さまざまな方法を使用して PHP で URL からドメイン名を抽出する方法

<code class="php">$regex = '/^(http|https):\/\/[a-z0-9]*\.[a-z0-9.]+/i';</code>

<code class="php">$info = parse_url($url);
$host = $info['host'];</code>

<code class="php">$host_names = explode(".", $host);
$bottom_host_name = $host_names[count($host_names)-2] . "." . $host_names[count($host_names)-1];</code>

<code class="php">$url = 'https://www.example.com/foo/bar';

// Using regular expression
preg_match($regex, $url, $matches);
$domain_name = $matches[0];

// Using parse_url and explode
$info = parse_url($url);
$host = $info['host'];
$host_names = explode(".", $host);
$bottom_host_name = $host_names[count($host_names)-2] . "." . $host_names[count($host_names)-1];

echo "Domain name (regex): " . $domain_name . "<br>";
echo "Domain name and TLD (parse_url): " . $bottom_host_name;</code>

Domain name (regex): example.com
Domain name and TLD (parse_url): example.com