path: create path.h
[git/git.git] / path.c
1 /*
2 * Utilities for paths and pathnames
3 */
4 #include "cache.h"
5 #include "repository.h"
6 #include "strbuf.h"
7 #include "string-list.h"
8 #include "dir.h"
9 #include "worktree.h"
10 #include "submodule-config.h"
11 #include "path.h"
12
13 static int get_st_mode_bits(const char *path, int *mode)
14 {
15 struct stat st;
16 if (lstat(path, &st) < 0)
17 return -1;
18 *mode = st.st_mode;
19 return 0;
20 }
21
22 static char bad_path[] = "/bad-path/";
23
24 static struct strbuf *get_pathname(void)
25 {
26 static struct strbuf pathname_array[4] = {
27 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
28 };
29 static int index;
30 struct strbuf *sb = &pathname_array[index];
31 index = (index + 1) % ARRAY_SIZE(pathname_array);
32 strbuf_reset(sb);
33 return sb;
34 }
35
36 static char *cleanup_path(char *path)
37 {
38 /* Clean it up */
39 if (!memcmp(path, "./", 2)) {
40 path += 2;
41 while (*path == '/')
42 path++;
43 }
44 return path;
45 }
46
47 static void strbuf_cleanup_path(struct strbuf *sb)
48 {
49 char *path = cleanup_path(sb->buf);
50 if (path > sb->buf)
51 strbuf_remove(sb, 0, path - sb->buf);
52 }
53
54 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
55 {
56 va_list args;
57 unsigned len;
58
59 va_start(args, fmt);
60 len = vsnprintf(buf, n, fmt, args);
61 va_end(args);
62 if (len >= n) {
63 strlcpy(buf, bad_path, n);
64 return buf;
65 }
66 return cleanup_path(buf);
67 }
68
69 static int dir_prefix(const char *buf, const char *dir)
70 {
71 int len = strlen(dir);
72 return !strncmp(buf, dir, len) &&
73 (is_dir_sep(buf[len]) || buf[len] == '\0');
74 }
75
76 /* $buf =~ m|$dir/+$file| but without regex */
77 static int is_dir_file(const char *buf, const char *dir, const char *file)
78 {
79 int len = strlen(dir);
80 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
81 return 0;
82 while (is_dir_sep(buf[len]))
83 len++;
84 return !strcmp(buf + len, file);
85 }
86
87 static void replace_dir(struct strbuf *buf, int len, const char *newdir)
88 {
89 int newlen = strlen(newdir);
90 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
91 !is_dir_sep(newdir[newlen - 1]);
92 if (need_sep)
93 len--; /* keep one char, to be replaced with '/' */
94 strbuf_splice(buf, 0, len, newdir, newlen);
95 if (need_sep)
96 buf->buf[newlen] = '/';
97 }
98
99 struct common_dir {
100 /* Not considered garbage for report_linked_checkout_garbage */
101 unsigned ignore_garbage:1;
102 unsigned is_dir:1;
103 /* Not common even though its parent is */
104 unsigned exclude:1;
105 const char *dirname;
106 };
107
108 static struct common_dir common_list[] = {
109 { 0, 1, 0, "branches" },
110 { 0, 1, 0, "hooks" },
111 { 0, 1, 0, "info" },
112 { 0, 0, 1, "info/sparse-checkout" },
113 { 1, 1, 0, "logs" },
114 { 1, 1, 1, "logs/HEAD" },
115 { 0, 1, 1, "logs/refs/bisect" },
116 { 0, 1, 0, "lost-found" },
117 { 0, 1, 0, "objects" },
118 { 0, 1, 0, "refs" },
119 { 0, 1, 1, "refs/bisect" },
120 { 0, 1, 0, "remotes" },
121 { 0, 1, 0, "worktrees" },
122 { 0, 1, 0, "rr-cache" },
123 { 0, 1, 0, "svn" },
124 { 0, 0, 0, "config" },
125 { 1, 0, 0, "gc.pid" },
126 { 0, 0, 0, "packed-refs" },
127 { 0, 0, 0, "shallow" },
128 { 0, 0, 0, NULL }
129 };
130
131 /*
132 * A compressed trie. A trie node consists of zero or more characters that
133 * are common to all elements with this prefix, optionally followed by some
134 * children. If value is not NULL, the trie node is a terminal node.
135 *
136 * For example, consider the following set of strings:
137 * abc
138 * def
139 * definite
140 * definition
141 *
142 * The trie would look like:
143 * root: len = 0, children a and d non-NULL, value = NULL.
