git: support --list-cmds=list-<category>
[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
31 static const char *drop_prefix(const char *name)
32 {
33         const char *new_name;
34
35         if (skip_prefix(name, "git-", &new_name))
36                 return new_name;
37         return name;
38
39 }
40
41 static void extract_cmds(struct cmdname_help **p_cmds, uint32_t mask)
42 {
43         int i, nr = 0;
44         struct cmdname_help *cmds;
45
46         if (ARRAY_SIZE(command_list) == 0)
47                 BUG("empty command_list[] is a sign of broken generate-cmdlist.sh");
48
49         ALLOC_ARRAY(cmds, ARRAY_SIZE(command_list) + 1);
50
51         for (i = 0; i < ARRAY_SIZE(command_list); i++) {
52                 const struct cmdname_help *cmd = command_list + i;
53
54                 if (!(cmd->category & mask))
55                         continue;
56
57                 cmds[nr] = *cmd;
58                 cmds[nr].name = drop_prefix(cmd->name);
59
60                 nr++;
61         }
62         cmds[nr].name = NULL;
63         *p_cmds = cmds;
64 }
65
66 static void print_command_list(const struct cmdname_help *cmds,
67                                uint32_t mask, int longest)
68 {
69         int i;
70
71         for (i = 0; cmds[i].name; i++) {
72                 if (cmds[i].category & mask) {
73                         printf("   %s   ", cmds[i].name);
74                         mput_char(' ', longest - strlen(cmds[i].name));
75                         puts(_(cmds[i].help));
76                 }
77         }
78 }
79
80 static int cmd_name_cmp(const void *elem1, const void *elem2)
81 {
82         const struct cmdname_help *e1 = elem1;
83         const struct cmdname_help *e2 = elem2;
84
85         return strcmp(e1->name, e2->name);
86 }
87
88 static void print_cmd_by_category(const struct category_description *catdesc)
89 {
90         struct cmdname_help *cmds;
91         int longest = 0;
92         int i, nr = 0;
93         uint32_t mask = 0;
94
95         for (i = 0; catdesc[i].desc; i++)
96                 mask |= catdesc[i].category;
97
98         extract_cmds(&cmds, mask);
99
100         for (i = 0; cmds[i].name; i++, nr++) {
101                 if (longest < strlen(cmds[i].name))
102                         longest = strlen(cmds[i].name);
103         }
104         QSORT(cmds, nr, cmd_name_cmp);
105
106         for (i = 0; catdesc[i].desc; i++) {
107                 uint32_t mask = catdesc[i].category;
108                 const char *desc = catdesc[i].desc;
109
110                 printf("\n%s\n", _(desc));
111                 print_command_list(cmds, mask, longest);
112         }
113         free(cmds);
114 }
115
116 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
117 {
118         struct cmdname *ent;
119         FLEX_ALLOC_MEM(ent, name, name, len);
120         ent->len = len;
121
122         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
123         cmds->names[cmds->cnt++] = ent;
124 }
125
126 static void clean_cmdnames(struct cmdnames *cmds)
127 {
128         int i;
129         for (i = 0; i < cmds->cnt; ++i)
130                 free(cmds->names[i]);
131         free(cmds->names);
132         cmds->cnt = 0;
133         cmds->alloc = 0;
134 }
135
136 static int cmdname_compare(const void *a_, const void *b_)
137 {
138         struct cmdname *a = *(struct cmdname **)a_;
139         struct cmdname *b = *(struct cmdname **)b_;
140         return strcmp(a->name, b->name);
141 }
142
143 static void uniq(struct cmdnames *cmds)
144 {
145         int i, j;
146
147         if (!cmds->cnt)
148                 return;
149
150         for (i = j = 1; i < cmds->cnt; i++) {
151                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
152                         free(cmds->names[i]);
153                 else
154                         cmds->names[j++] = cmds->names[i];
155         }
156
157         cmds->cnt = j;
158 }
159
160 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
161 {
162         int ci, cj, ei;
163         int cmp;
164
165         ci = cj = ei = 0;
166         while (ci < cmds->cnt && ei < excludes->cnt) {
167                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
168                 if (cmp < 0)
169                         cmds->names[cj++] = cmds->names[ci++];
170                 else if (cmp == 0) {
171                         ei++;
172                         free(cmds->names[ci++]);
173                 } else if (cmp > 0)
