/*
* Try to read the location of the git directory from the .git file,
* return path to git directory if found.
*/
const char *read_gitfile(const char *path)
{
char *buf;
char *dir;
const char *slash;
struct stat st;
int fd;
ssize_t len;
if (stat(path, &st))
return NULL;
if (!S_ISREG(st.st_mode))
return NULL;
fd = open(path, O_RDONLY);
if (fd < 0)
die_errno("Error opening '%s'", path);
buf = xmalloc(st.st_size + 1);
len = read_in_full(fd, buf, st.st_size);
close(fd);
if (len != st.st_size)
die("Error reading %s", path);
buf[len] = '\0';
if (!starts_with(buf, "gitdir: "))
die("Invalid gitfile format: %s", path);
while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
len--;
if (len < 9)
die("No path in gitfile: %s", path);
buf[len] = '\0';
dir = buf + 8;
if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
size_t pathlen = slash+1 - path;
size_t dirlen = pathlen + len - 8;
dir = xmalloc(dirlen + 1);
strncpy(dir, path, pathlen);
strncpy(dir + pathlen, buf + 8, len - 8);
dir[dirlen] = '\0';
free(buf);
buf = dir;
}
if (!is_git_directory(dir))
die("Not a git repository: %s", dir);
update_linked_gitdir(path, dir);
path = real_path(dir);
free(buf);
return path;
}
/*
* Try to read the location of the git directory from the .git file,
* return path to git directory if found.
*
* On failure, if return_error_code is not NULL, return_error_code
* will be set to an error code and NULL will be returned. If
* return_error_code is NULL the function will die instead (for most
* cases).
*/
const char *read_gitfile_gently(const char *path, int *return_error_code)
{
const int max_file_size = 1 << 20; /* 1MB */
int error_code = 0;
char *buf = NULL;
char *dir = NULL;
const char *slash;
struct stat st;
int fd;
ssize_t len;
if (stat(path, &st)) {
error_code = READ_GITFILE_ERR_STAT_FAILED;
goto cleanup_return;
}
if (!S_ISREG(st.st_mode)) {
error_code = READ_GITFILE_ERR_NOT_A_FILE;
goto cleanup_return;
}
if (st.st_size > max_file_size) {
error_code = READ_GITFILE_ERR_TOO_LARGE;
goto cleanup_return;
}
fd = open(path, O_RDONLY);
if (fd < 0) {
error_code = READ_GITFILE_ERR_OPEN_FAILED;
goto cleanup_return;
}
buf = xmalloc(st.st_size + 1);
len = read_in_full(fd, buf, st.st_size);
close(fd);
if (len != st.st_size) {
error_code = READ_GITFILE_ERR_READ_FAILED;
goto cleanup_return;
}
buf[len] = '\0';
if (!starts_with(buf, "gitdir: ")) {
error_code = READ_GITFILE_ERR_INVALID_FORMAT;
goto cleanup_return;
}
while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
len--;
if (len < 9) {
error_code = READ_GITFILE_ERR_NO_PATH;
goto cleanup_return;
}
buf[len] = '\0';
dir = buf + 8;
if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
size_t pathlen = slash+1 - path;
dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
(int)(len - 8), buf + 8);
free(buf);
buf = dir;
}
if (!is_git_directory(dir)) {
error_code = READ_GITFILE_ERR_NOT_A_REPO;
goto cleanup_return;
}
update_linked_gitdir(path, dir);
path = real_path(dir);
cleanup_return:
if (return_error_code)
*return_error_code = error_code;
else if (error_code) {
switch (error_code) {
case READ_GITFILE_ERR_STAT_FAILED:
case READ_GITFILE_ERR_NOT_A_FILE:
/* non-fatal; follow return path */
break;
case READ_GITFILE_ERR_OPEN_FAILED:
die_errno("Error opening '%s'", path);
case READ_GITFILE_ERR_TOO_LARGE:
die("Too large to be a .git file: '%s'", path);
case READ_GITFILE_ERR_READ_FAILED:
die("Error reading %s", path);
case READ_GITFILE_ERR_INVALID_FORMAT:
die("Invalid gitfile format: %s", path);
case READ_GITFILE_ERR_NO_PATH:
die("No path in gitfile: %s", path);
case READ_GITFILE_ERR_NOT_A_REPO:
die("Not a git repository: %s", dir);
default:
assert(0);
}
}
free(buf);
return error_code ? NULL : path;
}