LJ Archive

More Letters to the Editor

These letters were not printed in the magazine and appear here unedited.

BTS: Re: Netscape Mail article Dec 1998

I am replying about the article in the December 1998 issue of Linux Journal, in Best of Technical Support, about Bill's question on Netscape Mail, Demon Internet and Red Hat 5.0:

Demon Internet are unusual as an ISP in terms of providing a full SMTP feed to you, treating you like a “real” Internet host, rather than relying on POP3. It is only recently that they have started providing a POP3 service for collection of mail.

The reason you are getting some mail in Netscape and some in Sendmail is that Demon open an SMTP socket to you as soon as you log on, and start sending mail to you. If you also connect via POP3, some will come down via each method.

The solution for Red Hat 5.0 is to turn off Sendmail, using the command 'chkconfig sendmail off' - this will prevent Sendmail starting, thus preventing you from having anything listening for an SMTP connection, preventing Demon from connecting to you. All your mail will stay on the Demon side, waiting for you to pick it up with your POP3 client.

Sorry for being so wordy. Please feel free to edit this down a bit if you want to publish any of it.

Hope this helps,
—Peter Denison

Re: Netscape Mail

Peter Struijk writes in LJ:
Sendmail is most likely sending out mail with your full host name. When a recipient replies to a message you sent from elm, the reply is sent directly to your computer and not to your mailbox at your ISP.
Peter, you have inadvertently misled Bill here. Demon Internet, a large UK service provider, have an uncommon setup for email.

Your actual host name 'mirrim.demon.co.uk' is the same as in your email address. Demon users have an unlimited number of email address in the form <user>@<hostname>.demon.co.uk. Demon set the MX records for the dial-in hosts to point the their own mail servers, so mail is never delivered directly from outside hosts to the clients' machine by SMTP.

However, Demon _do_ deliver mail by SMTP to client machines. This is their preferred method of mail delivery, and their 'Turnpike' software for Windows accepts mail in this way, and maintains multiple mailboxes.

Demon have recently started to offer an additional service, where mail for dialup hosts can be fetched by POP3 instead of by SMTP. Naturally this conflicts with the SMTP delivery, so some messages are delivered by each method. If you intend to use POP3 for mail delivery, then you should disable the SMTP daemon on your machine.

A simple way to do this is on a Red Hat box is to type (as root of course):

      /sbin/chkconfig --del sendmail

It's best to set up sendmail so that it will forward mail to Demon's mail hosts if it can't deliver it directly. That way, they can keep trying for you, even after you've disconnected.

I can't tell you how, though, because I don't use sendmail - I use Exim ( http://www.exim.org/) because it's more secure, faster and easier to configure.

I would suggest using a local mail service, though, and allowing Demon to deliver mail by SMTP. Then you can 'POP' it from your own machine. That way, you can easily use more than one of your unlimited mail addresses. Even if it's only ever going to be used by yourself, you might find it useful to have multiple addresses going into different mailboxes.

Demon sometimes takes a minute or two to deliver mail after you dial up. If you intend to dial up just for the purpose of fetching mail, and not doing anything else at all, then this might annoy you.

In this case, you could use a modified version of the 'fetchmail' POP client, which uses Demon's POP3 extensions to find out the intended recipient of the mail and deliver it to the right place. The patch to fetchmail ... isn't on my web site ATM for some reason. I'll mail it to you if you ask for it, and put it up for FTP somewhere.

Feel free to get in touch if you have any problems with it, or if you want further clarification.
—David Woodhouse

Midnight Commander

As an utter Linux newbie, it took me a month to find MC (http://www.gnome.org/mc/). Now that it's too late of course there it is on on my Red Hat distribution; for all I know, all I had to do was type MC....

Whatever, (1.) I wanted to thank from the bottom of my heart the creators of MC; I just can't express the feeling of freedom and release a little tree and file display produces; all your karmas are immensely enhanced! (2.) Distributions really ought to consider emphasizing this thing more. At this moment, Linux is poised for greatness, or at least to significantly annoy Bill Gates, and providing this kind of obvious file/directory support to new single-machine users like myself is an obvious way to encourage Linux use and distribution.

