生成短地址

<?php  
$chars=array("a","b","c","d","e","f","g","h",
				"i","j","k","l","m","n","o","p",
				"q","r","s","t","u","v","w","x",
				"y","z","0","1","2","3","4","5",
				"6","7","8","9","A","B","C","D",
				"E","F","G","H","I","J","K","L",
				"M","N","O","P","Q","R","S","T",
				"U","V","W","X","Y","Z");
$salt="www.joneto.com";
$hash=md5("http://www.sina.com".$salt);
$rs=array();
for($i=0;$i<4;$i++){
	$temp=substr($hash, $i*8,8);
	$temp=base_convert($temp, 16, 10) & base_convert("3fffffff", 16, 10);

	$str="";
	for($j=0;$j<6;$j++){
		$subtemp=$temp & intval(base_convert("3d", 16, 10));
		$str.=$chars[$subtemp];
		$temp=$temp>>5;
	}
	unset($temp);
	$rs[]=$str;
}

print_r($rs);

?>