Merge git://ozlabs.org/~paulus/gitk
[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
11 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
12 {
13         struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
14
15         ent->len = len;
16         memcpy(ent->name, name, len);
17         ent->name[len] = 0;
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_string_list(struct cmdnames *cmds,
81                                      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(WIN32) || defined(__CYGWIN__)
110 #if defined(__CYGWIN__)
111 if ((st.st_mode & S_IXUSR) == 0)
112 #endif
113 {       /* cannot trust the executable bit, peek into the file instead */
114         char buf[3] = { 0 };
115         int n;
116         int fd = open(name, O_RDONLY);
117         st.st_mode &= ~S_IXUSR;
118         if (fd >= 0) {
119                 n = read(fd, buf, 2);
120                 if (n == 2)
121                         /* DOS executables start with "MZ" */
122                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
123                                 st.st_mode |= S_IXUSR;
124                 close(fd);
125         }
126 }
127 #endif
128         return st.st_mode & S_IXUSR;
129 }
130
131 static void list_commands_in_dir(struct cmdnames *cmds,
132                                          const char *path,
133                                          const char *prefix)
134 {
135         int prefix_len;
136         DIR *dir = opendir(path);
137         struct dirent *de;
138         struct strbuf buf = STRBUF_INIT;
139         int len;
140
141         if (!dir)
142                 return;
143         if (!prefix)
144                 prefix = "git-";
145         prefix_len = strlen(prefix);
146
147         strbuf_addf(&buf, "%s/", path);
148         len = buf.len;
149
150         while ((de = readdir(dir)) != NULL) {
151                 int entlen;
152
153                 if (prefixcmp(de->d_name, prefix))
154                         continue;
155
156                 strbuf_setlen(&buf, len);
157                 strbuf_addstr(&buf, de->d_name);
158                 if (!is_executable(buf.buf))
159                         continue;
160
161                 entlen = strlen(de->d_name) - prefix_len;
162                 if (has_extension(de->d_name, ".exe"))
163                         entlen -= 4;
164
165                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
166         }
167         closedir(dir);
168         strbuf_release(&buf);
169 }
170
171 void load_command_list(const char *prefix,
172                 struct cmdnames *main_cmds,
173                 struct cmdnames *other_cmds)
174 {
175         const char *env_path = getenv("PATH");
176         const char *exec_path = git_exec_path();
177
178         if (exec_path) {
179                 list_commands_in_dir(main_cmds, exec_path, prefix);
180                 qsort(main_cmds->names, main_cmds->cnt,
181                       sizeof(*main_cmds->names), cmdname_compare);
182                 uniq(main_cmds);
183         }
184
185         if (env_path) {
186                 char *paths, *path, *colon;
187                 path = paths = xstrdup(env_path);
188                 while (1) {
189                         if ((colon = strchr(path, PATH_SEP)))
190                                 *colon = 0;
191                         if (!exec_path || strcmp(path, exec_path))
192                                 list_commands_in_dir(other_cmds, path, prefix);
193
194                         if (!colon)
195                                 break;
196                         path = colon + 1;
197                 }
198                 free(paths);
199
200                 qsort(other_cmds->names, other_cmds->cnt,
201                       sizeof(*other_cmds->names), cmdname_compare);
202                 uniq(other_cmds);
203         }
204         exclude_cmds(other_cmds, main_cmds);
205 }
206
207 void list_commands(unsigned int colopts,
208                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
209 {
210         if (main_cmds->cnt) {
211                 const char *exec_path = git_exec_path();
212                 printf_ln(_("available git commands in '%s'"), exec_path);
213                 putchar('\n');
214                 pretty_print_string_list(main_cmds, colopts);
215                 putchar('\n');
216         }
217
218         if (other_cmds->cnt) {
219                 printf_ln(_("git commands available from elsewhere on your $PATH"));
220                 putchar('\n');
221                 pretty_print_string_list(other_cmds, colopts);
222                 putchar('\n');
223         }
224 }
225
226 int is_in_cmdlist(struct cmdnames *c, const char *s)
227 {
228         int i;
229         for (i = 0; i < c->cnt; i++)
230                 if (!strcmp(s, c->names[i]->name))
231                         return 1;
232         return 0;
233 }
234
235 static int autocorrect;
236 static struct cmdnames aliases;
237
238 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
239 {
240         if (!strcmp(var, "help.autocorrect"))
241                 autocorrect = git_config_int(var,value);
242         /* Also use aliases for command lookup */
243         if (!prefixcmp(var, "alias."))
