help.con commit Merge branch 'jc/clean-after-sanity-tests' (1840443)
   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
  15struct category_description {
  16        uint32_t category;
  17        const char *desc;
  18};
  19static uint32_t common_mask =
  20        CAT_init | CAT_worktree | CAT_info |
  21        CAT_history | CAT_remote;
  22static 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};
  30static 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
  42static 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
  54static 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
  79static 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
  93static 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
 101static 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
 129void 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
 139static 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
 149static 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
 156static 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
 173void 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
 196static 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
 216static 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
 254void 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
 288void 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
 307void 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
 313void 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
 329void 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
 345void 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
 369void 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
 402void 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
 412struct 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
 419void list_config_help(int for_human)
 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                const char *var = keys.items[i].string;
 465                const char *wildcard, *tag, *cut;
 466
 467                if (for_human) {
 468                        puts(var);
 469                        continue;
 470                }
 471
 472                wildcard = strchr(var, '*');
 473                tag = strchr(var, '<');
 474
 475                if (!wildcard && !tag) {
 476                        puts(var);
 477                        continue;
 478                }
 479
 480                if (wildcard && !tag)
 481                        cut = wildcard;
 482                else if (!wildcard && tag)
 483                        cut = tag;
 484                else
 485                        cut = wildcard < tag ? wildcard : tag;
 486
 487                /*
 488                 * We may produce duplicates, but that's up to
 489                 * git-completion.bash to handle
 490                 */
 491                printf("%.*s\n", (int)(cut - var), var);
 492        }
 493        string_list_clear(&keys, 0);
 494}
 495
 496void list_all_cmds_help(void)
 497{
 498        print_cmd_by_category(main_categories);
 499}
 500
 501int is_in_cmdlist(struct cmdnames *c, const char *s)
 502{
 503        int i;
 504        for (i = 0; i < c->cnt; i++)
 505                if (!strcmp(s, c->names[i]->name))
 506                        return 1;
 507        return 0;
 508}
 509
 510static int autocorrect;
 511static struct cmdnames aliases;
 512
 513static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 514{
 515        const char *p;
 516
 517        if (!strcmp(var, "help.autocorrect"))
 518                autocorrect = git_config_int(var,value);
 519        /* Also use aliases for command lookup */
 520        if (skip_prefix(var, "alias.", &p))
 521                add_cmdname(&aliases, p, strlen(p));
 522
 523        return git_default_config(var, value, cb);
 524}
 525
 526static int levenshtein_compare(const void *p1, const void *p2)
 527{
 528        const struct cmdname *const *c1 = p1, *const *c2 = p2;
 529        const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 530        int l1 = (*c1)->len;
 531        int l2 = (*c2)->len;
 532        return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 533}
 534
 535static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 536{
 537        int i;
 538        ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 539
 540        for (i = 0; i < old->cnt; i++)
 541                cmds->names[cmds->cnt++] = old->names[i];
 542        FREE_AND_NULL(old->names);
 543        old->cnt = 0;
 544}
 545
 546/* An empirically derived magic number */
 547#define SIMILARITY_FLOOR 7
 548#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 549
 550static const char bad_interpreter_advice[] =
 551        N_("'%s' appears to be a git command, but we were not\n"
 552        "able to execute it. Maybe git-%s is broken?");
 553
 554const char *help_unknown_cmd(const char *cmd)
 555{
 556        int i, n, best_similarity = 0;
 557        struct cmdnames main_cmds, other_cmds;
 558        struct cmdname_help *common_cmds;
 559
 560        memset(&main_cmds, 0, sizeof(main_cmds));
 561        memset(&other_cmds, 0, sizeof(other_cmds));
 562        memset(&aliases, 0, sizeof(aliases));
 563
 564        read_early_config(git_unknown_cmd_config, NULL);
 565
 566        load_command_list("git-", &main_cmds, &other_cmds);
 567
 568        add_cmd_list(&main_cmds, &aliases);
 569        add_cmd_list(&main_cmds, &other_cmds);
 570        QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 571        uniq(&main_cmds);
 572
 573        extract_cmds(&common_cmds, common_mask);
 574
 575        /* This abuses cmdname->len for levenshtein distance */
 576        for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 577                int cmp = 0; /* avoid compiler stupidity */
 578                const char *candidate = main_cmds.names[i]->name;
 579
 580                /*
 581                 * An exact match means we have the command, but
 582                 * for some reason exec'ing it gave us ENOENT; probably
 583                 * it's a bad interpreter in the #! line.
