<?php
 
function extrairHostPorIndice($url){
	// Extraí tudo que estiver depois das duas primeiras barras "//"
	$depois  = substr($url, strpos($url, "//") + strlen("//"));
 
	// Extraí tudo que estiver antes da primeira barra "/"
	$antes = substr($depois, 0, strpos($depois, "/"));
 
	// Retorna o resultado
	return $antes;
}
 
$url  = "https://docs.google.com/uc?id=0B7zY19LCJa8XeXZtWklZbFBEVG8&export=download";
$site = extrairHostPorIndice($url);
 
echo $site . "\n";

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