transport-helper: avoid reading past end-of-string
[git/git.git] / help.c
CommitLineData
70827b15
LT
1#include "cache.h"
2#include "builtin.h"
3#include "exec_cmd.h"
8af84dad 4#include "levenshtein.h"
940208a7 5#include "help.h"
6612b9e4 6#include "common-cmds.h"
dbfae689
NTND
7#include "string-list.h"
8#include "column.h"
816fb46b 9#include "version.h"
e5618106 10#include "refs.h"
64949984 11
940208a7 12void add_cmdname(struct cmdnames *cmds, const char *name, int len)
70827b15 13{
940208a7 14 struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
1eb05690 15
70827b15
LT
16 ent->len = len;
17 memcpy(ent->name, name, len);
18 ent->name[len] = 0;
1eb05690
SP
19
20 ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
21 cmds->names[cmds->cnt++] = ent;
70827b15
LT
22}
23
8af84dad
JS
24static 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
70827b15
LT
34static 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
1eb05690
SP
41static void uniq(struct cmdnames *cmds)
42{
43 int i, j;
44
45 if (!cmds->cnt)
46 return;
47
4a15758f
JK
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
1eb05690 52 cmds->names[j++] = cmds->names[i];
4a15758f 53 }
1eb05690
SP
54
55 cmds->cnt = j;
56}
57
940208a7 58void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
f3fa1838 59{
1eb05690
SP
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++];
6a17f583
JH
68 else if (cmp == 0) {
69 ei++;
70 free(cmds->names[ci++]);
71 } else if (cmp > 0)
1eb05690
SP
72 ei++;
73 }
74
75 while (ci < cmds->cnt)
76 cmds->names[cj++] = cmds->names[ci++];
77
78 cmds->cnt = cj;
79}
80
d10cb3df 81static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
70827b15 82{
dbfae689
NTND
83 struct string_list list = STRING_LIST_INIT_NODUP;
84 struct column_options copts;
85 int i;
70827b15 86
dbfae689
NTND
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);
70827b15
LT
99}
100
cc3b7a97
JS
101static 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
f66450ae 109#if defined(GIT_WINDOWS_NATIVE)
0d30ad71 110{ /* cannot trust the executable bit, peek into the file instead */
cc3b7a97
JS
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 }
0d30ad71 123}
cc3b7a97
JS
124#endif
125 return st.st_mode & S_IXUSR;
126}
127
e321180e 128static void list_commands_in_dir(struct cmdnames *cmds,
940208a7
MV
129 const char *path,
130 const char *prefix)
70827b15 131{
940208a7 132 int prefix_len;
1eb05690 133 DIR *dir = opendir(path);
70827b15 134 struct dirent *de;
f5d600e2
JS
135 struct strbuf buf = STRBUF_INIT;
136 int len;
70827b15 137
f5d600e2 138 if (!dir)
e321180e 139 return;
940208a7
MV
140 if (!prefix)
141 prefix = "git-";
142 prefix_len = strlen(prefix);
70827b15 143
f5d600e2
JS
144 strbuf_addf(&buf, "%s/", path);
145 len = buf.len;
146
70827b15 147 while ((de = readdir(dir)) != NULL) {
70827b15
LT
148 int entlen;
149
59556548 150 if (!starts_with(de->d_name, prefix))
70827b15 151 continue;
0966003c 152
f5d600e2
JS
153 strbuf_setlen(&buf, len);
154 strbuf_addstr(&buf, de->d_name);
155 if (!is_executable(buf.buf))
70827b15
LT
156 continue;
157
edb6ddc5 158 entlen = strlen(de->d_name) - prefix_len;
5bb1cda5 159 if (has_extension(de->d_name, ".exe"))
70827b15
LT
160 entlen -= 4;
161
1eb05690 162 add_cmdname(cmds, de->d_name + prefix_len, entlen);
70827b15
LT
163 }
164 closedir(dir);
f5d600e2 165 strbuf_release(&buf);
1eb05690
SP
166}
167
e321180e 168void load_command_list(const char *prefix,
940208a7
MV
169 struct cmdnames *main_cmds,
170 struct cmdnames *other_cmds)
1eb05690 171{
1eb05690 172 const char *env_path = getenv("PATH");
1eb05690
SP
173 const char *exec_path = git_exec_path();
174
1f08e5ce 175 if (exec_path) {
e321180e 176 list_commands_in_dir(main_cmds, exec_path, prefix);
1f08e5ce
AR
177 qsort(main_cmds->names, main_cmds->cnt,
178 sizeof(*main_cmds->names), cmdname_compare);
179 uniq(main_cmds);
