If you'd only like a single timezone ID returned (whichever one is returned first by the system's readdir()), you can use sed's q command to quit after the first match. This is much more performant than starting up head for instance. However, this causes find to break the pipe with md5sum early, causing an error to print to fd 2. You may ignore this error by piping it to /dev/null as the following complete command demonstrates: