2 * I'm tired of doing "vsnprintf()" etc just to open a
3 * file, so here's a "return static buffer with printf"
6 * It's obviously not thread-safe. Sue me. But it's quite
7 * useful for doing things like
9 * f = open(mkpath("%s/%s.git", base, name), O_RDONLY);
11 * which is what it's designed for.
16 static char bad_path[] = "/bad-path/";
18 static char *get_pathname(void)
20 static char pathname_array[4][PATH_MAX];
22 return pathname_array[3 & ++index];
25 static char *cleanup_path(char *path)
28 if (!memcmp(path, "./", 2)) {
36 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
42 len = vsnprintf(buf, n, fmt, args);
45 strlcpy(buf, bad_path, n);
48 return cleanup_path(buf);
51 static char *git_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
53 const char *git_dir = get_git_dir();
56 len = strlen(git_dir);
59 memcpy(buf, git_dir, len);
60 if (len && !is_dir_sep(git_dir[len-1]))
62 len += vsnprintf(buf + len, n - len, fmt, args);
65 return cleanup_path(buf);
67 strlcpy(buf, bad_path, n);
71 char *git_snpath(char *buf, size_t n, const char *fmt, ...)
75 (void)git_vsnpath(buf, n, fmt, args);
80 char *git_pathdup(const char *fmt, ...)
85 (void)git_vsnpath(path, sizeof(path), fmt, args);
90 char *mkpath(const char *fmt, ...)
94 char *pathname = get_pathname();
97 len = vsnprintf(pathname, PATH_MAX, fmt, args);
101 return cleanup_path(pathname);
104 char *git_path(const char *fmt, ...)
106 const char *git_dir = get_git_dir();
107 char *pathname = get_pathname();
111 len = strlen(git_dir);
112 if (len > PATH_MAX-100)
114 memcpy(pathname, git_dir, len);
115 if (len && git_dir[len-1] != '/')
116 pathname[len++] = '/';
118 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
122 return cleanup_path(pathname);
126 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
127 int git_mkstemp(char *path, size_t len, const char *template)
132 tmp = getenv("TMPDIR");
135 n = snprintf(path, len, "%s/%s", tmp, template);
137 errno = ENAMETOOLONG;
140 return mkstemp(path);
143 /* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
144 int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
149 tmp = getenv("TMPDIR");
152 n = snprintf(path, len, "%s/%s", tmp, template);
154 errno = ENAMETOOLONG;
157 return mkstemps(path, suffix_len);
160 /* Adapted from libiberty's mkstemp.c. */
163 #define TMP_MAX 16384
165 int gitmkstemps(char *pattern, int suffix_len)
167 static const char letters[] =
168 "abcdefghijklmnopqrstuvwxyz"
169 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
171 static const int num_letters = 62;
178 len = strlen(pattern);
180 if (len < 6 + suffix_len) {
185 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
191 * Replace pattern's XXXXXX characters with randomness.
192 * Try TMP_MAX different filenames.
194 gettimeofday(&tv, NULL);
195 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
196 template = &pattern[len - 6 - suffix_len];
197 for (count = 0; count < TMP_MAX; ++count) {
199 /* Fill in the random bits. */
200 template[0] = letters[v % num_letters]; v /= num_letters;
201 template[1] = letters[v % num_letters]; v /= num_letters;
202 template[2] = letters[v % num_letters]; v /= num_letters;
203 template[3] = letters[v % num_letters]; v /= num_letters;
204 template[4] = letters[v % num_letters]; v /= num_letters;
205 template[5] = letters[v % num_letters]; v /= num_letters;
207 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, 0600);
211 * Fatal error (EPERM, ENOSPC etc).
212 * It doesn't make sense to loop.
217 * This is a random value. It is only necessary that
218 * the next TMP_MAX values generated by adding 7777 to
219 * VALUE are different with (module 2^32).
223 /* We return the null string if we can't find a unique file name. */
229 int validate_headref(const char *path)
232 char *buf, buffer[256];
233 unsigned char sha1[20];
237 if (lstat(path, &st) < 0)
240 /* Make sure it is a "refs/.." symlink */
241 if (S_ISLNK(st.st_mode)) {
242 len = readlink(path, buffer, sizeof(buffer)-1);
243 if (len >= 5 && !memcmp("refs/", buffer, 5))
249 * Anything else, just open it and try to see if it is a symbolic ref.
251 fd = open(path, O_RDONLY);
254 len = read_in_full(fd, buffer, sizeof(buffer)-1);
258 * Is it a symbolic ref?