But again: thank you, MC creators.
—James G. Owen

Subnetting Table

The article about CIDR in issue 56 by David A. Bandel was very interesting. Sometime ago I created a subnetting table that illustrates these concepts.

It's available as PDF at


You might want to publish the link for your readers...
—Marc Liyanage

Funny attitude

Please accept this letter as it is, and not as an insult to your magazine.

Reading a couple of issues, I have noticed a weird attitude of the people writing articles. Everybody is against Microsoft, but in a very childish manner. Of course, I agree that Microsoft products are not the best, they are not even decent, but expressions like “In the continuing battle with the Evil Empire, I have recently reduced my dependence on ”Them“ blah-blah”(issue 47 page 64) or the Fry Electronics display window (issue 54 same page). Let's get serious, people. It's not the way you can fight software monopoly. Serious people don't bark against Microsoft, serious people (Linus, Alan and many more) write good and free software. Serious people don't publish articles about “Yes! In Zair we can make a full elephant migration survey using Linux!”. No. Serious things like that is made using more powerful software, powerful than Linux. Linux is a good OS, free, but it's still at its beginning. I've just got pissed off of that “Linux propaganda” many magazines are doing. You know, that propaganda makes Linus look like Lenin in Linnuxism (communism). I hate these extremist opinions, and please be more careful in the future. Linux Journal is still one of the best Linux magazines and I hope it will remain so. Above Linux (although it's free and makes a lot of people earning lots of money paying nothing instead) there is democracy and the freedom of choice.

I am sure this will not be published, but I am satisfied that what I had to speak was heard where it was supposed to.
—Stefan Laudat

IDG/LinuxWorld Expo alienates speakers?

The following is a quote from Alan Cox's Dec. 11th. dairy:

(http://www.linux.org.uk/diary) entry:
I also had some non fun mail from the LinuxWorld people (ie IDG) when I asked them to clarify arrangements for speakers expenses. Answer “we wont be paying any”. Thats one less speaker. I know three other speakers who will also probably be dropping out and no doubt more will follow when they discover this.
Now in my case sure I can probably extract the money from someone but there is a principle at stake. Many Linux hackers are in it for fun and don't get paid for it. A conference whose financial greed extends to excluding all the non commercial Linux hackers is wrong. It may be how those dreadful non technical all gloss networking/windows shows run but its not how a technical conference should be run. It's not how other Linux events are run and its not how Usenix is run.
I may be a member of the small club of Linux people who can get funding to attend and speak at such an event but I want no part in it.
I am one of the organizers of the Atlanta Linux showcase and have been since it was started over three years ago. I think things like this are an important distinction between a Linux trade show whose sole purpose seems to be to take advantage of the Linux community in order to generate trade show revenue and ALS, which is as close as we can get to an Open Source type of Linux trade show. ALS is put on by a not-for-profit corporation made up of volunteers from the Atlanta Linux Enthusiasts user group and we have always covered travel expenses for people who were willing to take time out of their busy schedules to come and speak at ALS.

I think it is important for the Linux community to realize the possible consequences that can happen when pure commercial interests intersect with the Open Source community. Some times becoming the hot press topic and being seen as the next Microsoft competitor may not always have pleasant results.
—Steven A. DuChene

ATI video cards

Some time ago I bought an ATI all-in-wonder. This card was support by Xfree86 on the video side but not the TV tuner side. When someone, I can't remember who, tried to enlist ATI for assistance to write a driver for the tuner, they declined and have declined in spite of a large assault from many Linux users.

All that said I was distressed when I read in the December 1998 issue #56 in the 'Best of Technical Support' in a reply to the email entitled 'Networking' LJ printing a reply which plugged ATI products.

If vendors do not support Linux then the Linux community should not support same.

As far as I know ATI is one of these vendors.

