Merge branch 'ab/conditional-config-with-symlinks'
[git] / help.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "exec_cmd.h"
4 #include "run-command.h"
5 #include "levenshtein.h"
6 #include "help.h"
7 #include "common-cmds.h"
8 #include "string-list.h"
9 #include "column.h"
10 #include "version.h"
11 #include "refs.h"
12
13 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
14 {
15         struct cmdname *ent;
16         FLEX_ALLOC_MEM(ent, name, name, len);
17         ent->len = len;
18
19         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
20         cmds->names[cmds->cnt++] = ent;
21 }
22
23 static void clean_cmdnames(struct cmdnames *cmds)
24 {
25         int i;
26         for (i = 0; i < cmds->cnt; ++i)
27                 free(cmds->names[i]);
28         free(cmds->names);
29         cmds->cnt = 0;
30         cmds->alloc = 0;
31 }
32
33 static int cmdname_compare(const void *a_, const void *b_)
34 {
35         struct cmdname *a = *(struct cmdname **)a_;
36         struct cmdname *b = *(struct cmdname **)b_;
37         return strcmp(a->name, b->name);
38 }
39
40 static void uniq(struct cmdnames *cmds)
41 {
42         int i, j;
43
44         if (!cmds->cnt)
45                 return;
46
47         for (i = j = 1; i < cmds->cnt; i++) {
48                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
49                         free(cmds->names[i]);
50                 else
51                         cmds->names[j++] = cmds->names[i];
52         }
53
54         cmds->cnt = j;
55 }
56
57 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
58 {
59         int ci, cj, ei;
60         int cmp;
61
62         ci = cj = ei = 0;
63         while (ci < cmds->cnt && ei < excludes->cnt) {
64                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
65                 if (cmp < 0)
66                         cmds->names[cj++] = cmds->names[ci++];
67                 else if (cmp == 0) {
68                         ei++;
69                         free(cmds->names[ci++]);
70                 } else if (cmp > 0)
71                         ei++;
72         }
73
74         while (ci < cmds->cnt)
75                 cmds->names[cj++] = cmds->names[ci++];
76
77         cmds->cnt = cj;
78 }
79
80 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
81 {
82         struct string_list list = STRING_LIST_INIT_NODUP;
83         struct column_options copts;
84         int i;
85
86         for (i = 0; i < cmds->cnt; i++)
87                 string_list_append(&list, cmds->names[i]->name);
88         /*
89          * always enable column display, we only consult column.*
90          * about layout strategy and stuff
91          */
92         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
93         memset(&copts, 0, sizeof(copts));
94         copts.indent = "  ";
95         copts.padding = 2;
96         print_columns(&list, colopts, &copts);
97         string_list_clear(&list, 0);
98 }
99
100 static void list_commands_in_dir(struct cmdnames *cmds,
101                                          const char *path,
102                                          const char *prefix)
103 {
104         DIR *dir = opendir(path);
105         struct dirent *de;
106         struct strbuf buf = STRBUF_INIT;
107         int len;
108
109         if (!dir)
110                 return;
111         if (!prefix)
112                 prefix = "git-";
113
114         strbuf_addf(&buf, "%s/", path);
115         len = buf.len;
116
117         while ((de = readdir(dir)) != NULL) {
118                 const char *ent;
119                 size_t entlen;
120
121                 if (!skip_prefix(de->d_name, prefix, &ent))
122                         continue;
123
124                 strbuf_setlen(&buf, len);
125                 strbuf_addstr(&buf, de->d_name);
126                 if (!is_executable(buf.buf))
127                         continue;
128
129                 entlen = strlen(ent);
130                 strip_suffix(ent, ".exe", &entlen);
131
132                 add_cmdname(cmds, ent, entlen);
133         }
134         closedir(dir);
135         strbuf_release(&buf);
136 }
137
138 void load_command_list(const char *prefix,
139                 struct cmdnames *main_cmds,
140                 struct cmdnames *other_cmds)
141 {
142         const char *env_path = getenv("PATH");
143         const char *exec_path = git_exec_path();
144
145         if (exec_path) {
146                 list_commands_in_dir(main_cmds, exec_path, prefix);
147                 QSORT(main_cmds->names, main_cmds->cnt, cmdname_compare);
148                 uniq(main_cmds);
149         }
150
151         if (env_path) {
152                 char *paths, *path, *colon;
153                 path = paths = xstrdup(env_path);
154                 while (1) {
155                         if ((colon = strchr(path, PATH_SEP)))
156                                 *colon = 0;
157                         if (!exec_path || strcmp(path, exec_path))
158                                 list_commands_in_dir(other_cmds, path, prefix);
159
160                         if (!colon)
161                                 break;
162                         path = colon + 1;
163                 }