1eb05690
SP
180 }
181
1f08e5ce
AR
182 if (env_path) {
183 char *paths, *path, *colon;
184 path = paths = xstrdup(env_path);
185 while (1) {
186 if ((colon = strchr(path, PATH_SEP)))
187 *colon = 0;
746c221a
PB
188 if (!exec_path || strcmp(path, exec_path))
189 list_commands_in_dir(other_cmds, path, prefix);
1eb05690 190
1f08e5ce
AR
191 if (!colon)
192 break;
193 path = colon + 1;
194 }
195 free(paths);
1eb05690 196
1f08e5ce
AR
197 qsort(other_cmds->names, other_cmds->cnt,
198 sizeof(*other_cmds->names), cmdname_compare);
199 uniq(other_cmds);
200 }
940208a7 201 exclude_cmds(other_cmds, main_cmds);
2156435f
JK
202}
203
f4ed0af6 204void list_commands(unsigned int colopts,
dbfae689 205 struct cmdnames *main_cmds, struct cmdnames *other_cmds)
2156435f 206{
940208a7 207 if (main_cmds->cnt) {
61c5d431 208 const char *exec_path = git_exec_path();
4470ef94 209 printf_ln(_("available git commands in '%s'"), exec_path);
1eb05690 210 putchar('\n');
d10cb3df 211 pretty_print_cmdnames(main_cmds, colopts);
1eb05690
SP
212 putchar('\n');
213 }
214
940208a7 215 if (other_cmds->cnt) {
4470ef94 216 printf_ln(_("git commands available from elsewhere on your $PATH"));
940208a7 217 putchar('\n');
d10cb3df 218 pretty_print_cmdnames(other_cmds, colopts);
1eb05690
SP
219 putchar('\n');
220 }
70827b15
LT
221}
222
1542d4cd
JH
223void list_common_cmds_help(void)
224{
225 int i, longest = 0;
226
227 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
228 if (longest < strlen(common_cmds[i].name))
229 longest = strlen(common_cmds[i].name);
230 }
231
232 puts(_("The most commonly used git commands are:"));
233 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
234 printf(" %s ", common_cmds[i].name);
235 mput_char(' ', longest - strlen(common_cmds[i].name));
236 puts(_(common_cmds[i].help));
237 }
238}
239
940208a7 240int is_in_cmdlist(struct cmdnames *c, const char *s)
2156435f
JK
241{
242 int i;
243 for (i = 0; i < c->cnt; i++)
244 if (!strcmp(s, c->names[i]->name))
245 return 1;
246 return 0;
247}
248
f0e90716 249static int autocorrect;
746c221a 250static struct cmdnames aliases;
f0e90716
AR
251
252static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
253{
254 if (!strcmp(var, "help.autocorrect"))
255 autocorrect = git_config_int(var,value);
746c221a 256 /* Also use aliases for command lookup */
59556548 257 if (starts_with(var, "alias."))
746c221a 258 add_cmdname(&aliases, var + 6, strlen(var + 6));
f0e90716
AR
259
260 return git_default_config(var, value, cb);
261}
262
8af84dad 263static int levenshtein_compare(const void *p1, const void *p2)
822a7d50 264{
8af84dad
JS
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);
270}
271
746c221a
PB
272static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
273{
274 int i;
275 ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
276
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;
282}
283
06500a02 284/* An empirically derived magic number */
6612b9e4
EFL
285#define SIMILARITY_FLOOR 7
286#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
06500a02 287
823e0ded
MS
288static 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?");
291
8af84dad 292const char *help_unknown_cmd(const char *cmd)
822a7d50 293{
8af84dad
JS
294 int i, n, best_similarity = 0;
295 struct cmdnames main_cmds, other_cmds;
296
297 memset(&main_cmds, 0, sizeof(main_cmds));
0b74f5dc 298 memset(&other_cmds, 0, sizeof(other_cmds));
746c221a 299 memset(&aliases, 0, sizeof(aliases));
8af84dad 300
f0e90716
AR
301 git_config(git_unknown_cmd_config, NULL);
302
8af84dad
JS
303 load_command_list("git-", &main_cmds, &other_cmds);
304
746c221a
PB
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);
8af84dad 310
6612b9e4
EFL
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;
315
823e0ded
MS
316 /*
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.
