I am trying to print the files in the current directory that are not perl scripts

Well, in fact not... you are trying to avoid the files in your directory that have a name ending in .pl, and this is a much different history. Your starting design is poor.

what about .pm?, or .pl~? or im-a-perlscript?

If you want to play seriously you need to look at the contents of the file, either use the program file (or a derivative of file) or read the first characters of your file and look for perl code