I don't know if this helps for anything, this doesn't Iterate Recursively as shown, but I use readdir in the following code to create an array $dots of filenames from a directory, excluding any "." prefix in unix. Then I can grep out anything I don't want to operate on, etc. Or in this case put the contents of all the files into a single array $foo, then grep out or split out whatever I'm looking for. I think it can be modified to do something useful without a module.

  $sd = "../data/data_forthis";
  opendir( DIR, $sd) || die;
  while( ($filename = readdir(DIR))){
    next if "$sd\/$filename" =~ /\/\./;
    push @dots, "$sd\/$filename";
  }  ## end of while
  @dots = sort @dots;
  closedir(DIR);

  for(my $a=0;$a<@dots;$a++){
    open (FILE, $dots[$a]);
    push @foo, <FILE>;
    if ($a+1 eq @dots) {
      close FILE;
      open (FILE, $dots[$a]);
      push @foo2, <FILE>;
      } ## end of if
    close FILE;
  }  ## end of for
### At this point @foo has everything and $foo2 has just the last file
+ in the directory...
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