320 */
321 if (!strcmp(candidate, cmd))
322 die(_(bad_interpreter_advice), cmd, cmd);
323
6612b9e4
EFL
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[] */
59556548 331 if (starts_with(candidate, cmd)) {
6612b9e4
EFL
332 /* Give prefix match a very good score */
333 main_cmds.names[i]->len = 0;
334 continue;
335 }
336 }
337
8af84dad 338 main_cmds.names[i]->len =
c41494f8 339 levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
6612b9e4 340 }
8af84dad
JS
341
342 qsort(main_cmds.names, main_cmds.cnt,
343 sizeof(*main_cmds.names), levenshtein_compare);
344
345 if (!main_cmds.cnt)
9665627d 346 die(_("Uh oh. Your system reports no Git commands at all."));
8af84dad 347
6612b9e4
EFL
348 /* skip and count prefix matches */
349 for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
350 ; /* still counting */
351
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 */
362 }
06500a02 363 if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
8af84dad
JS
364 const char *assumed = main_cmds.names[0]->name;
365 main_cmds.names[0] = NULL;
366 clean_cmdnames(&main_cmds);
9665627d
NTND
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'"),
8af84dad 371 cmd, assumed);
f0e90716 372 if (autocorrect > 0) {
9665627d 373 fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
f0e90716
AR
374 (float)autocorrect/10.0);
375 poll(NULL, 0, autocorrect * 100);
376 }
8af84dad
JS
377 return assumed;
378 }
379
9665627d 380 fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
8af84dad 381
06500a02 382 if (SIMILAR_ENOUGH(best_similarity)) {
9665627d
NTND
383 fprintf_ln(stderr,
384 Q_("\nDid you mean this?",
385 "\nDid you mean one of these?",
386 n));
8af84dad
JS
387
388 for (i = 0; i < n; i++)
389 fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
390 }
391
822a7d50
RJ
392 exit(1);
393}
394
a633fca0 395int cmd_version(int argc, const char **argv, const char *prefix)
70827b15 396{
f2de0b97
DA
397 /*
398 * The format of this string should be kept stable for compatibility
399 * with external projects that rely on the output of "git version".
400 */
70827b15
LT
401 printf("git version %s\n", git_version_string);
402 return 0;
403}
e5618106
VV
404
405struct similar_ref_cb {
406 const char *base_ref;
407 struct string_list *similar_refs;
408};
409
410static int append_similar_ref(const char *refname, const unsigned char *sha1,
411 int flags, void *cb_data)
412{
413 struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
414 char *branch = strrchr(refname, '/') + 1;
415 /* A remote branch of the same name is deemed similar */
59556548 416 if (starts_with(refname, "refs/remotes/") &&
e5618106
VV
417 !strcmp(branch, cb->base_ref))
418 string_list_append(cb->similar_refs,
419 refname + strlen("refs/remotes/"));
420 return 0;
421}
422
423static struct string_list guess_refs(const char *ref)
424{
425 struct similar_ref_cb ref_cb;
426 struct string_list similar_refs = STRING_LIST_INIT_NODUP;
427
428 ref_cb.base_ref = ref;
429 ref_cb.similar_refs = &similar_refs;
430 for_each_ref(append_similar_ref, &ref_cb);
431 return similar_refs;
432}
433
434void help_unknown_ref(const char *ref, const char *cmd, const char *error)
435{
436 int i;
437 struct string_list suggested_refs = guess_refs(ref);
438
439 fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
440
441 if (suggested_refs.nr > 0) {
442 fprintf_ln(stderr,
443 Q_("\nDid you mean this?",
444 "\nDid you mean one of these?",
445 suggested_refs.nr));
446 for (i = 0; i < suggested_refs.nr; i++)
447 fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
448 }
449
450 string_list_clear(&suggested_refs, 0);
451 exit(1);
452}