Merge branch 'sg/completion-commit-cleanup'
[git] / help.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "exec_cmd.h"
4 #include "levenshtein.h"
5 #include "help.h"
6 #include "common-cmds.h"
7 #include "string-list.h"
8 #include "column.h"
9 #include "version.h"
10 #include "refs.h"
11
12 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
13 {
14         struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
15
16         ent->len = len;
17         memcpy(ent->name, name, len);
18         ent->name[len] = 0;
19
20         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
21         cmds->names[cmds->cnt++] = ent;
22 }
23
24 static void clean_cmdnames(struct cmdnames *cmds)
25 {
26         int i;
27         for (i = 0; i < cmds->cnt; ++i)
28                 free(cmds->names[i]);
29         free(cmds->names);
30         cmds->cnt = 0;
31         cmds->alloc = 0;
32 }
33
34 static int cmdname_compare(const void *a_, const void *b_)
35 {
36         struct cmdname *a = *(struct cmdname **)a_;
37         struct cmdname *b = *(struct cmdname **)b_;
38         return strcmp(a->name, b->name);
39 }
40
41 static void uniq(struct cmdnames *cmds)
42 {
43         int i, j;
44
45         if (!cmds->cnt)
46                 return;
47
48         for (i = j = 1; i < cmds->cnt; i++) {
49                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
50                         free(cmds->names[i]);
51                 else
52                         cmds->names[j++] = cmds->names[i];
53         }
54
55         cmds->cnt = j;
56 }
57
58 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
59 {
60         int ci, cj, ei;
61         int cmp;
62
63         ci = cj = ei = 0;
64         while (ci < cmds->cnt && ei < excludes->cnt) {
65                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
66                 if (cmp < 0)
67                         cmds->names[cj++] = cmds->names[ci++];
68                 else if (cmp == 0) {
69                         ei++;
70                         free(cmds->names[ci++]);
71                 } else if (cmp > 0)
72                         ei++;
73         }
74
75         while (ci < cmds->cnt)
76                 cmds->names[cj++] = cmds->names[ci++];
77
78         cmds->cnt = cj;
79 }
80
81 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
82 {
83         struct string_list list = STRING_LIST_INIT_NODUP;
84         struct column_options copts;
85         int i;
86
87         for (i = 0; i < cmds->cnt; i++)
88                 string_list_append(&list, cmds->names[i]->name);
89         /*
90          * always enable column display, we only consult column.*
91          * about layout strategy and stuff
92          */
93         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
94         memset(&copts, 0, sizeof(copts));
95         copts.indent = "  ";
96         copts.padding = 2;
97         print_columns(&list, colopts, &copts);
98         string_list_clear(&list, 0);
99 }
100
101 static int is_executable(const char *name)
102 {
103         struct stat st;
104
105         if (stat(name, &st) || /* stat, not lstat */
106             !S_ISREG(st.st_mode))
107                 return 0;
108
109 #if defined(GIT_WINDOWS_NATIVE)
110 {       /* cannot trust the executable bit, peek into the file instead */
111         char buf[3] = { 0 };
112         int n;
113         int fd = open(name, O_RDONLY);
114         st.st_mode &= ~S_IXUSR;
115         if (fd >= 0) {
116                 n = read(fd, buf, 2);
117                 if (n == 2)
118                         /* DOS executables start with "MZ" */
119                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
120                                 st.st_mode |= S_IXUSR;
121                 close(fd);
122         }
123 }
124 #endif
125         return st.st_mode & S_IXUSR;
126 }
127
128 static void list_commands_in_dir(struct cmdnames *cmds,
129                                          const char *path,
130                                          const char *prefix)
131 {
132         DIR *dir = opendir(path);
133         struct dirent *de;
134         struct strbuf buf = STRBUF_INIT;
135         int len;
136
137         if (!dir)
138                 return;
139         if (!prefix)
140                 prefix = "git-";
141
142         strbuf_addf(&buf, "%s/", path);
143         len = buf.len;
144
145         while ((de = readdir(dir)) != NULL) {
146                 const char *ent;
147                 size_t entlen;
148
149                 if (!skip_prefix(de->d_name, prefix, &ent))
150                         continue;
151
152                 strbuf_setlen(&buf, len);
153                 strbuf_addstr(&buf, de->d_name);
154                 if (!is_executable(buf.buf))
155                         continue;
156
157                 entlen = strlen(ent);
158                 strip_suffix(ent, ".exe", &entlen);
159
160                 add_cmdname(cmds, ent, entlen);
161         }
162         closedir(dir);
163         strbuf_release(&buf);
164 }
165
166 void load_command_list(const char *prefix,
167                 struct cmdnames *main_cmds,
168                 struct cmdnames *other_cmds)
169 {
170         const char *env_path = getenv("PATH");
171         const char *exec_path = git_exec_path();
172
173         if (exec_path) {
174                 list_commands_in_dir(main_cmds, exec_path, prefix);
175                 qsort(main_cmds->names, main_cmds->cnt,
176                       sizeof(*main_cmds->names), cmdname_compare);
177                 uniq(main_cmds);
178         }
179
180         if (env_path) {
181                 char *paths, *path, *colon;
182                 path = paths = xstrdup(env_path);
183                 while (1) {
