grep "^([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.$"
输入ip，检查其是否满足的ip书写规范，即不能大于255，不能有字母，和其他标点，参考网上的，自己搞了个如下，做个标记！@
echo -n 'Enter the Server-ip:'
read BISSip
echo $BISSip > /tmp/tmpserverip
echo $BISSip|grep "^[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}$" > /dev/null
num=$?
if [ $num = 1 ]
then
echo error ip,please enter correct
else
{
a=$(cut -d. -f1 /tmp/tmpserverip)
b=$(cut -d. -f2 /tmp/tmpserverip)
c=$(cut -d. -f3 /tmp/tmpserverip)
d=$(cut -d. -f4 /tmp/tmpserverip)
{
if [ $a -ge 255 ]||[ $a -le 0 ]
then
echo a:error ip
else
echo 1 > /tmp/jack
fi
}
{
if [ $b -ge 255 ]||[ $b -lt 0 ]
then
echo b:error ip
else
echo 1 >>/tmp/jack
fi
}
{ if [ $c -ge 255 ]||[ $c -lt 0 ]
then
echo c:error ip
else
echo 1 >>/tmp/jack
fi
}
{ if [ $d -ge 255 ]||[ $d -le 0 ]
then
echo d:error ip
else
echo 1 >> /tmp/jack
fi
}