 584                 */
 585                if (!strcmp(candidate, cmd))
 586                        die(_(bad_interpreter_advice), cmd, cmd);
 587
 588                /* Does the candidate appear in common_cmds list? */
 589                while (common_cmds[n].name &&
 590                       (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 591                        n++;
 592                if (common_cmds[n].name && !cmp) {
 593                        /* Yes, this is one of the common commands */
 594                        n++; /* use the entry from common_cmds[] */
 595                        if (starts_with(candidate, cmd)) {
 596                                /* Give prefix match a very good score */
 597                                main_cmds.names[i]->len = 0;
 598                                continue;
 599                        }
 600                }
 601
 602                main_cmds.names[i]->len =
 603                        levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 604        }
 605        FREE_AND_NULL(common_cmds);
 606
 607        QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 608
 609        if (!main_cmds.cnt)
 610                die(_("Uh oh. Your system reports no Git commands at all."));
 611
 612        /* skip and count prefix matches */
 613        for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 614                ; /* still counting */
 615
 616        if (main_cmds.cnt <= n) {
 617                /* prefix matches with everything? that is too ambiguous */
 618                best_similarity = SIMILARITY_FLOOR + 1;
 619        } else {
 620                /* count all the most similar ones */
 621                for (best_similarity = main_cmds.names[n++]->len;
 622                     (n < main_cmds.cnt &&
 623                      best_similarity == main_cmds.names[n]->len);
 624                     n++)
 625                        ; /* still counting */
 626        }
 627        if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 628                const char *assumed = main_cmds.names[0]->name;
 629                main_cmds.names[0] = NULL;
 630                clean_cmdnames(&main_cmds);
 631                fprintf_ln(stderr,
 632                           _("WARNING: You called a Git command named '%s', "
 633                             "which does not exist."),
 634                           cmd);
 635                if (autocorrect < 0)
 636                        fprintf_ln(stderr,
 637                                   _("Continuing under the assumption that "
 638                                     "you meant '%s'."),
 639                                   assumed);
 640                else {
 641                        fprintf_ln(stderr,
 642                                   _("Continuing in %0.1f seconds, "
 643                                     "assuming that you meant '%s'."),
 644                                   (float)autocorrect/10.0, assumed);
 645                        sleep_millisec(autocorrect * 100);
 646                }
 647                return assumed;
 648        }
 649
 650        fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 651
 652        if (SIMILAR_ENOUGH(best_similarity)) {
 653                fprintf_ln(stderr,
 654                           Q_("\nThe most similar command is",
 655                              "\nThe most similar commands are",
 656                           n));
 657
 658                for (i = 0; i < n; i++)
 659                        fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 660        }
 661
 662        exit(1);
 663}
 664
 665int cmd_version(int argc, const char **argv, const char *prefix)
 666{
 667        int build_options = 0;
 668        const char * const usage[] = {
 669                N_("git version [<options>]"),
 670                NULL
 671        };
 672        struct option options[] = {
 673                OPT_BOOL(0, "build-options", &build_options,
 674                         "also print build options"),
 675                OPT_END()
 676        };
 677
 678        argc = parse_options(argc, argv, prefix, options, usage, 0);
 679
 680        /*
 681         * The format of this string should be kept stable for compatibility
 682         * with external projects that rely on the output of "git version".
 683         *
 684         * Always show the version, even if other options are given.
 685         */
 686        printf("git version %s\n", git_version_string);
 687
 688        if (build_options) {
 689                printf("cpu: %s\n", GIT_HOST_CPU);
 690                if (git_built_from_commit_string[0])
 691                        printf("built from commit: %s\n",
 692                               git_built_from_commit_string);
 693                else
 694                        printf("no commit associated with this build\n");
 695                printf("sizeof-long: %d\n", (int)sizeof(long));
 696                /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 697        }
 698        return 0;
 699}
 700
 701struct similar_ref_cb {
 702        const char *base_ref;
 703        struct string_list *similar_refs;
 704};
 705
 706static int append_similar_ref(const char *refname, const struct object_id *oid,
 707                              int flags, void *cb_data)
 708{
 709        struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 710        char *branch = strrchr(refname, '/') + 1;
 711        const char *remote;
 712
 713        /* A remote branch of the same name is deemed similar */
 714        if (skip_prefix(refname, "refs/remotes/", &remote) &&
 715            !strcmp(branch, cb->base_ref))
 716                string_list_append(cb->similar_refs, remote);
 717        return 0;
 718}
 719
 720static struct string_list guess_refs(const char *ref)
 721{
 722        struct similar_ref_cb ref_cb;
 723        struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 724
 725        ref_cb.base_ref = ref;
 726        ref_cb.similar_refs = &similar_refs;
 727        for_each_ref(append_similar_ref, &ref_cb);
 728        return similar_refs;
 729}
 730
 731void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 732{
 733        int i;
 734        struct string_list suggested_refs = guess_refs(ref);
 735
 736        fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 737
 738        if (suggested_refs.nr > 0) {
 739                fprintf_ln(stderr,
 740                           Q_("\nDid you mean this?",
 741                              "\nDid you mean one of these?",
 742                              suggested_refs.nr));
 743                for (i = 0; i < suggested_refs.nr; i++)
 744                        fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 745        }
 746
 747        string_list_clear(&suggested_refs, 0);
 748        exit(1);
 749}