You are asking about general advice, so that's what you'll get ;-).

What you have done (implicitly) is creating a global variable. That's a Bad Thing (tm).

Why? Because your subs become dependent on each other. On its turn that means that your code becomes harder to debug/ maintain, harder to reuse ("Where the hack does that $error come from?") and easier to break, among others.

So, pass the variable to your sub. Or pass an object or hash that contains the info or has the right methods. Everything is better than a global.

Try to read 'Code Complete' by McConnell to get it explained better than I could....

Jeroen
"We are not alone"(FZ)

PS: ++ for the use of strict, and for your approach to break the sub into components. Maybe try to think of the different functionalities. Like: Is error reporting a subfunction of logging, or something separate, or at another level, or something that the average user should be protected from (yes!)?