174                         ei++;
175         }
176
177         while (ci < cmds->cnt)
178                 cmds->names[cj++] = cmds->names[ci++];
179
180         cmds->cnt = cj;
181 }
182
183 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
184 {
185         struct string_list list = STRING_LIST_INIT_NODUP;
186         struct column_options copts;
187         int i;
188
189         for (i = 0; i < cmds->cnt; i++)
190                 string_list_append(&list, cmds->names[i]->name);
191         /*
192          * always enable column display, we only consult column.*
193          * about layout strategy and stuff
194          */
195         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
196         memset(&copts, 0, sizeof(copts));
197         copts.indent = "  ";
198         copts.padding = 2;
199         print_columns(&list, colopts, &copts);
200         string_list_clear(&list, 0);
201 }
202
203 static void list_commands_in_dir(struct cmdnames *cmds,
204                                          const char *path,
205                                          const char *prefix)
206 {
207         DIR *dir = opendir(path);
208         struct dirent *de;
209         struct strbuf buf = STRBUF_INIT;
210         int len;
211
212         if (!dir)
213                 return;
214         if (!prefix)
215                 prefix = "git-";
216
217         strbuf_addf(&buf, "%s/", path);
218         len = buf.len;
219
220         while ((de = readdir(dir)) != NULL) {
221                 const char *ent;
222                 size_t entlen;
223
224                 if (!skip_prefix(de->d_name, prefix, &ent))
225                         continue;
226
227                 strbuf_setlen(&buf, len);
228                 strbuf_addstr(&buf, de->d_name);
229                 if (!is_executable(buf.buf))
230                         continue;
231
232                 entlen = strlen(ent);
233                 strip_suffix(ent, ".exe", &entlen);
234
235                 add_cmdname(cmds, ent, entlen);
236         }
237         closedir(dir);
238         strbuf_release(&buf);
239 }
240
241 void load_command_list(const char *prefix,
242                 struct cmdnames *main_cmds,
243                 struct cmdnames *other_cmds)
244 {
245         const char *env_path = getenv("PATH");
246         const char *exec_path = git_exec_path();
247
248         if (exec_path) {
249                 list_commands_in_dir(main_cmds, exec_path, prefix);
250                 QSORT(main_cmds->names, main_cmds->cnt, cmdname_compare);
251                 uniq(main_cmds);
252         }
253
254         if (env_path) {
255                 char *paths, *path, *colon;
256                 path = paths = xstrdup(env_path);
257                 while (1) {
258                         if ((colon = strchr(path, PATH_SEP)))
259                                 *colon = 0;
260                         if (!exec_path || strcmp(path, exec_path))
261                                 list_commands_in_dir(other_cmds, path, prefix);
262
263                         if (!colon)
264                                 break;
265                         path = colon + 1;
266                 }
267                 free(paths);
268
269                 QSORT(other_cmds->names, other_cmds->cnt, cmdname_compare);
270                 uniq(other_cmds);
271         }
272         exclude_cmds(other_cmds, main_cmds);
273 }
274
275 void list_commands(unsigned int colopts,
276                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
277 {
278         if (main_cmds->cnt) {
279                 const char *exec_path = git_exec_path();
280                 printf_ln(_("available git commands in '%s'"), exec_path);
281                 putchar('\n');
282                 pretty_print_cmdnames(main_cmds, colopts);
283                 putchar('\n');
284         }
285
286         if (other_cmds->cnt) {
287                 printf_ln(_("git commands available from elsewhere on your $PATH"));
288                 putchar('\n');
289                 pretty_print_cmdnames(other_cmds, colopts);
290                 putchar('\n');
291         }
292 }
293
294 void list_common_cmds_help(void)
295 {
296         puts(_("These are common Git commands used in various situations:"));
297         print_cmd_by_category(common_categories);
298 }
299
300 void list_all_main_cmds(struct string_list *list)
301 {
302         struct cmdnames main_cmds, other_cmds;
303         int i;
