Validate domain name using filter_var function in PHP

The filter_var function of php is capable of validating many things like emails, urls, ip addresses etc. It does not have a direct option to validate a domain name however. So I coded up this little snippet that the filter_var function with a little tweak so that it can validate domain names as well.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

function filter_var_domain($domain) {     if(stripos($domain, 'http://') === 0)     {         $domain = substr($domain, 7);     }           ///Not even a single . this will eliminate things like abcd, since http://abcd is reported valid     if(!substr_count($domain, '.'))     {         return false;     }           if(stripos($domain, 'www.') === 0)     {         $domain = substr($domain, 4);     }           $again = 'http://' . $domain;     return filter_var ($again, FILTER_VALIDATE_URL); }

Now use it as

1 2 3 4

if(!filter_var_domain('www.gmail.com.')) { //Not a valid domain name }