#!/usr/bin/perl --
use strict;
use warnings;
use Data::Dump qw/ dd pp /;
use Path::Tiny qw/ path /;
use File::Find::Rule qw/ find /;

my $thisdir = shift || path( __FILE__ )->parent;
my @all  = File::Find::Rule->in( "$thisdir" );
my @dirs = File::Find::Rule->directory
->name( qr/^[IPD]\d{8}$/ )
->prune ## don't descend 
->in( $thisdir );
dd( \@all, \@dirs );
dd(
    find(
        directory =>
        name => qr/^[IPD]\d{8}$/,
        prune => ## don't descend 
        in => $thisdir,
    )
);
__END__
$ perl ffindrule.pl .
(
  [
    ".",
    "ffindrule.pl",
    "a",
    "a/echo.txt",
    "a/q",
    "a/q/echo.txt",
    "a/r",
    "a/r/D20131114",
    "a/r/D20131114/fa",
    "a/r/I20131114",
    "a/r/I20131114/fa",
    "a/r/P20131114",
    "a/r/P20131114/fa",
    "a/r/P20131114/P20131114",
    "b",
    "b/echo.txt",
    "b/s",
    "b/s/D20131114",
    "b/s/D20131114/away",
    "b/s/I20131114",
    "b/s/I20131114/ru",
    "b/s/P20131114",
    "b/s/P20131114/P20131114",
    "b/s/P20131114/run",
    "b/s/t",
    "b/s/t/o",
    "b/s/t/o/p",
    "b/s/t/o/p/D20131114",
    "b/s/t/o/p/I20131114",
    "b/s/t/o/p/P20131114",
    "b/t",
    "b/t/echo.txt",
  ],
  [
    "a/r/D20131114",
    "a/r/I20131114",
    "a/r/P20131114",
    "b/s/D20131114",
    "b/s/I20131114",
    "b/s/P20131114",
    "b/s/t/o/p/D20131114",
    "b/s/t/o/p/I20131114",
    "b/s/t/o/p/P20131114",
  ],
)
(
  "a/r/D20131114",
  "a/r/I20131114",
  "a/r/P20131114",
  "b/s/D20131114",
  "b/s/I20131114",
  "b/s/P20131114",
  "b/s/t/o/p/D20131114",
  "b/s/t/o/p/I20131114",
  "b/s/t/o/p/P20131114",
)