Merge branch 'jk/maint-null-in-trees' into maint-1.7.11
[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
10 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
11 {
12         struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
13
14         ent->len = len;
15         memcpy(ent->name, name, len);
16         ent->name[len] = 0;
17
18         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
19         cmds->names[cmds->cnt++] = ent;
20 }
21
22 static void clean_cmdnames(struct cmdnames *cmds)
23 {
24         int i;
25         for (i = 0; i < cmds->cnt; ++i)
26                 free(cmds->names[i]);
27         free(cmds->names);
28         cmds->cnt = 0;
29         cmds->alloc = 0;
30 }
31
32 static int cmdname_compare(const void *a_, const void *b_)
33 {
34         struct cmdname *a = *(struct cmdname **)a_;
35         struct cmdname *b = *(struct cmdname **)b_;
36         return strcmp(a->name, b->name);
37 }
38
39 static void uniq(struct cmdnames *cmds)
40 {
41         int i, j;
42
43         if (!cmds->cnt)
44                 return;
45
46         for (i = j = 1; i < cmds->cnt; i++)
47                 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
48                         cmds->names[j++] = cmds->names[i];
49
50         cmds->cnt = j;
51 }
52
53 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
54 {
55         int ci, cj, ei;
56         int cmp;
57
58         ci = cj = ei = 0;
59         while (ci < cmds->cnt && ei < excludes->cnt) {
60                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
61                 if (cmp < 0)
62                         cmds->names[cj++] = cmds->names[ci++];
63                 else if (cmp == 0)
64                         ci++, ei++;
65                 else if (cmp > 0)
66                         ei++;
67         }
68
69         while (ci < cmds->cnt)
70                 cmds->names[cj++] = cmds->names[ci++];
71
72         cmds->cnt = cj;
73 }
74
75 static void pretty_print_string_list(struct cmdnames *cmds,
76                                      unsigned int colopts)
77 {
78         struct string_list list = STRING_LIST_INIT_NODUP;
79         struct column_options copts;
80         int i;
81
82         for (i = 0; i < cmds->cnt; i++)
83                 string_list_append(&list, cmds->names[i]->name);
84         /*
85          * always enable column display, we only consult column.*
86          * about layout strategy and stuff
87          */
88         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
89         memset(&copts, 0, sizeof(copts));
90         copts.indent = "  ";
91         copts.padding = 2;
92         print_columns(&list, colopts, &copts);
93         string_list_clear(&list, 0);
94 }
95
96 static int is_executable(const char *name)
97 {
98         struct stat st;
99
100         if (stat(name, &st) || /* stat, not lstat */
101             !S_ISREG(st.st_mode))
102                 return 0;
103
104 #if defined(WIN32) || defined(__CYGWIN__)
105 #if defined(__CYGWIN__)
106 if ((st.st_mode & S_IXUSR) == 0)
107 #endif
108 {       /* cannot trust the executable bit, peek into the file instead */
109         char buf[3] = { 0 };
110         int n;
111         int fd = open(name, O_RDONLY);
112         st.st_mode &= ~S_IXUSR;
113         if (fd >= 0) {
114                 n = read(fd, buf, 2);
115                 if (n == 2)
116                         /* DOS executables start with "MZ" */
117                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
118                                 st.st_mode |= S_IXUSR;
119                 close(fd);
120         }
121 }
122 #endif
123         return st.st_mode & S_IXUSR;
124 }
125
126 static void list_commands_in_dir(struct cmdnames *cmds,
127                                          const char *path,
128                                          const char *prefix)
129 {
130         int prefix_len;
131         DIR *dir = opendir(path);
132         struct dirent *de;
133         struct strbuf buf = STRBUF_INIT;
134         int len;
135
136         if (!dir)
137                 return;
138         if (!prefix)
139                 prefix = "git-";
140         prefix_len = strlen(prefix);
141
142         strbuf_addf(&buf, "%s/", path);
143         len = buf.len;
144
145         while ((de = readdir(dir)) != NULL) {
146                 int entlen;
147
148                 if (prefixcmp(de->d_name, prefix))
149                         continue;
150
151                 strbuf_setlen(&buf, len);
152                 strbuf_addstr(&buf, de->d_name);
153                 if (!is_executable(buf.buf))
154                         continue;
155
156                 entlen = strlen(de->d_name) - prefix_len;
157                 if (has_extension(de->d_name, ".exe"))
158                         entlen -= 4;
159
160                 add_cmdname(cmds, de->d_name + prefix_len, 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_string_list(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_string_list(other_cmds, colopts);
217                 putchar('\n');
218         }
219 }
220
221 int is_in_cmdlist(struct cmdnames *c, const char *s)
222 {
223         int i;
224         for (i = 0; i < c->cnt; i++)
225                 if (!strcmp(s, c->names[i]->name))
226                         return 1;
227         return 0;
228 }
229
230 static int autocorrect;
231 static struct cmdnames aliases;
232
233 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
234 {
235         if (!strcmp(var, "help.autocorrect"))
236                 autocorrect = git_config_int(var,value);
237         /* Also use aliases for command lookup */
238         if (!prefixcmp(var, "alias."))
