Merge branch 'rs/janitorial' into maint
[git.git] / path.c
blob6b537ccfff452b7fbbe41446c001c8fda0679bea
1 /*
2 * Utilities for paths and pathnames
3 */
4 #include "cache.h"
5 #include "strbuf.h"
6 #include "string-list.h"
8 static int get_st_mode_bits(const char *path, int *mode)
10 struct stat st;
11 if (lstat(path, &st) < 0)
12 return -1;
13 *mode = st.st_mode;
14 return 0;
17 static char bad_path[] = "/bad-path/";
19 static char *get_pathname(void)
21 static char pathname_array[4][PATH_MAX];
22 static int index;
23 return pathname_array[3 & ++index];
26 static char *cleanup_path(char *path)
28 /* Clean it up */
29 if (!memcmp(path, "./", 2)) {
30 path += 2;
31 while (*path == '/')
32 path++;
34 return path;
37 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
39 va_list args;
40 unsigned len;
42 va_start(args, fmt);
43 len = vsnprintf(buf, n, fmt, args);
44 va_end(args);
45 if (len >= n) {
46 strlcpy(buf, bad_path, n);
47 return buf;
49 return cleanup_path(buf);
52 static char *vsnpath(char *buf, size_t n, const char *fmt, va_list args)
54 const char *git_dir = get_git_dir();
55 size_t len;
57 len = strlen(git_dir);
58 if (n < len + 1)
59 goto bad;
60 memcpy(buf, git_dir, len);
61 if (len && !is_dir_sep(git_dir[len-1]))
62 buf[len++] = '/';
63 len += vsnprintf(buf + len, n - len, fmt, args);
64 if (len >= n)
65 goto bad;
66 return cleanup_path(buf);
67 bad:
68 strlcpy(buf, bad_path, n);
69 return buf;
72 char *git_snpath(char *buf, size_t n, const char *fmt, ...)
74 char *ret;
75 va_list args;
76 va_start(args, fmt);
77 ret = vsnpath(buf, n, fmt, args);
78 va_end(args);
79 return ret;
82 char *git_pathdup(const char *fmt, ...)
84 char path[PATH_MAX], *ret;
85 va_list args;
86 va_start(args, fmt);
87 ret = vsnpath(path, sizeof(path), fmt, args);
88 va_end(args);
89 return xstrdup(ret);
92 char *mkpathdup(const char *fmt, ...)
94 char *path;
95 struct strbuf sb = STRBUF_INIT;
96 va_list args;
98 va_start(args, fmt);
99 strbuf_vaddf(&sb, fmt, args);
100 va_end(args);
101 path = xstrdup(cleanup_path(sb.buf));
103 strbuf_release(&sb);
104 return path;
107 char *mkpath(const char *fmt, ...)
109 va_list args;
110 unsigned len;
111 char *pathname = get_pathname();
113 va_start(args, fmt);
114 len = vsnprintf(pathname, PATH_MAX, fmt, args);
115 va_end(args);
116 if (len >= PATH_MAX)
117 return bad_path;
118 return cleanup_path(pathname);
121 char *git_path(const char *fmt, ...)
123 char *pathname = get_pathname();
124 va_list args;
125 char *ret;
127 va_start(args, fmt);
128 ret = vsnpath(pathname, PATH_MAX, fmt, args);
129 va_end(args);
130 return ret;
133 char *git_path_submodule(const char *path, const char *fmt, ...)
135 char *pathname = get_pathname();
136 struct strbuf buf = STRBUF_INIT;
137 const char *git_dir;
138 va_list args;
139 unsigned len;
141 len = strlen(path);
142 if (len > PATH_MAX-100)
143 return bad_path;
145 strbuf_addstr(&buf, path);
146 if (len && path[len-1] != '/')
147 strbuf_addch(&buf, '/');
148 strbuf_addstr(&buf, ".git");
150 git_dir = read_gitfile(buf.buf);
151 if (git_dir) {
152 strbuf_reset(&buf);
153 strbuf_addstr(&buf, git_dir);
155 strbuf_addch(&buf, '/');
157 if (buf.len >= PATH_MAX)
158 return bad_path;
159 memcpy(pathname, buf.buf, buf.len + 1);
161 strbuf_release(&buf);
162 len = strlen(pathname);
164 va_start(args, fmt);
165 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
166 va_end(args);
167 if (len >= PATH_MAX)
168 return bad_path;
169 return cleanup_path(pathname);
172 int validate_headref(const char *path)
174 struct stat st;
175 char *buf, buffer[256];
176 unsigned char sha1[20];
177 int fd;
178 ssize_t len;
180 if (lstat(path, &st) < 0)
181 return -1;
183 /* Make sure it is a "refs/.." symlink */
184 if (S_ISLNK(st.st_mode)) {
185 len = readlink(path, buffer, sizeof(buffer)-1);
186 if (len >= 5 && !memcmp("refs/", buffer, 5))
187 return 0;
188 return -1;
192 * Anything else, just open it and try to see if it is a symbolic ref.