244                 add_cmdname(&aliases, var + 6, strlen(var + 6));
245
246         return git_default_config(var, value, cb);
247 }
248
249 static int levenshtein_compare(const void *p1, const void *p2)
250 {
251         const struct cmdname *const *c1 = p1, *const *c2 = p2;
252         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
253         int l1 = (*c1)->len;
254         int l2 = (*c2)->len;
255         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
256 }
257
258 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
259 {
260         int i;
261         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
262
263         for (i = 0; i < old->cnt; i++)
264                 cmds->names[cmds->cnt++] = old->names[i];
265         free(old->names);
266         old->cnt = 0;
267         old->names = NULL;
268 }
269
270 /* An empirically derived magic number */
271 #define SIMILARITY_FLOOR 7
272 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
273
274 static const char bad_interpreter_advice[] =
275         N_("'%s' appears to be a git command, but we were not\n"
276         "able to execute it. Maybe git-%s is broken?");
277
278 const char *help_unknown_cmd(const char *cmd)
279 {
280         int i, n, best_similarity = 0;
281         struct cmdnames main_cmds, other_cmds;
282
283         memset(&main_cmds, 0, sizeof(main_cmds));
284         memset(&other_cmds, 0, sizeof(other_cmds));
285         memset(&aliases, 0, sizeof(aliases));
286
287         git_config(git_unknown_cmd_config, NULL);
288
289         load_command_list("git-", &main_cmds, &other_cmds);
290
291         add_cmd_list(&main_cmds, &aliases);
292         add_cmd_list(&main_cmds, &other_cmds);
293         qsort(main_cmds.names, main_cmds.cnt,
294               sizeof(main_cmds.names), cmdname_compare);
295         uniq(&main_cmds);
296
297         /* This abuses cmdname->len for levenshtein distance */
298         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
299                 int cmp = 0; /* avoid compiler stupidity */
300                 const char *candidate = main_cmds.names[i]->name;
301
302                 /*
303                  * An exact match means we have the command, but
304                  * for some reason exec'ing it gave us ENOENT; probably
305                  * it's a bad interpreter in the #! line.
306                  */
307                 if (!strcmp(candidate, cmd))
308                         die(_(bad_interpreter_advice), cmd, cmd);
309
310                 /* Does the candidate appear in common_cmds list? */
311                 while (n < ARRAY_SIZE(common_cmds) &&
312                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
313                         n++;
314                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
315                         /* Yes, this is one of the common commands */
316                         n++; /* use the entry from common_cmds[] */
317                         if (!prefixcmp(candidate, cmd)) {
318                                 /* Give prefix match a very good score */
319                                 main_cmds.names[i]->len = 0;
320                                 continue;
321                         }
322                 }
323
324                 main_cmds.names[i]->len =
325                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
326         }
327
328         qsort(main_cmds.names, main_cmds.cnt,
329               sizeof(*main_cmds.names), levenshtein_compare);
330
331         if (!main_cmds.cnt)
332                 die(_("Uh oh. Your system reports no Git commands at all."));
333
334         /* skip and count prefix matches */
335         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
336                 ; /* still counting */
337
338         if (main_cmds.cnt <= n) {
339                 /* prefix matches with everything? that is too ambiguous */
340                 best_similarity = SIMILARITY_FLOOR + 1;
341         } else {
342                 /* count all the most similar ones */
343                 for (best_similarity = main_cmds.names[n++]->len;
344                      (n < main_cmds.cnt &&
345                       best_similarity == main_cmds.names[n]->len);
346                      n++)
347                         ; /* still counting */
348         }
349         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
350                 const char *assumed = main_cmds.names[0]->name;
351                 main_cmds.names[0] = NULL;
352                 clean_cmdnames(&main_cmds);
353                 fprintf_ln(stderr,
354                            _("WARNING: You called a Git command named '%s', "
355                              "which does not exist.\n"
356                              "Continuing under the assumption that you meant '%s'"),
357                         cmd, assumed);
358                 if (autocorrect > 0) {
359                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
360                                 (float)autocorrect/10.0);
361                         poll(NULL, 0, autocorrect * 100);
362                 }
363                 return assumed;
364         }
365
366         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
367
368         if (SIMILAR_ENOUGH(best_similarity)) {
369                 fprintf_ln(stderr,
370                            Q_("\nDid you mean this?",
371                               "\nDid you mean one of these?",
372                            n));
373
374                 for (i = 0; i < n; i++)
375                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
376         }
377
378         exit(1);
379 }
380
381 int cmd_version(int argc, const char **argv, const char *prefix)
382 {
383         printf("git version %s\n", git_version_string);
384         return 0;
385 }