Mark Cullen wrote: What does the ^= mean in the above? Assign bitwise xor. If you want to learn C, these threads might be interesting to you: http://leaf.dragonflybsd.org/mailarchive/kernel/2004-09/index.html#00084 http://leaf.dragonflybsd.org/mailarchive/kernel/2004-10/index.html#00006 Sascha -- http://yoyodyne.ath.cx