184                         if ((colon = strchr(path, PATH_SEP)))
185                                 *colon = 0;
186                         if (!exec_path || strcmp(path, exec_path))
187                                 list_commands_in_dir(other_cmds, path, prefix);
188
189                         if (!colon)
190                                 break;
191                         path = colon + 1;
192                 }
193                 free(paths);
194
195                 qsort(other_cmds->names, other_cmds->cnt,
196                       sizeof(*other_cmds->names), cmdname_compare);
197                 uniq(other_cmds);
198         }
199         exclude_cmds(other_cmds, main_cmds);
200 }
201
202 void list_commands(unsigned int colopts,
203                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
204 {
205         if (main_cmds->cnt) {
206                 const char *exec_path = git_exec_path();
207                 printf_ln(_("available git commands in '%s'"), exec_path);
208                 putchar('\n');
209                 pretty_print_cmdnames(main_cmds, colopts);
210                 putchar('\n');
211         }
212
213         if (other_cmds->cnt) {
214                 printf_ln(_("git commands available from elsewhere on your $PATH"));
215                 putchar('\n');
216                 pretty_print_cmdnames(other_cmds, colopts);
217                 putchar('\n');
218         }
219 }
220
221 static int cmd_group_cmp(const void *elem1, const void *elem2)
222 {
223         const struct cmdname_help *e1 = elem1;
224         const struct cmdname_help *e2 = elem2;
225
226         if (e1->group < e2->group)
227                 return -1;
228         if (e1->group > e2->group)
229                 return 1;
230         return strcmp(e1->name, e2->name);
231 }
232
233 void list_common_cmds_help(void)
234 {
235         int i, longest = 0;
236         int current_grp = -1;
237
238         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
239                 if (longest < strlen(common_cmds[i].name))
240                         longest = strlen(common_cmds[i].name);
241         }
242
243         qsort(common_cmds, ARRAY_SIZE(common_cmds),
244                 sizeof(common_cmds[0]), cmd_group_cmp);
245
246         puts(_("These are common Git commands used in various situations:"));
247
248         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
249                 if (common_cmds[i].group != current_grp) {
250                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
251                         current_grp = common_cmds[i].group;
252                 }
253
254                 printf("   %s   ", common_cmds[i].name);
255                 mput_char(' ', longest - strlen(common_cmds[i].name));
256                 puts(_(common_cmds[i].help));
257         }
258 }
259
260 int is_in_cmdlist(struct cmdnames *c, const char *s)
261 {
262         int i;
263         for (i = 0; i < c->cnt; i++)
264                 if (!strcmp(s, c->names[i]->name))
265                         return 1;
266         return 0;
267 }
268
269 static int autocorrect;
270 static struct cmdnames aliases;
271
272 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
273 {
274         const char *p;
275
276         if (!strcmp(var, "help.autocorrect"))
277                 autocorrect = git_config_int(var,value);
278         /* Also use aliases for command lookup */
279         if (skip_prefix(var, "alias.", &p))
280                 add_cmdname(&aliases, p, strlen(p));
281
282         return git_default_config(var, value, cb);
283 }
284
285 static int levenshtein_compare(const void *p1, const void *p2)
286 {
287         const struct cmdname *const *c1 = p1, *const *c2 = p2;
288         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
289         int l1 = (*c1)->len;
290         int l2 = (*c2)->len;
291         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
292 }
293
294 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
295 {
296         int i;
297         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
298
299         for (i = 0; i < old->cnt; i++)
300                 cmds->names[cmds->cnt++] = old->names[i];
301         free(old->names);
302         old->cnt = 0;
303         old->names = NULL;
304 }
305
306 /* An empirically derived magic number */
307 #define SIMILARITY_FLOOR 7
308 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
309
310 static const char bad_interpreter_advice[] =
311         N_("'%s' appears to be a git command, but we were not\n"
312         "able to execute it. Maybe git-%s is broken?");
313
314 const char *help_unknown_cmd(const char *cmd)
315 {
316         int i, n, best_similarity = 0;
317         struct cmdnames main_cmds, other_cmds;
318
319         memset(&main_cmds, 0, sizeof(main_cmds));
320         memset(&other_cmds, 0, sizeof(other_cmds));
321         memset(&aliases, 0, sizeof(aliases));
322
323         git_config(git_unknown_cmd_config, NULL);
324
325         load_command_list("git-", &main_cmds, &other_cmds);
326
327         add_cmd_list(&main_cmds, &aliases);
328         add_cmd_list(&main_cmds, &other_cmds);
329         qsort(main_cmds.names, main_cmds.cnt,
330               sizeof(*main_cmds.names), cmdname_compare);
331         uniq(&main_cmds);
332
333         /* This abuses cmdname->len for levenshtein distance */
334         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
335                 int cmp = 0; /* avoid compiler stupidity */
336                 const char *candidate = main_cmds.names[i]->name;
337
338                 /*
339                  * An exact match means we have the command, but
340                  * for some reason exec'ing it gave us ENOENT; probably
341                  * it's a bad interpreter in the #! line.