144 * a: len = 2, contents = bc, value = (data for "abc")
145 * d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
146 * i: len = 3, contents = nit, children e and i non-NULL, value = NULL
147 * e: len = 0, children all NULL, value = (data for "definite")
148 * i: len = 2, contents = on, children all NULL,
149 * value = (data for "definition")
150 */
151 struct trie {
152 struct trie *children[256];
153 int len;
154 char *contents;
155 void *value;
156 };
157
158 static struct trie *make_trie_node(const char *key, void *value)
159 {
160 struct trie *new_node = xcalloc(1, sizeof(*new_node));
161 new_node->len = strlen(key);
162 if (new_node->len) {
163 new_node->contents = xmalloc(new_node->len);
164 memcpy(new_node->contents, key, new_node->len);
165 }
166 new_node->value = value;
167 return new_node;
168 }
169
170 /*
171 * Add a key/value pair to a trie. The key is assumed to be \0-terminated.
172 * If there was an existing value for this key, return it.
173 */
174 static void *add_to_trie(struct trie *root, const char *key, void *value)
175 {
176 struct trie *child;
177 void *old;
178 int i;
179
180 if (!*key) {
181 /* we have reached the end of the key */
182 old = root->value;
183 root->value = value;
184 return old;
185 }
186
187 for (i = 0; i < root->len; i++) {
188 if (root->contents[i] == key[i])
189 continue;
190
191 /*
192 * Split this node: child will contain this node's
193 * existing children.
194 */
195 child = malloc(sizeof(*child));
196 memcpy(child->children, root->children, sizeof(root->children));
197
198 child->len = root->len - i - 1;
199 if (child->len) {
200 child->contents = xstrndup(root->contents + i + 1,
201 child->len);
202 }
203 child->value = root->value;
204 root->value = NULL;
205 root->len = i;
206
207 memset(root->children, 0, sizeof(root->children));
208 root->children[(unsigned char)root->contents[i]] = child;
209
210 /* This is the newly-added child. */
211 root->children[(unsigned char)key[i]] =
212 make_trie_node(key + i + 1, value);
213 return NULL;
214 }
215
216 /* We have matched the entire compressed section */
217 if (key[i]) {
218 child = root->children[(unsigned char)key[root->len]];
219 if (child) {
220 return add_to_trie(child, key + root->len + 1, value);
221 } else {
222 child = make_trie_node(key + root->len + 1, value);
223 root->children[(unsigned char)key[root->len]] = child;
224 return NULL;
225 }
226 }
227
228 old = root->value;
229 root->value = value;
230 return old;
231 }
232
233 typedef int (*match_fn)(const char *unmatched, void *data, void *baton);
234
235 /*
236 * Search a trie for some key. Find the longest /-or-\0-terminated
237 * prefix of the key for which the trie contains a value. Call fn
238 * with the unmatched portion of the key and the found value, and
239 * return its return value. If there is no such prefix, return -1.
240 *
241 * The key is partially normalized: consecutive slashes are skipped.
242 *
243 * For example, consider the trie containing only [refs,
244 * refs/worktree] (both with values).
245 *
246 * | key | unmatched | val from node | return value |
247 * |-----------------|------------|---------------|--------------|
248 * | a | not called | n/a | -1 |
249 * | refs | \0 | refs | as per fn |
250 * | refs/ | / | refs | as per fn |
251 * | refs/w | /w | refs | as per fn |
252 * | refs/worktree | \0 | refs/worktree | as per fn |
253 * | refs/worktree/ | / | refs/worktree | as per fn |
254 * | refs/worktree/a | /a | refs/worktree | as per fn |
255 * |-----------------|------------|---------------|--------------|
256 *
257 */
258 static int trie_find(struct trie *root, const char *key, match_fn fn,
259 void *baton)
260 {
261 int i;
262 int result;
263 struct trie *child;
264
265 if (!*key) {
266 /* we have reached the end of the key */
267 if (root->value && !root->len)
268 return fn(key, root->value, baton);
269 else
270 return -1;
271 }
272
273 for (i = 0; i < root->len; i++) {
274 /* Partial path normalization: skip consecutive slashes. */
275 if (key[i] == '/' && key[i+1] == '/') {
276 key++;
277 continue;
278 }
279 if (root->contents[i] != key[i])
280 return -1;
281 }
282
283 /* Matched the entire compressed section */
284 key += i;
285 if (!*key)
286 /* End of key */
287 return fn(key, root->value, baton);
288
289 /* Partial path normalization: skip consecutive slashes */
290 while (key[0] == '/' && key[1] == '/')
291 key++;
292
293 child = root->children[(unsigned char)*key];
294 if (child)
295 result = trie_find(child, key + 1, fn, baton);
296 else
297 result = -1;
298
299 if (result >= 0 || (*key != '/' && *key != 0))
300 return result;
301 if (root->value)
302 return fn(key, root->value, baton);
303 else
304 return -1;
305 }
306
307 static struct trie common_trie;
308 static int common_trie_done_setup;
309
310 static void init_common_trie(void)
311 {
312 struct common_dir *p;
313
314 if (common_trie_done_setup)
315 return;
316
317 for (p = common_list; p->dirname; p++)
318 add_to_trie(&common_trie, p->dirname, p);
319
320 common_trie_done_setup = 1;
321 }
322
323 /*
324 * Helper function for update_common_dir: returns 1 if the dir
325 * prefix is common.
