Assuming you are not testing
Perl programs, but binary programs (written in C/C++ or something else)
There are some things that depending on the situation may be useful (they are useful to me):
* knowing how to start programs (via
system backticks or
eval)
*
Expect module can prove useful for interactive shell programs (for UNIX at least)
*
Win32::GuiTest and
X11::GUITest
* knowledge of writing daemons (i.e.: using but not limited to
fork)
* wrapping your programs in
Test::Simple,
Test::Harness or other.
Of course there are some other fine tools out there, it's up to you to find them ;-)