The executeable is perl, you might have to supply the full path name, for example: /usr/bin/perl. Make sure it is exactly the same executable as caused the dump. If you are new to core dumps and gdb, one of the most useful short commands is bt, or "backtrace". This should give the routine it crashed in and the call stack. However you will only get that if perl have been compiled in debug (-g option to cc/gcc). Alos, if the call stack has been overwritten by the bug then you can't go much further.

Perl *shouldn't* crash, if it does then you have uncovered a bug which should be reported. Unless, that is, you are using some hokey module written in XS, have embedded C, or the like.