326 */
327 static int check_common(const char *unmatched, void *value, void *baton)
328 {
329 struct common_dir *dir = value;
330
331 if (!dir)
332 return 0;
333
334 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
335 return !dir->exclude;
336
337 if (!dir->is_dir && unmatched[0] == 0)
338 return !dir->exclude;
339
340 return 0;
341 }
342
343 static void update_common_dir(struct strbuf *buf, int git_dir_len,
344 const char *common_dir)
345 {
346 char *base = buf->buf + git_dir_len;
347 init_common_trie();
348 if (!common_dir)
349 common_dir = get_git_common_dir();
350 if (trie_find(&common_trie, base, check_common, NULL) > 0)
351 replace_dir(buf, git_dir_len, common_dir);
352 }
353
354 void report_linked_checkout_garbage(void)
355 {
356 struct strbuf sb = STRBUF_INIT;
357 const struct common_dir *p;
358 int len;
359
360 if (!the_repository->different_commondir)
361 return;
362 strbuf_addf(&sb, "%s/", get_git_dir());
363 len = sb.len;
364 for (p = common_list; p->dirname; p++) {
365 const char *path = p->dirname;
366 if (p->ignore_garbage)
367 continue;
368 strbuf_setlen(&sb, len);
369 strbuf_addstr(&sb, path);
370 if (file_exists(sb.buf))
371 report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
372 }
373 strbuf_release(&sb);
374 }
375
376 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
377 {
378 const char *base = buf->buf + git_dir_len;
379 if (is_dir_file(base, "info", "grafts"))
380 strbuf_splice(buf, 0, buf->len,
381 get_graft_file(), strlen(get_graft_file()));
382 else if (!strcmp(base, "index"))
383 strbuf_splice(buf, 0, buf->len,
384 get_index_file(), strlen(get_index_file()));
385 else if (dir_prefix(base, "objects"))
386 replace_dir(buf, git_dir_len + 7, get_object_directory());
387 else if (git_hooks_path && dir_prefix(base, "hooks"))
388 replace_dir(buf, git_dir_len + 5, git_hooks_path);
389 else if (the_repository->different_commondir)
390 update_common_dir(buf, git_dir_len, NULL);
391 }
392
393 static void do_git_path(const struct worktree *wt, struct strbuf *buf,
394 const char *fmt, va_list args)
395 {
396 int gitdir_len;
397 strbuf_addstr(buf, get_worktree_git_dir(wt));
398 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
399 strbuf_addch(buf, '/');
400 gitdir_len = buf->len;
401 strbuf_vaddf(buf, fmt, args);
402 adjust_git_path(buf, gitdir_len);
403 strbuf_cleanup_path(buf);
404 }
405
406 char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
407 {
408 va_list args;
409 strbuf_reset(buf);
410 va_start(args, fmt);
411 do_git_path(NULL, buf, fmt, args);
412 va_end(args);
413 return buf->buf;
414 }
415
416 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
417 {
418 va_list args;
419 va_start(args, fmt);
420 do_git_path(NULL, sb, fmt, args);
421 va_end(args);
422 }
423
424 const char *git_path(const char *fmt, ...)
425 {
426 struct strbuf *pathname = get_pathname();
427 va_list args;
428 va_start(args, fmt);
429 do_git_path(NULL, pathname, fmt, args);
430 va_end(args);
431 return pathname->buf;
432 }
433
434 char *git_pathdup(const char *fmt, ...)
435 {
436 struct strbuf path = STRBUF_INIT;
437 va_list args;
438 va_start(args, fmt);
439 do_git_path(NULL, &path, fmt, args);
440 va_end(args);
441 return strbuf_detach(&path, NULL);
442 }
443
444 char *mkpathdup(const char *fmt, ...)
445 {
446 struct strbuf sb = STRBUF_INIT;
447 va_list args;
448 va_start(args, fmt);
449 strbuf_vaddf(&sb, fmt, args);
450 va_end(args);
451 strbuf_cleanup_path(&sb);
452 return strbuf_detach(&sb, NULL);
453 }
454
455 const char *mkpath(const char *fmt, ...)