194 fd = open(path, O_RDONLY);
195 if (fd < 0)
196 return -1;
197 len = read_in_full(fd, buffer, sizeof(buffer)-1);
198 close(fd);
201 * Is it a symbolic ref?
203 if (len < 4)
204 return -1;
205 if (!memcmp("ref:", buffer, 4)) {
206 buf = buffer + 4;
207 len -= 4;
208 while (len && isspace(*buf))
209 buf++, len--;
210 if (len >= 5 && !memcmp("refs/", buf, 5))
211 return 0;
215 * Is this a detached HEAD?
217 if (!get_sha1_hex(buffer, sha1))
218 return 0;
220 return -1;
223 static struct passwd *getpw_str(const char *username, size_t len)
225 struct passwd *pw;
226 char *username_z = xmemdupz(username, len);
227 pw = getpwnam(username_z);
228 free(username_z);
229 return pw;
233 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
234 * then it is a newly allocated string. Returns NULL on getpw failure or
235 * if path is NULL.
237 char *expand_user_path(const char *path)
239 struct strbuf user_path = STRBUF_INIT;
240 const char *to_copy = path;
242 if (path == NULL)
243 goto return_null;
244 if (path[0] == '~') {
245 const char *first_slash = strchrnul(path, '/');
246 const char *username = path + 1;
247 size_t username_len = first_slash - username;
248 if (username_len == 0) {
249 const char *home = getenv("HOME");
250 if (!home)
251 goto return_null;
252 strbuf_addstr(&user_path, home);
253 } else {
254 struct passwd *pw = getpw_str(username, username_len);
255 if (!pw)
256 goto return_null;
257 strbuf_addstr(&user_path, pw->pw_dir);
259 to_copy = first_slash;
261 strbuf_addstr(&user_path, to_copy);
262 return strbuf_detach(&user_path, NULL);
263 return_null:
264 strbuf_release(&user_path);
265 return NULL;
269 * First, one directory to try is determined by the following algorithm.
271 * (0) If "strict" is given, the path is used as given and no DWIM is
272 * done. Otherwise:
273 * (1) "~/path" to mean path under the running user's home directory;
274 * (2) "~user/path" to mean path under named user's home directory;
275 * (3) "relative/path" to mean cwd relative directory; or
276 * (4) "/absolute/path" to mean absolute directory.
278 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
279 * in this order. We select the first one that is a valid git repository, and
280 * chdir() to it. If none match, or we fail to chdir, we return NULL.
282 * If all goes well, we return the directory we used to chdir() (but
283 * before ~user is expanded), avoiding getcwd() resolving symbolic
284 * links. User relative paths are also returned as they are given,
285 * except DWIM suffixing.
287 const char *enter_repo(const char *path, int strict)
289 static char used_path[PATH_MAX];
290 static char validated_path[PATH_MAX];
292 if (!path)
293 return NULL;
295 if (!strict) {
296 static const char *suffix[] = {
297 "/.git", "", ".git/.git", ".git", NULL,
299 const char *gitfile;
300 int len = strlen(path);
301 int i;
302 while ((1 < len) && (path[len-1] == '/'))
303 len--;
305 if (PATH_MAX <= len)
306 return NULL;
307 strncpy(used_path, path, len); used_path[len] = 0 ;
308 strcpy(validated_path, used_path);
310 if (used_path[0] == '~') {
311 char *newpath = expand_user_path(used_path);
312 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
313 free(newpath);
314 return NULL;
317 * Copy back into the static buffer. A pity
318 * since newpath was not bounded, but other
319 * branches of the if are limited by PATH_MAX
320 * anyway.