164                 free(paths);
165
166                 QSORT(other_cmds->names, other_cmds->cnt, cmdname_compare);
167                 uniq(other_cmds);
168         }
169         exclude_cmds(other_cmds, main_cmds);
170 }
171
172 void list_commands(unsigned int colopts,
173                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
174 {
175         if (main_cmds->cnt) {
176                 const char *exec_path = git_exec_path();
177                 printf_ln(_("available git commands in '%s'"), exec_path);
178                 putchar('\n');
179                 pretty_print_cmdnames(main_cmds, colopts);
180                 putchar('\n');
181         }
182
183         if (other_cmds->cnt) {
184                 printf_ln(_("git commands available from elsewhere on your $PATH"));
185                 putchar('\n');
186                 pretty_print_cmdnames(other_cmds, colopts);
187                 putchar('\n');
188         }
189 }
190
191 static int cmd_group_cmp(const void *elem1, const void *elem2)
192 {
193         const struct cmdname_help *e1 = elem1;
194         const struct cmdname_help *e2 = elem2;
195
196         if (e1->group < e2->group)
197                 return -1;
198         if (e1->group > e2->group)
199                 return 1;
200         return strcmp(e1->name, e2->name);
201 }
202
203 void list_common_cmds_help(void)
204 {
205         int i, longest = 0;
206         int current_grp = -1;
207
208         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
209                 if (longest < strlen(common_cmds[i].name))
210                         longest = strlen(common_cmds[i].name);
211         }
212
213         QSORT(common_cmds, ARRAY_SIZE(common_cmds), cmd_group_cmp);
214
215         puts(_("These are common Git commands used in various situations:"));
216
217         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
218                 if (common_cmds[i].group != current_grp) {
219                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
220                         current_grp = common_cmds[i].group;
221                 }
222
223                 printf("   %s   ", common_cmds[i].name);
224                 mput_char(' ', longest - strlen(common_cmds[i].name));
225                 puts(_(common_cmds[i].help));
226         }
227 }
228
229 int is_in_cmdlist(struct cmdnames *c, const char *s)
230 {
231         int i;
232         for (i = 0; i < c->cnt; i++)
233                 if (!strcmp(s, c->names[i]->name))
234                         return 1;
235         return 0;
236 }
237
238 static int autocorrect;
239 static struct cmdnames aliases;
240
241 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
242 {
243         const char *p;
244
245         if (!strcmp(var, "help.autocorrect"))
246                 autocorrect = git_config_int(var,value);
247         /* Also use aliases for command lookup */
248         if (skip_prefix(var, "alias.", &p))
249                 add_cmdname(&aliases, p, strlen(p));
250
251         return git_default_config(var, value, cb);
252 }
253
254 static int levenshtein_compare(const void *p1, const void *p2)
255 {
256         const struct cmdname *const *c1 = p1, *const *c2 = p2;
257         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
258         int l1 = (*c1)->len;
259         int l2 = (*c2)->len;
260         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
261 }
262
263 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
264 {
265         int i;
266         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
267
268         for (i = 0; i < old->cnt; i++)
269                 cmds->names[cmds->cnt++] = old->names[i];
270         free(old->names);
271         old->cnt = 0;
272         old->names = NULL;
273 }
274
275 /* An empirically derived magic number */
276 #define SIMILARITY_FLOOR 7
277 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
278
279 static const char bad_interpreter_advice[] =
280         N_("'%s' appears to be a git command, but we were not\n"
281         "able to execute it. Maybe git-%s is broken?");
282
283 const char *help_unknown_cmd(const char *cmd)
284 {
285         int i, n, best_similarity = 0;
286         struct cmdnames main_cmds, other_cmds;
287
288         memset(&main_cmds, 0, sizeof(main_cmds));
289         memset(&other_cmds, 0, sizeof(other_cmds));
290         memset(&aliases, 0, sizeof(aliases));
291
292         git_config(git_unknown_cmd_config, NULL);
293
294         load_command_list("git-", &main_cmds, &other_cmds);
295
296         add_cmd_list(&main_cmds, &aliases);
297         add_cmd_list(&main_cmds, &other_cmds);
298         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
299         uniq(&main_cmds);
300
301         /* This abuses cmdname->len for levenshtein distance */
302         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
303                 int cmp = 0; /* avoid compiler stupidity */
304                 const char *candidate = main_cmds.names[i]->name;
305
306                 /*
307                  * An exact match means we have the command, but
308                  * for some reason exec'ing it gave us ENOENT; probably
309                  * it's a bad interpreter in the #! line.
