Another way to recurse a directory and print the files you want to get,the following is the code.

  use   strict;   
  use   warnings;   
  sub   ransack   
  {   
  #dir,\@files   
  my   $dir=shift;   
  my   $files=shift;   
  my   @array=glob("$dir\\*");   
  foreach   my   $item   (@array)   {   
            if(-d   $item)   {   
                    ransack($item,$files);  
            }   
                 else   {   
                     $files->[@$files]=$item;   
                 }   
  }   
  }   
    my  ($array, @array);   
  ransack("path of your directory",\@array);   #path of your directory
  foreach  $array (@array)   
  {   
      if ($array=~/txt|csv/) {    #match your file format
  print ("$array\n");   
    }
  }
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Enjoy!