#!/usr/bin/perl -w

use strict;
use Cwd;
use File::Find;

my $filespec   =  qr/\.(?:txt|pl)$/;
my %dirskip = ( 'path/to/dir' => 1,
                'path/to/another/dir' => 1 );
                
my $dir        =  $ARGV[0] || getcwd(); 

find( { wanted => \&find_function, preprocess => \&globber }, $dir );

sub find_function {
  return if $File::Find::name !~ /$filespec/ || (-d $File::Find::name);
  print $File::Find::name.$/;
}

sub globber{
  my @files;
  foreach(@_){
     push(@files, $_) unless $dirskip{$File::Find::name};
  }
  return @files;
}