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<H2>October 2001, Issue 71 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Published by <I>Linux Journal</I></H2>
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<LI> <a HREF="lg_mail71.html">The MailBag</A>
<LI> <a HREF="lg_bytes71.html">News Bytes</A>
<LI> <a HREF="lg_answer71.html">The Answer Gang</A>
<LI> <a HREF="lg_tips71.html">More 2-Cent Tips</A>
<LI> <a HREF="arndt.html">A Need for Documentation</A> , <EM>by Matthias Arndt</EM>
<LI> <a HREF="joshi.html">Code Optimization Using the GNU C Compiler</A> , <EM>by Rahul U Joshi</EM>
<LI> <a HREF="orr.html">The Foolish Things We Do With Our Computers</A> , <EM>by Mike "Iron" Orr</EM>
<LI> <a HREF="qubism.html">Qubism</A> , <EM>by Jon "Sir Flakey" Harsem</EM>
<LI> <a HREF="spiel.html">Numerical Workbenches, part III</A> , <EM>by Christoph Spiel</EM>
<LI> <a HREF="lg_backpage71.html">The Back Page</A>
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<H3 ALIGN="center"><EM>Linux Gazette</EM> Staff and The Answer Gang</H3>
<BLOCKQUOTE>
<STRONG>Editor:</STRONG> Michael Orr<BR>
<STRONG>Technical Editor:</STRONG> Heather Stern<BR>
<STRONG>Senior Contributing Editor:</STRONG> Jim Dennis<BR>
<STRONG>Contributing Editors:</STRONG>
Ben Okopnik, Dan Wilder, Don Marti
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<H1><A NAME="wanted"><IMG ALIGN=MIDDLE ALT="" SRC="../gx/mailbox.gif">
The Mailbag</A></H1> <BR>
<!-- BEGIN wanted -->
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<P> <hr> <P>
<!-- =================================================================== -->
<center><H3><font color="maroon">HELP WANTED : Article Ideas</font></H3></center>
<P>
<P> Send tech-support questions, Tips, answers and article ideas to The Answer Gang
&lt;<A HREF="mailto:linux-questions-only@ssc.com"
>linux-questions-only@ssc.com</A>&gt;. Other mail (including
questions or comments about the <EM>Gazette</EM> itself) should go to
&lt;<A HREF="mailto:gazette@ssc.com">gazette@ssc.com</A>&gt;. All material
sent to either of these addresses will be considered for publication in the
next issue. <EM>Please send answers to the original querent too, so that s/he
can get the answer without waiting for the next issue.</EM>
<P> Unanswered questions might appear here. Questions with
answers--or answers only--appear in The Answer Gang, 2-Cent Tips, or here,
depending on their content. There is no guarantee that questions will
<em>ever</em> be answered, especially if not related to Linux.
<P> <STRONG>Before asking a question, please check the
<A HREF=../faq/index.html><I>Linux Gazette</I> FAQ</A> to see if it has been
answered there.</STRONG>
<P> <HR> <P>
<!--====================================================================-->
<!-- BEGIN HELP WANTED : Article Ideas -->
<UL>
<!-- index_text begins -->
<li><A HREF="#wanted/1"
><strong>Suggestion on Gazette contents.</strong></a>
<li><A HREF="#wanted/4"
><strong>Asound Ethernet card</strong></a>
<li><A HREF="#wanted/5"
><strong>Linux in other languages</strong></a>
<li><A HREF="#wanted/8"
><strong>Content Suggestion</strong></a>
<!-- index_text ends -->
</UL>
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="wanted/1"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Suggestion on Gazette contents.</FONT></H3>
Thu, 6 Sep 2001 11:04:37 +0530 (IST)
<BR>Atul Sowani (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20help%20wanted%20%231">asowani from ptc.com</a>)
<P><STRONG>
I've been TLG reader since long time (almost from the first issue).