456 {
457 va_list args;
458 struct strbuf *pathname = get_pathname();
459 va_start(args, fmt);
460 strbuf_vaddf(pathname, fmt, args);
461 va_end(args);
462 return cleanup_path(pathname->buf);
463 }
464
465 const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
466 {
467 struct strbuf *pathname = get_pathname();
468 va_list args;
469 va_start(args, fmt);
470 do_git_path(wt, pathname, fmt, args);
471 va_end(args);
472 return pathname->buf;
473 }
474
475 /* Returns 0 on success, negative on failure. */
476 static int do_submodule_path(struct strbuf *buf, const char *path,
477 const char *fmt, va_list args)
478 {
479 struct strbuf git_submodule_common_dir = STRBUF_INIT;
480 struct strbuf git_submodule_dir = STRBUF_INIT;
481 int ret;
482
483 ret = submodule_to_gitdir(&git_submodule_dir, path);
484 if (ret)
485 goto cleanup;
486
487 strbuf_complete(&git_submodule_dir, '/');
488 strbuf_addbuf(buf, &git_submodule_dir);
489 strbuf_vaddf(buf, fmt, args);
490
491 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
492 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
493
494 strbuf_cleanup_path(buf);
495
496 cleanup:
497 strbuf_release(&git_submodule_dir);
498 strbuf_release(&git_submodule_common_dir);
499 return ret;
500 }
501
502 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
503 {
504 int err;
505 va_list args;
506 struct strbuf buf = STRBUF_INIT;
507 va_start(args, fmt);
508 err = do_submodule_path(&buf, path, fmt, args);
509 va_end(args);
510 if (err) {
511 strbuf_release(&buf);
512 return NULL;
513 }
514 return strbuf_detach(&buf, NULL);
515 }
516
517 int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
518 const char *fmt, ...)
519 {
520 int err;
521 va_list args;
522 va_start(args, fmt);
523 err = do_submodule_path(buf, path, fmt, args);
524 va_end(args);
525
526 return err;
527 }
528
529 static void do_git_common_path(struct strbuf *buf,
530 const char *fmt,
531 va_list args)
532 {
533 strbuf_addstr(buf, get_git_common_dir());
534 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
535 strbuf_addch(buf, '/');
536 strbuf_vaddf(buf, fmt, args);
537 strbuf_cleanup_path(buf);
538 }
539
540 const char *git_common_path(const char *fmt, ...)
541 {
542 struct strbuf *pathname = get_pathname();
543 va_list args;
544 va_start(args, fmt);
545 do_git_common_path(pathname, fmt, args);
546 va_end(args);
547 return pathname->buf;
548 }
549
550 void strbuf_git_common_path(struct strbuf *sb, const char *fmt, ...)
551 {
552 va_list args;
553 va_start(args, fmt);
554 do_git_common_path(sb, fmt, args);
555 va_end(args);
556 }
557
558 int validate_headref(const char *path)
559 {
560 struct stat st;
561 char *buf, buffer[256];
562 unsigned char sha1[20];
563 int fd;
564 ssize_t len;
565
566 if (lstat(path, &st) < 0)
567 return -1;
568
569 /* Make sure it is a "refs/.." symlink */
570 if (S_ISLNK(st.st_mode)) {
571 len = readlink(path, buffer, sizeof(buffer)-1);
572 if (len >= 5 && !memcmp("refs/", buffer, 5))
573 return 0;
574 return -1;
575 }
576
577 /*
578 * Anything else, just open it and try to see if it is a symbolic ref.
579 */
580 fd = open(path, O_RDONLY);
581 if (fd < 0)
582 return -1;
583 len = read_in_full(fd, buffer, sizeof(buffer)-1);
584 close(fd);
585
586 /*
587 * Is it a symbolic ref?
588 */
589 if (len < 4)
590 return -1;
591 if (!memcmp("ref:", buffer, 4)) {
592 buf = buffer + 4;
593 len -= 4;
594 while (len && isspace(*buf))
595 buf++, len--;
596 if (len >= 5 && !memcmp("refs/", buf, 5))
597 return 0;
598 }
599
600 /*
601 * Is this a detached HEAD?
602 */
603 if (!get_sha1_hex(buffer, sha1))
604 return 0;
605
606 return -1;
607 }
608
609 static struct passwd *getpw_str(const char *username, size_t len)
610 {
611 struct passwd *pw;
612 char *username_z = xmemdupz(username, len);
613 pw = getpwnam(username_z);
614 free(username_z);
615 return pw;
616 }
617
618 /*
619 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
620 * then it is a newly allocated string. Returns NULL on getpw failure or
621 * if path is NULL.
622 *
623 * If real_home is true, real_path($HOME) is used in the expansion.
624 */
625 char *expand_user_path(const char *path, int real_home)
626 {
627 struct strbuf user_path = STRBUF_INIT;
628 const char *to_copy = path;
629
630 if (path == NULL)
631 goto return_null;
632 if (path[0] == '~') {
633 const char *first_slash = strchrnul(path, '/');
634 const char *username = path + 1;
635 size_t username_len = first_slash - username;
636 if (username_len == 0) {
637 const char *home = getenv("HOME");
638 if (!home)
639 goto return_null;
640 if (real_home)
641 strbuf_addstr(&user_path, real_path(home));
642 else
643 strbuf_addstr(&user_path, home);
644 #ifdef GIT_WINDOWS_NATIVE
645 convert_slashes(user_path.buf);
646 #endif
647 } else {
648 struct passwd *pw = getpw_str(username, username_len);
649 if (!pw)
650 goto return_null;
651 strbuf_addstr(&user_path, pw->pw_dir);
652 }
653 to_copy = first_slash;
654 }
655 strbuf_addstr(&user_path, to_copy);
656 return strbuf_detach(&user_path, NULL);
657 return_null:
658 strbuf_release(&user_path);
659 return NULL;
660 }
661
662 /*
663 * First, one directory to try is determined by the following algorithm.
