95acbafa6883b4418f19a208cb9889f5642f3925
[git/git.git] / path.c
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
9 static int get_st_mode_bits(const char *path, int *mode)
10 {
11 struct stat st;
12 if (lstat(path, &st) < 0)
13 return -1;
14 *mode = st.st_mode;
15 return 0;
16 }
17
18 static char bad_path[] = "/bad-path/";
19
20 static struct strbuf *get_pathname(void)
21 {
22 static struct strbuf pathname_array[4] = {
23 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
24 };
25 static int index;
26 struct strbuf *sb = &pathname_array[3 & ++index];
27 strbuf_reset(sb);
28 return sb;
29 }
30
31 static char *cleanup_path(char *path)
32 {
33 /* Clean it up */
34 if (!memcmp(path, "./", 2)) {
35 path += 2;
36 while (*path == '/')
37 path++;
38 }
39 return path;
40 }
41
42 static void strbuf_cleanup_path(struct strbuf *sb)
43 {
44 char *path = cleanup_path(sb->buf);
45 if (path > sb->buf)
46 strbuf_remove(sb, 0, path - sb->buf);
47 }
48
49 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
50 {
51 va_list args;
52 unsigned len;
53
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;
60 }
61 return cleanup_path(buf);
62 }
63
64 static int dir_prefix(const char *buf, const char *dir)
65 {
66 int len = strlen(dir);
67 return !strncmp(buf, dir, len) &&
68 (is_dir_sep(buf[len]) || buf[len] == '\0');
69 }
70
71 /* $buf =~ m|$dir/+$file| but without regex */
72 static int is_dir_file(const char *buf, const char *dir, const char *file)
73 {
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);
80 }
81
82 static void replace_dir(struct strbuf *buf, int len, const char *newdir)
83 {
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] = '/';
92 }
93
94 static const char *common_list[] = {
95 "/branches", "/hooks", "/info", "!/logs", "/lost-found",
96 "/objects", "/refs", "/remotes", "/worktrees", "/rr-cache", "/svn",
97 "config", "!gc.pid", "packed-refs", "shallow",
98 NULL
99 };
100
101 static void update_common_dir(struct strbuf *buf, int git_dir_len)
102 {
103 char *base = buf->buf + git_dir_len;
104 const char **p;
105
106 if (is_dir_file(base, "logs", "HEAD") ||
107 is_dir_file(base, "info", "sparse-checkout"))
108 return; /* keep this in $GIT_DIR */
109 for (p = common_list; *p; p++) {
110 const char *path = *p;
111 int is_dir = 0;
112 if (*path == '!')
113 path++;
114 if (*path == '/') {
115 path++;
116 is_dir = 1;
117 }
118 if (is_dir && dir_prefix(base, path)) {
119 replace_dir(buf, git_dir_len, get_git_common_dir());
120 return;
121 }
122 if (!is_dir && !strcmp(base, path)) {
123 replace_dir(buf, git_dir_len, get_git_common_dir());
124 return;
125 }
126 }
127 }
128
129 void report_linked_checkout_garbage(void)
130 {
131 struct strbuf sb = STRBUF_INIT;
132 const char **p;
133 int len;
134
135 if (!git_common_dir_env)
136 return;
137 strbuf_addf(&sb, "%s/", get_git_dir());
138 len = sb.len;
139 for (p = common_list; *p; p++) {
140 const char *path = *p;
141 if (*path == '!')
142 continue;
143 strbuf_setlen(&sb, len);
144 strbuf_addstr(&sb, path);
145 if (file_exists(sb.buf))
146 report_garbage("unused in linked checkout", sb.buf);
147 }
148 strbuf_release(&sb);
149 }
150
151 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
152 {
153 const char *base = buf->buf + git_dir_len;
154 if (git_graft_env && is_dir_file(base, "info", "grafts"))
155 strbuf_splice(buf, 0, buf->len,
156 get_graft_file(), strlen(get_graft_file()));
157 else if (git_index_env && !strcmp(base, "index"))
158 strbuf_splice(buf, 0, buf->len,
159 get_index_file(), strlen(get_index_file()));
160 else if (git_db_env && dir_prefix(base, "objects"))
161 replace_dir(buf, git_dir_len + 7, get_object_directory());
162 else if (git_common_dir_env)
163 update_common_dir(buf, git_dir_len);
164 }
165
166 static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
167 {
168 int gitdir_len;
169 strbuf_addstr(buf, get_git_dir());
170 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
171 strbuf_addch(buf, '/');
172 gitdir_len = buf->len;
173 strbuf_vaddf(buf, fmt, args);
174 adjust_git_path(buf, gitdir_len);
175 strbuf_cleanup_path(buf);
176 }
177
178 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
179 {
180 va_list args;
181 va_start(args, fmt);
182 do_git_path(sb, fmt, args);
183 va_end(args);
184 }
185
186 const char *git_path(const char *fmt, ...)
