Generate Random String with PHP

This purpose of this function is to generate a random string comprise of alphanumeric string but excludes i, l, 1, o and 0 to avoid confusion. You can use it to generate activation code or password.

PHP

Usage: you can either call getCode() - the length of the code will be 12, otherwise, you can specify the length you preferred.

function getCode($length=12) {
	
	//Ascii Code for number, lowercase, uppercase and special characters
	$no = range(48,57); 
	$lo = range(97,122);
	$up = range(65,90);	
	
	//exclude character I, l, 1, 0, O
	$eno = array(48, 49);
	$elo = array(108);
	$eup = array(73,79);
	$no = array_diff($no,$eno);
	$lo = array_diff($lo,$elo);
	$up = array_diff($up,$eup);
	$chr = array_merge($no, $lo, $up);

	
	for ($i=1;$i<=$length;$i++) {
		
		$code.= chr($chr[rand(0,count($chr)-1)]);	
	}
	return $code;
}