PHP method to determine whether the IP is a valid IP address PHP example

This article mainly introduces the method for PHP to determine whether an IP is a valid IP address. Friends who need it can refer to it

Most people who see this log will have the first impression that it is about how to pass Regular expression to judge.

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
}

Determine whether it is a legal public IPv4 address, private IP addresses such as 192.168.1.1 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
}

Source of this article: http://www.electrictoolbox.com/php-validate-ip-address-filter-var/

Normally, we can Choose to use regular expressions. For details, please refer to this article.

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