git-multimail: update to release 1.2.0
[git.git] / path.c
blob65beb2dca3335912b81b19564ae1db3ca51067be
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"
9 static int get_st_mode_bits(const char *path, int *mode)
11 struct stat st;
12 if (lstat(path, &st) < 0)
13 return -1;
14 *mode = st.st_mode;
15 return 0;
18 static char bad_path[] = "/bad-path/";
20 static struct strbuf *get_pathname(void)
22 static struct strbuf pathname_array[4] = {
23 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
25 static int index;
26 struct strbuf *sb = &pathname_array[3 & ++index];
27 strbuf_reset(sb);
28 return sb;
31 static char *cleanup_path(char *path)
33 /* Clean it up */
34 if (!memcmp(path, "./", 2)) {
35 path += 2;
36 while (*path == '/')
37 path++;
39 return path;
42 static void strbuf_cleanup_path(struct strbuf *sb)
44 char *path = cleanup_path(sb->buf);
45 if (path > sb->buf)
46 strbuf_remove(sb, 0, path - sb->buf);
49 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
51 va_list args;
52 unsigned len;
54 va_start(args, fmt);
55 len = vsnprintf(buf, n, fmt, args);
56 va_end(args);
57 if (len >= n) {
58 strlcpy(buf, bad_path, n);
59 return buf;
61 return cleanup_path(buf);
64 static int dir_prefix(const char *buf, const char *dir)
66 int len = strlen(dir);
67 return !strncmp(buf, dir, len) &&
68 (is_dir_sep(buf[len]) || buf[len] == '\0');
71 /* $buf =~ m|$dir/+$file| but without regex */
72 static int is_dir_file(const char *buf, const char *dir, const char *file)
74 int len = strlen(dir);
75 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
76 return 0;
77 while (is_dir_sep(buf[len]))
78 len++;
79 return !strcmp(buf + len, file);
82 static void replace_dir(struct strbuf *buf, int len, const char *newdir)
84 int newlen = strlen(newdir);
85 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
86 !is_dir_sep(newdir[newlen - 1]);
87 if (need_sep)
88 len--; /* keep one char, to be replaced with '/' */
89 strbuf_splice(buf, 0, len, newdir, newlen);
90 if (need_sep)
91 buf->buf[newlen] = '/';
94 struct common_dir {
95 /* Not considered garbage for report_linked_checkout_garbage */
96 unsigned ignore_garbage:1;
97 unsigned is_dir:1;
98 /* Not common even though its parent is */
99 unsigned exclude:1;
100 const char *dirname;
103 static struct common_dir common_list[] = {
104 { 0, 1, 0, "branches" },
105 { 0, 1, 0, "hooks" },
106 { 0, 1, 0, "info" },
107 { 0, 0, 1, "info/sparse-checkout" },
108 { 1, 1, 0, "logs" },
109 { 1, 1, 1, "logs/HEAD" },
110 { 0, 1, 1, "logs/refs/bisect" },
111 { 0, 1, 0, "lost-found" },
112 { 0, 1, 0, "objects" },
113 { 0, 1, 0, "refs" },
114 { 0, 1, 1, "refs/bisect" },
115 { 0, 1, 0, "remotes" },
116 { 0, 1, 0, "worktrees" },
117 { 0, 1, 0, "rr-cache" },
118 { 0, 1, 0, "svn" },
119 { 0, 0, 0, "config" },
120 { 1, 0, 0, "gc.pid" },
121 { 0, 0, 0, "packed-refs" },
122 { 0, 0, 0, "shallow" },
123 { 0, 0, 0, NULL }
127 * A compressed trie. A trie node consists of zero or more characters that
128 * are common to all elements with this prefix, optionally followed by some
129 * children. If value is not NULL, the trie node is a terminal node.
131 * For example, consider the following set of strings:
132 * abc
133 * def
134 * definite
135 * definition
137 * The trie would look look like:
138 * root: len = 0, children a and d non-NULL, value = NULL.
