whmcs-test-ssl.sh

#!/usr/bin/env bash
yum install -y php
cat <<\PHP > test.php
<?php
$domain = 'www.whmcs.com';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://' . $domain);
curl_setopt($ch, CURLOPT_CERTINFO, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_VERBOSE, true);

if(curl_exec($ch) === false){
    echo 'Curl error: ' . curl_error($ch);
}

$certInfo = curl_getinfo($ch, CURLINFO_CERTINFO);
print_r($certInfo);
?>
PHP

php -q test.php