664 *
665 * (0) If "strict" is given, the path is used as given and no DWIM is
666 * done. Otherwise:
667 * (1) "~/path" to mean path under the running user's home directory;
668 * (2) "~user/path" to mean path under named user's home directory;
669 * (3) "relative/path" to mean cwd relative directory; or
670 * (4) "/absolute/path" to mean absolute directory.
671 *
672 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
673 * in this order. We select the first one that is a valid git repository, and
674 * chdir() to it. If none match, or we fail to chdir, we return NULL.
675 *
676 * If all goes well, we return the directory we used to chdir() (but
677 * before ~user is expanded), avoiding getcwd() resolving symbolic
678 * links. User relative paths are also returned as they are given,
679 * except DWIM suffixing.
680 */
681 const char *enter_repo(const char *path, int strict)
682 {
683 static struct strbuf validated_path = STRBUF_INIT;
684 static struct strbuf used_path = STRBUF_INIT;
685
686 if (!path)
687 return NULL;
688
689 if (!strict) {
690 static const char *suffix[] = {
691 "/.git", "", ".git/.git", ".git", NULL,
692 };
693 const char *gitfile;
694 int len = strlen(path);
695 int i;
696 while ((1 < len) && (path[len-1] == '/'))
697 len--;
698
699 /*
700 * We can handle arbitrary-sized buffers, but this remains as a
701 * sanity check on untrusted input.
702 */
703 if (PATH_MAX <= len)
704 return NULL;
705
706 strbuf_reset(&used_path);
707 strbuf_reset(&validated_path);
708 strbuf_add(&used_path, path, len);
709 strbuf_add(&validated_path, path, len);
710
711 if (used_path.buf[0] == '~') {
712 char *newpath = expand_user_path(used_path.buf, 0);
713 if (!newpath)
714 return NULL;
715 strbuf_attach(&used_path, newpath, strlen(newpath),
716 strlen(newpath));
717 }
718 for (i = 0; suffix[i]; i++) {
719 struct stat st;
720 size_t baselen = used_path.len;
721 strbuf_addstr(&used_path, suffix[i]);
722 if (!stat(used_path.buf, &st) &&
723 (S_ISREG(st.st_mode) ||
724 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
725 strbuf_addstr(&validated_path, suffix[i]);
726 break;
727 }
728 strbuf_setlen(&used_path, baselen);
729 }
730 if (!suffix[i])
731 return NULL;
732 gitfile = read_gitfile(used_path.buf);
733 if (gitfile) {
734 strbuf_reset(&used_path);
735 strbuf_addstr(&used_path, gitfile);
736 }
737 if (chdir(used_path.buf))
738 return NULL;
739 path = validated_path.buf;
740 }
741 else {
742 const char *gitfile = read_gitfile(path);
743 if (gitfile)
744 path = gitfile;
745 if (chdir(path))
746 return NULL;
747 }
748
749 if (is_git_directory(".")) {
750 set_git_dir(".");
751 check_repository_format();
752 return path;
753 }
754
755 return NULL;
756 }
757
758 static int calc_shared_perm(int mode)
759 {
760 int tweak;
761
762 if (get_shared_repository() < 0)
763 tweak = -get_shared_repository();
764 else
765 tweak = get_shared_repository();
766
767 if (!(mode & S_IWUSR))
768 tweak &= ~0222;
769 if (mode & S_IXUSR)
770 /* Copy read bits to execute bits */
771 tweak |= (tweak & 0444) >> 2;
772 if (get_shared_repository() < 0)
773 mode = (mode & ~0777) | tweak;
774 else
775 mode |= tweak;
776
777 return mode;
778 }
779
780
781 int adjust_shared_perm(const char *path)
782 {
783 int old_mode, new_mode;
784
785 if (!get_shared_repository())
786 return 0;
787 if (get_st_mode_bits(path, &old_mode) < 0)
788 return -1;
789
790 new_mode = calc_shared_perm(old_mode);
791 if (S_ISDIR(old_mode)) {
792 /* Copy read bits to execute bits */
793 new_mode |= (new_mode & 0444) >> 2;
794 new_mode |= FORCE_DIR_SET_GID;
795 }
796
797 if (((old_mode ^ new_mode) & ~S_IFMT) &&
798 chmod(path, (new_mode & ~S_IFMT)) < 0)
799 return -2;
800 return 0;
801 }
802
803 void safe_create_dir(const char *dir, int share)
804 {
805 if (mkdir(dir, 0777) < 0) {
806 if (errno != EEXIST) {
807 perror(dir);
808 exit(1);
809 }
810 }
811 else if (share && adjust_shared_perm(dir))
812 die(_("Could not make %s writable by group"), dir);
813 }
814
815 static int have_same_root(const char *path1, const char *path2)
816 {
817 int is_abs1, is_abs2;
818
819 is_abs1 = is_absolute_path(path1);
820 is_abs2 = is_absolute_path(path2);
821 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
822 (!is_abs1 && !is_abs2);
823 }
824
825 /*
826 * Give path as relative to prefix.
