DevShed has posted the seventh part of their "validator" series today. This time they look at validating IP addresses with the filter_var function.

You can surely appreciate this functionality when developing modules, classes, plug-ins, etc. that must perform some kind of strong validation on incoming data. The filter extension comes armed with another handy filter, though, that permits you to check some common things, such as the IP addresses of client machines.

The give an example of using the FILTER_VALIDATE_IP constant to check the IP address format and include the optional FILTER_FLAG_IPV4 check for the IPv4 format.