what does callbacks option in ssh2 stream wrapper do?

Question

http://www.php.net/manual/en/wrappers.ssh2.php

One of the context options is callbacks but it doesn't have a description next to it. In fact it's the only context option that doesn't have a description next to it.

Any ideas?

Answer 1

Usually callbacks are user functions that can be called by api for errors, async IO and similar. Better definition here.

There's a codesnip here that uses them in this fashion.

Maybe more info here too.