827 *
828 * The strbuf may or may not be used, so do not assume it contains the
829 * returned path.
830 */
831 const char *relative_path(const char *in, const char *prefix,
832 struct strbuf *sb)
833 {
834 int in_len = in ? strlen(in) : 0;
835 int prefix_len = prefix ? strlen(prefix) : 0;
836 int in_off = 0;
837 int prefix_off = 0;
838 int i = 0, j = 0;
839
840 if (!in_len)
841 return "./";
842 else if (!prefix_len)
843 return in;
844
845 if (have_same_root(in, prefix))
846 /* bypass dos_drive, for "c:" is identical to "C:" */
847 i = j = has_dos_drive_prefix(in);
848 else {
849 return in;
850 }
851
852 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
853 if (is_dir_sep(prefix[i])) {
854 while (is_dir_sep(prefix[i]))
855 i++;
856 while (is_dir_sep(in[j]))
857 j++;
858 prefix_off = i;
859 in_off = j;
860 } else {
861 i++;
862 j++;
863 }
864 }
865
866 if (
867 /* "prefix" seems like prefix of "in" */
868 i >= prefix_len &&
869 /*
870 * but "/foo" is not a prefix of "/foobar"
871 * (i.e. prefix not end with '/')
872 */
873 prefix_off < prefix_len) {
874 if (j >= in_len) {
875 /* in="/a/b", prefix="/a/b" */
876 in_off = in_len;
877 } else if (is_dir_sep(in[j])) {
878 /* in="/a/b/c", prefix="/a/b" */
879 while (is_dir_sep(in[j]))
880 j++;
881 in_off = j;
882 } else {
883 /* in="/a/bbb/c", prefix="/a/b" */
884 i = prefix_off;
885 }
886 } else if (
887 /* "in" is short than "prefix" */
888 j >= in_len &&
889 /* "in" not end with '/' */
890 in_off < in_len) {
891 if (is_dir_sep(prefix[i])) {
892 /* in="/a/b", prefix="/a/b/c/" */
893 while (is_dir_sep(prefix[i]))
894 i++;
895 in_off = in_len;
896 }
897 }
898 in += in_off;
899 in_len -= in_off;
900
901 if (i >= prefix_len) {
902 if (!in_len)
903 return "./";
904 else
905 return in;
906 }
907
908 strbuf_reset(sb);
909 strbuf_grow(sb, in_len);
910
911 while (i < prefix_len) {
912 if (is_dir_sep(prefix[i])) {
913 strbuf_addstr(sb, "../");
914 while (is_dir_sep(prefix[i]))
915 i++;
916 continue;
917 }
918 i++;
919 }
920 if (!is_dir_sep(prefix[prefix_len - 1]))
921 strbuf_addstr(sb, "../");
922
923 strbuf_addstr(sb, in);
924
925 return sb->buf;
926 }
927
928 /*
929 * A simpler implementation of relative_path
930 *
931 * Get relative path by removing "prefix" from "in". This function
932 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
933 * to increase performance when traversing the path to work_tree.
934 */
935 const char *remove_leading_path(const char *in, const char *prefix)
936 {
937 static struct strbuf buf = STRBUF_INIT;
938 int i = 0, j = 0;
939
940 if (!prefix || !prefix[0])
941 return in;
942 while (prefix[i]) {
943 if (is_dir_sep(prefix[i])) {
944 if (!is_dir_sep(in[j]))
945 return in;
946 while (is_dir_sep(prefix[i]))
947 i++;
948 while (is_dir_sep(in[j]))
949 j++;
950 continue;
951 } else if (in[j] != prefix[i]) {
952 return in;
953 }
954 i++;
955 j++;
956 }
957 if (
958 /* "/foo" is a prefix of "/foo" */
959 in[j] &&
960 /* "/foo" is not a prefix of "/foobar" */
961 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
962 )
963 return in;
964 while (is_dir_sep(in[j]))
965 j++;
966
967 strbuf_reset(&buf);
968 if (!in[j])
969 strbuf_addstr(&buf, ".");
970 else
971 strbuf_addstr(&buf, in + j);
972 return buf.buf;
973 }
974
975 /*
976 * It is okay if dst == src, but they should not overlap otherwise.
