Kozz, the post you were looking for might be here. Not trying to blow my own horn, just thought it answered what you were asking.

Of course, it just covers the seek, truncate, and tell portions of your question. If you need more info about flocking, it doesn't address that.

As a side note: always keep in mind that using flock is only a polite way of asking others to stay out. If they don't check, flock won't help. I'm sure you know that, but I think it's always safe to mention that.

Cheers!