262 if (!memcmp("ref:", buffer, 4)) {
265 while (len && isspace(*buf))
267 if (len >= 5 && !memcmp("refs/", buf, 5))
272 * Is this a detached HEAD?
274 if (!get_sha1_hex(buffer, sha1))
280 static struct passwd *getpw_str(const char *username, size_t len)
283 char *username_z = xmalloc(len + 1);
284 memcpy(username_z, username, len);
285 username_z[len] = '\0';
286 pw = getpwnam(username_z);
292 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
293 * then it is a newly allocated string. Returns NULL on getpw failure or
296 char *expand_user_path(const char *path)
298 struct strbuf user_path = STRBUF_INIT;
299 const char *first_slash = strchrnul(path, '/');
300 const char *to_copy = path;
304 if (path[0] == '~') {
305 const char *username = path + 1;
306 size_t username_len = first_slash - username;
307 if (username_len == 0) {
308 const char *home = getenv("HOME");
309 strbuf_add(&user_path, home, strlen(home));
311 struct passwd *pw = getpw_str(username, username_len);
314 strbuf_add(&user_path, pw->pw_dir, strlen(pw->pw_dir));
316 to_copy = first_slash;
318 strbuf_add(&user_path, to_copy, strlen(to_copy));
319 return strbuf_detach(&user_path, NULL);
321 strbuf_release(&user_path);
326 * First, one directory to try is determined by the following algorithm.
328 * (0) If "strict" is given, the path is used as given and no DWIM is
330 * (1) "~/path" to mean path under the running user's home directory;
331 * (2) "~user/path" to mean path under named user's home directory;
332 * (3) "relative/path" to mean cwd relative directory; or
333 * (4) "/absolute/path" to mean absolute directory.
335 * Unless "strict" is given, we try access() for existence of "%s.git/.git",
336 * "%s/.git", "%s.git", "%s" in this order. The first one that exists is
339 * Second, we try chdir() to that. Upon failure, we return NULL.
341 * Then, we try if the current directory is a valid git repository.
342 * Upon failure, we return NULL.
344 * If all goes well, we return the directory we used to chdir() (but
345 * before ~user is expanded), avoiding getcwd() resolving symbolic
346 * links. User relative paths are also returned as they are given,
347 * except DWIM suffixing.
349 char *enter_repo(char *path, int strict)
351 static char used_path[PATH_MAX];
352 static char validated_path[PATH_MAX];
358 static const char *suffix[] = {
359 ".git/.git", "/.git", ".git", "", NULL,
361 int len = strlen(path);
363 while ((1 < len) && (path[len-1] == '/')) {
369 if (path[0] == '~') {
370 char *newpath = expand_user_path(path);
371 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
376 * Copy back into the static buffer. A pity
377 * since newpath was not bounded, but other
378 * branches of the if are limited by PATH_MAX
381 strcpy(used_path, newpath); free(newpath);
382 strcpy(validated_path, path);
385 else if (PATH_MAX - 10 < len)
388 path = strcpy(used_path, path);
389 strcpy(validated_path, path);
392 for (i = 0; suffix[i]; i++) {
393 strcpy(path + len, suffix[i]);
394 if (!access(path, F_OK)) {
395 strcat(validated_path, suffix[i]);
399 if (!suffix[i] || chdir(path))
401 path = validated_path;
403 else if (chdir(path))
406 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
407 validate_headref("HEAD") == 0) {
408 setenv(GIT_DIR_ENVIRONMENT, ".", 1);
409 check_repository_format();
416 int set_shared_perm(const char *path, int mode)
419 int tweak, shared, orig_mode;
421 if (!shared_repository) {
423 return chmod(path, mode & ~S_IFMT);
427 if (lstat(path, &st) < 0)
433 if (shared_repository < 0)
434 shared = -shared_repository;
436 shared = shared_repository;
439 if (!(mode & S_IWUSR))
442 /* Copy read bits to execute bits */
443 tweak |= (tweak & 0444) >> 2;
444 if (shared_repository < 0)
445 mode = (mode & ~0777) | tweak;
450 /* Copy read bits to execute bits */
451 mode |= (shared & 0444) >> 2;
452 mode |= FORCE_DIR_SET_GID;
455 if (((shared_repository < 0
456 ? (orig_mode & (FORCE_DIR_SET_GID | 0777))
457 : (orig_mode & mode)) != mode) &&
458 chmod(path, (mode & ~S_IFMT)) < 0)
463 const char *make_relative_path(const char *abs, const char *base)
465 static char buf[PATH_MAX + 1];
468 if (!base || !base[0])
471 if (is_dir_sep(base[i])) {
472 if (!is_dir_sep(abs[j]))
474 while (is_dir_sep(base[i]))
476 while (is_dir_sep(abs[j]))
479 } else if (abs[j] != base[i]) {
486 /* "/foo" is a prefix of "/foo" */
488 /* "/foo" is not a prefix of "/foobar" */
489 !is_dir_sep(base[i-1]) && !is_dir_sep(abs[j])
492 while (is_dir_sep(abs[j]))
497 strcpy(buf, abs + j);
502 * It is okay if dst == src, but they should not overlap otherwise.