—Gene Imes

Linux on Macintosh

After years of using Wintel equipment and successfully installing Red Hat Linux on a 90MHz Pentium with 32MB of RAM and a 1.2 Gigabyte disk I purchased an Apple Macintosh G3. I use Macs at work and I'm familiar with them. It wasn't until I started using a Mac exclusively that I realized the I much preferred the elegance of the interface and the integration of the software from third parties.

I have an interest in learning UNIX and the obvious course of action was to learn Linux, And even though I have a Mac now I still have a great interest in learning Linux. Having heard a little about Linux on Mac equipment I decided to look for myself to see what was available.

When I visited your web site and saw that the January issue would have an article regarding Linux on a Mac. I was really excited and could hardly wait for it to arrive in the mail.

That day has arrived.

I am very disappointed.

I am currently preparing to install LinuxPPC on my PowerMac G3. With a 4 Gigabyte disk I can partition it and run both the Mac OS and Linux peacefully and actually communicate between the two partitions. I would like to direct your attention to http://www.linuxppc.org. At that site you will find much more up-to -date information regarding Linux and Macintosh.

I would also like to point out MKLinux,to my understanding, was developed by Apple for the 68k chip. Apple is no longer developing MKLinux.

A new distribution is in development called Yellow Dog.

After I found all the information available regarding Linux on Macs I started looking though back issues of Linux Journal to see if there was anything I had missed on the subject. Unfortunately there wasn't.

For inside, blood and guts, info on Apple Macintosh architecture and Motorola chip architecture I would like to direct you to the Inside Macintosh series of books. They are published by Addison Wesley with information provided by Apple. The series has been available for at least four years and is regularly updated. Motorola has information on their chip architecture in the Motorola user's manuals.
—Brian Vawter

Sorry you were disappointed in Alan's article but as you pointed out, it was meant only as a discussion of porting the kernel not a HOWTO. Linux Journal has had other articles on Linux and the Macintosh: “How to Build a Mac” in issue 19, “MkLinux: Linux Comes to the Power Macintosh” in issue 31, “Linux? On the Macintosh? With Mach?” in issue 37, and “Netatalk, Linux and the Macintosh” in issue 45. We also have one promised but not yet delivered for future publication. —Editor

Stone Age hardware in PC

In “Linux for Macintosh 68K Port”, Alan Cox complains about the Mac's Stone Age hardware design. The PC also has a little Stone Age hardware.

The Intel 8259 interrupt controller was introduced as a peripheral for the Intel 8080 eight-bit microprocessor. The 8259A added a mode for compatibility with the 8088 and 8086 processors.

The 8259A has a mode where the interrupt vector is returned as three bytes. This mode is not used with x86 processors, so I do not know if modern 8259A emulations include it.

The three-byte mode emits an 8080 machine-language CALL instruction. The 8080 executes this instruction to get to the interrupt service routine.
—Peter Traneus Anderson

Choosing between VI and World Domination

One again we have had the survey about favourite editors and once again VI emerged victor and if I judge by what happened last year you are receiving loads of e-mail of VI partisans happy of the outcome.

But. It is not to an old statician like me you will teach him about sample bias and about the problem of spontaneous votes who tend to over represent the most vocal and activist group.

LJ readership is only a tiny fraction of Linux population and tends to be more extremist and Unixically correct than your average Linuxer.

More importantly you are not asking to the people who saw Unix and hated it. Each time I meet one of them I ask him. So far the first thing they mentioned has always been the same: “Unix's awful editor”. They were not speaking about Emacs :-).

When did Unix reach world domination? NEVER. The crown went directly from mainframes to DOS. And blindly following the traditions of a system who never won is a sure way to defeat. A system who got an awful reputation and lost many potential followers in no small measure thanks to VI.

Because Linux will reach world domination the day people like lawyers or writers will use it. And lawyers will NEVER use VI.

So, VI is the editor you will find in every UNIX? Linux will crush proprietary Unixes, the sooner, the better. Who cares about their editor?

