Why Socat is sending back the input to client?

Question

I am using this command

socat -lm -d -d TCP4-LISTEN:5555,reuseaddr,fork EXEC:/bin/myscript,chroot=/root/,su=root,pty,stderr

to start a server but when i send the i connect to it through netcat and send some input, it sends back input+output . Why is that ? I don't want my input back .

Terminal 1:

socat -lm -d -d TCP4-LISTEN:5555,reuseaddr,fork EXEC:/bin/myscript,chroot=/root/,su=root,pty,stderr

Terminal 2:

root@vm:echo "AAAAAA" | nc localhost 5555
AAAAAA[i don't want this to be coming back to me]
output(AAAAAA)

Can you maybe elaborate a little bit more, like paste netcat command you are using, and show what you mean by "it sends back input+output"? — Jakov Sosic, Jun 29 '14 at 05:45
I believe you seeing your input is just a result of you specifying the `pty` option. How is this used, do you need the `pty` option? — Håkan Lindqvist, Jun 29 '14 at 10:57
@HåkanLindqvist - Please can you create answer based on your comment ? — Iwan Aucamp, Oct 02 '14 at 10:00

score 2 · Accepted Answer · answered Oct 12 '14 at 09:50

2

The input being echoed back to the client is a result of using the pty option.

If there is no requirement for having pty the easiest solution would be to simply drop that from the command line.

answered Oct 12 '14 at 09:50

Håkan Lindqvist

35,011
5
69
94

Why Socat is sending back the input to client?

Terminal 1:

Terminal 2:

1 Answers1