139 * a: len = 2, contents = bc, value = (data for "abc")
140 * d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
141 * i: len = 3, contents = nit, children e and i non-NULL, value = NULL
142 * e: len = 0, children all NULL, value = (data for "definite")
143 * i: len = 2, contents = on, children all NULL,
144 * value = (data for "definition")
146 struct trie {
147 struct trie *children[256];
148 int len;
149 char *contents;
150 void *value;
153 static struct trie *make_trie_node(const char *key, void *value)
155 struct trie *new_node = xcalloc(1, sizeof(*new_node));
156 new_node->len = strlen(key);
157 if (new_node->len) {
158 new_node->contents = xmalloc(new_node->len);
159 memcpy(new_node->contents, key, new_node->len);
161 new_node->value = value;
162 return new_node;
166 * Add a key/value pair to a trie. The key is assumed to be \0-terminated.
167 * If there was an existing value for this key, return it.
169 static void *add_to_trie(struct trie *root, const char *key, void *value)
171 struct trie *child;
172 void *old;
173 int i;
175 if (!*key) {
176 /* we have reached the end of the key */
177 old = root->value;
178 root->value = value;
179 return old;
182 for (i = 0; i < root->len; i++) {
183 if (root->contents[i] == key[i])
184 continue;
187 * Split this node: child will contain this node's
188 * existing children.
190 child = malloc(sizeof(*child));
191 memcpy(child->children, root->children, sizeof(root->children));
193 child->len = root->len - i - 1;
194 if (child->len) {
195 child->contents = xstrndup(root->contents + i + 1,
196 child->len);
198 child->value = root->value;
199 root->value = NULL;
200 root->len = i;
202 memset(root->children, 0, sizeof(root->children));
203 root->children[(unsigned char)root->contents[i]] = child;
205 /* This is the newly-added child. */
206 root->children[(unsigned char)key[i]] =
207 make_trie_node(key + i + 1, value);
208 return NULL;
211 /* We have matched the entire compressed section */
212 if (key[i]) {
213 child = root->children[(unsigned char)key[root->len]];
214 if (child) {
215 return add_to_trie(child, key + root->len + 1, value);
216 } else {
217 child = make_trie_node(key + root->len + 1, value);
218 root->children[(unsigned char)key[root->len]] = child;
219 return NULL;
223 old = root->value;
224 root->value = value;
225 return old;
228 typedef int (*match_fn)(const char *unmatched, void *data, void *baton);
231 * Search a trie for some key. Find the longest /-or-\0-terminated
232 * prefix of the key for which the trie contains a value. Call fn
233 * with the unmatched portion of the key and the found value, and
234 * return its return value. If there is no such prefix, return -1.
236 * The key is partially normalized: consecutive slashes are skipped.
238 * For example, consider the trie containing only [refs,
239 * refs/worktree] (both with values).
241 * | key | unmatched | val from node | return value |
242 * |-----------------|------------|---------------|--------------|
243 * | a | not called | n/a | -1 |
244 * | refs | \0 | refs | as per fn |
245 * | refs/ | / | refs | as per fn |
246 * | refs/w | /w | refs | as per fn |
247 * | refs/worktree | \0 | refs/worktree | as per fn |
248 * | refs/worktree/ | / | refs/worktree | as per fn |
249 * | refs/worktree/a | /a | refs/worktree | as per fn |
250 * |-----------------|------------|---------------|--------------|
253 static int trie_find(struct trie *root, const char *key, match_fn fn,
254 void *baton)
256 int i;
257 int result;
258 struct trie *child;
260 if (!*key) {
261 /* we have reached the end of the key */
262 if (root->value && !root->len)
263 return fn(key, root->value, baton);
264 else
265 return -1;
268 for (i = 0; i < root->len; i++) {
269 /* Partial path normalization: skip consecutive slashes. */
270 if (key[i] == '/' && key[i+1] == '/') {
271 key++;
272 continue;
274 if (root->contents[i] != key[i])
275 return -1;
278 /* Matched the entire compressed section */
279 key += i;
280 if (!*key)
281 /* End of key */
282 return fn(key, root->value, baton);
284 /* Partial path normalization: skip consecutive slashes */
285 while (key[0] == '/' && key[1] == '/')
286 key++;
288 child = root->children[(unsigned char)*key];
289 if (child)
290 result = trie_find(child, key + 1, fn, baton);
291 else
292 result = -1;
294 if (result >= 0 || (*key != '/' && *key != 0))
295 return result;
296 if (root->value)
297 return fn(key, root->value, baton);
298 else
299 return -1;
302 static struct trie common_trie;
303 static int common_trie_done_setup;
305 static void init_common_trie(void)
307 struct common_dir *p;
309 if (common_trie_done_setup)
310 return;
312 for (p = common_list; p->dirname; p++)
313 add_to_trie(&common_trie, p->dirname, p);
315 common_trie_done_setup = 1;
319 * Helper function for update_common_dir: returns 1 if the dir
320 * prefix is common.
