#!/usr/bin/perl -w
use strict;
use File::Find;

my $base_dir = "C:/Temp";
my @pdf_files;

find(\&collect_pdf_files, $base_dir);
print @pdf_files;

sub collect_pdf_files
{
   return unless (-f);      # only real files, not directories
   return unless (/.pdf$/); # continue if name ends in .pdf
   push (@pdf_files, $File::Find::name);
}

#prints: C:/Temp/something.pdf