<?php
$str = "differentcontentLocationhttps://e...content-available-to-author-only...e.com/api/result/13548/data/123456differentstuffincludingwhitespacesandnewlines8484";
$str2 = "differentcontentLocationhttps://e...content-available-to-author-only...e.com/api/result/13548/data/123456";
preg_match("@/data/([0-9]+)@i", $str2, $matches2);
PD9waHAKCiRzdHIgPSAiZGlmZmVyZW50Y29udGVudExvY2F0aW9uaHR0cHM6Ly9lLi4uY29udGVudC1hdmFpbGFibGUtdG8tYXV0aG9yLW9ubHkuLi5lLmNvbS9hcGkvcmVzdWx0LzEzNTQ4L2RhdGEvMTIzNDU2ZGlmZmVyZW50c3R1ZmZpbmNsdWRpbmd3aGl0ZXNwYWNlc2FuZG5ld2xpbmVzODQ4NCI7CiRzdHIyID0gImRpZmZlcmVudGNvbnRlbnRMb2NhdGlvbmh0dHBzOi8vZS4uLmNvbnRlbnQtYXZhaWxhYmxlLXRvLWF1dGhvci1vbmx5Li4uZS5jb20vYXBpL3Jlc3VsdC8xMzU0OC9kYXRhLzEyMzQ1NiI7CnByZWdfbWF0Y2goIkAvZGF0YS8oWzAtOV0rKUBpIiwgJHN0ciwgJG1hdGNoZXMpOwpwcmludF9yKCRtYXRjaGVzKTsKcHJlZ19tYXRjaCgiQC9kYXRhLyhbMC05XSspQGkiLCAkc3RyMiwgJG1hdGNoZXMyKTsKcHJpbnRfcigkbWF0Y2hlczIpOw==