322 static int check_common(const char *unmatched, void *value, void *baton)
324 struct common_dir *dir = value;
326 if (!dir)
327 return 0;
329 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
330 return !dir->exclude;
332 if (!dir->is_dir && unmatched[0] == 0)
333 return !dir->exclude;
335 return 0;
338 static void update_common_dir(struct strbuf *buf, int git_dir_len)
340 char *base = buf->buf + git_dir_len;
341 init_common_trie();
342 if (trie_find(&common_trie, base, check_common, NULL) > 0)
343 replace_dir(buf, git_dir_len, get_git_common_dir());
346 void report_linked_checkout_garbage(void)
348 struct strbuf sb = STRBUF_INIT;
349 const struct common_dir *p;
350 int len;
352 if (!git_common_dir_env)
353 return;
354 strbuf_addf(&sb, "%s/", get_git_dir());
355 len = sb.len;
356 for (p = common_list; p->dirname; p++) {
357 const char *path = p->dirname;
358 if (p->ignore_garbage)
359 continue;
360 strbuf_setlen(&sb, len);
361 strbuf_addstr(&sb, path);
362 if (file_exists(sb.buf))
363 report_garbage("unused in linked checkout", sb.buf);
365 strbuf_release(&sb);
368 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
370 const char *base = buf->buf + git_dir_len;
371 if (git_graft_env && is_dir_file(base, "info", "grafts"))
372 strbuf_splice(buf, 0, buf->len,
373 get_graft_file(), strlen(get_graft_file()));
374 else if (git_index_env && !strcmp(base, "index"))
375 strbuf_splice(buf, 0, buf->len,
376 get_index_file(), strlen(get_index_file()));
377 else if (git_db_env && dir_prefix(base, "objects"))
378 replace_dir(buf, git_dir_len + 7, get_object_directory());
379 else if (git_common_dir_env)
380 update_common_dir(buf, git_dir_len);
383 static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
385 int gitdir_len;
386 strbuf_addstr(buf, get_git_dir());
387 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
388 strbuf_addch(buf, '/');
389 gitdir_len = buf->len;
390 strbuf_vaddf(buf, fmt, args);
391 adjust_git_path(buf, gitdir_len);
392 strbuf_cleanup_path(buf);
395 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
397 va_list args;
398 va_start(args, fmt);
399 do_git_path(sb, fmt, args);
400 va_end(args);
403 const char *git_path(const char *fmt, ...)
405 struct strbuf *pathname = get_pathname();
406 va_list args;
407 va_start(args, fmt);
408 do_git_path(pathname, fmt, args);
409 va_end(args);
410 return pathname->buf;
413 char *git_pathdup(const char *fmt, ...)
415 struct strbuf path = STRBUF_INIT;
416 va_list args;
417 va_start(args, fmt);
418 do_git_path(&path, fmt, args);
419 va_end(args);
420 return strbuf_detach(&path, NULL);
423 char *mkpathdup(const char *fmt, ...)
