; e++)
 463                 if (!e->found)
 464                         BUG("slot_expansion %s.%s is not used",
 465                             e->prefix, e->placeholder);
 466
 467         string_list_sort(&keys);
 468         for (i = 0; i < keys.nr; i++) {
 469                 const char *var = keys.items[i].string;
 470                 const char *wildcard, *tag, *cut;
 471
 472                 if (for_human) {
 473                         puts(var);
 474                         continue;
 475                 }
 476
 477                 wildcard = strchr(var, '*');
 478                 tag = strchr(var, '<');
 479
 480                 if (!wildcard && !tag) {
 481                         puts(var);
 482                         continue;
 483                 }
 484
 485                 if (wildcard && !tag)
 486                         cut = wildcard;
 487                 else if (!wildcard && tag)
 488                         cut = tag;
 489                 else
 490                         cut = wildcard < tag ? wildcard : tag;
 491
 492                 /*
 493                  * We may produce duplicates, but that's up to
 494                  * git-completion.bash to handle
 495                  */
 496                 printf("%.*s\n", (int)(cut - var), var);
 497         }
 498         string_list_clear(&keys, 0);
 499 }
 500
 501 static int get_alias(const char *var, const char *value, void *data)
 502 {
 503         struct string_list *list = data;
 504
 505         if (skip_prefix(var, "alias.", &var))
 506                 string_list_append(list, var)->util = xstrdup(value);
 507
 508         return 0;
 509 }
 510
 511 void list_all_cmds_help(void)
 512 {
 513         struct string_list others = STRING_LIST_INIT_DUP;
 514         struct string_list alias_list = STRING_LIST_INIT_DUP;
 515         struct cmdname_help *aliases;
 516         int i, longest;
 517
 518         printf_ln(_("See 'git help <command>' to read about a specific subcommand"));
 519         print_cmd_by_category(main_categories, &longest);
 520
 521         list_all_other_cmds(&others);
 522         if (others.nr)
 523                 printf("\n%s\n", _("External commands"));
 524         for (i = 0; i < others.nr; i++)
 525                 printf("   %s\n", others.items[i].string);
 526         string_list_clear(&others, 0);
 527
 528         git_config(get_alias, &alias_list);
 529         string_list_sort(&alias_list);
 530
 531         for (i = 0; i < alias_list.nr; i++) {
 532                 size_t len = strlen(alias_list.items[i].string);
 533                 if (longest < len)
 534                         longest = len;
 535         }
 536
 537         if (alias_list.nr) {
 538                 printf("\n%s\n", _("Command aliases"));
 539                 ALLOC_ARRAY(aliases, alias_list.nr + 1);
 540                 for (i = 0; i < alias_list.nr; i++) {
 541                         aliases[i].name = alias_list.items[i].string;
 542                         aliases[i].help = alias_list.items[i].util;
 543                         aliases[i].category = 1;
 544                 }
 545                 aliases[alias_list.nr].name = NULL;
 546                 print_command_list(aliases, 1, longest);
 547                 free(aliases);
 548         }
 549         string_list_clear(&alias_list, 1);
 550 }
 551
 552 int is_in_cmdlist(struct cmdnames *c, const char *s)
 553 {
 554         int i;
 555         for (i = 0; i < c->cnt; i++)
 556                 if (!strcmp(s, c->names[i]->name))
 557                         return 1;
 558         return 0;
 559 }
 560
 561 static int autocorrect;
 562 static struct cmdnames aliases;
 563
 564 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 565 {
 566         const char *p;
 567
 568         if (!strcmp(var, "help.autocorrect"))
 569                 autocorrect = git_config_int(var,value);
 570         /* Also use aliases for command lookup */
 571         if (skip_prefix(var, "alias.", &p))
 572                 add_cmdname(&aliases, p, strlen(p));
 573
 574         return git_default_config(var, value, cb);
 575 }
 576
 577 static int levenshtein_compare(const void *p1, const void *p2)
 578 {
 579         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 580         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 581         int l1 = (*c1)->len;
 582         int l2 = (*c2)->len;
 583         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 584 }
 585
 586 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 587 {
 588         int i;
 589         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 590
 591         for (i = 0; i < old->cnt; i++)
 592                 cmds->names[cmds->cnt++] = old->names[i];
 593         FREE_AND_NULL(old->names);
 594         old->cnt = 0;
 595 }
 596
 597 /* An empirically derived magic number */
 598 #define SIMILARITY_FLOOR 7
 599 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 600
 601 static const char bad_interpreter_advice[] =
 602         N_("'%s' appears to be a git command, but we were not\n"
 603         "able to execute it. Maybe git-%s is broken?");
 604
 605 const char *help_unknown_cmd(const char *cmd)
 606 {
 607         int i, n, best_similarity = 0;
 608         struct cmdnames main_cmds, other_cmds;
 609         struct cmdname_help *common_cmds;
 610
 611         memset(&main_cmds, 0, sizeof(main_cmds));
 612         memset(&other_cmds, 0, sizeof(other_cmds));
 613         memset(&aliases, 0, sizeof(aliases));
 614
 615         read_early_config(git_unknown_cmd_config, NULL);
 616
 617         load_command_list("git-", &main_cmds, &other_cmds);
 618
 619         add_cmd_list(&main_cmds, &aliases);
 620         add_cmd_list(&main_cmds, &other_cmds);
 621         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 622         uniq(&main_cmds);
 623
 624         extract_cmds(&common_cmds, common_mask);
 625
 626         /* This abuses cmdname->len for levenshtein distance */
 627         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 628                 int cmp = 0; /* avoid compiler stupidity */
 629                 const char *candidate = main_cmds.names[i]->name;
 630
 631                 /*
 632                  * An exact match means we have the command, but
 633                  * for some reason exec'ing it gave us ENOENT; probably
 634                  * it's a bad interpreter in the #! line.
