I personally believe that you may be even more astonished to learn that under Windows (which works much with "extensions" that OTOH are in turn "mostly" an unexisting concept under *NIX) if you program is somewhere under %PATH% and .pl is included in %PATHEXT%, then you may just call you your program like my_prog. You will only have problems with one kind of shell redirection. But I don't think you care much...