425 struct strbuf sb = STRBUF_INIT;
426 va_list args;
427 va_start(args, fmt);
428 strbuf_vaddf(&sb, fmt, args);
429 va_end(args);
430 strbuf_cleanup_path(&sb);
431 return strbuf_detach(&sb, NULL);
434 const char *mkpath(const char *fmt, ...)
436 va_list args;
437 struct strbuf *pathname = get_pathname();
438 va_start(args, fmt);
439 strbuf_vaddf(pathname, fmt, args);
440 va_end(args);
441 return cleanup_path(pathname->buf);
444 static void do_submodule_path(struct strbuf *buf, const char *path,
445 const char *fmt, va_list args)
447 const char *git_dir;
449 strbuf_addstr(buf, path);
450 if (buf->len && buf->buf[buf->len - 1] != '/')
451 strbuf_addch(buf, '/');
452 strbuf_addstr(buf, ".git");
454 git_dir = read_gitfile(buf->buf);
455 if (git_dir) {
456 strbuf_reset(buf);
457 strbuf_addstr(buf, git_dir);
459 strbuf_addch(buf, '/');
461 strbuf_vaddf(buf, fmt, args);
462 strbuf_cleanup_path(buf);
465 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
467 va_list args;
468 struct strbuf buf = STRBUF_INIT;
469 va_start(args, fmt);
470 do_submodule_path(&buf, path, fmt, args);
471 va_end(args);
472 return strbuf_detach(&buf, NULL);
475 void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
476 const char *fmt, ...)
478 va_list args;
479 va_start(args, fmt);
480 do_submodule_path(buf, path, fmt, args);
481 va_end(args);
484 int validate_headref(const char *path)
486 struct stat st;
487 char *buf, buffer[256];
488 unsigned char sha1[20];
489 int fd;
490 ssize_t len;
492 if (lstat(path, &st) < 0)
493 return -1;
495 /* Make sure it is a "refs/.." symlink */
496 if (S_ISLNK(st.st_mode)) {
497 len = readlink(path, buffer, sizeof(buffer)-1);
498 if (len >= 5 && !memcmp("refs/", buffer, 5))
499 return 0;
500 return -1;
504 * Anything else, just open it and try to see if it is a symbolic ref.
506 fd = open(path, O_RDONLY);
507 if (fd < 0)
508 return -1;
509 len = read_in_full(fd, buffer, sizeof(buffer)-1);
510 close(fd);
513 * Is it a symbolic ref?
515 if (len < 4)
516 return -1;
517 if (!memcmp("ref:", buffer, 4)) {
518 buf = buffer + 4;
519 len -= 4;
520 while (len && isspace(*buf))
521 buf++, len--;
522 if (len >= 5 && !memcmp("refs/", buf, 5))
523 return 0;
527 * Is this a detached HEAD?
529 if (!get_sha1_hex(buffer, sha1))
530 return 0;
532 return -1;
535 static struct passwd *getpw_str(const char *username, size_t len)
537 struct passwd *pw;
538 char *username_z = xmemdupz(username, len);
539 pw = getpwnam(username_z);
540 free(username_z);
541 return pw;
545 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
546 * then it is a newly allocated string. Returns NULL on getpw failure or
547 * if path is NULL.
549 char *expand_user_path(const char *path)
551 struct strbuf user_path = STRBUF_INIT;
552 const char *to_copy = path;
554 if (path == NULL)
555 goto return_null;
556 if (path[0] == '~') {
557 const char *first_slash = strchrnul(path, '/');
558 const char *username = path + 1;
559 size_t username_len = first_slash - username;
560 if (username_len == 0) {
561 const char *home = getenv("HOME");
562 if (!home)
563 goto return_null;
564 strbuf_addstr(&user_path, home);
565 } else {
566 struct passwd *pw = getpw_str(username, username_len);
567 if (!pw)
568 goto return_null;
569 strbuf_addstr(&user_path, pw->pw_dir);
571 to_copy = first_slash;
573 strbuf_addstr(&user_path, to_copy);
574 return strbuf_detach(&user_path, NULL);
575 return_null:
576 strbuf_release(&user_path);
577 return NULL;
581 * First, one directory to try is determined by the following algorithm.