Some time back, there used to be a column "Graphics Musings" (I
hope I've got the name correctly), which used to have information
about various graphics packages and utilities. Could you revive
that column or a new one on similar lines? i.e., not essentially on
graphics utilities alone, but also including other noteworthy
utilities too?
</STRONG></P>
<P>
Atul, the column was The Graphics Muse by Michael Hammel
(<A HREF="mailto:mjhammel@graphics-muse.org"
>mjhammel@graphics-muse.org</A>, whom I'm cc'ing). His farewell article was
<A HREF="../issue46/gm.html"
>http://www.linuxgazette.com/issue46/gm.html</A>
Michael stopped writing his Linux Gazette column because (1) he wanted
to consolidate his free graphics-related work on one web site
(<A HREF="http://www.graphics-muse.org"
>http://www.graphics-muse.org</A>), and (2) he needed to spend more time on
paid employment. Nevertheless, Michael remains a friend of Linux Gazette
(part of the Clueful Horde) and occasionally answers questions from the
Mailbag or helps the Gazette with graphics issues. He is also active in
a Colorado Linux users group, if I remember correctly.
</P>
<P>
If somebody would like to start a new
graphics-related series for LG, we'd be glad to publish it. But it can't
be called The Graphics Muse since Michael is still using that title.
</P>
<P>
Since Linux Gazette's articles come from our readers, "we" cannot revive
the column, but "you" as a reader can. Even if you're not a graphics
expert, if you use Linux graphics programs regularly, you can write about
your experiences (and frustrations) with them. It just has to be "new
information": stuff that hasn't been published in LG before (or is so old
it needs an update), and hasn't been overreported elsewhere.
</P>
<P>
As for other utilities, those are some of the things Thomas Adam writes
about in his series The Weekend Mechanic.
If you have any suggestions for topics you'd like to see him cover,
e-mail him at <A HREF="mailto:thomas_adam16@yahoo.com"
>thomas_adam16@yahoo.com</A>. Or send article requests to The
Answer Gang (<A HREF="mailto:linux-questions-only@ssc.com"
>linux-questions-only@ssc.com</A>) and we'll put them in the
Mailbag.
</P>
<p><em>... and having been copied on this, Michael Hammel chimed in ...</em></p>
<P>
Someone actually remembers that column?
<IMG SRC="../gx/dennis/smily.gif" ALT=":-)"
height="24" width="20" align="middle">
</P>
<P>
Actually, the ".org" address is for my personal stuff. The ".com" address
holds the Graphics Muse content. Of course, last year I started dating my
high school sweetheart, and now we're married. So I haven't actually had
time to update that site in over a year. I hope to get back to it
eventually, but its not on the near term schedule.
</P>
<P><STRONG>
paid employment. Nevertheless, Michael remains a friend of Linux Gazette
</STRONG></P>
<P>
Paid employment is taking precedence these days. Articles on graphics for
Linux Journal and Linux Magazine are usually as close as I come to doing 'Muse
style writings these days.
</P>
<P><STRONG>
(part of the Clueful Horde) and occasionally answers questions from the
Mailbag or helps the Gazette with graphics issues. He is also active in
a Colorado Linux users group, if I remember correctly.
</STRONG></P>
<P>
Sort of. I moved to Houston to be with my (now) wife and her daughter,
though I still participate on the Colorado LUGs mailing list (BLUG and
CLUE, specifically). I also am Senior Editor for LWN.net and write the On
The Desktop page.
</P>
<P><STRONG>
If somebody would like to start a new
graphics-related series for LG, we'd be glad to publish it. But it can't
be called The Graphics Muse since Michael is still using that title.
</STRONG></P>
<P>
That's correct. It's still copyrighted by me. I'd hoped to do a series of
books under the umbrella "Graphics Muse", but that hasn't happened.
</P>
<P>
Interesting that someone would remember that column from so long ago.
Especially now that graphics on Linux has become big business.
</P>
<P>
Later.