187 {
188 struct strbuf *pathname = get_pathname();
189 va_list args;
190 va_start(args, fmt);
191 do_git_path(pathname, fmt, args);
192 va_end(args);
193 return pathname->buf;
194 }
195
196 char *git_pathdup(const char *fmt, ...)
197 {
198 struct strbuf path = STRBUF_INIT;
199 va_list args;
200 va_start(args, fmt);
201 do_git_path(&path, fmt, args);
202 va_end(args);
203 return strbuf_detach(&path, NULL);
204 }
205
206 char *mkpathdup(const char *fmt, ...)
207 {
208 struct strbuf sb = STRBUF_INIT;
209 va_list args;
210 va_start(args, fmt);
211 strbuf_vaddf(&sb, fmt, args);
212 va_end(args);
213 strbuf_cleanup_path(&sb);
214 return strbuf_detach(&sb, NULL);
215 }
216
217 const char *mkpath(const char *fmt, ...)
218 {
219 va_list args;
220 struct strbuf *pathname = get_pathname();
221 va_start(args, fmt);
222 strbuf_vaddf(pathname, fmt, args);
223 va_end(args);
224 return cleanup_path(pathname->buf);
225 }
226
227 static void do_submodule_path(struct strbuf *buf, const char *path,
228 const char *fmt, va_list args)
229 {
230 const char *git_dir;
231
232 strbuf_addstr(buf, path);
233 if (buf->len && buf->buf[buf->len - 1] != '/')
234 strbuf_addch(buf, '/');
235 strbuf_addstr(buf, ".git");
236
237 git_dir = read_gitfile(buf->buf);
238 if (git_dir) {
239 strbuf_reset(buf);
240 strbuf_addstr(buf, git_dir);
241 }
242 strbuf_addch(buf, '/');
243
244 strbuf_vaddf(buf, fmt, args);
245 strbuf_cleanup_path(buf);
246 }
247
248 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
249 {
250 va_list args;
251 struct strbuf buf = STRBUF_INIT;
252 va_start(args, fmt);
253 do_submodule_path(&buf, path, fmt, args);
254 va_end(args);
255 return strbuf_detach(&buf, NULL);
256 }
257
258 void strbuf_git_path_submodule(struct strbuf *buf, const char *path,
259 const char *fmt, ...)
260 {
261 va_list args;
262 va_start(args, fmt);
263 do_submodule_path(buf, path, fmt, args);
264 va_end(args);
265 }
266
267 int validate_headref(const char *path)
268 {
269 struct stat st;
270 char *buf, buffer[256];
271 unsigned char sha1[20];
272 int fd;
273 ssize_t len;
274
275 if (lstat(path, &st) < 0)
276 return -1;
277
278 /* Make sure it is a "refs/.." symlink */
279 if (S_ISLNK(st.st_mode)) {
280 len = readlink(path, buffer, sizeof(buffer)-1);
281 if (len >= 5 && !memcmp("refs/", buffer, 5))
282 return 0;
283 return -1;
284 }
285
286 /*
287 * Anything else, just open it and try to see if it is a symbolic ref.
288 */
289 fd = open(path, O_RDONLY);
290 if (fd < 0)
291 return -1;
292 len = read_in_full(fd, buffer, sizeof(buffer)-1);
293 close(fd);
294
295 /*
296 * Is it a symbolic ref?
297 */
298 if (len < 4)
299 return -1;
300 if (!memcmp("ref:", buffer, 4)) {
301 buf = buffer + 4;
302 len -= 4;
303 while (len && isspace(*buf))
304 buf++, len--;
305 if (len >= 5 && !memcmp("refs/", buf, 5))
306 return 0;
307 }
308
309 /*
310 * Is this a detached HEAD?
311 */
312 if (!get_sha1_hex(buffer, sha1))
313 return 0;
314
315 return -1;
316 }
317
318 static struct passwd *getpw_str(const char *username, size_t len)
319 {
320 struct passwd *pw;
321 char *username_z = xmemdupz(username, len);
322 pw = getpwnam(username_z);
323 free(username_z);
324 return pw;
325 }
326
327 /*
328 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
329 * then it is a newly allocated string. Returns NULL on getpw failure or
330 * if path is NULL.
