This section of the Perl FAQ covers questions involving operating system interaction. This involves interprocess communication (IPC), control over the user-interface (keyboard, screen and
pointing devices), and most anything else not related to data manipulation.
Read the FAQs and documentation specific to the port of perl to your operating system (eg, the perlvms manpage, the perlplan9 manpage, ...). These should contain more detailed information
on the vagaries of your perl.