583 * (0) If "strict" is given, the path is used as given and no DWIM is
584 * done. Otherwise:
585 * (1) "~/path" to mean path under the running user's home directory;
586 * (2) "~user/path" to mean path under named user's home directory;
587 * (3) "relative/path" to mean cwd relative directory; or
588 * (4) "/absolute/path" to mean absolute directory.
590 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
591 * in this order. We select the first one that is a valid git repository, and
592 * chdir() to it. If none match, or we fail to chdir, we return NULL.
594 * If all goes well, we return the directory we used to chdir() (but
595 * before ~user is expanded), avoiding getcwd() resolving symbolic
596 * links. User relative paths are also returned as they are given,
597 * except DWIM suffixing.
599 const char *enter_repo(const char *path, int strict)
601 static char used_path[PATH_MAX];
602 static char validated_path[PATH_MAX];
604 if (!path)
605 return NULL;
607 if (!strict) {
608 static const char *suffix[] = {
609 "/.git", "", ".git/.git", ".git", NULL,
611 const char *gitfile;
612 int len = strlen(path);
613 int i;
614 while ((1 < len) && (path[len-1] == '/'))
615 len--;
617 if (PATH_MAX <= len)
618 return NULL;
619 strncpy(used_path, path, len); used_path[len] = 0 ;
620 strcpy(validated_path, used_path);
622 if (used_path[0] == '~') {
623 char *newpath = expand_user_path(used_path);
624 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
625 free(newpath);
626 return NULL;
629 * Copy back into the static buffer. A pity
630 * since newpath was not bounded, but other
631 * branches of the if are limited by PATH_MAX
632 * anyway.
634 strcpy(used_path, newpath); free(newpath);
636 else if (PATH_MAX - 10 < len)
637 return NULL;
638 len = strlen(used_path);
639 for (i = 0; suffix[i]; i++) {
640 struct stat st;
641 strcpy(used_path + len, suffix[i]);
642 if (!stat(used_path, &st) &&
643 (S_ISREG(st.st_mode) ||
644 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
645 strcat(validated_path, suffix[i]);
646 break;
649 if (!suffix[i])
650 return NULL;
651 gitfile = read_gitfile(used_path) ;
652 if (gitfile)
653 strcpy(used_path, gitfile);
654 if (chdir(used_path))
655 return NULL;
656 path = validated_path;
658 else if (chdir(path))
659 return NULL;
661 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
662 validate_headref("HEAD") == 0) {
663 set_git_dir(".");
664 check_repository_format();
665 return path;
668 return NULL;
671 static int calc_shared_perm(int mode)
673 int tweak;
675 if (shared_repository < 0)
676 tweak = -shared_repository;
677 else
678 tweak = shared_repository;
680 if (!(mode & S_IWUSR))
681 tweak &= ~0222;
682 if (mode & S_IXUSR)
683 /* Copy read bits to execute bits */
684 tweak |= (tweak & 0444) >> 2;
685 if (shared_repository < 0)
686 mode = (mode & ~0777) | tweak;
687 else
688 mode |= tweak;
690 return mode;
694 int adjust_shared_perm(const char *path)
696 int old_mode, new_mode;
698 if (!shared_repository)
699 return 0;
700 if (get_st_mode_bits(path, &old_mode) < 0)
701 return -1;
703 new_mode = calc_shared_perm(old_mode);
704 if (S_ISDIR(old_mode)) {
705 /* Copy read bits to execute bits */
706 new_mode |= (new_mode & 0444) >> 2;
707 new_mode |= FORCE_DIR_SET_GID;
710 if (((old_mode ^ new_mode) & ~S_IFMT) &&
711 chmod(path, (new_mode & ~S_IFMT)) < 0)
712 return -2;
713 return 0;
716 static int have_same_root(const char *path1, const char *path2)
718 int is_abs1, is_abs2;
720 is_abs1 = is_absolute_path(path1);
721 is_abs2 = is_absolute_path(path2);
722 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
723 (!is_abs1 && !is_abs2);
727 * Give path as relative to prefix.
729 * The strbuf may or may not be used, so do not assume it contains the
730 * returned path.
732 const char *relative_path(const char *in, const char *prefix,
733 struct strbuf *sb)
735 int in_len = in ? strlen(in) : 0;
736 int prefix_len = prefix ? strlen(prefix) : 0;
737 int in_off = 0;
738 int prefix_off = 0;
739 int i = 0, j = 0;
741 if (!in_len)
742 return "./";
743 else if (!prefix_len)
744 return in;
746 if (have_same_root(in, prefix)) {
747 /* bypass dos_drive, for "c:" is identical to "C:" */
748 if (has_dos_drive_prefix(in)) {
749 i = 2;
750 j = 2;
752 } else {
753 return in;
756 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
757 if (is_dir_sep(prefix[i])) {
758 while (is_dir_sep(prefix[i]))
759 i++;
760 while (is_dir_sep(in[j]))
761 j++;
762 prefix_off = i;
763 in_off = j;
764 } else {
765 i++;
766 j++;
770 if (
771 /* "prefix" seems like prefix of "in" */
772 i >= prefix_len &&
774 * but "/foo" is not a prefix of "/foobar"
775 * (i.e. prefix not end with '/')
777 prefix_off < prefix_len) {
778 if (j >= in_len) {
779 /* in="/a/b", prefix="/a/b" */
780 in_off = in_len;
781 } else if (is_dir_sep(in[j])) {
782 /* in="/a/b/c", prefix="/a/b" */
783 while (is_dir_sep(in[j]))
784 j++;
785 in_off = j;
786 } else {
787 /* in="/a/bbb/c", prefix="/a/b" */
788 i = prefix_off;
790 } else if (
791 /* "in" is short than "prefix" */
792 j >= in_len &&
793 /* "in" not end with '/' */
794 in_off < in_len) {
795 if (is_dir_sep(prefix[i])) {
796 /* in="/a/b", prefix="/a/b/c/" */
797 while (is_dir_sep(prefix[i]))
798 i++;
799 in_off = in_len;
802 in += in_off;
803 in_len -= in_off;
805 if (i >= prefix_len) {
806 if (!in_len)
807 return "./";
808 else
809 return in;
812 strbuf_reset(sb);
813 strbuf_grow(sb, in_len);
815 while (i < prefix_len) {
816 if (is_dir_sep(prefix[i])) {
817 strbuf_addstr(sb, "../");
818 while (is_dir_sep(prefix[i]))
819 i++;
820 continue;
822 i++;
824 if (!is_dir_sep(prefix[prefix_len - 1]))
825 strbuf_addstr(sb, "../");
827 strbuf_addstr(sb, in);
829 return sb->buf;
833 * A simpler implementation of relative_path
835 * Get relative path by removing "prefix" from "in". This function
836 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
837 * to increase performance when traversing the path to work_tree.
839 const char *remove_leading_path(const char *in, const char *prefix)
841 static char buf[PATH_MAX + 1];
842 int i = 0, j = 0;
844 if (!prefix || !prefix[0])
845 return in;
846 while (prefix[i]) {
847 if (is_dir_sep(prefix[i])) {
848 if (!is_dir_sep(in[j]))
849 return in;
850 while (is_dir_sep(prefix[i]))
851 i++;
852 while (is_dir_sep(in[j]))
853 j++;
854 continue;
855 } else if (in[j] != prefix[i]) {
856 return in;
858 i++;
859 j++;
861 if (
862 /* "/foo" is a prefix of "/foo" */
863 in[j] &&
864 /* "/foo" is not a prefix of "/foobar" */
865 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
867 return in;
868 while (is_dir_sep(in[j]))
869 j++;
870 if (!in[j])
871 strcpy(buf, ".");
872 else
873 strcpy(buf, in + j);
874 return buf;
878 * It is okay if dst == src, but they should not overlap otherwise.
