Merge branch 'ab/fetch-tags-noclobber'
[git] / 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(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
496 void list_all_cmds_help(void)
497 {
498         print_cmd_by_category(main_categories);
499 }
500
501 int 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
510 static int autocorrect;
511 static struct cmdnames aliases;
512
513 static 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
526 static 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
535 static 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
550 static 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
554 const 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
665 int 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                 printf("sizeof-size_t: %d\n", (int)sizeof(size_t));
697                 /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
698         }
699         return 0;
700 }
701
702 struct similar_ref_cb {
703         const char *base_ref;
704         struct string_list *similar_refs;
705 };
706
707 static int append_similar_ref(const char *refname, const struct object_id *oid,
708                               int flags, void *cb_data)
709 {
710         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
711         char *branch = strrchr(refname, '/') + 1;
712         const char *remote;
713
714         /* A remote branch of the same name is deemed similar */
715         if (skip_prefix(refname, "refs/remotes/", &remote) &&
716             !strcmp(branch, cb->base_ref))
717                 string_list_append(cb->similar_refs, remote);
718         return 0;
719 }
720
721 static struct string_list guess_refs(const char *ref)
722 {
723         struct similar_ref_cb ref_cb;
724         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
725
726         ref_cb.base_ref = ref;
727         ref_cb.similar_refs = &similar_refs;
728         for_each_ref(append_similar_ref, &ref_cb);
729         return similar_refs;
730 }
731
732 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
733 {
734         int i;
735         struct string_list suggested_refs = guess_refs(ref);
736
737         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
738
739         if (suggested_refs.nr > 0) {
740                 fprintf_ln(stderr,
741                            Q_("\nDid you mean this?",
742                               "\nDid you mean one of these?",
743                               suggested_refs.nr));
744                 for (i = 0; i < suggested_refs.nr; i++)
745                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
746         }
747
748         string_list_clear(&suggested_refs, 0);
749         exit(1);
750 }