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