use strict;
use warnings;
use WWW::Mechanize;

my $start = "http://www.domain.com";
my $mech = WWW::Mechanize->new( autocheck => 1 );
my $regex = qr/\d+.+\.pdf$/;
my @aLinks = findAllLinks($mech, $start, $regex);

for my $link ( @links ) {
   my $url = $link->url_abs;
   my $bytecount = getByteCount($mech, $url);
   print "Fetching $url";
   print "   $bytecount bytes\n";
} 

sub findAllLinks {
  my ( $mech, $start, $regex ) = @_;

  $mech->get( $start );
  return $mech->find_all_links( url_regex => $regex );
}

sub getByteCount {
  my ($mech,$url) = @_;
  my $filename = $url;
  $filename =~ s[^.+/][];
  $mech->get( $url, ':content_file' => $filename );
  return -s $filename;
}