Linux shell关闭端口占用的进程

#!/bin/bash
# to kill process that port already used
# ./kill_port.sh 8080

index=1
if [ ! -n "$1" ] ;then
    echo "do nothing!"
else
    for var in $(echo $(netstat -pln | grep tcp | grep :$1))
	do
		if [ `expr $index % 7` == 0 ]
		then
			array=(${var//\// })
			if [ ${#array[*]} == 2 ]
			then
				echo "kill process, id=${var}"
				kill -9 ${array[0]}
			fi
		fi
		index=`expr $index + 1`
	done
fi