322 strcpy(used_path, newpath); free(newpath);
324 else if (PATH_MAX - 10 < len)
325 return NULL;
326 len = strlen(used_path);
327 for (i = 0; suffix[i]; i++) {
328 struct stat st;
329 strcpy(used_path + len, suffix[i]);
330 if (!stat(used_path, &st) &&
331 (S_ISREG(st.st_mode) ||
332 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
333 strcat(validated_path, suffix[i]);
334 break;
337 if (!suffix[i])
338 return NULL;
339 gitfile = read_gitfile(used_path) ;
340 if (gitfile)
341 strcpy(used_path, gitfile);
342 if (chdir(used_path))
343 return NULL;
344 path = validated_path;
346 else if (chdir(path))
347 return NULL;
349 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
350 validate_headref("HEAD") == 0) {
351 set_git_dir(".");
352 check_repository_format();
353 return path;
356 return NULL;
359 static int calc_shared_perm(int mode)
361 int tweak;
363 if (shared_repository < 0)
364 tweak = -shared_repository;
365 else
366 tweak = shared_repository;
368 if (!(mode & S_IWUSR))
369 tweak &= ~0222;
370 if (mode & S_IXUSR)
371 /* Copy read bits to execute bits */
372 tweak |= (tweak & 0444) >> 2;
373 if (shared_repository < 0)
374 mode = (mode & ~0777) | tweak;
375 else
376 mode |= tweak;
378 return mode;
382 int adjust_shared_perm(const char *path)
384 int old_mode, new_mode;
386 if (!shared_repository)
387 return 0;
388 if (get_st_mode_bits(path, &old_mode) < 0)
389 return -1;
391 new_mode = calc_shared_perm(old_mode);
392 if (S_ISDIR(old_mode)) {
393 /* Copy read bits to execute bits */
394 new_mode |= (new_mode & 0444) >> 2;
395 new_mode |= FORCE_DIR_SET_GID;
398 if (((old_mode ^ new_mode) & ~S_IFMT) &&
399 chmod(path, (new_mode & ~S_IFMT)) < 0)
400 return -2;
401 return 0;
404 static int have_same_root(const char *path1, const char *path2)
406 int is_abs1, is_abs2;
408 is_abs1 = is_absolute_path(path1);
409 is_abs2 = is_absolute_path(path2);
410 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
411 (!is_abs1 && !is_abs2);
415 * Give path as relative to prefix.
417 * The strbuf may or may not be used, so do not assume it contains the
418 * returned path.
420 const char *relative_path(const char *in, const char *prefix,
421 struct strbuf *sb)
423 int in_len = in ? strlen(in) : 0;
424 int prefix_len = prefix ? strlen(prefix) : 0;
425 int in_off = 0;
426 int prefix_off = 0;
427 int i = 0, j = 0;
429 if (!in_len)
430 return "./";
431 else if (!prefix_len)
432 return in;
434 if (have_same_root(in, prefix)) {
435 /* bypass dos_drive, for "c:" is identical to "C:" */
436 if (has_dos_drive_prefix(in)) {
437 i = 2;
438 j = 2;
440 } else {
441 return in;
444 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
445 if (is_dir_sep(prefix[i])) {
446 while (is_dir_sep(prefix[i]))
447 i++;
448 while (is_dir_sep(in[j]))
449 j++;
450 prefix_off = i;
451 in_off = j;
452 } else {
453 i++;
454 j++;
458 if (
459 /* "prefix" seems like prefix of "in" */
460 i >= prefix_len &&
462 * but "/foo" is not a prefix of "/foobar"
463 * (i.e. prefix not end with '/')
465 prefix_off < prefix_len) {
466 if (j >= in_len) {
467 /* in="/a/b", prefix="/a/b" */
468 in_off = in_len;
469 } else if (is_dir_sep(in[j])) {
470 /* in="/a/b/c", prefix="/a/b" */
471 while (is_dir_sep(in[j]))
472 j++;
473 in_off = j;
474 } else {
475 /* in="/a/bbb/c", prefix="/a/b" */
476 i = prefix_off;
478 } else if (
479 /* "in" is short than "prefix" */
480 j >= in_len &&
481 /* "in" not end with '/' */
482 in_off < in_len) {
483 if (is_dir_sep(prefix[i])) {
484 /* in="/a/b", prefix="/a/b/c/" */
485 while (is_dir_sep(prefix[i]))
486 i++;
487 in_off = in_len;
490 in += in_off;
491 in_len -= in_off;
493 if (i >= prefix_len) {
494 if (!in_len)
495 return "./";
496 else
497 return in;
500 strbuf_reset(sb);
501 strbuf_grow(sb, in_len);
503 while (i < prefix_len) {
504 if (is_dir_sep(prefix[i])) {
505 strbuf_addstr(sb, "../");
506 while (is_dir_sep(prefix[i]))
507 i++;
508 continue;
510 i++;
512 if (!is_dir_sep(prefix[prefix_len - 1]))
513 strbuf_addstr(sb, "../");
515 strbuf_addstr(sb, in);
517 return sb->buf;
521 * A simpler implementation of relative_path
523 * Get relative path by removing "prefix" from "in". This function
524 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
525 * to increase performance when traversing the path to work_tree.
