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                 if (i)
 128                         putchar('\n');
 129                 puts(_(desc));
 130                 print_command_list(cmds, mask, longest);
 131         }
 132         free(cmds);
 133         if (longest_p)
 134                 *longest_p = longest;
 135 }
 136
 137 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 138 {
 139         struct cmdname *ent;
 140         FLEX_ALLOC_MEM(ent, name, name, len);
 141         ent->len = len;
 142
 143         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 144         cmds->names[cmds->cnt++] = ent;
 145 }
 146
 147 static void clean_cmdnames(struct cmdnames *cmds)
 148 {
 149         int i;
 150         for (i = 0; i < cmds->cnt; ++i)
 151                 free(cmds->names[i]);
 152         free(cmds->names);
 153         cmds->cnt = 0;
 154         cmds->alloc = 0;
 155 }
 156
 157 static int cmdname_compare(const void *a_, const void *b_)
 158 {
 159         struct cmdname *a = *(struct cmdname **)a_;
 160         struct cmdname *b = *(struct cmdname **)b_;
 161         return strcmp(a->name, b->name);
 162 }
 163
 164 static void uniq(struct cmdnames *cmds)
 165 {
 166         int i, j;
 167
 168         if (!cmds->cnt)
 169                 return;
 170
 171         for (i = j = 1; i < cmds->cnt; i++) {
 172                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
 173                         free(cmds->names[i]);
 174                 else
 175                         cmds->names[j++] = cmds->names[i];
 176         }
 177
 178         cmds->cnt = j;
 179 }
 180
 181 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 182 {
 183         int ci, cj, ei;
 184         int cmp;
 185
 186         ci = cj = ei = 0;
 187         while (ci < cmds->cnt && ei < excludes->cnt) {
 188                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 189                 if (cmp < 0)
 190                         cmds->names[cj++] = cmds->names[ci++];
 191                 else if (cmp == 0) {
 192                         ei++;
 193                         free(cmds->names[ci++]);
 194                 } else if (cmp > 0)
 195                         ei++;
 196         }
 197
 198         while (ci < cmds->cnt)
 199                 cmds->names[cj++] = cmds->names[ci++];
 200
 201         cmds->cnt = cj;
 202 }
 203
 204 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
 205 {
 206         struct string_list list = STRING_LIST_INIT_NODUP;
 207         struct column_options copts;
 208         int i;
 209
 210         for (i = 0; i < cmds->cnt; i++)
 211                 string_list_append(&list, cmds->names[i]->name);
 212         /*
 213          * always enable column display, we only consult column.*
 214          * about layout strategy and stuff
 215          */
 216         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
 217         memset(&copts, 0, sizeof(copts));
 218         copts.indent = "  ";
 219         copts.padding = 2;
 220         print_columns(&list, colopts, &copts);
 221         string_list_clear(&list, 0);
 222 }
 223
 224 static void list_commands_in_dir(struct cmdnames *cmds,
 225                                          const char *path,
 226                                          const char *prefix)
 227 {
 228         DIR *dir = opendir(path);
 229         struct dirent *de;
 230         struct strbuf buf = STRBUF_INIT;
 231         int len;
 232
 233         if (!dir)
 234                 return;
 235         if (!prefix)
 236                 prefix = "git-";
 237
 238         strbuf_addf(&buf, "%s/", path);
 239         len = buf.len;
 240
 241         while ((de = readdir(dir)) != NULL) {
 242                 const char *ent;
 243                 size_t entlen;
 244
 245                 if (!skip_prefix(de->d_name, prefix, &ent))
 246                         continue;
 247
 248                 strbuf_setlen(&buf, len);
 249                 strbuf_addstr(&buf, de->d_name);
 250                 if (!is_executable(buf.buf))
 251                         continue;
 252
 253                 entlen = strlen(ent);
 254                 strip_suffix(ent, ".exe", &entlen);
 255
 256                 add_cmdname(cmds, ent, entlen);
 257         }
 258         closedir(dir);
 259         strbuf_release(&buf);
 260 }
 261
 262 void load_command_list(const char *prefix,
 263                 struct cmdnames *main_cmds,
 264                 struct cmdnames *other_cmds)
 265 {
 266         const char *env_path = getenv("PATH");
 267         const char *exec_path = git_exec_path();
 268
 269         load_builtin_commands(prefix, main_cmds);
 270
 271         if (exec_path) {
 272                 list_commands_in_dir(main_cmds, exec_path, prefix);
 273                 QSORT(main_cmds->names, main_cmds->cnt, cmdname_compare);
 274                 uniq(main_cmds);
 275         }
 276
 277         if (env_path) {
 278                 char *paths, *path, *colon;
 279                 path = paths = xstrdup(env_path);
 280                 while (1) {
 281                         if ((colon = strchr(path, PATH_SEP)))
 282                                 *colon = 0;
 283                         if (!exec_path || strcmp(path, exec_path))
 284                                 list_commands_in_dir(other_cmds, path, prefix);
 285
 286                         if (!colon)
 287                                 break;
 288                         path = colon + 1;
 289                 }
 290                 free(paths);
 291
 292                 QSORT(other_cmds->names, other_cmds->cnt, cmdname_compare);
 293                 uniq(other_cmds);
 294         }
 295         exclude_cmds(other_cmds, main_cmds);
 296 }
 297
 298 static int get_colopts(const char *var, const char *value, void *data)
 299 {
 300         unsigned int *colopts = data;
 301
 302         if (starts_with(var, "column."))
