Detailed explanation of the steps to determine whether the IP is a valid IP address in PHP

This time I will give you a detailed explanation of the steps for PHP to determine whether an IP is a valid IP address. What are the precautions for PHP to determine whether an IP is a valid IP address? The following is a practical case, let's take a look.

No, after php5.2.0, there is a special

function to make this judgment.

Judge whether it is a legal IP

if(filter_var($ip, FILTER_VALIDATE_IP)) {
// it's valid
}
else {
// it's not valid
}

Judge whether it is a legal IPv4 IP address

if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
// it's valid
}
else {
// it's not valid
}

Judge whether it is a legal public IPv4 address, private IP such as 192.168.1.1 The address will be excluded

if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE)) {
// it's valid
}
else {
// it's not valid
}

Determine whether it is a legal IPv6 address

if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE)) {
// it's valid
}
else {
// it's not valid
}

Determine whether it is a public IPv4 IP or a legal Public IPv6 IP address

if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
// it's valid
}
else {
// it's not valid
}

I believe I read it You have mastered the method in the case of this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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