Bash: Loop until command exit status equals 0

Question

I have a netcat installed on my local machine and a service running on port 25565. Using the command:

nc 127.0.0.1 25565 < /dev/null; echo $?

<

Answer 1

You could try something like

while true; do
    nc 127.0.0.1 25565 < /dev/null
    if [ $? -eq 0 ]; then
        break
    fi
    sleep 1
done
echo "The command output changed!"