239                 add_cmdname(&aliases, var + 6, strlen(var + 6));
240
241         return git_default_config(var, value, cb);
242 }
243
244 static int levenshtein_compare(const void *p1, const void *p2)
245 {
246         const struct cmdname *const *c1 = p1, *const *c2 = p2;
247         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
248         int l1 = (*c1)->len;
249         int l2 = (*c2)->len;
250         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
251 }
252
253 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
254 {
255         int i;
256         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
257
258         for (i = 0; i < old->cnt; i++)
259                 cmds->names[cmds->cnt++] = old->names[i];
260         free(old->names);
261         old->cnt = 0;
262         old->names = NULL;
263 }
264
265 /* An empirically derived magic number */
266 #define SIMILARITY_FLOOR 7
267 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
268
269 static const char bad_interpreter_advice[] =
270         N_("'%s' appears to be a git command, but we were not\n"
271         "able to execute it. Maybe git-%s is broken?");
272
273 const char *help_unknown_cmd(const char *cmd)
274 {
275         int i, n, best_similarity = 0;
276         struct cmdnames main_cmds, other_cmds;
277
278         memset(&main_cmds, 0, sizeof(main_cmds));
279         memset(&other_cmds, 0, sizeof(other_cmds));
280         memset(&aliases, 0, sizeof(aliases));
281
282         git_config(git_unknown_cmd_config, NULL);
283
284         load_command_list("git-", &main_cmds, &other_cmds);
285
286         add_cmd_list(&main_cmds, &aliases);
287         add_cmd_list(&main_cmds, &other_cmds);
288         qsort(main_cmds.names, main_cmds.cnt,
289               sizeof(main_cmds.names), cmdname_compare);
290         uniq(&main_cmds);
291
292         /* This abuses cmdname->len for levenshtein distance */
293         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
294                 int cmp = 0; /* avoid compiler stupidity */
295                 const char *candidate = main_cmds.names[i]->name;
296
297                 /*
298                  * An exact match means we have the command, but
299                  * for some reason exec'ing it gave us ENOENT; probably
300                  * it's a bad interpreter in the #! line.
301                  */
302                 if (!strcmp(candidate, cmd))
303                         die(_(bad_interpreter_advice), cmd, cmd);
304
305                 /* Does the candidate appear in common_cmds list? */
306                 while (n < ARRAY_SIZE(common_cmds) &&
307                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
308                         n++;
309                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
310                         /* Yes, this is one of the common commands */
311                         n++; /* use the entry from common_cmds[] */
312                         if (!prefixcmp(candidate, cmd)) {
313                                 /* Give prefix match a very good score */
314                                 main_cmds.names[i]->len = 0;
315                                 continue;
316                         }
317                 }
318
319                 main_cmds.names[i]->len =
320                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
321         }
322
323         qsort(main_cmds.names, main_cmds.cnt,
324               sizeof(*main_cmds.names), levenshtein_compare);
325
326         if (!main_cmds.cnt)
327                 die(_("Uh oh. Your system reports no Git commands at all."));
328
329         /* skip and count prefix matches */
330         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
331                 ; /* still counting */
332
333         if (main_cmds.cnt <= n) {
334                 /* prefix matches with everything? that is too ambiguous */
335                 best_similarity = SIMILARITY_FLOOR + 1;
336         } else {
337                 /* count all the most similar ones */
338                 for (best_similarity = main_cmds.names[n++]->len;
339                      (n < main_cmds.cnt &&
340                       best_similarity == main_cmds.names[n]->len);
341                      n++)
342                         ; /* still counting */
343         }
344         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
345                 const char *assumed = main_cmds.names[0]->name;
346                 main_cmds.names[0] = NULL;
347                 clean_cmdnames(&main_cmds);
348                 fprintf_ln(stderr,
349                            _("WARNING: You called a Git command named '%s', "
350                              "which does not exist.\n"
351                              "Continuing under the assumption that you meant '%s'"),
352                         cmd, assumed);
353                 if (autocorrect > 0) {
354                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
355                                 (float)autocorrect/10.0);
356                         poll(NULL, 0, autocorrect * 100);
357                 }
358                 return assumed;
359         }
360
361         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
362
363         if (SIMILAR_ENOUGH(best_similarity)) {
364                 fprintf_ln(stderr,
365                            Q_("\nDid you mean this?",
366                               "\nDid you mean one of these?",
367                            n));
368
369                 for (i = 0; i < n; i++)
370                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
371         }
372
373         exit(1);
374 }
375
376 int cmd_version(int argc, const char **argv, const char *prefix)
377 {
378         printf("git version %s\n", git_version_string);
379         return 0;
380 }