331 */
332 char *expand_user_path(const char *path)
333 {
334 struct strbuf user_path = STRBUF_INIT;
335 const char *to_copy = path;
336
337 if (path == NULL)
338 goto return_null;
339 if (path[0] == '~') {
340 const char *first_slash = strchrnul(path, '/');
341 const char *username = path + 1;
342 size_t username_len = first_slash - username;
343 if (username_len == 0) {
344 const char *home = getenv("HOME");
345 if (!home)
346 goto return_null;
347 strbuf_addstr(&user_path, home);
348 } else {
349 struct passwd *pw = getpw_str(username, username_len);
350 if (!pw)
351 goto return_null;
352 strbuf_addstr(&user_path, pw->pw_dir);
353 }
354 to_copy = first_slash;
355 }
356 strbuf_addstr(&user_path, to_copy);
357 return strbuf_detach(&user_path, NULL);
358 return_null:
359 strbuf_release(&user_path);
360 return NULL;
361 }
362
363 /*
364 * First, one directory to try is determined by the following algorithm.
365 *
366 * (0) If "strict" is given, the path is used as given and no DWIM is
367 * done. Otherwise:
368 * (1) "~/path" to mean path under the running user's home directory;
369 * (2) "~user/path" to mean path under named user's home directory;
370 * (3) "relative/path" to mean cwd relative directory; or
371 * (4) "/absolute/path" to mean absolute directory.
372 *
373 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
374 * in this order. We select the first one that is a valid git repository, and
375 * chdir() to it. If none match, or we fail to chdir, we return NULL.
376 *
377 * If all goes well, we return the directory we used to chdir() (but
378 * before ~user is expanded), avoiding getcwd() resolving symbolic
379 * links. User relative paths are also returned as they are given,
380 * except DWIM suffixing.
381 */
382 const char *enter_repo(const char *path, int strict)
383 {
384 static char used_path[PATH_MAX];
385 static char validated_path[PATH_MAX];
386
387 if (!path)
388 return NULL;
389
390 if (!strict) {
391 static const char *suffix[] = {
392 "/.git", "", ".git/.git", ".git", NULL,
393 };
394 const char *gitfile;
395 int len = strlen(path);
396 int i;
397 while ((1 < len) && (path[len-1] == '/'))
398 len--;
399
400 if (PATH_MAX <= len)
401 return NULL;
402 strncpy(used_path, path, len); used_path[len] = 0 ;
403 strcpy(validated_path, used_path);
404
405 if (used_path[0] == '~') {
406 char *newpath = expand_user_path(used_path);
407 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
408 free(newpath);
409 return NULL;
410 }
411 /*
412 * Copy back into the static buffer. A pity
413 * since newpath was not bounded, but other
414 * branches of the if are limited by PATH_MAX
415 * anyway.
416 */
417 strcpy(used_path, newpath); free(newpath);
418 }
419 else if (PATH_MAX - 10 < len)
420 return NULL;
421 len = strlen(used_path);
422 for (i = 0; suffix[i]; i++) {
423 struct stat st;
424 strcpy(used_path + len, suffix[i]);
425 if (!stat(used_path, &st) &&
426 (S_ISREG(st.st_mode) ||
427 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
428 strcat(validated_path, suffix[i]);
429 break;
430 }
431 }
432 if (!suffix[i])
433 return NULL;
434 gitfile = read_gitfile(used_path) ;
435 if (gitfile)
436 strcpy(used_path, gitfile);
437 if (chdir(used_path))
438 return NULL;
439 path = validated_path;
440 }
441 else if (chdir(path))
442 return NULL;
443
444 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
445 validate_headref("HEAD") == 0) {
446 set_git_dir(".");
447 check_repository_format();
448 return path;
449 }
450
451 return NULL;
452 }
453
454 static int calc_shared_perm(int mode)
455 {
456 int tweak;
457
458 if (shared_repository < 0)
459 tweak = -shared_repository;
460 else
461 tweak = shared_repository;
462
463 if (!(mode & S_IWUSR))
464 tweak &= ~0222;
465 if (mode & S_IXUSR)
466 /* Copy read bits to execute bits */
467 tweak |= (tweak & 0444) >> 2;
468 if (shared_repository < 0)
469 mode = (mode & ~0777) | tweak;
470 else
471 mode |= tweak;
472
473 return mode;
474 }
475
476
477 int adjust_shared_perm(const char *path)
478 {
479 int old_mode, new_mode;
480
481 if (!shared_repository)
482 return 0;
483 if (get_st_mode_bits(path, &old_mode) < 0)
484 return -1;
485
486 new_mode = calc_shared_perm(old_mode);
487 if (S_ISDIR(old_mode)) {
488 /* Copy read bits to execute bits */
489 new_mode |= (new_mode & 0444) >> 2;
490 new_mode |= FORCE_DIR_SET_GID;
491 }
492
493 if (((old_mode ^ new_mode) & ~S_IFMT) &&
494 chmod(path, (new_mode & ~S_IFMT)) < 0)
495 return -2;
496 return 0;
497 }
498
499 static int have_same_root(const char *path1, const char *path2)
500 {
501 int is_abs1, is_abs2;
502
503 is_abs1 = is_absolute_path(path1);
504 is_abs2 = is_absolute_path(path2);
505 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
506 (!is_abs1 && !is_abs2);
507 }
508
509 /*
510 * Give path as relative to prefix.
