Using an overkill amount of global variables will have to get them unset at the end of socket operation, otherwise you occupy quite a space of variables. In this snippet, for example, it has many global and local variables combined, which make the script appear messy at first glance. The $sock().mark is a temporary storage place, which can store up to 512 bytes, where you have all the values held together for socket to refer to as you go along with its operation. If something useful is there, why not make the most of it? Just food for thought.