880 * Performs the following normalizations on src, storing the result in dst:
881 * - Ensures that components are separated by '/' (Windows only)
882 * - Squashes sequences of '/'.
883 * - Removes "." components.
884 * - Removes ".." components, and the components the precede them.
885 * Returns failure (non-zero) if a ".." component appears as first path
886 * component anytime during the normalization. Otherwise, returns success (0).
888 * Note that this function is purely textual. It does not follow symlinks,
889 * verify the existence of the path, or make any system calls.
891 * prefix_len != NULL is for a specific case of prefix_pathspec():
892 * assume that src == dst and src[0..prefix_len-1] is already
893 * normalized, any time "../" eats up to the prefix_len part,
894 * prefix_len is reduced. In the end prefix_len is the remaining
895 * prefix that has not been overridden by user pathspec.
897 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
899 char *dst0;
901 if (has_dos_drive_prefix(src)) {
902 *dst++ = *src++;
903 *dst++ = *src++;
905 dst0 = dst;
907 if (is_dir_sep(*src)) {
908 *dst++ = '/';
909 while (is_dir_sep(*src))
910 src++;
913 for (;;) {
914 char c = *src;
917 * A path component that begins with . could be
918 * special:
919 * (1) "." and ends -- ignore and terminate.
920 * (2) "./" -- ignore them, eat slash and continue.
921 * (3) ".." and ends -- strip one and terminate.
922 * (4) "../" -- strip one, eat slash and continue.
924 if (c == '.') {
925 if (!src[1]) {
926 /* (1) */
927 src++;
928 } else if (is_dir_sep(src[1])) {
929 /* (2) */
930 src += 2;
931 while (is_dir_sep(*src))
932 src++;
933 continue;
934 } else if (src[1] == '.') {
935 if (!src[2]) {
936 /* (3) */
937 src += 2;
938 goto up_one;
939 } else if (is_dir_sep(src[2])) {
940 /* (4) */
941 src += 3;
942 while (is_dir_sep(*src))
943 src++;
944 goto up_one;
949 /* copy up to the next '/', and eat all '/' */
950 while ((c = *src++) != '\0' && !is_dir_sep(c))
951 *dst++ = c;
952 if (is_dir_sep(c)) {
953 *dst++ = '/';
954 while (is_dir_sep(c))
955 c = *src++;
956 src--;
957 } else if (!c)
958 break;
959 continue;
961 up_one:
963 * dst0..dst is prefix portion, and dst[-1] is '/';
964 * go up one level.
966 dst--; /* go to trailing '/' */
967 if (dst <= dst0)
968 return -1;
969 /* Windows: dst[-1] cannot be backslash anymore */
970 while (dst0 < dst && dst[-1] != '/')
971 dst--;
972 if (prefix_len && *prefix_len > dst - dst0)
973 *prefix_len = dst - dst0;
975 *dst = '\0';
976 return 0;
979 int normalize_path_copy(char *dst, const char *src)
981 return normalize_path_copy_len(dst, src, NULL);
985 * path = Canonical absolute path
986 * prefixes = string_list containing normalized, absolute paths without
987 * trailing slashes (except for the root directory, which is denoted by "/").
989 * Determines, for each path in prefixes, whether the "prefix"
990 * is an ancestor directory of path. Returns the length of the longest
991 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
992 * is an ancestor. (Note that this means 0 is returned if prefixes is
993 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
994 * are not considered to be their own ancestors. path must be in a
995 * canonical form: empty components, or "." or ".." components are not
996 * allowed.
