You haven't told asus much about what this sub is doing, so I'll just throw the easiest answer out there: you could do that in a separate process. However, I am guessing that you're asking the question because the code needs to share some state. Two other solutions that come to mind are that prompting modules like IO::Prompter have timeout options, or for something a little more low-level, alarm and a custom %SIGnal handler - but be aware the latter has some limitations on Win and that SIGALRM may also be used by other things (e.g. sleep). In general, I think it'd be best if you coud tell us more about your application (OS, modules, maybe some sample code, etc.) and then we could provide better answers.