Wait for a port in bash, should work on sysv linux

wait_port.sh

#!/usr/bin/env bash

# wait_port <port> <seconds>

check_port () 
{ 
    netstat -tpln 2> /dev/null | sed -E '/^[^t]/ d; s/^([^ ]+ +){3}//; s/ .*$//; s/^.*://;' | grep --color "^$1$" > /dev/null
}

wait_port () 
{ 
    typeset t
    t=$2
    while (( $t > 0 )) && ! check_port $1
    do
        echo "waiting for port $1 for $t secconds."
        sleep 1s
        (( t-- ))
    done
    check_port $1 && echo "Port $1 started." || {
        echo "Port $1 was not started"
        false
    }
}

wait_port $1 $2