morse2.sh 36:  morse2.sh:  Syntax error:  "(" unexpected.

#!/bin/bash

#be sure you have already installed nmap on your PI


PORT=11005
CW_PIN=25
echo "Start listening on port $PORT ..."
while read line
do

    #echo $line
    #echo $line | od -An -t uC

    cmd=${line:0:1}

    #echo $cmd
    #echo $cmd | od -An -t uC

case "$cmd" in

    0) #echo "000"
       gpio write $CW_PIN 0
       ;;

    1) #echo "111"
       gpio write $CW_PIN 1
       ;;

    3) echo "Going to stop listener ..."
       break
       ;;

    *) #echo "unknown cmd"
       ;;

esac

done < <((echo "Welcome. Please give me one of the following commands: 0 | 1 | 3") | ncat -k -l $PORT)
echo "... listener stopped."
exit 0