Documentation/describe: improve one-line summary
[git.git] / help.c
blob2072a873e2db784ca66c0f1736b12e523a96b7db
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"
12 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
14 struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
16 ent->len = len;
17 memcpy(ent->name, name, len);
18 ent->name[len] = 0;
20 ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
21 cmds->names[cmds->cnt++] = ent;
24 static void clean_cmdnames(struct cmdnames *cmds)
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;
34 static int cmdname_compare(const void *a_, const void *b_)
36 struct cmdname *a = *(struct cmdname **)a_;
37 struct cmdname *b = *(struct cmdname **)b_;
38 return strcmp(a->name, b->name);
41 static void uniq(struct cmdnames *cmds)
43 int i, j;
45 if (!cmds->cnt)
46 return;
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];
55 cmds->cnt = j;
58 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
60 int ci, cj, ei;
61 int cmp;
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++;
75 while (ci < cmds->cnt)
76 cmds->names[cj++] = cmds->names[ci++];
78 cmds->cnt = cj;
81 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
83 struct string_list list = STRING_LIST_INIT_NODUP;
84 struct column_options copts;
85 int i;
87 for (i = 0; i < cmds->cnt; i++)
88 string_list_append(&list, cmds->names[i]->name);
90 * always enable column display, we only consult column.*
91 * about layout strategy and stuff
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);
101 static int is_executable(const char *name)
103 struct stat st;
105 if (stat(name, &st) || /* stat, not lstat */
106 !S_ISREG(st.st_mode))
107 return 0;
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);
124 #endif
125 return st.st_mode & S_IXUSR;
128 static void list_commands_in_dir(struct cmdnames *cmds,
129 const char *path,
130 const char *prefix)
132 DIR *dir = opendir(path);
133 struct dirent *de;
134 struct strbuf buf = STRBUF_INIT;
135 int len;
137 if (!dir)
138 return;
139 if (!prefix)
140 prefix = "git-";
142 strbuf_addf(&buf, "%s/", path);
143 len = buf.len;
145 while ((de = readdir(dir)) != NULL) {
146 const char *ent;
147 size_t entlen;
149 if (!skip_prefix(de->d_name, prefix, &ent))
150 continue;
152 strbuf_setlen(&buf, len);
153 strbuf_addstr(&buf, de->d_name);
154 if (!is_executable(buf.buf))
155 continue;
157 entlen = strlen(ent);
158 strip_suffix(ent, ".exe", &entlen);
160 add_cmdname(cmds, ent, entlen);
162 closedir(dir);
163 strbuf_release(&buf);
166 void load_command_list(const char *prefix,
167 struct cmdnames *main_cmds,
168 struct cmdnames *other_cmds)
170 const char *env_path = getenv("PATH");
171 const char *exec_path = git_exec_path();
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);
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);
189 if (!colon)
190 break;
191 path = colon + 1;
193 free(paths);
195 qsort(other_cmds->names, other_cmds->cnt,
196 sizeof(*other_cmds->names), cmdname_compare);
197 uniq(other_cmds);
199 exclude_cmds(other_cmds, main_cmds);
202 void list_commands(unsigned int colopts,
203 struct cmdnames *main_cmds, struct cmdnames *other_cmds)
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');
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');
221 void list_common_cmds_help(void)
223 int i, longest = 0;
225 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
226 if (longest < strlen(common_cmds[i].name))
227 longest = strlen(common_cmds[i].name);
230 puts(_("The most commonly used git commands are:"));
231 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
232 printf(" %s ", common_cmds[i].name);
233 mput_char(' ', longest - strlen(common_cmds[i].name));
234 puts(_(common_cmds[i].help));
238 int is_in_cmdlist(struct cmdnames *c, const char *s)
240 int i;
241 for (i = 0; i < c->cnt; i++)
242 if (!strcmp(s, c->names[i]->name))
243 return 1;
244 return 0;
247 static int autocorrect;
248 static struct cmdnames aliases;
250 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
252 const char *p;
254 if (!strcmp(var, "help.autocorrect"))
255 autocorrect = git_config_int(var,value);
256 /* Also use aliases for command lookup */
257 if (skip_prefix(var, "alias.", &p))
258 add_cmdname(&aliases, p, strlen(p));
260 return git_default_config(var, value, cb);
263 static int levenshtein_compare(const void *p1, const void *p2)
265 const struct cmdname *const *c1 = p1, *const *c2 = p2;
266 const char *s1 = (*c1)->name, *s2 = (*c2)->name;
267 int l1 = (*c1)->len;
268 int l2 = (*c2)->len;
269 return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
272 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
274 int i;
275 ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
277 for (i = 0; i < old->cnt; i++)
278 cmds->names[cmds->cnt++] = old->names[i];
279 free(old->names);
280 old->cnt = 0;
281 old->names = NULL;
284 /* An empirically derived magic number */
285 #define SIMILARITY_FLOOR 7
286 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
288 static const char bad_interpreter_advice[] =
289 N_("'%s' appears to be a git command, but we were not\n"
290 "able to execute it. Maybe git-%s is broken?");
292 const char *help_unknown_cmd(const char *cmd)
294 int i, n, best_similarity = 0;
295 struct cmdnames main_cmds, other_cmds;
297 memset(&main_cmds, 0, sizeof(main_cmds));
298 memset(&other_cmds, 0, sizeof(other_cmds));
299 memset(&aliases, 0, sizeof(aliases));
301 git_config(git_unknown_cmd_config, NULL);
303 load_command_list("git-", &main_cmds, &other_cmds);
305 add_cmd_list(&main_cmds, &aliases);
306 add_cmd_list(&main_cmds, &other_cmds);
307 qsort(main_cmds.names, main_cmds.cnt,
308 sizeof(*main_cmds.names), cmdname_compare);
309 uniq(&main_cmds);
311 /* This abuses cmdname->len for levenshtein distance */
312 for (i = 0, n = 0; i < main_cmds.cnt; i++) {
313 int cmp = 0; /* avoid compiler stupidity */
314 const char *candidate = main_cmds.names[i]->name;
317 * An exact match means we have the command, but
318 * for some reason exec'ing it gave us ENOENT; probably
319 * it's a bad interpreter in the #! line.
