shell判断IP是否有效

Posted 2022-05-11

分析：IP由四位数字组成，以点【.】分割，最一组最长为3位并且每个字段不能大于255
#!/bin/bash
function checkip()

if echo $IP|egrep"^[0-9]1,3\.[0-9]1,3\.[0-9]1,3\.[0-9]1,3$" >/dev/null; then
    if [ $VALID_CHECK == "yes" ]; then
     echo "IP $IP  available!"
        return 0
    else
        echo "IP $IP not available!"
        return 1
    fi
else
    echo "IP format error!"
    return 1
fi

while true; do
read -p "Please enter IP: " IP
checkip $IP
[ $? -eq 0 ] && break
done