You can use regex to check the
format: /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/
You can also explode $ip on "." and check if every part is numeric and less
than 255.
On 20 September 2012 14:44, lx <lxlenovostar@xxxxxxxxx> wrote:
> Hello:
> I want to use filter_var function by this way:
>
> $ip = "192.168.0.1";
>
> if( !filter_var($ip, FILTER_VALIDATE_IP) )
> {
> echo "IP is not valid";
> }
> else
> {
> echo "IP is valid";
> }
>
> I want to check the string $ip is IP address or not.but my PHP version is
> 5.1.6.
> and I know the filter_var requires at least PHP version 5.2.0.
> so, Any other function in PHP 5.1.6 can slove this work and replace the
> filter_var function ?
>
> Thank you, I'm a new one, so I don't know much about PHP documentation.
>
> By the way, The PHP version is required. so I can't upgrade it.
>