527 const char *remove_leading_path(const char *in, const char *prefix)
529 static char buf[PATH_MAX + 1];
530 int i = 0, j = 0;
532 if (!prefix || !prefix[0])
533 return in;
534 while (prefix[i]) {
535 if (is_dir_sep(prefix[i])) {
536 if (!is_dir_sep(in[j]))
537 return in;
538 while (is_dir_sep(prefix[i]))
539 i++;
540 while (is_dir_sep(in[j]))
541 j++;
542 continue;
543 } else if (in[j] != prefix[i]) {
544 return in;
546 i++;
547 j++;
549 if (
550 /* "/foo" is a prefix of "/foo" */
551 in[j] &&
552 /* "/foo" is not a prefix of "/foobar" */
553 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
555 return in;
556 while (is_dir_sep(in[j]))
557 j++;
558 if (!in[j])
559 strcpy(buf, ".");
560 else
561 strcpy(buf, in + j);
562 return buf;
566 * It is okay if dst == src, but they should not overlap otherwise.
568 * Performs the following normalizations on src, storing the result in dst:
569 * - Ensures that components are separated by '/' (Windows only)
570 * - Squashes sequences of '/'.
571 * - Removes "." components.
572 * - Removes ".." components, and the components the precede them.
573 * Returns failure (non-zero) if a ".." component appears as first path
574 * component anytime during the normalization. Otherwise, returns success (0).
576 * Note that this function is purely textual. It does not follow symlinks,
577 * verify the existence of the path, or make any system calls.
579 * prefix_len != NULL is for a specific case of prefix_pathspec():
580 * assume that src == dst and src[0..prefix_len-1] is already
581 * normalized, any time "../" eats up to the prefix_len part,
582 * prefix_len is reduced. In the end prefix_len is the remaining
583 * prefix that has not been overridden by user pathspec.
585 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
587 char *dst0;
589 if (has_dos_drive_prefix(src)) {
590 *dst++ = *src++;
591 *dst++ = *src++;
593 dst0 = dst;
595 if (is_dir_sep(*src)) {
596 *dst++ = '/';
597 while (is_dir_sep(*src))
598 src++;
601 for (;;) {
602 char c = *src;
605 * A path component that begins with . could be
606 * special:
607 * (1) "." and ends -- ignore and terminate.
608 * (2) "./" -- ignore them, eat slash and continue.
609 * (3) ".." and ends -- strip one and terminate.
610 * (4) "../" -- strip one, eat slash and continue.
612 if (c == '.') {
613 if (!src[1]) {
614 /* (1) */
615 src++;
616 } else if (is_dir_sep(src[1])) {
617 /* (2) */
618 src += 2;
619 while (is_dir_sep(*src))
620 src++;
621 continue;
622 } else if (src[1] == '.') {
623 if (!src[2]) {
624 /* (3) */
625 src += 2;
626 goto up_one;
627 } else if (is_dir_sep(src[2])) {
628 /* (4) */
629 src += 3;
630 while (is_dir_sep(*src))
631 src++;
632 goto up_one;
637 /* copy up to the next '/', and eat all '/' */
638 while ((c = *src++) != '\0' && !is_dir_sep(c))
639 *dst++ = c;
640 if (is_dir_sep(c)) {
641 *dst++ = '/';
642 while (is_dir_sep(c))
643 c = *src++;
644 src--;
645 } else if (!c)
646 break;
647 continue;
649 up_one:
651 * dst0..dst is prefix portion, and dst[-1] is '/';
652 * go up one level.
654 dst--; /* go to trailing '/' */
655 if (dst <= dst0)
656 return -1;
657 /* Windows: dst[-1] cannot be backslash anymore */
658 while (dst0 < dst && dst[-1] != '/')
659 dst--;
660 if (prefix_len && *prefix_len > dst - dst0)
661 *prefix_len = dst - dst0;
663 *dst = '\0';
664 return 0;
667 int normalize_path_copy(char *dst, const char *src)
669 return normalize_path_copy_len(dst, src, NULL);
673 * path = Canonical absolute path
674 * prefixes = string_list containing normalized, absolute paths without
675 * trailing slashes (except for the root directory, which is denoted by "/").
