Merge branch 'ab/grep-plug-pathspec-leak'
[alt-git.git] / path.c
blob302f9af2bd814eefe7bfeb2fbf703a4f8f6cb503
1 /*
2 * Utilities for paths and pathnames
3 */
4 #include "cache.h"
5 #include "strbuf.h"
6 #include "string-list.h"
7 #include "dir.h"
8 #include "worktree.h"
9 #include "submodule-config.h"
11 static int get_st_mode_bits(const char *path, int *mode)
13 struct stat st;
14 if (lstat(path, &st) < 0)
15 return -1;
16 *mode = st.st_mode;
17 return 0;
20 static char bad_path[] = "/bad-path/";
22 static struct strbuf *get_pathname(void)
24 static struct strbuf pathname_array[4] = {
25 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
27 static int index;
28 struct strbuf *sb = &pathname_array[index];
29 index = (index + 1) % ARRAY_SIZE(pathname_array);
30 strbuf_reset(sb);
31 return sb;
34 static char *cleanup_path(char *path)
36 /* Clean it up */
37 if (!memcmp(path, "./", 2)) {
38 path += 2;
39 while (*path == '/')
40 path++;
42 return path;
45 static void strbuf_cleanup_path(struct strbuf *sb)
47 char *path = cleanup_path(sb->buf);
48 if (path > sb->buf)
49 strbuf_remove(sb, 0, path - sb->buf);
52 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
54 va_list args;
55 unsigned len;
57 va_start(args, fmt);
58 len = vsnprintf(buf, n, fmt, args);
59 va_end(args);
60 if (len >= n) {
61 strlcpy(buf, bad_path, n);
62 return buf;
64 return cleanup_path(buf);
67 static int dir_prefix(const char *buf, const char *dir)
69 int len = strlen(dir);
70 return !strncmp(buf, dir, len) &&
71 (is_dir_sep(buf[len]) || buf[len] == '\0');
74 /* $buf =~ m|$dir/+$file| but without regex */
75 static int is_dir_file(const char *buf, const char *dir, const char *file)
77 int len = strlen(dir);
78 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
79 return 0;
80 while (is_dir_sep(buf[len]))
81 len++;
82 return !strcmp(buf + len, file);
85 static void replace_dir(struct strbuf *buf, int len, const char *newdir)
87 int newlen = strlen(newdir);
88 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
89 !is_dir_sep(newdir[newlen - 1]);
90 if (need_sep)
91 len--; /* keep one char, to be replaced with '/' */
92 strbuf_splice(buf, 0, len, newdir, newlen);
93 if (need_sep)
94 buf->buf[newlen] = '/';
97 struct common_dir {
98 /* Not considered garbage for report_linked_checkout_garbage */
99 unsigned ignore_garbage:1;
100 unsigned is_dir:1;
101 /* Not common even though its parent is */
102 unsigned exclude:1;
103 const char *dirname;
106 static struct common_dir common_list[] = {
107 { 0, 1, 0, "branches" },
108 { 0, 1, 0, "hooks" },
109 { 0, 1, 0, "info" },
110 { 0, 0, 1, "info/sparse-checkout" },
111 { 1, 1, 0, "logs" },
112 { 1, 1, 1, "logs/HEAD" },
113 { 0, 1, 1, "logs/refs/bisect" },
114 { 0, 1, 0, "lost-found" },
115 { 0, 1, 0, "objects" },
116 { 0, 1, 0, "refs" },
117 { 0, 1, 1, "refs/bisect" },
118 { 0, 1, 0, "remotes" },
119 { 0, 1, 0, "worktrees" },
120 { 0, 1, 0, "rr-cache" },
121 { 0, 1, 0, "svn" },
122 { 0, 0, 0, "config" },
123 { 1, 0, 0, "gc.pid" },
124 { 0, 0, 0, "packed-refs" },
125 { 0, 0, 0, "shallow" },
126 { 0, 0, 0, NULL }
130 * A compressed trie. A trie node consists of zero or more characters that
131 * are common to all elements with this prefix, optionally followed by some
132 * children. If value is not NULL, the trie node is a terminal node.
134 * For example, consider the following set of strings:
135 * abc
136 * def
137 * definite
138 * definition
140 * The trie would look like:
141 * root: len = 0, children a and d non-NULL, value = NULL.