304
305         memset(&main_cmds, 0, sizeof(main_cmds));
306         memset(&other_cmds, 0, sizeof(other_cmds));
307         load_command_list("git-", &main_cmds, &other_cmds);
308
309         for (i = 0; i < main_cmds.cnt; i++)
310                 string_list_append(list, main_cmds.names[i]->name);
311
312         clean_cmdnames(&main_cmds);
313         clean_cmdnames(&other_cmds);
314 }
315
316 void list_all_other_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 < other_cmds.cnt; i++)
326                 string_list_append(list, other_cmds.names[i]->name);
327
328         clean_cmdnames(&main_cmds);
329         clean_cmdnames(&other_cmds);
330 }
331
332 void list_cmds_by_category(struct string_list *list,
333                            const char *cat)
334 {
335         int i, n = ARRAY_SIZE(command_list);
336         uint32_t cat_id = 0;
337
338         for (i = 0; category_names[i]; i++) {
339                 if (!strcmp(cat, category_names[i])) {
340                         cat_id = 1UL << i;
341                         break;
342                 }
343         }
344         if (!cat_id)
345                 die(_("unsupported command listing type '%s'"), cat);
346
347         for (i = 0; i < n; i++) {
348                 struct cmdname_help *cmd = command_list + i;
349
350                 if (cmd->category & cat_id)
351                         string_list_append(list, drop_prefix(cmd->name));
352         }
353 }
354
355 int is_in_cmdlist(struct cmdnames *c, const char *s)
356 {
357         int i;
358         for (i = 0; i < c->cnt; i++)
359                 if (!strcmp(s, c->names[i]->name))
360                         return 1;
361         return 0;
362 }
363
364 static int autocorrect;
365 static struct cmdnames aliases;
366
367 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
368 {
369         const char *p;
370
371         if (!strcmp(var, "help.autocorrect"))
372                 autocorrect = git_config_int(var,value);
373         /* Also use aliases for command lookup */
374         if (skip_prefix(var, "alias.", &p))
375                 add_cmdname(&aliases, p, strlen(p));
376
377         return git_default_config(var, value, cb);
378 }
379
380 static int levenshtein_compare(const void *p1, const void *p2)
381 {
382         const struct cmdname *const *c1 = p1, *const *c2 = p2;
383         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
384         int l1 = (*c1)->len;
385         int l2 = (*c2)->len;
386         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
387 }
388
389 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
390 {
391         int i;
392         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
393
394         for (i = 0; i < old->cnt; i++)
395                 cmds->names[cmds->cnt++] = old->names[i];
396         FREE_AND_NULL(old->names);
397         old->cnt = 0;
398 }
399
400 /* An empirically derived magic number */
401 #define SIMILARITY_FLOOR 7
402 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
403
404 static const char bad_interpreter_advice[] =
405         N_("'%s' appears to be a git command, but we were not\n"
406         "able to execute it. Maybe git-%s is broken?");
407
408 const char *help_unknown_cmd(const char *cmd)
409 {
410         int i, n, best_similarity = 0;
411         struct cmdnames main_cmds, other_cmds;
412         struct cmdname_help *common_cmds;
413
414         memset(&main_cmds, 0, sizeof(main_cmds));
415         memset(&other_cmds, 0, sizeof(other_cmds));
416         memset(&aliases, 0, sizeof(aliases));
417
418         read_early_config(git_unknown_cmd_config, NULL);
419
420         load_command_list("git-", &main_cmds, &other_cmds);
421
422         add_cmd_list(&main_cmds, &aliases);
423         add_cmd_list(&main_cmds, &other_cmds);
424         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
425         uniq(&main_cmds);
426
427         extract_cmds(&common_cmds, common_mask);
428
429         /* This abuses cmdname->len for levenshtein distance */
430         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
431                 int cmp = 0; /* avoid compiler stupidity */
432                 const char *candidate = main_cmds.names[i]->name;
433
434                 /*
435                  * An exact match means we have the command, but
436                  * for some reason exec'ing it gave us ENOENT; probably
437                  * it's a bad interpreter in the #! line.