504 * Performs the following normalizations on src, storing the result in dst:
505 * - Ensures that components are separated by '/' (Windows only)
506 * - Squashes sequences of '/'.
507 * - Removes "." components.
508 * - Removes ".." components, and the components the precede them.
509 * Returns failure (non-zero) if a ".." component appears as first path
510 * component anytime during the normalization. Otherwise, returns success (0).
512 * Note that this function is purely textual. It does not follow symlinks,
513 * verify the existence of the path, or make any system calls.
515 int normalize_path_copy(char *dst, const char *src)
519 if (has_dos_drive_prefix(src)) {
525 if (is_dir_sep(*src)) {
527 while (is_dir_sep(*src))
535 * A path component that begins with . could be
537 * (1) "." and ends -- ignore and terminate.
538 * (2) "./" -- ignore them, eat slash and continue.
539 * (3) ".." and ends -- strip one and terminate.
540 * (4) "../" -- strip one, eat slash and continue.
546 } else if (is_dir_sep(src[1])) {
549 while (is_dir_sep(*src))
552 } else if (src[1] == '.') {
557 } else if (is_dir_sep(src[2])) {
560 while (is_dir_sep(*src))
567 /* copy up to the next '/', and eat all '/' */
568 while ((c = *src++) != '\0' && !is_dir_sep(c))
572 while (is_dir_sep(c))
581 * dst0..dst is prefix portion, and dst[-1] is '/';
584 dst--; /* go to trailing '/' */
587 /* Windows: dst[-1] cannot be backslash anymore */
588 while (dst0 < dst && dst[-1] != '/')
596 * path = Canonical absolute path
597 * prefix_list = Colon-separated list of absolute paths
599 * Determines, for each path in prefix_list, whether the "prefix" really
600 * is an ancestor directory of path. Returns the length of the longest
601 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
602 * is an ancestor. (Note that this means 0 is returned if prefix_list is
603 * "/".) "/foo" is not considered an ancestor of "/foobar". Directories
604 * are not considered to be their own ancestors. path must be in a
605 * canonical form: empty components, or "." or ".." components are not
606 * allowed. prefix_list may be null, which is like "".
608 int longest_ancestor_length(const char *path, const char *prefix_list)
610 char buf[PATH_MAX+1];
611 const char *ceil, *colon;
612 int len, max_len = -1;
614 if (prefix_list == NULL || !strcmp(path, "/"))
617 for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
618 for (colon = ceil; *colon && *colon != PATH_SEP; colon++);
620 if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
622 strlcpy(buf, ceil, len+1);
623 if (normalize_path_copy(buf, buf) < 0)
626 if (len > 0 && buf[len-1] == '/')
629 if (!strncmp(path, buf, len) &&
639 /* strip arbitrary amount of directory separators at end of path */
640 static inline int chomp_trailing_dir_sep(const char *path, int len)
642 while (len && is_dir_sep(path[len - 1]))
648 * If path ends with suffix (complete path components), returns the
649 * part before suffix (sans trailing directory separators).
650 * Otherwise returns NULL.
652 char *strip_path_suffix(const char *path, const char *suffix)
654 int path_len = strlen(path), suffix_len = strlen(suffix);
660 if (is_dir_sep(path[path_len - 1])) {
661 if (!is_dir_sep(suffix[suffix_len - 1]))
663 path_len = chomp_trailing_dir_sep(path, path_len);
664 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
666 else if (path[--path_len] != suffix[--suffix_len])
670 if (path_len && !is_dir_sep(path[path_len - 1]))
672 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
675 int daemon_avoid_alias(const char *p)
680 * This resurrects the belts and suspenders paranoia check by HPA
681 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
682 * does not do getcwd() based path canonicalizations.
684 * sl becomes true immediately after seeing '/' and continues to
685 * be true as long as dots continue after that without intervening
688 if (!p || (*p != '/' && *p != '~'))
698 else if (ch == '/') {
700 /* reject //, /./ and /../ */
705 if (0 < ndot && ndot < 3)
706 /* reject /.$ and /..$ */
715 else if (ch == '/') {