Using DJB's tcpclient or tcpcat bidirectionally

Question

Can someone post an example on how to use DJB's tcpclient bidirectionally?

We need to read from Tor's ControlPort as well as write to Tor's ControlPort. A "file" that is open for both, reading and writing. This is not a Tor specific question but a certain example fo what we are trying to do.

I looked through the documentation but am unsure on how to accomplish this specifically.

• The tcpclient program
• The tcpcat program

At the moment netcat is used this way:

nc 127.0.0.1 9051 < "$OUT" > "$IN" &

This doesn't work with tcpcat:

tcpcat 127.0.0.1 9051 < "$OUT" > "$IN" &

How can tcpcat or tcpclient be used to do this?