+int get_sha1_file(const char *path, unsigned char *result)
+{
+ char buffer[60];
+ int fd = open(path, O_RDONLY);
+ int len;
+
+ if (fd < 0)
+ return -1;
+ len = read(fd, buffer, sizeof(buffer));
+ close(fd);
+ if (len < 40)
+ return -1;
+ return get_sha1_hex(buffer, result);
+}
+
+int get_sha1(const char *str, unsigned char *sha1)
+{
+ static char pathname[PATH_MAX];
+
+ if (!get_sha1_hex(str, sha1))
+ return 0;
+ if (!get_sha1_file(str, sha1))
+ return 0;
+ snprintf(pathname, sizeof(pathname), ".git/%s", str);
+ if (!get_sha1_file(pathname, sha1))
+ return 0;
+ return -1;
+}
+