Letters
This photo was taken when my wife and I were waiting to get married in the chapel on the second floor of New York City Hall. I just received the 100th issue of LJ and brought it along. You can tell from the photo that my wife was a little jealous. So the title for the photo is “Beauty or LJ”. Hope you like it.
—Ning Qian

Beauty or LJ: Bride-to-be Qing Xiang peeks at fiancé Ning Qian's Linux Journal (photo: Nicole Xiang).
I enjoyed reading your article about setting up an FTP proxy [LJ, December 2002]. I was just curious about one point. You make a comment about not being able to configure the acceptable commands list differently for internal and external users. Is it possible to set up two proxies then route the incoming requests at the firewall for internal addresses to one proxy and those from external addresses to the other?
—John
Mick Bauer replies: That's an excellent idea! You could set up a proxy on the firewall for external users, with read-only permissions, and set up a proxy on some host on the inside for outbound transactions, with looser permissions. You could then configure your firewall to permit outbound FTP only if it originates from the designated internal proxy.
It's great to see those huge old machines coming back! I saw an advert in Linux Journal for a CDC 6400, the baby brother of the immense CDC 6600. Of course today we could not use Freon to cool it. And software is coming back! SOAP, for instance, the Symbolic Optimal Assembly Program for the IBM 650. Magnetic drum memory will never die! I have even seen articles about ASP, the Attached Support Processor for the IBM 360/65. Who says I'm a dinosaur?
—Peter Chase, Alpine, Texas
The articles on ptrace in the November and December 2002 issues were very informative. So what's to stop someone from using ptrace to insert some malevolent code in a running program? Forgive me for looking on the dark side.
—Walter S. Heath, Concord, Massachusetts
Keep thinking evil thoughts. You can't keep a system secure without studying possible attacks. Fortunately, you can only ptrace a process if it's your own process, or if you're root.
—Editor
I have found an error in my article, “OpenLDAP Everywhere” [LJ, December 2002]. In the auto.home section on page 54, the gomerp entry has the line:
cn: super3
The line should read:
cn: gomerpA reader contacted me after copying the entry exactly from the article. He has fixed his configuration and is up and running with unified logon. Matt Lung and I are very pleased with the article as published. Our mothers are very proud!
—Craig Swanson
We were a little disappointed by your article on the applications for the Zaurus. You listed many commercial applications and yet when it came to mapping/navigation software you listed only the free one. zNav and zNav Lite are the only Zaurus mapping/navigation products that use commercial navigation charts.
—Patrick Cannon, Barco Software, LLC
Here the world's highest Linux install event took place Saturday the 12th of December 2002, 11,000 feet above the sea. It was the first of its kind in this part of Bolivia—and maybe a world record when it comes to altitudes and Linux install events.

The organizers task force: Janus Sandsgaard, Edgar Ruiz, Juan Conorel, Devin Conde, Hardy Beltran, Christian Mollo and Jorge Castro.
—Janus Sandsgaard
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Enter to Win an Adafruit Pi Cobbler Breakout Kit for Raspberry Pi

It's Raspberry Pi month at Linux Journal. Each week in May, Adafruit will be giving away a Pi-related prize to a lucky, randomly drawn LJ reader. Winners will be announced weekly.
Fill out the fields below to enter to win this week's prize-- a Pi Cobbler Breakout Kit for Raspberry Pi.
Congratulations to our winners so far:
- 5-8-13, Pi Starter Pack: Jack Davis
- 5-15-13, Pi Model B 512MB RAM: Patrick Dunn
- 5-21-13, Prototyping Pi Plate Kit: Philip Kirby
- Next winner announced on 5-27-13!
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Free Webinar: Hadoop
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Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.
Some of key questions to be discussed are:
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