[script] portscan

https://github.com/linuxias/MyBox/blob/master/script/portscan.sh

#!/bin/bash
IP=127.0.0.1
first_port=$1
last_port=$2
function usage() {
    echo "Script for scanning port"
    echo "Usage   : ./portscan start_port end_port"
    echo "Example : ./portscan 1 100"
    exit
}
if [ $# -ne 2 ]
then
    usage
fi
for port in `seq $first_port $last_port`
do
    (echo >/dev/tcp/$IP/$port)> /dev/null 2>&1 && echo $port open || echo "$port closed"
done