shell script to remove IPv4 addresses from all fail2ban jails

fail2ban-unban-ip.sh

#!/usr/bin/env bash
function print_help {
    echo "remove an ip address from all fail2ban jails"
    echo "$(basename $0) ip_address [ip_address]  [ip_address]"
}

if [[ -z "$@"  ]]
then
    print_help
fi

for ip in "$@" 
do 
    # does it resemble an IPv4 address?
    if ( echo "$ip" | egrep -q "^([12]?[0-9]{1,2}[\.]){3}[12]?[0-9]{1,2}$" )
    then
        for jail in $(fail2ban-client status | grep 'Jail list:' | sed 's/.*Jail list://' | sed 's/,//g') 
        do 
            result=$(fail2ban-client set $jail unbanip $ip 2>&1 | grep -v 'IP.*is not banned')
            if [[ "$result" =~ $ip ]]
	    then
	        echo "$ip removed from $jail"
	    else
	        echo "$ip not in jail $jail"
	    fi
	done
    else
        echo "skipping $ip -- typo?"
        print_help
    fi
done