Readers sound off.
Problems with Paranoia

I'd like to point out a few things in the “Paranoid Penguin” article on DMZ networks (March 2001): RPC is remote procedure call and not RP control protocol; r commands like rsh, rlogin and rcp don't use RPC. In my humble opinion, examples should use runlevel three instead of two because three is the default runlevel for most Linux servers. Changes in level two don't have an effect because Linux runlevels are independents and not additionals as they are in other UNIX flavors.

—Vitaly Karasikvkarasik@ndsisrael.com

Bauer replies: You're right that RPC is remote procedure call and not RP control protocol and that r commands like rsh, rlogin and rcp don't use RPC. But my point was that both RPC and r commands are inappropriate for use on publicly accessible systems, and I stand by that. As far as which runlevel to use for examples, I could have been clearer on that. By the way, Debian defaults to runlevel two.

Korny Question

I hate to bother you with a question for Stew, but since it is a real newbie type of question you can probably answer it without getting him involved.

In his article in the April 2001 issue “Providing E-mail Services for a Small Office” he shares his cron job in Listing 5. I usually like Korn shell and write my little scripts there, but when I only use one > on redirecting output, I only get the last line sent to the file. Is Bourne better about understanding > vs. >> ? According to the way I read his tracking script, he would not get the output in listing 6. I would have had to put >> on all the lines except the first one if I wanted the output in listing 6. Am I missing something?

—Richard Keatingrkeating@ins.com

So far as I'm aware, > and >> mean the same thing in Korn, Bourne and, for that matter, csh. > replaces the file, >> appends to it. Listing 5 would not produce the output seen in listing 6. Looking at the author's original, it read:

if [ -s $ST -a -f $MS ]; then
        echo "General Mail Statistics" > $MSO
        echo ""
        echo "local = Mail local to fileserver

        echo "smtp  = Internet mail"
        echo "relay = Mail from/to Sun system

        echo ""
        cp /dev/null $ST
echo ""
echo "Mail Filter/Forwarding Statistics
echo ""
/usr/bin/mailstat -l /home/thriftycompany/mail/from
chown thriftycompany /home/thriftycompany/mail/from
cat $MSO | mail -s "Daily Email Summary"
rm $MSO
exit 0

Apparently the original was inadvertently modified at some point in the production process. The listing on our FTP site is correct. Our apologies.


Searching for Open Edition

Thank you all for the best computer-related magazine in all categories. I eagerly await every issue of LJ (we have a subscription at the school where I work as a teacher) and read almost everything from the front cover on. In the April 2001 issue I read a presentation of Kylix, which I have been waiting for, being a Pascal and Delphi programmer, but the price of these two commercial products has made it impossible for my budget. When I read your article “Stop the Presses” new hope came to me as I thought an Open Edition existed for free download. That hope turned to disappointment when I went to Borland's web page and didn't find any mention of an Open Edition, only the two overpriced commercial products. So where is this Open Edition of Kylix?

—Bertil Wergeliuswbertil@tjohoo.se

The free download version of Open Edition is expected to be available sometime in Summer 2001.



I wanted to let you know that I think you're doing a great job with Linux Journal, and the article “The New Vernacular” was one of the most intelligent articles I've ever read in a magazine.

—Jeremy Hayescotk_hayes@hotmail.com

O Captain, My Captain

I enjoyed the review on Descent 3 from Loki (Linux Journal, April 2001). I think I will enjoy this game because I like the thought of controlling a doomed ship and trying to find help from others, as well as investigating sabotage done to the ship and sending out radio transmissions. Everything about this game is quite intriguing. I do believe you sold me!

—Jose CausingSilhouet98@cs.com


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