TCPdump抓包命令详解2

[root@linhexiao shellTest]# cat yanghuisanjiao.sh
#!/bin/bash
export LANG="zh_CN.GB18030"
#create by 林鹤霄QQ:858993860
#mail:858993860@qq.com

#judge input  如果启动脚本时没有指定杨辉三角的最大长度就提示输入
if [ -z $1 ];then     #-z $1字符串的长度是0的话，返回真
read -p "Input Max Int Lines:" MAX   # read -p 打印一行字符串，用MAX接收输入
else
MAX=$1
fi

#judge int
[ -n "`echo $MAX|sed 's/[0-9]//g'`" ] && \
echo "you input not a int!" && exit 1

#requir <10
[ $MAX -ge 10 ] && echo "you input number ge 10!" && exit 1

#start
a[0]=1
for((i=0;i<=MAX;i++))
do
for((j=$i;j>0;j--))
do
((a[$j]+=a[$j-1]))
done

for((j=0;j<$[MAX-$i];j++))
do
if [ $MAX -le 10 ];then
echo -en "\t"
else
echo -n " "
fi
done

for((j=0;j<$i;j++))
do
if [ $MAX -lt 10 ];then
echo -en "\t\t"${a[${j}]}
else
echo -n ${a[$j]}
fi
done
echo
done