I like all of your answers, but I can't see how that would help him debug his program. He will need some sort of debug mechanism, not just knowing when his program dies. It would be certainly more useful to know 1) why it died and 2) how to stop it from dying. For this purpose, I would recommend an error log to identifz weak spots and Perl error messages. (It's unlikelz that you'll get much useful error reports from the return value of the program.) He should also try setting up program "areas": which region of code can be said as "doing one task". Once he has these isolated, he can use debug messaging or error logs to determine what works, what doesn't and on which reiteration of the code the program dies. In C/C++, program crashes could be linked to memory leaks 90% of the time. Since Perl handles all memory management, he'll need to isolate his weak spot using basic report programming techniques.