This is usually solved by having the script "daemonize" itself. It only requires a few steps and isn't really that complicated, but you might want to at least take a few minutes to examine some of the pre-rolled implementations, several of which can be found with the simple search: daemonize. (At my current job, we already had that particular bit of code already pre-rolled locally by somebody who predated my employment significantly, so I made significant improvements to that version rather than evaluating the ones on CPAN.)