142 * a: len = 2, contents = bc, value = (data for "abc")
143 * d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
144 * i: len = 3, contents = nit, children e and i non-NULL, value = NULL
145 * e: len = 0, children all NULL, value = (data for "definite")
146 * i: len = 2, contents = on, children all NULL,
147 * value = (data for "definition")
149 struct trie {
150 struct trie *children[256];
151 int len;
152 char *contents;
153 void *value;
156 static struct trie *make_trie_node(const char *key, void *value)
158 struct trie *new_node = xcalloc(1, sizeof(*new_node));
159 new_node->len = strlen(key);
160 if (new_node->len) {
161 new_node->contents = xmalloc(new_node->len);
162 memcpy(new_node->contents, key, new_node->len);
164 new_node->value = value;
165 return new_node;
169 * Add a key/value pair to a trie. The key is assumed to be \0-terminated.
170 * If there was an existing value for this key, return it.
172 static void *add_to_trie(struct trie *root, const char *key, void *value)
174 struct trie *child;
175 void *old;
176 int i;
178 if (!*key) {
179 /* we have reached the end of the key */
180 old = root->value;
181 root->value = value;
182 return old;
185 for (i = 0; i < root->len; i++) {
186 if (root->contents[i] == key[i])
187 continue;
190 * Split this node: child will contain this node's
191 * existing children.
193 child = malloc(sizeof(*child));
194 memcpy(child->children, root->children, sizeof(root->children));
196 child->len = root->len - i - 1;
197 if (child->len) {
198 child->contents = xstrndup(root->contents + i + 1,
199 child->len);
201 child->value = root->value;
202 root->value = NULL;
203 root->len = i;
205 memset(root->children, 0, sizeof(root->children));
206 root->children[(unsigned char)root->contents[i]] = child;
208 /* This is the newly-added child. */
209 root->children[(unsigned char)key[i]] =
210 make_trie_node(key + i + 1, value);
211 return NULL;
214 /* We have matched the entire compressed section */
215 if (key[i]) {
216 child = root->children[(unsigned char)key[root->len]];
217 if (child) {
218 return add_to_trie(child, key + root->len + 1, value);
219 } else {
220 child = make_trie_node(key + root->len + 1, value);
221 root->children[(unsigned char)key[root->len]] = child;
222 return NULL;
226 old = root->value;
227 root->value = value;
228 return old;
231 typedef int (*match_fn)(const char *unmatched, void *data, void *baton);
234 * Search a trie for some key. Find the longest /-or-\0-terminated
235 * prefix of the key for which the trie contains a value. Call fn
236 * with the unmatched portion of the key and the found value, and
237 * return its return value. If there is no such prefix, return -1.
239 * The key is partially normalized: consecutive slashes are skipped.
241 * For example, consider the trie containing only [refs,
242 * refs/worktree] (both with values).
244 * | key | unmatched | val from node | return value |
245 * |-----------------|------------|---------------|--------------|
246 * | a | not called | n/a | -1 |
247 * | refs | \0 | refs | as per fn |
248 * | refs/ | / | refs | as per fn |
249 * | refs/w | /w | refs | as per fn |
250 * | refs/worktree | \0 | refs/worktree | as per fn |
251 * | refs/worktree/ | / | refs/worktree | as per fn |
252 * | refs/worktree/a | /a | refs/worktree | as per fn |
253 * |-----------------|------------|---------------|--------------|
256 static int trie_find(struct trie *root, const char *key, match_fn fn,
257 void *baton)
259 int i;
260 int result;
261 struct trie *child;
263 if (!*key) {
264 /* we have reached the end of the key */
265 if (root->value && !root->len)
266 return fn(key, root->value, baton);
267 else
268 return -1;
271 for (i = 0; i < root->len; i++) {
272 /* Partial path normalization: skip consecutive slashes. */
273 if (key[i] == '/' && key[i+1] == '/') {
274 key++;
275 continue;
277 if (root->contents[i] != key[i])
278 return -1;
281 /* Matched the entire compressed section */
282 key += i;
283 if (!*key)
284 /* End of key */
285 return fn(key, root->value, baton);
287 /* Partial path normalization: skip consecutive slashes */
288 while (key[0] == '/' && key[1] == '/')
289 key++;
291 child = root->children[(unsigned char)*key];
292 if (child)
293 result = trie_find(child, key + 1, fn, baton);
294 else
295 result = -1;
297 if (result >= 0 || (*key != '/' && *key != 0))
298 return result;
299 if (root->value)
300 return fn(key, root->value, baton);
301 else
302 return -1;
305 static struct trie common_trie;
306 static int common_trie_done_setup;
308 static void init_common_trie(void)
310 struct common_dir *p;
312 if (common_trie_done_setup)
313 return;
315 for (p = common_list; p->dirname; p++)
316 add_to_trie(&common_trie, p->dirname, p);
318 common_trie_done_setup = 1;
322 * Helper function for update_common_dir: returns 1 if the dir
323 * prefix is common.