 303                 return git_column_config(var, value, "help", colopts);
 304
 305         return 0;
 306 }
 307
 308 void list_commands(struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 309 {
 310         unsigned int colopts = 0;
 311         git_config(get_colopts, &colopts);
 312
 313         if (main_cmds->cnt) {
 314                 const char *exec_path = git_exec_path();
 315                 printf_ln(_("available git commands in '%s'"), exec_path);
 316                 putchar('\n');
 317                 pretty_print_cmdnames(main_cmds, colopts);
 318                 putchar('\n');
 319         }
 320
 321         if (other_cmds->cnt) {
 322                 puts(_("git commands available from elsewhere on your $PATH"));
 323                 putchar('\n');
 324                 pretty_print_cmdnames(other_cmds, colopts);
 325                 putchar('\n');
 326         }
 327 }
 328
 329 void list_common_cmds_help(void)
 330 {
 331         puts(_("These are common Git commands used in various situations:"));
 332         putchar('\n');
 333         print_cmd_by_category(common_categories, NULL);
 334 }
 335
 336 void list_all_main_cmds(struct string_list *list)
 337 {
 338         struct cmdnames main_cmds, other_cmds;
 339         int i;
 340
 341         memset(&main_cmds, 0, sizeof(main_cmds));
 342         memset(&other_cmds, 0, sizeof(other_cmds));
 343         load_command_list("git-", &main_cmds, &other_cmds);
 344
 345         for (i = 0; i < main_cmds.cnt; i++)
 346                 string_list_append(list, main_cmds.names[i]->name);
 347
 348         clean_cmdnames(&main_cmds);
 349         clean_cmdnames(&other_cmds);
 350 }
 351
 352 void list_all_other_cmds(struct string_list *list)
 353 {
 354         struct cmdnames main_cmds, other_cmds;
 355         int i;
 356
 357         memset(&main_cmds, 0, sizeof(main_cmds));
 358         memset(&other_cmds, 0, sizeof(other_cmds));
 359         load_command_list("git-", &main_cmds, &other_cmds);
 360
 361         for (i = 0; i < other_cmds.cnt; i++)
 362                 string_list_append(list, other_cmds.names[i]->name);
 363
 364         clean_cmdnames(&main_cmds);
 365         clean_cmdnames(&other_cmds);
 366 }
 367
 368 void list_cmds_by_category(struct string_list *list,
 369                            const char *cat)
 370 {
 371         int i, n = ARRAY_SIZE(command_list);
 372         uint32_t cat_id = 0;
 373
 374         for (i = 0; category_names[i]; i++) {
 375                 if (!strcmp(cat, category_names[i])) {
 376                         cat_id = 1UL << i;
 377                         break;
 378                 }
 379         }
 380         if (!cat_id)
 381                 die(_("unsupported command listing type '%s'"), cat);
 382
 383         for (i = 0; i < n; i++) {
 384                 struct cmdname_help *cmd = command_list + i;
 385
 386                 if (!(cmd->category & cat_id))
 387                         continue;
 388                 string_list_append(list, drop_prefix(cmd->name, cmd->category));
 389         }
 390 }
 391
 392 void list_cmds_by_config(struct string_list *list)
 393 {
 394         const char *cmd_list;
 395
 396         if (git_config_get_string_tmp("completion.commands", &cmd_list))
 397                 return;
 398
 399         string_list_sort(list);
 400         string_list_remove_duplicates(list, 0);
 401
 402         while (*cmd_list) {
 403                 struct strbuf sb = STRBUF_INIT;
 404                 const char *p = strchrnul(cmd_list, ' ');
 405
 406                 strbuf_add(&sb, cmd_list, p - cmd_list);
 407                 if (sb.buf[0] == '-')
 408                         string_list_remove(list, sb.buf + 1, 0);
 409                 else
 410                         string_list_insert(list, sb.buf);
 411                 strbuf_release(&sb);
 412                 while (*p == ' ')
 413                         p++;
 414                 cmd_list = p;
 415         }
 416 }
 417
 418 void list_guides_help(void)
 419 {
 420         struct category_description catdesc[] = {
 421                 { CAT_guide, N_("The Git concept guides are:") },
 422                 { 0, NULL }
 423         };
 424         print_cmd_by_category(catdesc, NULL);
 425         putchar('\n');
 426 }
 427
 428 static int get_alias(const char *var, const char *value, void *data)
 429 {
 430         struct string_list *list = data;
 431
 432         if (skip_prefix(var, "alias.", &var))
 433                 string_list_append(list, var)->util = xstrdup(value);
 434
 435         return 0;
 436 }
 437
 438 static void list_all_cmds_help_external_commands(void)
 439 {
 440         struct string_list others = STRING_LIST_INIT_DUP;
 441         int i;
 442
 443         list_all_other_cmds(&others);
 444         if (others.nr)
 445                 printf("\n%s\n", _("External commands"));
 446         for (i = 0; i < others.nr; i++)
 447                 printf("   %s\n", others.items[i].string);
 448         string_list_clear(&others, 0);
 449 }
 450
 451 static void list_all_cmds_help_aliases(int longest)
 452 {
 453         struct string_list alias_list = STRING_LIST_INIT_DUP;
