Here it is; sloppy but works great! It's written so that perl beginners can understand it.

#!/usr/bin/perl -w
use Net::Pcap;

my $err;
my $dev = $ARGV[0];
my $object;

$object = Net::Pcap::open_offline($dev, \$err);
unless (defined $object) {
    die 'Unable to create packet capture on device ', $dev, ' - ', $er
+r;
}

Net::Pcap::loop($object, -1, \&callback_function, '');
Net::Pcap::close($object);

sub callback_function {
  my ($user_data,$header,$packet) =@_;

  if (length($packet)>36) {
    my $o = unpack ('H2*',substr($packet,0,1)); #find out what kind of
+ packet it is
    if ($o eq "80") { #if it is a broadcast
      my $sourcemac = unpack ('H12',substr($packet,10,6)); #the packet
+s source mac address
      my $len = hex unpack ('H2',substr($packet,37)); #get the size of
+ the ssid
      my $bs = unpack ('H12',substr($packet,16,6)); #get the basestati
+on mac
      $ssid=unpack ('A*',substr($packet,38,$len)); #get the ssid
      if ($len==0) { #if the ssid isnt broadcasted
        $ssid=">no ssid<";
      }
      print "Beacon Frame: source mac:",$sourcemac," basestation id: $
+bs other: ",$o," ssid: $ssid
 len: $len\n";
    }
    if ($o eq "40") { #if it's a probe for ssid's
      my $offmac=unpack ('H12',substr($packet,10,6)); #get the source 
+mac
      print "PROBE! source mac: $offmac\n";
    }
    if ($o eq "50") { #if it's a probe response
      my $offmac=unpack ('H12',substr($packet,5,6));
      my $sourcemac = unpack ('H12',substr($packet,10,6));
      my $bs = unpack ('H12',substr($packet,16,6));
      my $len = hex unpack ('H2',substr($packet,37));
      my $ssid=unpack ('A*',substr($packet,38,$len));
      if ($len==0) {
        $ssid=">no ssid<";
      }
      print "PROBE RESPONSES! source mac: $offmac $len $ssid\n";
    }
  }
}
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