<?php 
function email_check($email) {
	$isValid=TRUE;
	$atIndex = strrpos($email, "@");
	if (is_bool($atIndex) && !$atIndex) {
		$isValid = FALSE;
	} else {
		$domain = substr($email, $atIndex+1);
		$local = substr($email, 0, $atIndex);
		$localLen = strlen($local);
		$domainLen = strlen($domain);
		//user troppo lungo
		if ($localLen < 1 || $localLen > 64) {
			$isValid = FALSE;
			//l'user incomincia o termina con un . o a 2 .. consecutivi
		} elseif ($local[0] == '.' || $local[$localLen-1] == '.' || consecutive_dot($local)) {
			$isValid = FALSE;
		} elseif (! isValidDomain($domain)) {
			$isValid = FALSE;
		} elseif(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/', str_replace("\\\\","",$local))) {
			// character not valid in local part unless
			// local part is quoted
			if (!preg_match('/^"(\\\\"|[^"])+"$/', str_replace("\\\\","",$local))) {
				$isValid = FALSE;
			}
		}
	}
	
	return $isValid;
}

function isValidDomain($domain) {
	$isValid=true;
	$domainLen = strlen($domain);

	if ($domainLen < 4 || $domainLen > 255) {
		$isValid = FALSE;
		//l'user incomincia o termina con un . o a 2 .. consecutivi
	} elseif (consecutive_dot($domain) || $domain[0] == '.' || $domain[$domainLen-1] == '.' ) {
		$isValid = FALSE;
	} elseif (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain)) {
		$isValid = FALSE;
		//ha almeno un punto
	} elseif (! strpos($domain, ".")) {
		$isValid = FALSE;
	} else {
		//il dominio di primo livello è almeno 2 caratteri
		$arr=explode(".", $domain);
		if(strlen($arr[count($arr)-1])<2)
			$isValid = FALSE;
	}

	return $isValid;
}

function consecutive_dot($string) {
	$ret=false;

	if(preg_match('/\\.\\./',$string))
		$ret=true;

	return $ret;
}

/**
 * estrae dominio di secondo livello
 */
function dom($name){
	$zon=explode(".",$name);
	return implode(".",array_slice($zon,-3));
}

/* gets the data from a URL */
function get_data($url) {
	$ch = curl_init();
	$timeout = 5;
	curl_setopt($ch, CURLOPT_URL, $url);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
	$data = curl_exec($ch);
	curl_close($ch);

	return $data;
}
?>