#!/usr/bin/perl -w
use strict;
use File::Find;

# The shift here takes the first command line
# argument and uses that as our path.

find(\&rot_cat,shift);

sub rot_cat {
    unless (open(INFILE,$_)) {
        warn "Can't open $_ - $!\n";
        return;
    }
    local $/ = undef; # Slurp mode.
    my $contents = <INFILE>;

    # Rot13 our contents.
    $contents =~ tr/A-Za-z/N-ZA-Mn-za-m/;

    # Print our new file.
    print $contents;
}