<br>--
<br>Michael J. Hammel
<br>The Graphics Muse
</P>
<!-- end 3 -->
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<P> <A NAME="wanted/4"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Asound Ethernet card</FONT></H3>
Thu, 20 Sep 2001 20:31:24 -0700
<BR>Mike Orr (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20help%20wanted%20%234"><em>LG</em> Editor</a>)
<P>
Has anybody had any luck with the Asound ALM2 Ethernet card?
I usually stick with 3com, epro or ne2000 cards to avoid driver
problems, but this one said Linux driver on the box and it was $10,
so I thought it was an ne2000 compatible. Turns out it has a RealTek
8139 chip, which corresponds to the experimental 8139too module
(Linux 2.4.3). But the driver doesn't recognize the card.
"init_module: no such device. Hint: insmod errors can be caused by
incorrect module parameters, including invalid IO or IRQ parameters."
</P>
<P>
Thinking it was futile, I looked up the I/O address of the card in
<TT>/proc/pci</TT> and tried "modprobe 8139too io=0xa000". This resulted in,
"invalid parameter parm_io".
</P>
<!-- end 4 -->
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<P> <A NAME="wanted/5"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Linux in other languages</FONT></H3>
Mon, 3 Sep 2001 15:34:19 +0100
<BR>Ravishankar Rajendran (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20help%20wanted%20%235">RRajendran from dljdirect.co.uk</a>)
<P><STRONG>
I am interested in developing a linux version in Tamil( an Indian
language). It would be very helpful, if you can provide an article
providing an outline of the process of going about it.
</STRONG></P>
<p><em>... Mike likes the idea ...</em></p>
<P>
This would make an excellent
article, if there's anybody with experience to be able to write it.
Even an article on how the Spanish or Chinese versions of Linux were
built would be worthwhile.
</P>
<p><em>... Mike also encouraged him to contact those most likely to have
experience with language ports ...</em></p>
<P>
Ravishanker, talk with the distributions that already offer multilingual
versions of Linux. Linux--and the Unix programs and tools it is bundled
with--were originally written in English, but several distributions have
appeared in non-English-speaking countries with Linux speaking their
language. <A HREF="http://www.turbolinux.com/">TurboLinux</A> 6.5 for the iSeries
(<A HREF="http://www.turbolinux.com/products/index.html"
>http://www.turbolinux.com/products/index.html</A>) supports "English,
Japanese, Korean, and Simplified and Traditional Chinese with the
unified code base", and claims to have the leading support for wide
character sets. Conectiva Linux (<A HREF="http://www.conectiva.com"
>http://www.conectiva.com</A>) is based in
Brazil and offers Portuguese, Spanish and English versions. <A HREF="http://www.suse.com/">SuSE</A>
(<A HREF="http://www.suse.de"
>http://www.suse.de</A>) is based in Germany and offers versions in seven
Western European languages and Czech.
<A HREF="http://www.linux-mandrake.com/">Mandrake</A>,
<A HREF="http://www.redhat.com/">Red Hat</A> and others also
offer various levels of multilingual support.
</P>
<P>
Some of the issues you will face include:
</P>
<ul>
<li> Character set. Does Tamil have an alphabetic or idiographic writing
system? Is it supported in Unicode? Is there an acceptable ASCII
version of the writing system, or do one of the established 8-bit
character sets support it? Linux currently works best with the 8-bit
character sets, but parts of the system and some applications support
16-bit Unicode. Support for Unicode characters above 16 bits is less.
<li> Time zone, keyboard, locale, etc. This is the easy part; just use the
standard Linux utilities to configure these. Is there a standard
locale name for Tamil?
<li> GNU gettext is a set of C functions to enable your program to speak
multiple languages. For programs which use gettext, it's a "simple"
matter of having a translator prepare catalog files containing
translated versions of all the strings in the programs. For programs
which don't use gettext, you'll either have to modify the program to
make it gettext-aware, or do something else.
<li> Certain points of grammar are hard to internationalize consistently.
This makes it a huge logical challenge to come up with catalog strings.
