Hello,
I've created an IOLib tutorial which describes how to write clients and servers with IPV4 TCP using blocking I/O with the stream interface and nonblocking I/O with the event multiplexer and send-to receive-from.
The tutorial and the source for which it is written is in the examples/ directory of the checked out IOLib source codes. The tutorial and source code in the official source release of IOLib will always be the authoritative version. It is recommended one inspects and tries out the example source code along with the tutorial.
I happen to have a link up to the tutorial here: http://pages.cs.wisc.edu/~psilord/blog/data/iolib-tutorial/tutorial.html
Have a nice day.
-pete