977 *
978 * Performs the following normalizations on src, storing the result in dst:
979 * - Ensures that components are separated by '/' (Windows only)
980 * - Squashes sequences of '/' except "//server/share" on Windows
981 * - Removes "." components.
982 * - Removes ".." components, and the components the precede them.
983 * Returns failure (non-zero) if a ".." component appears as first path
984 * component anytime during the normalization. Otherwise, returns success (0).
985 *
986 * Note that this function is purely textual. It does not follow symlinks,
987 * verify the existence of the path, or make any system calls.
988 *
989 * prefix_len != NULL is for a specific case of prefix_pathspec():
990 * assume that src == dst and src[0..prefix_len-1] is already
991 * normalized, any time "../" eats up to the prefix_len part,
992 * prefix_len is reduced. In the end prefix_len is the remaining
993 * prefix that has not been overridden by user pathspec.
994 *
995 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
996 * For everything but the root folder itself, the normalized path should not
997 * end with a '/', then the callers need to be fixed up accordingly.
998 *
999 */
1000 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1001 {
1002 char *dst0;
1003 const char *end;
1004
1005 /*
1006 * Copy initial part of absolute path: "/", "C:/", "//server/share/".
1007 */
1008 end = src + offset_1st_component(src);
1009 while (src < end) {
1010 char c = *src++;
1011 if (is_dir_sep(c))
1012 c = '/';
1013 *dst++ = c;
1014 }
1015 dst0 = dst;
1016
1017 while (is_dir_sep(*src))
1018 src++;
1019
1020 for (;;) {
1021 char c = *src;
1022
1023 /*
1024 * A path component that begins with . could be
1025 * special:
1026 * (1) "." and ends -- ignore and terminate.
1027 * (2) "./" -- ignore them, eat slash and continue.
1028 * (3) ".." and ends -- strip one and terminate.
1029 * (4) "../" -- strip one, eat slash and continue.
1030 */
1031 if (c == '.') {
1032 if (!src[1]) {
1033 /* (1) */
1034 src++;
1035 } else if (is_dir_sep(src[1])) {
1036 /* (2) */
1037 src += 2;
1038 while (is_dir_sep(*src))
1039 src++;
1040 continue;
1041 } else if (src[1] == '.') {
1042 if (!src[2]) {
1043 /* (3) */
1044 src += 2;
1045 goto up_one;
1046 } else if (is_dir_sep(src[2])) {
1047 /* (4) */
1048 src += 3;
1049 while (is_dir_sep(*src))
1050 src++;
1051 goto up_one;
1052 }
1053 }
1054 }
1055
1056 /* copy up to the next '/', and eat all '/' */
1057 while ((c = *src++) != '\0' && !is_dir_sep(c))
1058 *dst++ = c;
1059 if (is_dir_sep(c)) {
1060 *dst++ = '/';
1061 while (is_dir_sep(c))
1062 c = *src++;
1063 src--;
1064 } else if (!c)
1065 break;
1066 continue;
1067
1068 up_one:
1069 /*
1070 * dst0..dst is prefix portion, and dst[-1] is '/';
1071 * go up one level.
1072 */
1073 dst--; /* go to trailing '/' */
1074 if (dst <= dst0)
1075 return -1;
1076 /* Windows: dst[-1] cannot be backslash anymore */
1077 while (dst0 < dst && dst[-1] != '/')
1078 dst--;
1079 if (prefix_len && *prefix_len > dst - dst0)
1080 *prefix_len = dst - dst0;
1081 }
1082 *dst = '\0';
1083 return 0;
1084 }
1085
1086 int normalize_path_copy(char *dst, const char *src)
1087 {
1088 return normalize_path_copy_len(dst, src, NULL);
1089 }
1090
1091 /*
1092 * path = Canonical absolute path
1093 * prefixes = string_list containing normalized, absolute paths without
1094 * trailing slashes (except for the root directory, which is denoted by "/").
1095 *
1096 * Determines, for each path in prefixes, whether the "prefix"
1097 * is an ancestor directory of path. Returns the length of the longest
1098 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1099 * is an ancestor. (Note that this means 0 is returned if prefixes is
1100 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1101 * are not considered to be their own ancestors. path must be in a
1102 * canonical form: empty components, or "." or ".." components are not
1103 * allowed.