321 if (!strcmp(candidate, cmd))
322 die(_(bad_interpreter_advice), cmd, cmd);
324 /* Does the candidate appear in common_cmds list? */
325 while (n < ARRAY_SIZE(common_cmds) &&
326 (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
327 n++;
328 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
329 /* Yes, this is one of the common commands */
330 n++; /* use the entry from common_cmds[] */
331 if (starts_with(candidate, cmd)) {
332 /* Give prefix match a very good score */
333 main_cmds.names[i]->len = 0;
334 continue;
338 main_cmds.names[i]->len =
339 levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
342 qsort(main_cmds.names, main_cmds.cnt,
343 sizeof(*main_cmds.names), levenshtein_compare);
345 if (!main_cmds.cnt)
346 die(_("Uh oh. Your system reports no Git commands at all."));
348 /* skip and count prefix matches */
349 for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
350 ; /* still counting */
352 if (main_cmds.cnt <= n) {
353 /* prefix matches with everything? that is too ambiguous */
354 best_similarity = SIMILARITY_FLOOR + 1;
355 } else {
356 /* count all the most similar ones */
357 for (best_similarity = main_cmds.names[n++]->len;
358 (n < main_cmds.cnt &&
359 best_similarity == main_cmds.names[n]->len);
360 n++)
361 ; /* still counting */
363 if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
364 const char *assumed = main_cmds.names[0]->name;
365 main_cmds.names[0] = NULL;
366 clean_cmdnames(&main_cmds);
367 fprintf_ln(stderr,
368 _("WARNING: You called a Git command named '%s', "
369 "which does not exist.\n"
370 "Continuing under the assumption that you meant '%s'"),
371 cmd, assumed);
372 if (autocorrect > 0) {
373 fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
374 (float)autocorrect/10.0);
375 poll(NULL, 0, autocorrect * 100);
377 return assumed;
380 fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
382 if (SIMILAR_ENOUGH(best_similarity)) {
383 fprintf_ln(stderr,
384 Q_("\nDid you mean this?",
385 "\nDid you mean one of these?",
386 n));
388 for (i = 0; i < n; i++)
389 fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
392 exit(1);
395 int cmd_version(int argc, const char **argv, const char *prefix)
398 * The format of this string should be kept stable for compatibility
399 * with external projects that rely on the output of "git version".
401 printf("git version %s\n", git_version_string);
402 return 0;
405 struct similar_ref_cb {
406 const char *base_ref;
407 struct string_list *similar_refs;
410 static int append_similar_ref(const char *refname, const unsigned char *sha1,
411 int flags, void *cb_data)
413 struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
414 char *branch = strrchr(refname, '/') + 1;
415 const char *remote;
417 /* A remote branch of the same name is deemed similar */
418 if (skip_prefix(refname, "refs/remotes/", &remote) &&
419 !strcmp(branch, cb->base_ref))
420 string_list_append(cb->similar_refs, remote);
421 return 0;
424 static struct string_list guess_refs(const char *ref)
426 struct similar_ref_cb ref_cb;
427 struct string_list similar_refs = STRING_LIST_INIT_NODUP;
429 ref_cb.base_ref = ref;
430 ref_cb.similar_refs = &similar_refs;
431 for_each_ref(append_similar_ref, &ref_cb);
432 return similar_refs;
435 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
437 int i;
438 struct string_list suggested_refs = guess_refs(ref);
440 fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
442 if (suggested_refs.nr > 0) {
443 fprintf_ln(stderr,
444 Q_("\nDid you mean this?",
445 "\nDid you mean one of these?",
446 suggested_refs.nr));
447 for (i = 0; i < suggested_refs.nr; i++)
448 fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
451 string_list_clear(&suggested_refs, 0);
452 exit(1);