 454         struct cmdname_help *aliases;
 455         int i;
 456
 457         git_config(get_alias, &alias_list);
 458         string_list_sort(&alias_list);
 459
 460         for (i = 0; i < alias_list.nr; i++) {
 461                 size_t len = strlen(alias_list.items[i].string);
 462                 if (longest < len)
 463                         longest = len;
 464         }
 465
 466         if (alias_list.nr) {
 467                 printf("\n%s\n", _("Command aliases"));
 468                 ALLOC_ARRAY(aliases, alias_list.nr + 1);
 469                 for (i = 0; i < alias_list.nr; i++) {
 470                         aliases[i].name = alias_list.items[i].string;
 471                         aliases[i].help = alias_list.items[i].util;
 472                         aliases[i].category = 1;
 473                 }
 474                 aliases[alias_list.nr].name = NULL;
 475                 print_command_list(aliases, 1, longest);
 476                 free(aliases);
 477         }
 478         string_list_clear(&alias_list, 1);
 479 }
 480
 481 void list_all_cmds_help(int show_external_commands, int show_aliases)
 482 {
 483         int longest;
 484
 485         puts(_("See 'git help <command>' to read about a specific subcommand"));
 486         putchar('\n');
 487         print_cmd_by_category(main_categories, &longest);
 488
 489         if (show_external_commands)
 490                 list_all_cmds_help_external_commands();
 491         if (show_aliases)
 492                 list_all_cmds_help_aliases(longest);
 493 }
 494
 495 int is_in_cmdlist(struct cmdnames *c, const char *s)
 496 {
 497         int i;
 498         for (i = 0; i < c->cnt; i++)
 499                 if (!strcmp(s, c->names[i]->name))
 500                         return 1;
 501         return 0;
 502 }
 503
 504 static int autocorrect;
 505 static struct cmdnames aliases;
 506
 507 #define AUTOCORRECT_PROMPT (-3)
 508 #define AUTOCORRECT_NEVER (-2)
 509 #define AUTOCORRECT_IMMEDIATELY (-1)
 510
 511 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 512 {
 513         const char *p;
 514
 515         if (!strcmp(var, "help.autocorrect")) {
 516                 if (!value)
 517                         return config_error_nonbool(var);
 518                 if (!strcmp(value, "never")) {
 519                         autocorrect = AUTOCORRECT_NEVER;
 520                 } else if (!strcmp(value, "immediate")) {
 521                         autocorrect = AUTOCORRECT_IMMEDIATELY;
 522                 } else if (!strcmp(value, "prompt")) {
 523                         autocorrect = AUTOCORRECT_PROMPT;
 524                 } else {
 525                         int v = git_config_int(var, value);
 526                         autocorrect = (v < 0)
 527                                 ? AUTOCORRECT_IMMEDIATELY : v;
 528                 }
 529         }
 530         /* Also use aliases for command lookup */
 531         if (skip_prefix(var, "alias.", &p))
 532                 add_cmdname(&aliases, p, strlen(p));
 533
 534         return git_default_config(var, value, cb);
 535 }
 536
 537 static int levenshtein_compare(const void *p1, const void *p2)
 538 {
 539         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 540         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 541         int l1 = (*c1)->len;
 542         int l2 = (*c2)->len;
 543         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 544 }
 545
 546 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 547 {
 548         int i;
 549         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 550
 551         for (i = 0; i < old->cnt; i++)
 552                 cmds->names[cmds->cnt++] = old->names[i];
 553         FREE_AND_NULL(old->names);
 554         old->cnt = 0;
 555 }
 556
 557 /* An empirically derived magic number */
 558 #define SIMILARITY_FLOOR 7
 559 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 560
 561 static const char bad_interpreter_advice[] =
 562         N_("'%s' appears to be a git command, but we were not\n"
 563         "able to execute it. Maybe git-%s is broken?");
 564
 565 const char *help_unknown_cmd(const char *cmd)
 566 {
 567         int i, n, best_similarity = 0;
 568         struct cmdnames main_cmds, other_cmds;
 569         struct cmdname_help *common_cmds;
 570
 571         memset(&main_cmds, 0, sizeof(main_cmds));
 572         memset(&other_cmds, 0, sizeof(other_cmds));
 573         memset(&aliases, 0, sizeof(aliases));
 574
 575         read_early_config(git_unknown_cmd_config, NULL);
 576
 577         /*
 578          * Disable autocorrection prompt in a non-interactive session
 579          */
 580         if ((autocorrect == AUTOCORRECT_PROMPT) && (!isatty(0) || !isatty(2)))
 581                 autocorrect = AUTOCORRECT_NEVER;
 582
 583         if (autocorrect == AUTOCORRECT_NEVER) {
 584                 fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 585                 exit(1);
 586         }
 587
 588         load_command_list("git-", &main_cmds, &other_cmds);
 589
 590         add_cmd_list(&main_cmds, &aliases);
 591         add_cmd_list(&main_cmds, &other_cmds);
