opendir DIR, "./" or die "Can't open: $!";
    my @files = grep { /\.txt\z/ } readdir DIR;
closedir DIR;

##</code><code>##

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

foreach my $file (@files) {
    open FILE, $file or die "Can't open file: $!";
    while (<FILE>) {
        print $_;
    }
}