325 static int check_common(const char *unmatched, void *value, void *baton)
327 struct common_dir *dir = value;
329 if (!dir)
330 return 0;
332 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
333 return !dir->exclude;
335 if (!dir->is_dir && unmatched[0] == 0)
336 return !dir->exclude;
338 return 0;
341 static void update_common_dir(struct strbuf *buf, int git_dir_len,
342 const char *common_dir)
344 char *base = buf->buf + git_dir_len;
345 init_common_trie();
346 if (!common_dir)
347 common_dir = get_git_common_dir();
348 if (trie_find(&common_trie, base, check_common, NULL) > 0)
349 replace_dir(buf, git_dir_len, common_dir);
352 void report_linked_checkout_garbage(void)
354 struct strbuf sb = STRBUF_INIT;
355 const struct common_dir *p;
356 int len;
358 if (!git_common_dir_env)
359 return;
360 strbuf_addf(&sb, "%s/", get_git_dir());
361 len = sb.len;
362 for (p = common_list; p->dirname; p++) {
363 const char *path = p->dirname;
364 if (p->ignore_garbage)
365 continue;
366 strbuf_setlen(&sb, len);
367 strbuf_addstr(&sb, path);
368 if (file_exists(sb.buf))
369 report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
371 strbuf_release(&sb);
374 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
376 const char *base = buf->buf + git_dir_len;
377 if (git_graft_env && is_dir_file(base, "info", "grafts"))
378 strbuf_splice(buf, 0, buf->len,
379 get_graft_file(), strlen(get_graft_file()));
380 else if (git_index_env && !strcmp(base, "index"))
381 strbuf_splice(buf, 0, buf->len,
382 get_index_file(), strlen(get_index_file()));
383 else if (git_db_env && dir_prefix(base, "objects"))
384 replace_dir(buf, git_dir_len + 7, get_object_directory());
385 else if (git_hooks_path && dir_prefix(base, "hooks"))
386 replace_dir(buf, git_dir_len + 5, git_hooks_path);
387 else if (git_common_dir_env)
388 update_common_dir(buf, git_dir_len, NULL);
391 static void do_git_path(const struct worktree *wt, struct strbuf *buf,
392 const char *fmt, va_list args)
394 int gitdir_len;
395 strbuf_addstr(buf, get_worktree_git_dir(wt));
396 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
397 strbuf_addch(buf, '/');
398 gitdir_len = buf->len;
399 strbuf_vaddf(buf, fmt, args);
400 adjust_git_path(buf, gitdir_len);
401 strbuf_cleanup_path(buf);
404 char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
406 va_list args;
407 strbuf_reset(buf);
408 va_start(args, fmt);
409 do_git_path(NULL, buf, fmt, args);
410 va_end(args);
411 return buf->buf;
414 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
416 va_list args;
417 va_start(args, fmt);
418 do_git_path(NULL, sb, fmt, args);
419 va_end(args);
422 const char *git_path(const char *fmt, ...)
424 struct strbuf *pathname = get_pathname();
425 va_list args;
426 va_start(args, fmt);
427 do_git_path(NULL, pathname, fmt, args);
428 va_end(args);
429 return pathname->buf;
432 char *git_pathdup(const char *fmt, ...)
434 struct strbuf path = STRBUF_INIT;
435 va_list args;
436 va_start(args, fmt);
437 do_git_path(NULL, &path, fmt, args);
438 va_end(args);
439 return strbuf_detach(&path, NULL);
442 char *mkpathdup(const char *fmt, ...)
444 struct strbuf sb = STRBUF_INIT;
445 va_list args;
446 va_start(args, fmt);
447 strbuf_vaddf(&sb, fmt, args);
448 va_end(args);
449 strbuf_cleanup_path(&sb);
450 return strbuf_detach(&sb, NULL);
453 const char *mkpath(const char *fmt, ...)