1104 */
1105 int longest_ancestor_length(const char *path, struct string_list *prefixes)
1106 {
1107 int i, max_len = -1;
1108
1109 if (!strcmp(path, "/"))
1110 return -1;
1111
1112 for (i = 0; i < prefixes->nr; i++) {
1113 const char *ceil = prefixes->items[i].string;
1114 int len = strlen(ceil);
1115
1116 if (len == 1 && ceil[0] == '/')
1117 len = 0; /* root matches anything, with length 0 */
1118 else if (!strncmp(path, ceil, len) && path[len] == '/')
1119 ; /* match of length len */
1120 else
1121 continue; /* no match */
1122
1123 if (len > max_len)
1124 max_len = len;
1125 }
1126
1127 return max_len;
1128 }
1129
1130 /* strip arbitrary amount of directory separators at end of path */
1131 static inline int chomp_trailing_dir_sep(const char *path, int len)
1132 {
1133 while (len && is_dir_sep(path[len - 1]))
1134 len--;
1135 return len;
1136 }
1137
1138 /*
1139 * If path ends with suffix (complete path components), returns the
1140 * part before suffix (sans trailing directory separators).
1141 * Otherwise returns NULL.
1142 */
1143 char *strip_path_suffix(const char *path, const char *suffix)
1144 {
1145 int path_len = strlen(path), suffix_len = strlen(suffix);
1146
1147 while (suffix_len) {
1148 if (!path_len)
1149 return NULL;
1150
1151 if (is_dir_sep(path[path_len - 1])) {
1152 if (!is_dir_sep(suffix[suffix_len - 1]))
1153 return NULL;
1154 path_len = chomp_trailing_dir_sep(path, path_len);
1155 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1156 }
1157 else if (path[--path_len] != suffix[--suffix_len])
1158 return NULL;
1159 }
1160
1161 if (path_len && !is_dir_sep(path[path_len - 1]))
1162 return NULL;
1163 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1164 }
1165
1166 int daemon_avoid_alias(const char *p)
1167 {
1168 int sl, ndot;
1169
1170 /*
1171 * This resurrects the belts and suspenders paranoia check by HPA
1172 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1173 * does not do getcwd() based path canonicalization.
1174 *
1175 * sl becomes true immediately after seeing '/' and continues to
1176 * be true as long as dots continue after that without intervening
1177 * non-dot character.
1178 */
1179 if (!p || (*p != '/' && *p != '~'))
1180 return -1;
1181 sl = 1; ndot = 0;
1182 p++;
1183
1184 while (1) {
1185 char ch = *p++;
1186 if (sl) {
1187 if (ch == '.')
1188 ndot++;
1189 else if (ch == '/') {
1190 if (ndot < 3)
1191 /* reject //, /./ and /../ */
1192 return -1;
1193 ndot = 0;
1194 }
1195 else if (ch == 0) {
1196 if (0 < ndot && ndot < 3)
1197 /* reject /.$ and /..$ */
1198 return -1;
1199 return 0;
1200 }
1201 else
1202 sl = ndot = 0;
1203 }
1204 else if (ch == 0)
1205 return 0;
1206 else if (ch == '/') {
1207 sl = 1;
1208 ndot = 0;
1209 }
1210 }
1211 }
1212
1213 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1214 {
1215 if (len < skip)
1216 return 0;
1217 len -= skip;
1218 path += skip;
1219 while (len-- > 0) {
1220 char c = *(path++);
1221 if (c != ' ' && c != '.')
1222 return 0;
1223 }
1224 return 1;
1225 }
1226
1227 int is_ntfs_dotgit(const char *name)
1228 {
1229 int len;
1230
1231 for (len = 0; ; len++)
1232 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1233 if (only_spaces_and_periods(name, len, 4) &&
1234 !strncasecmp(name, ".git", 4))
1235 return 1;
1236 if (only_spaces_and_periods(name, len, 5) &&
1237 !strncasecmp(name, "git~1", 5))
1238 return 1;
1239 if (name[len] != '\\')
1240 return 0;
1241 name += len + 1;
1242 len = -1;
1243 }
1244 }
1245
1246 char *xdg_config_home(const char *filename)
1247 {
1248 const char *home, *config_home;
1249
1250 assert(filename);
1251 config_home = getenv("XDG_CONFIG_HOME");
1252 if (config_home && *config_home)
1253 return mkpathdup("%s/git/%s", config_home, filename);
1254
1255 home = getenv("HOME");
1256 if (home)
1257 return mkpathdup("%s/.config/git/%s", home, filename);
1258 return NULL;
1259 }
1260
1261 char *xdg_cache_home(const char *filename)
1262 {
1263 const char *home, *cache_home;
1264
1265 assert(filename);
1266 cache_home = getenv("XDG_CACHE_HOME");
1267 if (cache_home && *cache_home)
1268 return mkpathdup("%s/git/%s", cache_home, filename);
1269
1270 home = getenv("HOME");
1271 if (home)
1272 return mkpathdup("%s/.cache/git/%s", home, filename);
1273 return NULL;
1274 }
1275
1276 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1277 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1278 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1279 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1280 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1281 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1282 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1283 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1284 GIT_PATH_FUNC(git_path_shallow, "shallow")