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