455 va_list args;
456 struct strbuf *pathname = get_pathname();
457 va_start(args, fmt);
458 strbuf_vaddf(pathname, fmt, args);
459 va_end(args);
460 return cleanup_path(pathname->buf);
463 const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
465 struct strbuf *pathname = get_pathname();
466 va_list args;
467 va_start(args, fmt);
468 do_git_path(wt, pathname, fmt, args);
469 va_end(args);
470 return pathname->buf;
473 /* Returns 0 on success, negative on failure. */
474 static int do_submodule_path(struct strbuf *buf, const char *path,
475 const char *fmt, va_list args)
477 struct strbuf git_submodule_common_dir = STRBUF_INIT;
478 struct strbuf git_submodule_dir = STRBUF_INIT;
479 int ret;
481 ret = submodule_to_gitdir(&git_submodule_dir, path);
482 if (ret)
483 goto cleanup;
485 strbuf_complete(&git_submodule_dir, '/');
486 strbuf_addbuf(buf, &git_submodule_dir);
487 strbuf_vaddf(buf, fmt, args);
489 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
490 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
492 strbuf_cleanup_path(buf);
494 cleanup:
495 strbuf_release(&git_submodule_dir);
496 strbuf_release(&git_submodule_common_dir);
497 return ret;
500 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
502 int err;
503 va_list args;
504 struct strbuf buf = STRBUF_INIT;
505 va_start(args, fmt);
506 err = do_submodule_path(&buf, path, fmt, args);
507 va_end(args);
508 if (err) {
509 strbuf_release(&buf);
510 return NULL;
512 return strbuf_detach(&buf, NULL);
515 int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
516 const char *fmt, ...)
518 int err;
519 va_list args;
520 va_start(args, fmt);
521 err = do_submodule_path(buf, path, fmt, args);
522 va_end(args);
524 return err;
527 static void do_git_common_path(struct strbuf *buf,
528 const char *fmt,
529 va_list args)
531 strbuf_addstr(buf, get_git_common_dir());
532 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
533 strbuf_addch(buf, '/');
534 strbuf_vaddf(buf, fmt, args);
535 strbuf_cleanup_path(buf);
538 const char *git_common_path(const char *fmt, ...)
540 struct strbuf *pathname = get_pathname();
541 va_list args;
542 va_start(args, fmt);
543 do_git_common_path(pathname, fmt, args);
544 va_end(args);
545 return pathname->buf;
548 void strbuf_git_common_path(struct strbuf *sb, const char *fmt, ...)
550 va_list args;
551 va_start(args, fmt);
552 do_git_common_path(sb, fmt, args);
553 va_end(args);
556 int validate_headref(const char *path)
558 struct stat st;
559 char *buf, buffer[256];
560 unsigned char sha1[20];
561 int fd;
562 ssize_t len;
564 if (lstat(path, &st) < 0)
565 return -1;
567 /* Make sure it is a "refs/.." symlink */
568 if (S_ISLNK(st.st_mode)) {
569 len = readlink(path, buffer, sizeof(buffer)-1);
570 if (len >= 5 && !memcmp("refs/", buffer, 5))
571 return 0;
572 return -1;
576 * Anything else, just open it and try to see if it is a symbolic ref.
578 fd = open(path, O_RDONLY);
579 if (fd < 0)
580 return -1;
581 len = read_in_full(fd, buffer, sizeof(buffer)-1);
582 close(fd);
585 * Is it a symbolic ref?
587 if (len < 4)
588 return -1;
589 if (!memcmp("ref:", buffer, 4)) {
590 buf = buffer + 4;
591 len -= 4;
592 while (len && isspace(*buf))
593 buf++, len--;
594 if (len >= 5 && !memcmp("refs/", buf, 5))
595 return 0;
599 * Is this a detached HEAD?
601 if (!get_sha1_hex(buffer, sha1))
602 return 0;
604 return -1;
607 static struct passwd *getpw_str(const char *username, size_t len)
609 struct passwd *pw;
610 char *username_z = xmemdupz(username, len);
611 pw = getpwnam(username_z);
612 free(username_z);
613 return pw;
617 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
618 * then it is a newly allocated string. Returns NULL on getpw failure or
619 * if path is NULL.
