Arduino-Makefile/bin/wait-connection-leonardo

#!/bin/bash

while [ ! -e $1 ]
do
    echo Waiting connection at $1
    sleep 0.2
done

sleep 1
# necessary for me...
# /dev/ttyACM0 used to disappear after the reset
# but no longer now. How can I tell whether the 
# connection is ready?

echo Connection Established