438                  */
439                 if (!strcmp(candidate, cmd))
440                         die(_(bad_interpreter_advice), cmd, cmd);
441
442                 /* Does the candidate appear in common_cmds list? */
443                 while (common_cmds[n].name &&
444                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
445                         n++;
446                 if (common_cmds[n].name && !cmp) {
447                         /* Yes, this is one of the common commands */
448                         n++; /* use the entry from common_cmds[] */
449                         if (starts_with(candidate, cmd)) {
450                                 /* Give prefix match a very good score */
451                                 main_cmds.names[i]->len = 0;
452                                 continue;
453                         }
454                 }
455
456                 main_cmds.names[i]->len =
457                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
458         }
459         FREE_AND_NULL(common_cmds);
460
461         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
462
463         if (!main_cmds.cnt)
464                 die(_("Uh oh. Your system reports no Git commands at all."));
465
466         /* skip and count prefix matches */
467         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
468                 ; /* still counting */
469
470         if (main_cmds.cnt <= n) {
471                 /* prefix matches with everything? that is too ambiguous */
472                 best_similarity = SIMILARITY_FLOOR + 1;
473         } else {
474                 /* count all the most similar ones */
475                 for (best_similarity = main_cmds.names[n++]->len;
476                      (n < main_cmds.cnt &&
477                       best_similarity == main_cmds.names[n]->len);
478                      n++)
479                         ; /* still counting */
480         }
481         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
482                 const char *assumed = main_cmds.names[0]->name;
483                 main_cmds.names[0] = NULL;
484                 clean_cmdnames(&main_cmds);
485                 fprintf_ln(stderr,
486                            _("WARNING: You called a Git command named '%s', "
487                              "which does not exist."),
488                            cmd);
489                 if (autocorrect < 0)
490                         fprintf_ln(stderr,
491                                    _("Continuing under the assumption that "
492                                      "you meant '%s'."),
493                                    assumed);
494                 else {
495                         fprintf_ln(stderr,
496                                    _("Continuing in %0.1f seconds, "
497                                      "assuming that you meant '%s'."),
498                                    (float)autocorrect/10.0, assumed);
499                         sleep_millisec(autocorrect * 100);
500                 }
501                 return assumed;
502         }
503
504         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
505
506         if (SIMILAR_ENOUGH(best_similarity)) {
507                 fprintf_ln(stderr,
508                            Q_("\nThe most similar command is",
509                               "\nThe most similar commands are",
510                            n));
511
512                 for (i = 0; i < n; i++)
513                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
514         }
515
516         exit(1);
517 }
518
519 int cmd_version(int argc, const char **argv, const char *prefix)
520 {
521         int build_options = 0;
522         const char * const usage[] = {
523                 N_("git version [<options>]"),
524                 NULL
525         };
526         struct option options[] = {
527                 OPT_BOOL(0, "build-options", &build_options,
528                          "also print build options"),
529                 OPT_END()
530         };
531
532         argc = parse_options(argc, argv, prefix, options, usage, 0);
533
534         /*
535          * The format of this string should be kept stable for compatibility
536          * with external projects that rely on the output of "git version".
537          *
538          * Always show the version, even if other options are given.
539          */
540         printf("git version %s\n", git_version_string);
541
542         if (build_options) {
543                 printf("cpu: %s\n", GIT_HOST_CPU);
544                 if (git_built_from_commit_string[0])
545                         printf("built from commit: %s\n",
546                                git_built_from_commit_string);
547                 else
548                         printf("no commit associated with this build\n");
549                 printf("sizeof-long: %d\n", (int)sizeof(long));
550                 /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
551         }
552         return 0;
553 }
554
555 struct similar_ref_cb {
556         const char *base_ref;
557         struct string_list *similar_refs;
558 };
559
560 static int append_similar_ref(const char *refname, const struct object_id *oid,
561                               int flags, void *cb_data)
562 {
563         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
564         char *branch = strrchr(refname, '/') + 1;
565         const char *remote;
566
567         /* A remote branch of the same name is deemed similar */
568         if (skip_prefix(refname, "refs/remotes/", &remote) &&
569             !strcmp(branch, cb->base_ref))
570                 string_list_append(cb->similar_refs, remote);
571         return 0;
572 }
573
574 static struct string_list guess_refs(const char *ref)
575 {
576         struct similar_ref_cb ref_cb;
577         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
578
579         ref_cb.base_ref = ref;
580         ref_cb.similar_refs = &similar_refs;
581         for_each_ref(append_similar_ref, &ref_cb);
582         return similar_refs;
583 }
584
585 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
586 {
587         int i;
588         struct string_list suggested_refs = guess_refs(ref);
589
590         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
591
592         if (suggested_refs.nr > 0) {
593                 fprintf_ln(stderr,
594                            Q_("\nDid you mean this?",
595                               "\nDid you mean one of these?",
596                               suggested_refs.nr));
597                 for (i = 0; i < suggested_refs.nr; i++)
598                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
599         }
600
601         string_list_clear(&suggested_refs, 0);
602         exit(1);
603 }