621 char *expand_user_path(const char *path)
623 struct strbuf user_path = STRBUF_INIT;
624 const char *to_copy = path;
626 if (path == NULL)
627 goto return_null;
628 if (path[0] == '~') {
629 const char *first_slash = strchrnul(path, '/');
630 const char *username = path + 1;
631 size_t username_len = first_slash - username;
632 if (username_len == 0) {
633 const char *home = getenv("HOME");
634 if (!home)
635 goto return_null;
636 strbuf_addstr(&user_path, home);
637 #ifdef GIT_WINDOWS_NATIVE
638 convert_slashes(user_path.buf);
639 #endif
640 } else {
641 struct passwd *pw = getpw_str(username, username_len);
642 if (!pw)
643 goto return_null;
644 strbuf_addstr(&user_path, pw->pw_dir);
646 to_copy = first_slash;
648 strbuf_addstr(&user_path, to_copy);
649 return strbuf_detach(&user_path, NULL);
650 return_null:
651 strbuf_release(&user_path);
652 return NULL;
656 * First, one directory to try is determined by the following algorithm.
658 * (0) If "strict" is given, the path is used as given and no DWIM is
659 * done. Otherwise:
660 * (1) "~/path" to mean path under the running user's home directory;
661 * (2) "~user/path" to mean path under named user's home directory;
662 * (3) "relative/path" to mean cwd relative directory; or
663 * (4) "/absolute/path" to mean absolute directory.
665 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
666 * in this order. We select the first one that is a valid git repository, and
667 * chdir() to it. If none match, or we fail to chdir, we return NULL.
669 * If all goes well, we return the directory we used to chdir() (but
670 * before ~user is expanded), avoiding getcwd() resolving symbolic
671 * links. User relative paths are also returned as they are given,
672 * except DWIM suffixing.
674 const char *enter_repo(const char *path, int strict)
676 static struct strbuf validated_path = STRBUF_INIT;
677 static struct strbuf used_path = STRBUF_INIT;
679 if (!path)
680 return NULL;
682 if (!strict) {
683 static const char *suffix[] = {
684 "/.git", "", ".git/.git", ".git", NULL,
686 const char *gitfile;
687 int len = strlen(path);
688 int i;
689 while ((1 < len) && (path[len-1] == '/'))
690 len--;
693 * We can handle arbitrary-sized buffers, but this remains as a
694 * sanity check on untrusted input.
696 if (PATH_MAX <= len)
697 return NULL;
699 strbuf_reset(&used_path);
700 strbuf_reset(&validated_path);
701 strbuf_add(&used_path, path, len);
702 strbuf_add(&validated_path, path, len);
704 if (used_path.buf[0] == '~') {
705 char *newpath = expand_user_path(used_path.buf);
706 if (!newpath)
707 return NULL;
708 strbuf_attach(&used_path, newpath, strlen(newpath),
709 strlen(newpath));
711 for (i = 0; suffix[i]; i++) {
712 struct stat st;
713 size_t baselen = used_path.len;
714 strbuf_addstr(&used_path, suffix[i]);
715 if (!stat(used_path.buf, &st) &&
716 (S_ISREG(st.st_mode) ||
717 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
718 strbuf_addstr(&validated_path, suffix[i]);
719 break;
721 strbuf_setlen(&used_path, baselen);
723 if (!suffix[i])
724 return NULL;
725 gitfile = read_gitfile(used_path.buf);
726 if (gitfile) {
727 strbuf_reset(&used_path);
728 strbuf_addstr(&used_path, gitfile);
730 if (chdir(used_path.buf))
731 return NULL;
732 path = validated_path.buf;
734 else {
735 const char *gitfile = read_gitfile(path);
736 if (gitfile)
737 path = gitfile;
738 if (chdir(path))
739 return NULL;
742 if (is_git_directory(".")) {
743 set_git_dir(".");
744 check_repository_format();
745 return path;
748 return NULL;
751 static int calc_shared_perm(int mode)
753 int tweak;
755 if (get_shared_repository() < 0)
756 tweak = -get_shared_repository();
757 else
758 tweak = get_shared_repository();
760 if (!(mode & S_IWUSR))
761 tweak &= ~0222;
762 if (mode & S_IXUSR)
763 /* Copy read bits to execute bits */
764 tweak |= (tweak & 0444) >> 2;
765 if (get_shared_repository() < 0)
766 mode = (mode & ~0777) | tweak;
767 else
768 mode |= tweak;
770 return mode;
774 int adjust_shared_perm(const char *path)
776 int old_mode, new_mode;
778 if (!get_shared_repository())
779 return 0;
780 if (get_st_mode_bits(path, &old_mode) < 0)
781 return -1;
783 new_mode = calc_shared_perm(old_mode);
784 if (S_ISDIR(old_mode)) {
785 /* Copy read bits to execute bits */
786 new_mode |= (new_mode & 0444) >> 2;
787 new_mode |= FORCE_DIR_SET_GID;
790 if (((old_mode ^ new_mode) & ~S_IFMT) &&
791 chmod(path, (new_mode & ~S_IFMT)) < 0)
792 return -2;
793 return 0;
796 void safe_create_dir(const char *dir, int share)
798 if (mkdir(dir, 0777) < 0) {
799 if (errno != EEXIST) {
800 perror(dir);
801 exit(1);
804 else if (share && adjust_shared_perm(dir))
805 die(_("Could not make %s writable by group"), dir);
808 static int have_same_root(const char *path1, const char *path2)
810 int is_abs1, is_abs2;
812 is_abs1 = is_absolute_path(path1);
813 is_abs2 = is_absolute_path(path2);
814 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
815 (!is_abs1 && !is_abs2);
819 * Give path as relative to prefix.
