PHP method to determine whether it is a valid IP address

When most people see this blog, their first impression must be that it talks about how to judge through regular expressions. This article mainly introduces the method of determining whether an IP is a valid IP address in PHP. Friends who need it can refer to it. I hope it can help everyone.

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
}

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