310                  */
311                 if (!strcmp(candidate, cmd))
312                         die(_(bad_interpreter_advice), cmd, cmd);
313
314                 /* Does the candidate appear in common_cmds list? */
315                 while (n < ARRAY_SIZE(common_cmds) &&
316                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
317                         n++;
318                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
319                         /* Yes, this is one of the common commands */
320                         n++; /* use the entry from common_cmds[] */
321                         if (starts_with(candidate, cmd)) {
322                                 /* Give prefix match a very good score */
323                                 main_cmds.names[i]->len = 0;
324                                 continue;
325                         }
326                 }
327
328                 main_cmds.names[i]->len =
329                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
330         }
331
332         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
333
334         if (!main_cmds.cnt)
335                 die(_("Uh oh. Your system reports no Git commands at all."));
336
337         /* skip and count prefix matches */
338         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
339                 ; /* still counting */
340
341         if (main_cmds.cnt <= n) {
342                 /* prefix matches with everything? that is too ambiguous */
343                 best_similarity = SIMILARITY_FLOOR + 1;
344         } else {
345                 /* count all the most similar ones */
346                 for (best_similarity = main_cmds.names[n++]->len;
347                      (n < main_cmds.cnt &&
348                       best_similarity == main_cmds.names[n]->len);
349                      n++)
350                         ; /* still counting */
351         }
352         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
353                 const char *assumed = main_cmds.names[0]->name;
354                 main_cmds.names[0] = NULL;
355                 clean_cmdnames(&main_cmds);
356                 fprintf_ln(stderr,
357                            _("WARNING: You called a Git command named '%s', "
358                              "which does not exist.\n"
359                              "Continuing under the assumption that you meant '%s'"),
360                         cmd, assumed);
361                 if (autocorrect > 0) {
362                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
363                                 (float)autocorrect/10.0);
364                         sleep_millisec(autocorrect * 100);
365                 }
366                 return assumed;
367         }
368
369         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
370
371         if (SIMILAR_ENOUGH(best_similarity)) {
372                 fprintf_ln(stderr,
373                            Q_("\nThe most similar command is",
374                               "\nThe most similar commands are",
375                            n));
376
377                 for (i = 0; i < n; i++)
378                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
379         }
380
381         exit(1);
382 }
383
384 int cmd_version(int argc, const char **argv, const char *prefix)
385 {
386         /*
387          * The format of this string should be kept stable for compatibility
388          * with external projects that rely on the output of "git version".
389          */
390         printf("git version %s\n", git_version_string);
391         while (*++argv) {
392                 if (!strcmp(*argv, "--build-options")) {
393                         printf("sizeof-long: %d\n", (int)sizeof(long));
394                         /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
395                 }
396         }
397         return 0;
398 }
399
400 struct similar_ref_cb {
401         const char *base_ref;
402         struct string_list *similar_refs;
403 };
404
405 static int append_similar_ref(const char *refname, const struct object_id *oid,
406                               int flags, void *cb_data)
407 {
408         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
409         char *branch = strrchr(refname, '/') + 1;
410         const char *remote;
411
412         /* A remote branch of the same name is deemed similar */
413         if (skip_prefix(refname, "refs/remotes/", &remote) &&
414             !strcmp(branch, cb->base_ref))
415                 string_list_append(cb->similar_refs, remote);
416         return 0;
417 }
418
419 static struct string_list guess_refs(const char *ref)
420 {
421         struct similar_ref_cb ref_cb;
422         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
423
424         ref_cb.base_ref = ref;
425         ref_cb.similar_refs = &similar_refs;
426         for_each_ref(append_similar_ref, &ref_cb);
427         return similar_refs;
428 }
429
430 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
431 {
432         int i;
433         struct string_list suggested_refs = guess_refs(ref);
434
435         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
436
437         if (suggested_refs.nr > 0) {
438                 fprintf_ln(stderr,
439                            Q_("\nDid you mean this?",
440                               "\nDid you mean one of these?",
441                               suggested_refs.nr));
442                 for (i = 0; i < suggested_refs.nr; i++)
443                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
444         }
445
446         string_list_clear(&suggested_refs, 0);
447         exit(1);
448 }