It is time we begin designing things the Linux way and stop caring about Unix.
—Jean Francois Martinez

Corel WP for Linux.. Very nice :-)

Just like to tell you how easy it was to install, configure and run WP for Linux. I have worked with Linux for four years and this was one of the easiest apps I have ever installed.

So far I am very impressed.. I will forward this e-mail along to Linux Journal..

If you are looking for system config feed back..

FIC 2013 Mother board
AMD K6 350
128 MB ram
AGP 8 MB Matrox millennium II
17" AOC @ 1024 x 768

Kernel 2.0.36
Xwindows Xfree86 3.3.3

I hope to see more of your apps ported to Linux in the future

We are also selling Linux gaming computers and are considering an Office computer system.

Macsyma - yet another company that ported its product to Linux

Your review on Mathematica 3.0 for Linux by Patrick Galbraith (LJ, December 1998, page 75) gave me an idea that one could mention another big player from the Computer Algebra Software field, namely Macsyma, that just recently ported its product on Linux. The third one of the Big 3 from this field (MAPLE) has been available for quite some time.

You can find more about Macsyma, and its Linux version, at http://www.macsyma.com/

Let me just add that I find Macsyma to be extremely good. I suggested to some people at Macsyma last year to make it available for Linux users (I am not pretending that my suggestion was either first or the only one). My argument to them was that I see some similarity between Linux and Macsyma, that I believe that people using one of them will easily get to like the other one. In particular, I mentioned neatness, precision and “a mathematical carefulness” of Macsyma, together with its affordability. Namely, the price of Macsyma for Linux is around $200, versus $1,495 (according to the above mentioned LJ article). I did not check the price for Maple, but am pretty much sure that it is over $600. On the other side, Macsyma scored far better on some comprehensive independent tests (see the Macsyma's home page for the details), and it seems to be easier to learn for beginners.

Let me use this opportunity to add another idea. I have been subscribed to LJ for about a year, and using Linux (Slackware 3.0) for close to 2 years. I enjoy both, Linux and the LJ, very much. Many articles are over my head, but many are just right; and I read everything anyway. This particular January 1999 issue has so many articles that I found to be really great. I filled in a little feedback to 2-3 of them just a few minutes ago, but then got kind of tired of typing the same thing over and over again (I apologize to the other authors for my laziness). So here is my idea: Will it be possible to make link where one could pick several articles at once to send his feedback?

Thank you very much for your kind consideration, and for the great job that LJ has been doing.
—Milan Lukic

When Linux Journal Interactive gets up and going (soon, we hope). The response forms will go away—instead there will be discussion groups for each article. This will still be done on an article by article basis though, so I'll submit your idea for an “in general” group to our tech department. —Editor

MkLinux,LinuxPPC,Turbo and Debian

I realize the subject of my e-mail might seem weird so here is a clarification. The question: How many versions of Linux are there for the Power PC based Macs? The answer: 4, The subject of this e-mail (as far as I know).

This is not meant as a mean type of letter I just want you to know. The computer industry as a whole seems to be at the threshold of a new rule with Microsoft being dumped left and right. Where are these people going, Linux? This is a great opportunity for opening of standards and more freedom. As a Macintosh user I have noticed a big turn around in peoples perception of Apple, there machines, and there OS (I am a Mac Rep at CompUSA). I realize that most people who use Linux are using it on a Wintel style machine but as we all know, with Linux, this doesn't matter. Linux is an OS that really doesn't care about the machine that it is on. With LinuxPPC R5 able to run on iMac's ,and any PowerPC for that matter, also there is info out on the web that suggests that Apple will bundle a version of Linux on some of there machines. Would you please do some more articles that have some type of Mac connection so more Mac users can realize the power of Linux. Maybe an article a month and or a Special Issue that has info for Mac people so they can start using Linux also. For instance which of the 4 listed distributions should people use for there need? Why should they use Linux? Where can they locate software they will need?