677 * Determines, for each path in prefixes, whether the "prefix"
678 * is an ancestor directory of path. Returns the length of the longest
679 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
680 * is an ancestor. (Note that this means 0 is returned if prefixes is
681 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
682 * are not considered to be their own ancestors. path must be in a
683 * canonical form: empty components, or "." or ".." components are not
684 * allowed.
686 int longest_ancestor_length(const char *path, struct string_list *prefixes)
688 int i, max_len = -1;
690 if (!strcmp(path, "/"))
691 return -1;
693 for (i = 0; i < prefixes->nr; i++) {
694 const char *ceil = prefixes->items[i].string;
695 int len = strlen(ceil);
697 if (len == 1 && ceil[0] == '/')
698 len = 0; /* root matches anything, with length 0 */
699 else if (!strncmp(path, ceil, len) && path[len] == '/')
700 ; /* match of length len */
701 else
702 continue; /* no match */
704 if (len > max_len)
705 max_len = len;
708 return max_len;
711 /* strip arbitrary amount of directory separators at end of path */
712 static inline int chomp_trailing_dir_sep(const char *path, int len)
714 while (len && is_dir_sep(path[len - 1]))
715 len--;
716 return len;
720 * If path ends with suffix (complete path components), returns the
721 * part before suffix (sans trailing directory separators).
722 * Otherwise returns NULL.
724 char *strip_path_suffix(const char *path, const char *suffix)
726 int path_len = strlen(path), suffix_len = strlen(suffix);
728 while (suffix_len) {
729 if (!path_len)
730 return NULL;
732 if (is_dir_sep(path[path_len - 1])) {
733 if (!is_dir_sep(suffix[suffix_len - 1]))
734 return NULL;
735 path_len = chomp_trailing_dir_sep(path, path_len);
736 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
738 else if (path[--path_len] != suffix[--suffix_len])
739 return NULL;
742 if (path_len && !is_dir_sep(path[path_len - 1]))
743 return NULL;
744 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
747 int daemon_avoid_alias(const char *p)
749 int sl, ndot;
752 * This resurrects the belts and suspenders paranoia check by HPA
753 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
754 * does not do getcwd() based path canonicalization.
756 * sl becomes true immediately after seeing '/' and continues to
757 * be true as long as dots continue after that without intervening
758 * non-dot character.
760 if (!p || (*p != '/' && *p != '~'))
761 return -1;
762 sl = 1; ndot = 0;
763 p++;
765 while (1) {
766 char ch = *p++;
767 if (sl) {
768 if (ch == '.')
769 ndot++;
770 else if (ch == '/') {
771 if (ndot < 3)
772 /* reject //, /./ and /../ */
773 return -1;
774 ndot = 0;
776 else if (ch == 0) {
777 if (0 < ndot && ndot < 3)
778 /* reject /.$ and /..$ */
779 return -1;
780 return 0;
782 else
783 sl = ndot = 0;
785 else if (ch == 0)
786 return 0;
787 else if (ch == '/') {
788 sl = 1;
789 ndot = 0;
794 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
796 if (len < skip)
797 return 0;
798 len -= skip;
799 path += skip;
800 while (len-- > 0) {
801 char c = *(path++);
802 if (c != ' ' && c != '.')
803 return 0;
805 return 1;
808 int is_ntfs_dotgit(const char *name)
810 int len;
812 for (len = 0; ; len++)
813 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
814 if (only_spaces_and_periods(name, len, 4) &&
815 !strncasecmp(name, ".git", 4))
816 return 1;
817 if (only_spaces_and_periods(name, len, 5) &&
818 !strncasecmp(name, "git~1", 5))
819 return 1;
820 if (name[len] != '\\')
821 return 0;
822 name += len + 1;
823 len = -1;
827 char *xdg_config_home(const char *filename)
829 const char *home, *config_home;
831 assert(filename);
832 config_home = getenv("XDG_CONFIG_HOME");
833 if (config_home && *config_home)
834 return mkpathdup("%s/git/%s", config_home, filename);
836 home = getenv("HOME");
837 if (home)
838 return mkpathdup("%s/.config/git/%s", home, filename);
839 return NULL;