combine netcat with chat on bash for automatic udp responses

Question

I want to combine "chat" and "nc" on linux, so I will create a tiny udp server that responds on a specific request and sends back an answer.

In fact I want to redirect the stdout of "nc" to the stdin of "chat" and vice versa. My first attempt was:

nc -w 3000 -u -n -l -p 30000 >&1111 <2222 & 
chat -V 'request' 'answer' >&2222 <1111

But it didn't work.

I believe file descriptors have to be between 0 and 255. You should probably use named pipes instead anyway. — Dennis Williamson
– Dennis Williamson, Commented Mar 12, 2011 at 21:27

shodanex · Accepted Answer · 2011-03-14 13:47:27Z

3

use socat instead of netcat. Something like this :

socat UDP-LISTEN:5555 EXEC:"chat -sv ping pong",pty

To test it, you can open another terminal, and use socat to bridge stdio and an UDP socket :

socat - UDP:localhost:5555

Type ping, and you will get pong !

answered Mar 14, 2011 at 13:47

shodanex

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