$ gdb -c core /usr/local/bin/perl
[snip]
(gdb) set args my_test_script.pl
(gdb) run
...something about segfaulting
(gdb) where
... shows what function you were in
(gdb) bt
... shows a backtrace of the stack, showing the code path to this function
(gdb) print variable
... prints variable, amazingly (supposing it is in scope)
(gdb) print *0xdeadbeef
... prints memory address contents (best guess at what it contains)