I personally have a tri-boot of MkLinux DR3, LinuxPPC R4, and Mac OS 8.5.1. I have been using Linux for about 6 months and have gone through most of the newbie problems and still go through them. I will probably get a subscription to your magazine because I have been impressed by the depth of knowledge your articles present every month. Thanks for reading and for all the new and old Mac based Linux users we hope to see a new column soon.
—Chad J. Adelman


On page 61 of the Jan99 issue of Linux Journal, you raise the question of how to allow an ordinary user permission to shutdown the system, and the reply is that the user must use Alt-Ctrl-Del.

I have learned an alternate solution (I cannot claim credit for figuring out this one myself, though). If you set the UID bit on /sbin/shutdown, then ANY user can use /sbin/shutdown. That's the catch—it allows any user at all permission to execute /sbin/shutdown. As root, type: chmod 4766 /sbin/shutdown

This also allows remote shutdowns: rsh machinename /sbin/shutdown -h now (or -r now or whatever options you want).
—Capt Christopher A. Bohn

Re: BTS Shutting Down

In the Jan. 1999 Best of Technical Support in the Linux Journal, Thomas Okon asked about a utility to allow a user to shutdown the system without having to login as root. The solution is at sunsite as ftp://sunsite.unc.edu/pub/Linux/system/admin/su/usershutdown-1.1.tar.gz
—Andy Holder

BTS: GNU wget for updating web site

Re. the question “Updating Web Site” in the Jan 1999 Linux Journal, p. 61 ...

Haven't tried the mirror package - might be good, but you can also use GNU wget (prep.ai.mit.edu). Here is the script I use to keep the University of Maryland LUG's Slackware mirror up-to-date. “Crude but effective”.
—Judah Milgram

Consistency vital to growth of Linux

When designing systems, or writing software, consistency, not perfection is the goal. Perfection can not be achieved, and too much time is spent trying to achieve it. The next best alternative is consistency. With consistency, even poor designs can be used. Examine for a moment the most popular OS for PC's. When I first started using it, I disliked it. I still dislike it, but have observed its growth. It did not grow because it is great, it didn't even grow because it is good. It grew because it is consistent (and of course marketing - people love someone that can make used motor oil sound like a health drink).

I first tried Linux after I left my personal computer (S-100 CP/M) behind and bought my first PC. It came with with a crashing OS with a defective windowing system, but I could edit code with it and if I didn't make the names of the files too long, I could move files back and forth to work.

One day, while at the computer store I noticed a CD with a distribution of Linux. I am happy to say I bought it.

I installed Linux and used LILO to dual boot. I liked Linux because it was very close to the OS I used at work. I found myself using the crash OS less (I needed it to run FrameMaker) until, finally I had to upgrade to undertake a challenging project, writing a MUMPS to C++ translator for a program that was over 0.5M lines of code. I needed a system that was dependable, so I upgraded to a 486, 128M of memory, 8GB of disk, a dat tape drive, and the latest Linux distribution I could find.

To test the system, I ported the tools I used at work to Linux by making a simple change to the Makefile. I ran an analysis on the code that takes about one month to complete on a SPARC 10 server. It took about a month on my 486 PC running Linux (try that with the popular OS).

Why you may ask, is such a robust OS not as popular as the other OS running on PC's?

If consistency is maintained, it will be. I have quietly been using Linux and watching its growth. The only real threat to the growth of Linux is if the distributors want to play the games the hardware vendors and OS vendors play, by trying to make sure software developed on their system will not run on any other system (a.k.a. locking the client in). As a developer, I continually run my code on at least two platforms to make sure it is portable. I usually try for at least three. OK so portability is almost as important as consistency, but portability requires consistency and standardization.

I have run at least three different distributions of Linux on my computers. Currently, I am running the same distribution on all three, including my laptop. I purchase a Linux distribution on CD instead of getting it off the internet so I can get the value added. In my case the biggest value added is the support (after all, I am a designer/developer, not a system administrator).

Recently, I have read rumblings about distributors thinking about providing software that will not run on other distributions. To do so would be a fatal mistake for it could do something that the popular OS vendor can not do, by dividing the Linux community. I wonder if that is the reason a major hardware vendor bought into a Linux distributor that provides multi-platform support.
—Robert Witkop

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