 592         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 593         uniq(&main_cmds);
 594
 595         extract_cmds(&common_cmds, common_mask);
 596
 597         /* This abuses cmdname->len for levenshtein distance */
 598         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 599                 int cmp = 0; /* avoid compiler stupidity */
 600                 const char *candidate = main_cmds.names[i]->name;
 601
 602                 /*
 603                  * An exact match means we have the command, but
 604                  * for some reason exec'ing it gave us ENOENT; probably
 605                  * it's a bad interpreter in the #! line.
 606                  */
 607                 if (!strcmp(candidate, cmd))
 608                         die(_(bad_interpreter_advice), cmd, cmd);
 609
 610                 /* Does the candidate appear in common_cmds list? */
 611                 while (common_cmds[n].name &&
 612                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 613                         n++;
 614                 if (common_cmds[n].name && !cmp) {
 615                         /* Yes, this is one of the common commands */
 616                         n++; /* use the entry from common_cmds[] */
 617                         if (starts_with(candidate, cmd)) {
 618                                 /* Give prefix match a very good score */
 619                                 main_cmds.names[i]->len = 0;
 620                                 continue;
 621                         }
 622                 }
 623
 624                 main_cmds.names[i]->len =
 625                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 626         }
 627         FREE_AND_NULL(common_cmds);
 628
 629         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 630
 631         if (!main_cmds.cnt)
 632                 die(_("Uh oh. Your system reports no Git commands at all."));
 633
 634         /* skip and count prefix matches */
 635         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 636                 ; /* still counting */
 637
 638         if (main_cmds.cnt <= n) {
 639                 /* prefix matches with everything? that is too ambiguous */
 640                 best_similarity = SIMILARITY_FLOOR + 1;
 641         } else {
 642                 /* count all the most similar ones */
 643                 for (best_similarity = main_cmds.names[n++]->len;
 644                      (n < main_cmds.cnt &&
 645                       best_similarity == main_cmds.names[n]->len);
 646                      n++)
 647                         ; /* still counting */
 648         }
 649         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 650                 const char *assumed = main_cmds.names[0]->name;
 651                 main_cmds.names[0] = NULL;
 652                 clean_cmdnames(&main_cmds);
 653                 fprintf_ln(stderr,
 654                            _("WARNING: You called a Git command named '%s', "
 655                              "which does not exist."),
 656                            cmd);
 657                 if (autocorrect == AUTOCORRECT_IMMEDIATELY)
 658                         fprintf_ln(stderr,
 659                                    _("Continuing under the assumption that "
 660                                      "you meant '%s'."),
 661                                    assumed);
 662                 else if (autocorrect == AUTOCORRECT_PROMPT) {
 663                         char *answer;
 664                         struct strbuf msg = STRBUF_INIT;
 665                         strbuf_addf(&msg, _("Run '%s' instead [y/N]? "), assumed);
 666                         answer = git_prompt(msg.buf, PROMPT_ECHO);
 667                         strbuf_release(&msg);
 668                         if (!(starts_with(answer, "y") ||
 669                               starts_with(answer, "Y")))
 670                                 exit(1);
 671                 } else {
 672                         fprintf_ln(stderr,
 673                                    _("Continuing in %0.1f seconds, "
 674                                      "assuming that you meant '%s'."),
 675                                    (float)autocorrect/10.0, assumed);
 676                         sleep_millisec(autocorrect * 100);
 677                 }
 678                 return assumed;
 679         }
 680
 681         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 682
 683         if (SIMILAR_ENOUGH(best_similarity)) {
 684                 fprintf_ln(stderr,
 685                            Q_("\nThe most similar command is",
 686                               "\nThe most similar commands are",
 687                            n));
 688
 689                 for (i = 0; i < n; i++)
 690                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 691         }
 692
 693         exit(1);
 694 }
 695
 696 void get_version_info(struct strbuf *buf, int show_build_options)
 697 {
 698         /*
 699          * The format of this string should be kept stable for compatibility
 700          * with external projects that rely on the output of "git version".
