Connect to netcat through telnet and shut down computer

Question

I'm using the following bash script to start listening to connections on port 8585. When connected by telnet and sending the text "shutdown" I would like the host computer to shut down. As of now I'm using my mac.

#!/bin/bash

echo "Start listening on port 8585..."
while read line
do
    if [ "$line" == 'shutdown' ]; then
        # Execute shutdown now on the computer.
        break
    else
        echo "$line"
    fi
done < <((echo "Welcome.") | nc -k -l 8585)
echo "Good bye"

When I try to connect to it through telnet I just get this as response:

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Welcome.
Connection closed by foreign host.

Do any of you guys know why the connection gets closed straight away? Do you have any ideas?

I got the example code from here: https://askubuntu.com/questions/873788/bash-read-lines-from-netcat-connection#873794

Answer 1

Remove the (echo "Welcome.") |:

#!/bin/bash

echo "Start listening on port 8585..."
while read line
do
    if [ "$line" == 'shutdown' ]; then
        # Execute shutdown now on the computer.
        break
    else
        echo "$line"
    fi
done < <(nc -k -l 8585)
echo "Good bye"

Keep in mind that will only break the loop with the word shutdown but nc will continue listening