socat

Multipurpose relay (SOcket CAT). More information: http://www.dest-unreach.org/socat/.

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

sudo socat - TCP-LISTEN:8080,fork

• Listen on a port using SSL and print to STDOUT:

sudo socat OPENSSL-LISTEN:4433,reuseaddr,cert=./cert.pem,cafile=./ca.cert.pem,key=./key.pem,verify=0 STDOUT

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

sudo socat - TCP4:www.example.com:80

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

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