821 * The strbuf may or may not be used, so do not assume it contains the
822 * returned path.
824 const char *relative_path(const char *in, const char *prefix,
825 struct strbuf *sb)
827 int in_len = in ? strlen(in) : 0;
828 int prefix_len = prefix ? strlen(prefix) : 0;
829 int in_off = 0;
830 int prefix_off = 0;
831 int i = 0, j = 0;
833 if (!in_len)
834 return "./";
835 else if (!prefix_len)
836 return in;
838 if (have_same_root(in, prefix))
839 /* bypass dos_drive, for "c:" is identical to "C:" */
840 i = j = has_dos_drive_prefix(in);
841 else {
842 return in;
845 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
846 if (is_dir_sep(prefix[i])) {
847 while (is_dir_sep(prefix[i]))
848 i++;
849 while (is_dir_sep(in[j]))
850 j++;
851 prefix_off = i;
852 in_off = j;
853 } else {
854 i++;
855 j++;
859 if (
860 /* "prefix" seems like prefix of "in" */
861 i >= prefix_len &&
863 * but "/foo" is not a prefix of "/foobar"
864 * (i.e. prefix not end with '/')
866 prefix_off < prefix_len) {
867 if (j >= in_len) {
868 /* in="/a/b", prefix="/a/b" */
869 in_off = in_len;
870 } else if (is_dir_sep(in[j])) {
871 /* in="/a/b/c", prefix="/a/b" */
872 while (is_dir_sep(in[j]))
873 j++;
874 in_off = j;
875 } else {
876 /* in="/a/bbb/c", prefix="/a/b" */
877 i = prefix_off;
879 } else if (
880 /* "in" is short than "prefix" */
881 j >= in_len &&
882 /* "in" not end with '/' */
883 in_off < in_len) {
884 if (is_dir_sep(prefix[i])) {
885 /* in="/a/b", prefix="/a/b/c/" */
886 while (is_dir_sep(prefix[i]))
887 i++;
888 in_off = in_len;
891 in += in_off;
892 in_len -= in_off;
894 if (i >= prefix_len) {
895 if (!in_len)
896 return "./";
897 else
898 return in;
901 strbuf_reset(sb);
902 strbuf_grow(sb, in_len);
904 while (i < prefix_len) {
905 if (is_dir_sep(prefix[i])) {
906 strbuf_addstr(sb, "../");
907 while (is_dir_sep(prefix[i]))
908 i++;
909 continue;
911 i++;
913 if (!is_dir_sep(prefix[prefix_len - 1]))
914 strbuf_addstr(sb, "../");
916 strbuf_addstr(sb, in);
918 return sb->buf;
922 * A simpler implementation of relative_path
924 * Get relative path by removing "prefix" from "in". This function
925 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
926 * to increase performance when traversing the path to work_tree.
928 const char *remove_leading_path(const char *in, const char *prefix)
930 static struct strbuf buf = STRBUF_INIT;
931 int i = 0, j = 0;
933 if (!prefix || !prefix[0])
934 return in;
935 while (prefix[i]) {
936 if (is_dir_sep(prefix[i])) {
937 if (!is_dir_sep(in[j]))
938 return in;
939 while (is_dir_sep(prefix[i]))
940 i++;
941 while (is_dir_sep(in[j]))
942 j++;
943 continue;
944 } else if (in[j] != prefix[i]) {
945 return in;
947 i++;
948 j++;
950 if (
951 /* "/foo" is a prefix of "/foo" */
952 in[j] &&
953 /* "/foo" is not a prefix of "/foobar" */
954 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
956 return in;
957 while (is_dir_sep(in[j]))
958 j++;
960 strbuf_reset(&buf);
961 if (!in[j])
962 strbuf_addstr(&buf, ".");
963 else
964 strbuf_addstr(&buf, in + j);
965 return buf.buf;
969 * It is okay if dst == src, but they should not overlap otherwise.