998 int longest_ancestor_length(const char *path, struct string_list *prefixes)
1000 int i, max_len = -1;
1002 if (!strcmp(path, "/"))
1003 return -1;
1005 for (i = 0; i < prefixes->nr; i++) {
1006 const char *ceil = prefixes->items[i].string;
1007 int len = strlen(ceil);
1009 if (len == 1 && ceil[0] == '/')
1010 len = 0; /* root matches anything, with length 0 */
1011 else if (!strncmp(path, ceil, len) && path[len] == '/')
1012 ; /* match of length len */
1013 else
1014 continue; /* no match */
1016 if (len > max_len)
1017 max_len = len;
1020 return max_len;
1023 /* strip arbitrary amount of directory separators at end of path */
1024 static inline int chomp_trailing_dir_sep(const char *path, int len)
1026 while (len && is_dir_sep(path[len - 1]))
1027 len--;
1028 return len;
1032 * If path ends with suffix (complete path components), returns the
1033 * part before suffix (sans trailing directory separators).
1034 * Otherwise returns NULL.
1036 char *strip_path_suffix(const char *path, const char *suffix)
1038 int path_len = strlen(path), suffix_len = strlen(suffix);
1040 while (suffix_len) {
1041 if (!path_len)
1042 return NULL;
1044 if (is_dir_sep(path[path_len - 1])) {
1045 if (!is_dir_sep(suffix[suffix_len - 1]))
1046 return NULL;
1047 path_len = chomp_trailing_dir_sep(path, path_len);
1048 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1050 else if (path[--path_len] != suffix[--suffix_len])
1051 return NULL;
1054 if (path_len && !is_dir_sep(path[path_len - 1]))
1055 return NULL;
1056 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1059 int daemon_avoid_alias(const char *p)
1061 int sl, ndot;
1064 * This resurrects the belts and suspenders paranoia check by HPA
1065 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1066 * does not do getcwd() based path canonicalization.
1068 * sl becomes true immediately after seeing '/' and continues to
1069 * be true as long as dots continue after that without intervening
1070 * non-dot character.
1072 if (!p || (*p != '/' && *p != '~'))
1073 return -1;
1074 sl = 1; ndot = 0;
1075 p++;
1077 while (1) {
1078 char ch = *p++;
1079 if (sl) {
1080 if (ch == '.')
1081 ndot++;
1082 else if (ch == '/') {
1083 if (ndot < 3)
1084 /* reject //, /./ and /../ */
1085 return -1;
1086 ndot = 0;
1088 else if (ch == 0) {
1089 if (0 < ndot && ndot < 3)
1090 /* reject /.$ and /..$ */
1091 return -1;
1092 return 0;
1094 else
1095 sl = ndot = 0;
1097 else if (ch == 0)
1098 return 0;
1099 else if (ch == '/') {
1100 sl = 1;
1101 ndot = 0;
1106 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1108 if (len < skip)
1109 return 0;
1110 len -= skip;
1111 path += skip;
1112 while (len-- > 0) {
1113 char c = *(path++);
1114 if (c != ' ' && c != '.')
1115 return 0;
1117 return 1;
1120 int is_ntfs_dotgit(const char *name)
1122 int len;
1124 for (len = 0; ; len++)
1125 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1126 if (only_spaces_and_periods(name, len, 4) &&
1127 !strncasecmp(name, ".git", 4))
1128 return 1;
1129 if (only_spaces_and_periods(name, len, 5) &&
1130 !strncasecmp(name, "git~1", 5))
1131 return 1;
1132 if (name[len] != '\\')
1133 return 0;
1134 name += len + 1;
1135 len = -1;
1139 char *xdg_config_home(const char *filename)
1141 const char *home, *config_home;
1143 assert(filename);
1144 config_home = getenv("XDG_CONFIG_HOME");
1145 if (config_home && *config_home)
1146 return mkpathdup("%s/git/%s", config_home, filename);
1148 home = getenv("HOME");
1149 if (home)
1150 return mkpathdup("%s/.config/git/%s", home, filename);
1151 return NULL;
1154 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1155 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1156 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1157 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1158 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1159 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1160 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1161 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1162 GIT_PATH_FUNC(git_path_shallow, "shallow")