511 *
512 * The strbuf may or may not be used, so do not assume it contains the
513 * returned path.
514 */
515 const char *relative_path(const char *in, const char *prefix,
516 struct strbuf *sb)
517 {
518 int in_len = in ? strlen(in) : 0;
519 int prefix_len = prefix ? strlen(prefix) : 0;
520 int in_off = 0;
521 int prefix_off = 0;
522 int i = 0, j = 0;
523
524 if (!in_len)
525 return "./";
526 else if (!prefix_len)
527 return in;
528
529 if (have_same_root(in, prefix)) {
530 /* bypass dos_drive, for "c:" is identical to "C:" */
531 if (has_dos_drive_prefix(in)) {
532 i = 2;
533 j = 2;
534 }
535 } else {
536 return in;
537 }
538
539 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
540 if (is_dir_sep(prefix[i])) {
541 while (is_dir_sep(prefix[i]))
542 i++;
543 while (is_dir_sep(in[j]))
544 j++;
545 prefix_off = i;
546 in_off = j;
547 } else {
548 i++;
549 j++;
550 }
551 }
552
553 if (
554 /* "prefix" seems like prefix of "in" */
555 i >= prefix_len &&
556 /*
557 * but "/foo" is not a prefix of "/foobar"
558 * (i.e. prefix not end with '/')
559 */
560 prefix_off < prefix_len) {
561 if (j >= in_len) {
562 /* in="/a/b", prefix="/a/b" */
563 in_off = in_len;
564 } else if (is_dir_sep(in[j])) {
565 /* in="/a/b/c", prefix="/a/b" */
566 while (is_dir_sep(in[j]))
567 j++;
568 in_off = j;
569 } else {
570 /* in="/a/bbb/c", prefix="/a/b" */
571 i = prefix_off;
572 }
573 } else if (
574 /* "in" is short than "prefix" */
575 j >= in_len &&
576 /* "in" not end with '/' */
577 in_off < in_len) {
578 if (is_dir_sep(prefix[i])) {
579 /* in="/a/b", prefix="/a/b/c/" */
580 while (is_dir_sep(prefix[i]))
581 i++;
582 in_off = in_len;
583 }
584 }
585 in += in_off;
586 in_len -= in_off;
587
588 if (i >= prefix_len) {
589 if (!in_len)
590 return "./";
591 else
592 return in;
593 }
594
595 strbuf_reset(sb);
596 strbuf_grow(sb, in_len);
597
598 while (i < prefix_len) {
599 if (is_dir_sep(prefix[i])) {
600 strbuf_addstr(sb, "../");
601 while (is_dir_sep(prefix[i]))
602 i++;
603 continue;
604 }
605 i++;
606 }
607 if (!is_dir_sep(prefix[prefix_len - 1]))
608 strbuf_addstr(sb, "../");
609
610 strbuf_addstr(sb, in);
611
612 return sb->buf;
613 }
614
615 /*
616 * A simpler implementation of relative_path
617 *
618 * Get relative path by removing "prefix" from "in". This function
619 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
620 * to increase performance when traversing the path to work_tree.
