How to make an Echo server with Bash?

Question

How to write a echo server bash script using tools like nc, echo, xargs, etc capable of simultaneously processing requests from multiple clients each with durable connection

Answer 1

If you use ncat instead of nc your command line works fine with multiple connections but (as you pointed out) without -p.

ncat -l 2000 -k -c 'xargs -n1 echo'

ncat is available at http://nmap.org/ncat/.

P.S. with the original the Hobbit's netcat (nc) the -c flag is not supported.

Update: -k (--keep-open) is now required to handle multiple connections.