php生成订单号和guid

生成guid:

function guid() {    
    if (function_exists('com_create_guid')) {        
        return com_create_guid();    
    } else {     
        mt_srand((double)microtime()*10000);
        $charid = strtoupper(md5(uniqid(rand(), true))); 
        $hyphen = chr(45);        
        $uuid   = chr(123)            
                 .substr($charid, 0, 8).$hyphen               
                 .substr($charid, 8, 4).$hyphen            
                 .substr($charid,12, 4).$hyphen            
                 .substr($charid,16, 4).$hyphen            
                 .substr($charid,20,12)            
                 .chr(125);
        return $uuid;    
    }
}

生成订单号:

function build_order_no() {    
    return date('Ymd').substr(implode(NULL, array_map('ord', str_split(substr(uniqid(), 7, 13), 1))), 0, 8);