971 * Performs the following normalizations on src, storing the result in dst:
972 * - Ensures that components are separated by '/' (Windows only)
973 * - Squashes sequences of '/' except "//server/share" on Windows
974 * - Removes "." components.
975 * - Removes ".." components, and the components the precede them.
976 * Returns failure (non-zero) if a ".." component appears as first path
977 * component anytime during the normalization. Otherwise, returns success (0).
979 * Note that this function is purely textual. It does not follow symlinks,
980 * verify the existence of the path, or make any system calls.
982 * prefix_len != NULL is for a specific case of prefix_pathspec():
983 * assume that src == dst and src[0..prefix_len-1] is already
984 * normalized, any time "../" eats up to the prefix_len part,
985 * prefix_len is reduced. In the end prefix_len is the remaining
986 * prefix that has not been overridden by user pathspec.
988 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
989 * For everything but the root folder itself, the normalized path should not
990 * end with a '/', then the callers need to be fixed up accordingly.
993 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
995 char *dst0;
996 const char *end;
999 * Copy initial part of absolute path: "/", "C:/", "//server/share/".
1001 end = src + offset_1st_component(src);
1002 while (src < end) {
1003 char c = *src++;
1004 if (is_dir_sep(c))
1005 c = '/';
1006 *dst++ = c;
1008 dst0 = dst;
1010 while (is_dir_sep(*src))
1011 src++;
1013 for (;;) {
1014 char c = *src;
1017 * A path component that begins with . could be
1018 * special:
1019 * (1) "." and ends -- ignore and terminate.
1020 * (2) "./" -- ignore them, eat slash and continue.
1021 * (3) ".." and ends -- strip one and terminate.
1022 * (4) "../" -- strip one, eat slash and continue.
1024 if (c == '.') {
1025 if (!src[1]) {
1026 /* (1) */
1027 src++;
1028 } else if (is_dir_sep(src[1])) {
1029 /* (2) */
1030 src += 2;
1031 while (is_dir_sep(*src))
1032 src++;
1033 continue;
1034 } else if (src[1] == '.') {
1035 if (!src[2]) {
1036 /* (3) */
1037 src += 2;
1038 goto up_one;
1039 } else if (is_dir_sep(src[2])) {
1040 /* (4) */
1041 src += 3;
1042 while (is_dir_sep(*src))
1043 src++;
1044 goto up_one;
1049 /* copy up to the next '/', and eat all '/' */
1050 while ((c = *src++) != '\0' && !is_dir_sep(c))
1051 *dst++ = c;
1052 if (is_dir_sep(c)) {
1053 *dst++ = '/';
1054 while (is_dir_sep(c))
1055 c = *src++;
1056 src--;
1057 } else if (!c)
1058 break;
1059 continue;
1061 up_one:
1063 * dst0..dst is prefix portion, and dst[-1] is '/';
1064 * go up one level.
1066 dst--; /* go to trailing '/' */
1067 if (dst <= dst0)
1068 return -1;
1069 /* Windows: dst[-1] cannot be backslash anymore */
1070 while (dst0 < dst && dst[-1] != '/')
1071 dst--;
1072 if (prefix_len && *prefix_len > dst - dst0)
1073 *prefix_len = dst - dst0;
1075 *dst = '\0';
1076 return 0;
1079 int normalize_path_copy(char *dst, const char *src)
1081 return normalize_path_copy_len(dst, src, NULL);
1085 * path = Canonical absolute path
1086 * prefixes = string_list containing normalized, absolute paths without
1087 * trailing slashes (except for the root directory, which is denoted by "/").
1089 * Determines, for each path in prefixes, whether the "prefix"
1090 * is an ancestor directory of path. Returns the length of the longest
1091 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1092 * is an ancestor. (Note that this means 0 is returned if prefixes is
1093 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1094 * are not considered to be their own ancestors. path must be in a
1095 * canonical form: empty components, or "." or ".." components are not
1096 * allowed.