342                  */
343                 if (!strcmp(candidate, cmd))
344                         die(_(bad_interpreter_advice), cmd, cmd);
345
346                 /* Does the candidate appear in common_cmds list? */
347                 while (n < ARRAY_SIZE(common_cmds) &&
348                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
349                         n++;
350                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
351                         /* Yes, this is one of the common commands */
352                         n++; /* use the entry from common_cmds[] */
353                         if (starts_with(candidate, cmd)) {
354                                 /* Give prefix match a very good score */
355                                 main_cmds.names[i]->len = 0;
356                                 continue;
357                         }
358                 }
359
360                 main_cmds.names[i]->len =
361                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
362         }
363
364         qsort(main_cmds.names, main_cmds.cnt,
365               sizeof(*main_cmds.names), levenshtein_compare);
366
367         if (!main_cmds.cnt)
368                 die(_("Uh oh. Your system reports no Git commands at all."));
369
370         /* skip and count prefix matches */
371         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
372                 ; /* still counting */
373
374         if (main_cmds.cnt <= n) {
375                 /* prefix matches with everything? that is too ambiguous */
376                 best_similarity = SIMILARITY_FLOOR + 1;
377         } else {
378                 /* count all the most similar ones */
379                 for (best_similarity = main_cmds.names[n++]->len;
380                      (n < main_cmds.cnt &&
381                       best_similarity == main_cmds.names[n]->len);
382                      n++)
383                         ; /* still counting */
384         }
385         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
386                 const char *assumed = main_cmds.names[0]->name;
387                 main_cmds.names[0] = NULL;
388                 clean_cmdnames(&main_cmds);
389                 fprintf_ln(stderr,
390                            _("WARNING: You called a Git command named '%s', "
391                              "which does not exist.\n"
392                              "Continuing under the assumption that you meant '%s'"),
393                         cmd, assumed);
394                 if (autocorrect > 0) {
395                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
396                                 (float)autocorrect/10.0);
397                         sleep_millisec(autocorrect * 100);
398                 }
399                 return assumed;
400         }
401
402         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
403
404         if (SIMILAR_ENOUGH(best_similarity)) {
405                 fprintf_ln(stderr,
406                            Q_("\nDid you mean this?",
407                               "\nDid you mean one of these?",
408                            n));
409
410                 for (i = 0; i < n; i++)
411                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
412         }
413
414         exit(1);
415 }
416
417 int cmd_version(int argc, const char **argv, const char *prefix)
418 {
419         /*
420          * The format of this string should be kept stable for compatibility
421          * with external projects that rely on the output of "git version".
422          */
423         printf("git version %s\n", git_version_string);
424         return 0;
425 }
426
427 struct similar_ref_cb {
428         const char *base_ref;
429         struct string_list *similar_refs;
430 };
431
432 static int append_similar_ref(const char *refname, const struct object_id *oid,
433                               int flags, void *cb_data)
434 {
435         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
436         char *branch = strrchr(refname, '/') + 1;
437         const char *remote;
438
439         /* A remote branch of the same name is deemed similar */
440         if (skip_prefix(refname, "refs/remotes/", &remote) &&
441             !strcmp(branch, cb->base_ref))
442                 string_list_append(cb->similar_refs, remote);
443         return 0;
444 }
445
446 static struct string_list guess_refs(const char *ref)
447 {
448         struct similar_ref_cb ref_cb;
449         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
450
451         ref_cb.base_ref = ref;
452         ref_cb.similar_refs = &similar_refs;
453         for_each_ref(append_similar_ref, &ref_cb);
454         return similar_refs;
455 }
456
457 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
458 {
459         int i;
460         struct string_list suggested_refs = guess_refs(ref);
461
462         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
463
464         if (suggested_refs.nr > 0) {
465                 fprintf_ln(stderr,
466                            Q_("\nDid you mean this?",
467                               "\nDid you mean one of these?",
468                               suggested_refs.nr));
469                 for (i = 0; i < suggested_refs.nr; i++)
470                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
471         }
472
473         string_list_clear(&suggested_refs, 0);
474         exit(1);
475 }