31 May 2007

Theater e-Ushers

Saw this today and was mildly intrigued:

High-Tech Tattle-Tale Device Hits NYC Theaters

It's an article about how some NYC Regal cinemas are giving certain patrons the ability to page the management. So if you're one of these patrons and there's something wrong with the movie (sound, focus, etc.), you can page the management to send someone to the projection booth.

This can also be used to rat on unruly patrons, and this is the part that interests me. This is why I rarely go see a film in the theater anymore. It's not because theater admission prices are too high (they are), and it's not because Hollywood churns out utter crap in two-hour installments (it does). It's because I invariably end up sitting in front of some rotten bastard who thinks he's sitting in his living room, who can't keep his feet off my chair and can't keep his big mouth shut.

They just need to take this notion a bit further. If I'm watching a film and the guy behind me is talking back to the movie and kicking my seat, I want to push a button which does one of the following:
  • injects a harmless but potent tranquilizer into the noisy patron
  • closes a high-voltage electrical circuit connected to the noisy patron's chair
  • opens a trapdoor which sends the noisy patron down a metal slide and into a StarWars-like garbage masher, complete with a dianoga
The third option could be further enhanced if the movie could be briefly suspended while live footage from the garbage masher was projected on the movie screen. This would be especially effective in an IMAX theater.

26 May 2007

Firewalling NFS, testing SMTP

Yesterday I found a useful Web page explaining how to use Linux iptables to firewall an NFS server. Firewalling NFS is complicated, because NFS picks random listener ports when it starts up. But by following the instructions on this page, you can edit a few files to tell NFS which ports to use:


If you are using Red Hat (or something similar, like CentOS), you only have to edit /etc/modprobe.conf, /etc/sysconfig/nfs, and /etc/services. The only thing I'd add to this tutorial is that you can just put something like 'STATD_PORT=4000' in /etc/sysconfig/nfs, rather than hardcoding the rpc.statd port number in the nfslock startup file. Then you can use iptables to control access to the following ports (tcp and udp for each port): 111, 2049, 4000, 4001, 4002, and 4003. I actually had to reboot to get nfslock to start up on port 4001. Oh, well.

Another useful Web page shows how to run an SMTP session using telnet (you could also use netcat):


One useful application of this technique is testing the access rules of an SMTP server (for example, making sure you're not inadvertently relaying for certain hosts).

20070521 thunderstorm

Took a few pictures during a thunderstorm the other night, and here are a couple of my favorites:



06 May 2007

More photos (cool clouds)

I took some pictures the other day. It was a day with my favorite kind of weather: it was cloudy and cool, but not rainy. There were some horses in a nearby field, some wildflowers, and some pretty cool-looking clouds. The local topology really worked for me--very flat horizons made the photo contrast image-editing technique very effective.

Here are a few of my favorites.

horses and clouds

cool clouds

landscape w/ cool clouds

clouds and wildflowers