 635                  */
 636                 if (!strcmp(candidate, cmd))
 637                         die(_(bad_interpreter_advice), cmd, cmd);
 638
 639                 /* Does the candidate appear in common_cmds list? */
 640                 while (common_cmds[n].name &&
 641                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 642                         n++;
 643                 if (common_cmds[n].name && !cmp) {
 644                         /* Yes, this is one of the common commands */
 645                         n++; /* use the entry from common_cmds[] */
 646                         if (starts_with(candidate, cmd)) {
 647                                 /* Give prefix match a very good score */
 648                                 main_cmds.names[i]->len = 0;
 649                                 continue;
 650                         }
 651                 }
 652
 653                 main_cmds.names[i]->len =
 654                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 655         }
 656         FREE_AND_NULL(common_cmds);
 657
 658         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 659
 660         if (!main_cmds.cnt)
 661                 die(_("Uh oh. Your system reports no Git commands at all."));
 662
 663         /* skip and count prefix matches */
 664         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 665                 ; /* still counting */
 666
 667         if (main_cmds.cnt <= n) {
 668                 /* prefix matches with everything? that is too ambiguous */
 669                 best_similarity = SIMILARITY_FLOOR + 1;
 670         } else {
 671                 /* count all the most similar ones */
 672                 for (best_similarity = main_cmds.names[n++]->len;
 673                      (n < main_cmds.cnt &&
 674                       best_similarity == main_cmds.names[n]->len);
 675                      n++)
 676                         ; /* still counting */
 677         }
 678         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 679                 const char *assumed = main_cmds.names[0]->name;
 680                 main_cmds.names[0] = NULL;
 681                 clean_cmdnames(&main_cmds);
 682                 fprintf_ln(stderr,
 683                            _("WARNING: You called a Git command named '%s', "
 684                              "which does not exist."),
 685                            cmd);
 686                 if (autocorrect < 0)
 687                         fprintf_ln(stderr,
 688                                    _("Continuing under the assumption that "
 689                                      "you meant '%s'."),
 690                                    assumed);
 691                 else {
 692                         fprintf_ln(stderr,
 693                                    _("Continuing in %0.1f seconds, "
 694                                      "assuming that you meant '%s'."),
 695                                    (float)autocorrect/10.0, assumed);
 696                         sleep_millisec(autocorrect * 100);
 697                 }
 698                 return assumed;
 699         }
 700
 701         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 702
 703         if (SIMILAR_ENOUGH(best_similarity)) {
 704                 fprintf_ln(stderr,
 705                            Q_("\nThe most similar command is",
 706                               "\nThe most similar commands are",
 707                            n));
 708
 709                 for (i = 0; i < n; i++)
 710                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 711         }
 712
 713         exit(1);
 714 }
 715
 716 int cmd_version(int argc, const char **argv, const char *prefix)
 717 {
 718         int build_options = 0;
 719         const char * const usage[] = {
 720                 N_("git version [<options>]"),
 721                 NULL
 722         };
 723         struct option options[] = {
 724                 OPT_BOOL(0, "build-options", &build_options,
 725                          "also print build options"),
 726                 OPT_END()
 727         };
 728
 729         argc = parse_options(argc, argv, prefix, options, usage, 0);
 730
 731         /*
 732          * The format of this string should be kept stable for compatibility
 733          * with external projects that rely on the output of "git version".
 734          *
 735          * Always show the version, even if other options are given.
 736          */
 737         printf("git version %s\n", git_version_string);
 738
 739         if (build_options) {
 740                 printf("cpu: %s\n", GIT_HOST_CPU);
 741                 if (git_built_from_commit_string[0])
 742                         printf("built from commit: %s\n",
 743                                git_built_from_commit_string);
 744                 else
 745                         printf("no commit associated with this build\n");
 746                 printf("sizeof-long: %d\n", (int)sizeof(long));
 747                 printf("sizeof-size_t: %d\n", (int)sizeof(size_t));
 748                 /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 749         }
 750         return 0;
 751 }
 752
 753 struct similar_ref_cb {
 754         const char *base_ref;
 755         struct string_list *similar_refs;
 756 };
 757
 758 static int append_similar_ref(const char *refname, const struct object_id *oid,
 759                               int flags, void *cb_data)
 760 {
 761         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 762         char *branch = strrchr(refname, '/') + 1;
 763         const char *remote;
 764
 765         /* A remote branch of the same name is deemed similar */
 766         if (skip_prefix(refname, "refs/remotes/", &remote) &&
 767             !strcmp(branch, cb->base_ref))
 768                 string_list_append(cb->similar_refs, remote);
 769         return 0;
 770 }
 771
 772 static struct string_list guess_refs(const char *ref)
 773 {
 774         struct similar_ref_cb ref_cb;
 775         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 776
 777         ref_cb.base_ref = ref;
 778         ref_cb.similar_refs = &similar_refs;
 779         for_each_ref(append_similar_ref, &ref_cb);
 780         return similar_refs;
 781 }
 782
 783 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 784 {
 785         int i;
 786         struct string_list suggested_refs = guess_refs(ref);
 787
 788         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 789
 790         if (suggested_refs.nr > 0) {
 791                 fprintf_ln(stderr,
 792                            Q_("\nDid you mean this?",
 793                               "\nDid you mean one of these?",
 794                               suggested_refs.nr));
 795                 for (i = 0; i < suggested_refs.nr; i++)
 796                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 797         }
 798
 799         string_list_clear(&suggested_refs, 0);
 800         exit(1);
 801 }