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.

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

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

Last Updated On : 21st March 2013...

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Validate domain name using filter_var function in php