621 */
622 const char *remove_leading_path(const char *in, const char *prefix)
623 {
624 static char buf[PATH_MAX + 1];
625 int i = 0, j = 0;
626
627 if (!prefix || !prefix[0])
628 return in;
629 while (prefix[i]) {
630 if (is_dir_sep(prefix[i])) {
631 if (!is_dir_sep(in[j]))
632 return in;
633 while (is_dir_sep(prefix[i]))
634 i++;
635 while (is_dir_sep(in[j]))
636 j++;
637 continue;
638 } else if (in[j] != prefix[i]) {
639 return in;
640 }
641 i++;
642 j++;
643 }
644 if (
645 /* "/foo" is a prefix of "/foo" */
646 in[j] &&
647 /* "/foo" is not a prefix of "/foobar" */
648 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
649 )
650 return in;
651 while (is_dir_sep(in[j]))
652 j++;
653 if (!in[j])
654 strcpy(buf, ".");
655 else
656 strcpy(buf, in + j);
657 return buf;
658 }
659
660 /*
661 * It is okay if dst == src, but they should not overlap otherwise.
662 *
663 * Performs the following normalizations on src, storing the result in dst:
664 * - Ensures that components are separated by '/' (Windows only)
665 * - Squashes sequences of '/'.
666 * - Removes "." components.
667 * - Removes ".." components, and the components the precede them.
668 * Returns failure (non-zero) if a ".." component appears as first path
669 * component anytime during the normalization. Otherwise, returns success (0).
670 *
671 * Note that this function is purely textual. It does not follow symlinks,
672 * verify the existence of the path, or make any system calls.
673 *
674 * prefix_len != NULL is for a specific case of prefix_pathspec():
675 * assume that src == dst and src[0..prefix_len-1] is already
676 * normalized, any time "../" eats up to the prefix_len part,
677 * prefix_len is reduced. In the end prefix_len is the remaining
678 * prefix that has not been overridden by user pathspec.
679 */
680 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
681 {
682 char *dst0;
683
684 if (has_dos_drive_prefix(src)) {
685 *dst++ = *src++;
686 *dst++ = *src++;
687 }
688 dst0 = dst;
689
690 if (is_dir_sep(*src)) {
691 *dst++ = '/';
692 while (is_dir_sep(*src))
693 src++;
694 }
695
696 for (;;) {
697 char c = *src;
698
699 /*
700 * A path component that begins with . could be
701 * special:
702 * (1) "." and ends -- ignore and terminate.
703 * (2) "./" -- ignore them, eat slash and continue.
704 * (3) ".." and ends -- strip one and terminate.
705 * (4) "../" -- strip one, eat slash and continue.
706 */
707 if (c == '.') {
708 if (!src[1]) {
709 /* (1) */
710 src++;
711 } else if (is_dir_sep(src[1])) {
712 /* (2) */
713 src += 2;
714 while (is_dir_sep(*src))
715 src++;
716 continue;
717 } else if (src[1] == '.') {
718 if (!src[2]) {
719 /* (3) */
720 src += 2;
721 goto up_one;
722 } else if (is_dir_sep(src[2])) {
723 /* (4) */
724 src += 3;
725 while (is_dir_sep(*src))
726 src++;
727 goto up_one;
728 }
729 }
730 }
731
732 /* copy up to the next '/', and eat all '/' */
733 while ((c = *src++) != '\0' && !is_dir_sep(c))
734 *dst++ = c;
735 if (is_dir_sep(c)) {
736 *dst++ = '/';
737 while (is_dir_sep(c))
738 c = *src++;
739 src--;
740 } else if (!c)
741 break;
742 continue;
743
744 up_one:
745 /*
746 * dst0..dst is prefix portion, and dst[-1] is '/';
747 * go up one level.
748 */
749 dst--; /* go to trailing '/' */
750 if (dst <= dst0)
751 return -1;
752 /* Windows: dst[-1] cannot be backslash anymore */
753 while (dst0 < dst && dst[-1] != '/')
754 dst--;
755 if (prefix_len && *prefix_len > dst - dst0)
756 *prefix_len = dst - dst0;
757 }
758 *dst = '\0';
759 return 0;
760 }
761
762 int normalize_path_copy(char *dst, const char *src)
763 {
764 return normalize_path_copy_len(dst, src, NULL);
765 }
766
767 /*
768 * path = Canonical absolute path
769 * prefixes = string_list containing normalized, absolute paths without
770 * trailing slashes (except for the root directory, which is denoted by "/").
771 *
772 * Determines, for each path in prefixes, whether the "prefix"
773 * is an ancestor directory of path. Returns the length of the longest
774 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
775 * is an ancestor. (Note that this means 0 is returned if prefixes is
776 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
777 * are not considered to be their own ancestors. path must be in a
778 * canonical form: empty components, or "." or ".." components are not
779 * allowed.
