socat

Multipurpose relay (SOcket CAT).

• Listen to a port, wait for an incoming connection and transfer data to STDIO:

socat - TCP-LISTEN:8080,fork

• Create a connection to a host and port, transfer data in STDIO to connected host:

socat - TCP4:www.domain.com:80

• Forward incoming data of a local port to another host and port:

socat TCP-LISTEN:80,fork TCP4:www.domain.com:80