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