This won't help you at all, but just to be a pedant and provide a correct example for anyone else wanting to select a random file:

my @files = glob("/usr/bin/*");
my $range = $#files; #scalar(@files)-1;

while (1) {
    my $random = int(rand($range));
[download]

should be (if you want to include the possibility of getting the last file in /usr/bin):

my @files = glob("/usr/bin/*");

while (1) {
    my $random = int(rand(@files));
[download]

But GlitchMr has it correct in his answer.