Question

I have a field in which I ask for desired domain name, now it came to a point that some user includes http://www.desireddomain on the field. Having this value, the domain registrar API I have will return an error. The approach I have in mind is to omit any characters before period (including period), using preg_replace(). I have a <select> which contains (.com,.biz,.org,.net)

$desired_domain = "www.desireddomain"; // user input
$will_be = "desireddomain"; // final output after preg_replace() ?

And also, does this limits me to only the period or is there anything more I should know? Thanks.

Answer 1

You don’t need to use regular expressions since you are aren’t doing a “fuzzy” search. Just get everything from the last period on, if there is a period.

if ( strrpos('www.domain','.')!==false ) {
    $domain = substr('www.domain',strrpos('www.domain','.')+1);
}

Alternatively, if you want to make sure they didn’t enter .com,.biz,.org,.net, use explode and do a check.

$parts = explode('.', 'www.desireddomain.com.net');
$domain = array_pop($parts);
$invalid_parts = array('com','biz','org','net');
if ( in_array($domain, $invalid_parts) && count($parts)>0 ) {
    $domain = array_pop($parts);
} else {
    // No valid domain submitted
}

In this example, they are asking to use “com” as the domain, even though it’s no valid. You could create a loop instead, where you continuously pop items off the array until you find a valid part or run out of items.