<?php
// your code goes here
$file_content='blah blah onClick="rpd(56)"; blah blah\nblah blah onClick="rpd(43)"; blah blah\nblah blah onClick="rpd(11)"; blah blah\n';
//$file_content = file_get_contents($url);
$pattern= '/onClick="rpd\((\d+)\)";/';
PD9waHAKCi8vIHlvdXIgY29kZSBnb2VzIGhlcmUKJGZpbGVfY29udGVudD0nYmxhaCBibGFoIG9uQ2xpY2s9InJwZCg1NikiOyBibGFoIGJsYWhcbmJsYWggYmxhaCBvbkNsaWNrPSJycGQoNDMpIjsgYmxhaCBibGFoXG5ibGFoIGJsYWggb25DbGljaz0icnBkKDExKSI7IGJsYWggYmxhaFxuJzsKLy8kZmlsZV9jb250ZW50ID0gZmlsZV9nZXRfY29udGVudHMoJHVybCk7ICAgIAokcGF0dGVybj0gJy9vbkNsaWNrPSJycGRcKChcZCspXCkiOy8nOwpwcmVnX21hdGNoX2FsbCgkcGF0dGVybiwgJGZpbGVfY29udGVudCwgJG1hdGNoZXMpOwpwcmludF9yKCRtYXRjaGVzKTs=