Now that you really know how to use use Perl and do stuff with files and regular expressions we should do an assignment that is a bit more significant. What I want you to do is to write a script that will do a search and replace on all the files in a specified directory. The user will provide the directory, a regular expression to find, and the text to replace it with on the command line. The original files should be moved to a backup and the modified versions should have the original names.
So an invocation of this might look like this "replace.pl . fred barney". This simple example doesn't use the regular expression capabilities though your program should be able to do that.