780 */
781 int longest_ancestor_length(const char *path, struct string_list *prefixes)
782 {
783 int i, max_len = -1;
784
785 if (!strcmp(path, "/"))
786 return -1;
787
788 for (i = 0; i < prefixes->nr; i++) {
789 const char *ceil = prefixes->items[i].string;
790 int len = strlen(ceil);
791
792 if (len == 1 && ceil[0] == '/')
793 len = 0; /* root matches anything, with length 0 */
794 else if (!strncmp(path, ceil, len) && path[len] == '/')
795 ; /* match of length len */
796 else
797 continue; /* no match */
798
799 if (len > max_len)
800 max_len = len;
801 }
802
803 return max_len;
804 }
805
806 /* strip arbitrary amount of directory separators at end of path */
807 static inline int chomp_trailing_dir_sep(const char *path, int len)
808 {
809 while (len && is_dir_sep(path[len - 1]))
810 len--;
811 return len;
812 }
813
814 /*
815 * If path ends with suffix (complete path components), returns the
816 * part before suffix (sans trailing directory separators).
817 * Otherwise returns NULL.
818 */
819 char *strip_path_suffix(const char *path, const char *suffix)
820 {
821 int path_len = strlen(path), suffix_len = strlen(suffix);
822
823 while (suffix_len) {
824 if (!path_len)
825 return NULL;
826
827 if (is_dir_sep(path[path_len - 1])) {
828 if (!is_dir_sep(suffix[suffix_len - 1]))
829 return NULL;
830 path_len = chomp_trailing_dir_sep(path, path_len);
831 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
832 }
833 else if (path[--path_len] != suffix[--suffix_len])
834 return NULL;
835 }
836
837 if (path_len && !is_dir_sep(path[path_len - 1]))
838 return NULL;
839 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
840 }
841
842 int daemon_avoid_alias(const char *p)
843 {
844 int sl, ndot;
845
846 /*
847 * This resurrects the belts and suspenders paranoia check by HPA
848 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
849 * does not do getcwd() based path canonicalization.
850 *
851 * sl becomes true immediately after seeing '/' and continues to
852 * be true as long as dots continue after that without intervening
853 * non-dot character.
854 */
855 if (!p || (*p != '/' && *p != '~'))
856 return -1;
857 sl = 1; ndot = 0;
858 p++;
859
860 while (1) {
861 char ch = *p++;
862 if (sl) {
863 if (ch == '.')
864 ndot++;
865 else if (ch == '/') {
866 if (ndot < 3)
867 /* reject //, /./ and /../ */
868 return -1;
869 ndot = 0;
870 }
871 else if (ch == 0) {
872 if (0 < ndot && ndot < 3)
873 /* reject /.$ and /..$ */
874 return -1;
875 return 0;
876 }
877 else
878 sl = ndot = 0;
879 }
880 else if (ch == 0)
881 return 0;
882 else if (ch == '/') {
883 sl = 1;
884 ndot = 0;
885 }
886 }
887 }
888
889 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
890 {
891 if (len < skip)
892 return 0;
893 len -= skip;
894 path += skip;
895 while (len-- > 0) {
896 char c = *(path++);
897 if (c != ' ' && c != '.')
898 return 0;
899 }
900 return 1;
901 }
902
903 int is_ntfs_dotgit(const char *name)
904 {
905 int len;
906
907 for (len = 0; ; len++)
908 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
909 if (only_spaces_and_periods(name, len, 4) &&
910 !strncasecmp(name, ".git", 4))
911 return 1;
912 if (only_spaces_and_periods(name, len, 5) &&
913 !strncasecmp(name, "git~1", 5))
914 return 1;
915 if (name[len] != '\\')
916 return 0;
917 name += len + 1;
918 len = -1;
919 }
920 }
921
922 char *xdg_config_home(const char *filename)
923 {
924 const char *home, *config_home;
925
926 assert(filename);
927 config_home = getenv("XDG_CONFIG_HOME");
928 if (config_home && *config_home)
929 return mkpathdup("%s/git/%s", config_home, filename);
930
931 home = getenv("HOME");
932 if (home)
933 return mkpathdup("%s/.config/git/%s", home, filename);
934 return NULL;
935 }
936
937 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
938 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
939 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
940 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
941 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
942 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
943 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
944 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
945 GIT_PATH_FUNC(git_path_shallow, "shallow")