 701          *
 702          * Always show the version, even if other options are given.
 703          */
 704         strbuf_addf(buf, "git version %s\n", git_version_string);
 705
 706         if (show_build_options) {
 707                 strbuf_addf(buf, "cpu: %s\n", GIT_HOST_CPU);
 708                 if (git_built_from_commit_string[0])
 709                         strbuf_addf(buf, "built from commit: %s\n",
 710                                git_built_from_commit_string);
 711                 else
 712                         strbuf_addstr(buf, "no commit associated with this build\n");
 713                 strbuf_addf(buf, "sizeof-long: %d\n", (int)sizeof(long));
 714                 strbuf_addf(buf, "sizeof-size_t: %d\n", (int)sizeof(size_t));
 715                 strbuf_addf(buf, "shell-path: %s\n", SHELL_PATH);
 716                 /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 717         }
 718 }
 719
 720 int cmd_version(int argc, const char **argv, const char *prefix)
 721 {
 722         struct strbuf buf = STRBUF_INIT;
 723         int build_options = 0;
 724         const char * const usage[] = {
 725                 N_("git version [<options>]"),
 726                 NULL
 727         };
 728         struct option options[] = {
 729                 OPT_BOOL(0, "build-options", &build_options,
 730                          "also print build options"),
 731                 OPT_END()
 732         };
 733
 734         argc = parse_options(argc, argv, prefix, options, usage, 0);
 735
 736         get_version_info(&buf, build_options);
 737         printf("%s", buf.buf);
 738
 739         strbuf_release(&buf);
 740
 741         return 0;
 742 }
 743
 744 struct similar_ref_cb {
 745         const char *base_ref;
 746         struct string_list *similar_refs;
 747 };
 748
 749 static int append_similar_ref(const char *refname, const struct object_id *oid,
 750                               int flags, void *cb_data)
 751 {
 752         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 753         char *branch = strrchr(refname, '/') + 1;
 754
 755         /* A remote branch of the same name is deemed similar */
 756         if (starts_with(refname, "refs/remotes/") &&
 757             !strcmp(branch, cb->base_ref))
 758                 string_list_append_nodup(cb->similar_refs,
 759                                          shorten_unambiguous_ref(refname, 1));
 760         return 0;
 761 }
 762
 763 static struct string_list guess_refs(const char *ref)
 764 {
 765         struct similar_ref_cb ref_cb;
 766         struct string_list similar_refs = STRING_LIST_INIT_DUP;
 767
 768         ref_cb.base_ref = ref;
 769         ref_cb.similar_refs = &similar_refs;
 770         for_each_ref(append_similar_ref, &ref_cb);
 771         return similar_refs;
 772 }
 773
 774 NORETURN void help_unknown_ref(const char *ref, const char *cmd,
 775                                const char *error)
 776 {
 777         int i;
 778         struct string_list suggested_refs = guess_refs(ref);
 779
 780         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 781
 782         if (suggested_refs.nr > 0) {
 783                 fprintf_ln(stderr,
 784                            Q_("\nDid you mean this?",
 785                               "\nDid you mean one of these?",
 786                               suggested_refs.nr));
 787                 for (i = 0; i < suggested_refs.nr; i++)
 788                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 789         }
 790
 791         string_list_clear(&suggested_refs, 0);
 792         exit(1);
 793 }