You may want to look at File::Find to get the list of files. Something similar to the following code will find a list of all the .txt files in the start directory (Note: You can always modify the regex if need be):

use strict;
use warnings;
use File::Find;
my @files;
my $dir = "C:/Apache2/cgi-bin/start";
find( sub { push @files, $File::Find::name if -f && /.+\.txt/ }, $dir 
+);

print "Content-type: text/html\n\n";

foreach my $file (@files) {
  open FILE, '<', $file    # This is assuming you only want to read th
+e file
    or die("Can't open file ($file): $!");
  while (<FILE>) { print $_; }
  close (FILE)
    or die("File close error ($file): $!");
}
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