[bash] IP유효성 확인 스크립트

validate_IP(){
    if [[ $1 =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}$ ]]
    then
        for NUM in `sed 's/\./ /g' <<< $1`
        do
            if [ $NUM -ge 0 ] && [ $NUM -le 255 ] && [[ ! $NUM =~ ^0[0-9]{1,2}$ ]]
            then
                continue
            else
                echo "Invalid"
                return 1
            fi
        done
        echo "Valid"
        return 0
    else
        echo "Invalid"
        return 1
    fi
}