1098 int longest_ancestor_length(const char *path, struct string_list *prefixes)
1100 int i, max_len = -1;
1102 if (!strcmp(path, "/"))
1103 return -1;
1105 for (i = 0; i < prefixes->nr; i++) {
1106 const char *ceil = prefixes->items[i].string;
1107 int len = strlen(ceil);
1109 if (len == 1 && ceil[0] == '/')
1110 len = 0; /* root matches anything, with length 0 */
1111 else if (!strncmp(path, ceil, len) && path[len] == '/')
1112 ; /* match of length len */
1113 else
1114 continue; /* no match */
1116 if (len > max_len)
1117 max_len = len;
1120 return max_len;
1123 /* strip arbitrary amount of directory separators at end of path */
1124 static inline int chomp_trailing_dir_sep(const char *path, int len)
1126 while (len && is_dir_sep(path[len - 1]))
1127 len--;
1128 return len;
1132 * If path ends with suffix (complete path components), returns the
1133 * part before suffix (sans trailing directory separators).
1134 * Otherwise returns NULL.
1136 char *strip_path_suffix(const char *path, const char *suffix)
1138 int path_len = strlen(path), suffix_len = strlen(suffix);
1140 while (suffix_len) {
1141 if (!path_len)
1142 return NULL;
1144 if (is_dir_sep(path[path_len - 1])) {
1145 if (!is_dir_sep(suffix[suffix_len - 1]))
1146 return NULL;
1147 path_len = chomp_trailing_dir_sep(path, path_len);
1148 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1150 else if (path[--path_len] != suffix[--suffix_len])
1151 return NULL;
1154 if (path_len && !is_dir_sep(path[path_len - 1]))
1155 return NULL;
1156 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1159 int daemon_avoid_alias(const char *p)
1161 int sl, ndot;
1164 * This resurrects the belts and suspenders paranoia check by HPA
1165 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1166 * does not do getcwd() based path canonicalization.
1168 * sl becomes true immediately after seeing '/' and continues to
1169 * be true as long as dots continue after that without intervening
1170 * non-dot character.
1172 if (!p || (*p != '/' && *p != '~'))
1173 return -1;
1174 sl = 1; ndot = 0;
1175 p++;
1177 while (1) {
1178 char ch = *p++;
1179 if (sl) {
1180 if (ch == '.')
1181 ndot++;
1182 else if (ch == '/') {
1183 if (ndot < 3)
1184 /* reject //, /./ and /../ */
1185 return -1;
1186 ndot = 0;
1188 else if (ch == 0) {
1189 if (0 < ndot && ndot < 3)
1190 /* reject /.$ and /..$ */
1191 return -1;
1192 return 0;
1194 else
1195 sl = ndot = 0;
1197 else if (ch == 0)
1198 return 0;
1199 else if (ch == '/') {
1200 sl = 1;
1201 ndot = 0;
1206 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1208 if (len < skip)
1209 return 0;
1210 len -= skip;
1211 path += skip;
1212 while (len-- > 0) {
1213 char c = *(path++);
1214 if (c != ' ' && c != '.')
1215 return 0;
1217 return 1;
1220 int is_ntfs_dotgit(const char *name)
1222 int len;
1224 for (len = 0; ; len++)
1225 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1226 if (only_spaces_and_periods(name, len, 4) &&
1227 !strncasecmp(name, ".git", 4))
1228 return 1;
1229 if (only_spaces_and_periods(name, len, 5) &&
1230 !strncasecmp(name, "git~1", 5))
1231 return 1;
1232 if (name[len] != '\\')
1233 return 0;
1234 name += len + 1;
1235 len = -1;
1239 char *xdg_config_home(const char *filename)
1241 const char *home, *config_home;
1243 assert(filename);
1244 config_home = getenv("XDG_CONFIG_HOME");
1245 if (config_home && *config_home)
1246 return mkpathdup("%s/git/%s", config_home, filename);
1248 home = getenv("HOME");
1249 if (home)
1250 return mkpathdup("%s/.config/git/%s", home, filename);
1251 return NULL;
1254 char *xdg_cache_home(const char *filename)
1256 const char *home, *cache_home;
1258 assert(filename);
1259 cache_home = getenv("XDG_CACHE_HOME");
1260 if (cache_home && *cache_home)
1261 return mkpathdup("%s/git/%s", cache_home, filename);
1263 home = getenv("HOME");
1264 if (home)
1265 return mkpathdup("%s/.cache/git/%s", home, filename);
1266 return NULL;
1269 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1270 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1271 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1272 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1273 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1274 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1275 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1276 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1277 GIT_PATH_FUNC(git_path_shallow, "shallow")