The problem is that the string must be a unique key to find the
other-language string, but oftentimes a single string in English maps to
multiple strings in other languages. For instance, in
English we say, "0 dogs, 1 dog, 2+ dogs...". In Russian they say, "1
sobaka, 2-4 sobaki, 5+ sobak" (dog), "1 huligan, 2-4 huligana, 5+
huliganov" (hooligan), "1+ pal'to" (overcoat). Many programmers just
throw up their hands and write "1 file(s) copied" in the good ol' DOS
tradition. Worse yet is when some languages put filler words in a
different order than the default language. Or when a word has one form
in one language but multiple case-dependant forms in another. One must
artificially create identical-but-unique strings in the default language
to match all the distinct combinations in all the languages supported.
Or restructure your sentances to avoid differing case forms.
<br>
OK, just when you got that down, Russian has a second word for dog:
"1 pyos, 2-4 p'sa, 5+ p'sov". And two words for horse (loshad',
kon')....
<li> To localize X-windows, first determine whether there's an existing
8-bit or Unicode font that supports Tamil. If so, all users will have
to have that font installed, and every application configured to use
that font. If not, you'll have to create a font.
<li> If Tabil has other conventions (besides just the font) that differ
from Western languages, you may need to use or write a special version
of xterm to handle the characters. For instance, jterm handles
Japanese. Emacs has a bunch of optional features called MULE for
non-Western languages; you may have to install extra emacs packages to
use these.
<li> You'll need to find and install an X keymap for Tabil.
<li> To localize the console, you'll first have to determine whether
there's an existing font and keymap that can be used. If so, just
configure them as the default. If not, you'll have to write them.
Note that a console keymap can be used to generate an X keymap, so
you only have to maintain your keymap one place. The Unix display
driver has a Unicode mode, but unfortunately the ancient hardware
generator on PC video cards can display only 256 unique characters
at a time. You can configure a primary character set and an alternate
character set (2 x 256), but you have to switch between the two.
If you want to display a document that has both Russian and German
characters (to say nothing of Japanese), forget it.
<li> Being Unicode-compatible is a worthwhile goal, because that is the
direction other Linux systems are slowly going.
</ul>
<P>
Look through the HOWTOs at <A HREF="http://www.linuxdoc.org"
>http://www.linuxdoc.org</A>. Look at the
other-language HOWTOs like the Thai HOWTO, Chinese HOWTO, Danish HOWTO,
Esperanto HOWTO, etc. The Font HOWTO may help with font issues. The
Keyboard-and-Console HOWTO explains how to set up the text console for
different languages. The Unicode HOWTO explains some other aspects of
Unicode.
</P>
<P>
Contact Linux Focus (<A HREF="http://www.linuxfocus.com"
>http://www.linuxfocus.com</A>) and see if they have
any advice. Linux Focus is a zine with a lot more non-English-speaking
staff than LG.
</P>
<p><em>... and Ravishankar replies ...</em></p>
<strong><P>
Thanks a lot for the help. I will keep you posted on the progress.
</P></strong>
<!-- end 7 -->
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<P> <A NAME="wanted/8"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Content Suggestion</FONT></H3>
Fri, 28 Sep 2001 08:34:14 -0700
<BR>Boning, Mike (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20help%20wanted%20%238">Mike.Boning from UNIFORM.ARAMARK.com</a>)
<P>
After the recent suggestion from the Gartner Group to abandon Microsoft IIS,
many companies are going to be looking at moving to Linux/<A HREF="http://www.apache.org/">Apache</A>. It would
be wise to publish good information regarding comparisons, compatibilities,
and particularly migration paths.
</P>
<!-- end 8 -->
<P> <hr> </p>
<!-- =================================================================== -->
<center><H3><font color="maroon">GENERAL MAIL</font></H3></center>
<P> <HR> </P>
<!--====================================================================-->
<!-- BEGIN GENERAL MAIL -->
<UL>
<!-- index_text begins -->
<li><A HREF="#mailbag/1"
><strong>Thinking of and Praying for you</strong></a>
<li><A HREF="#mailbag/3"
><strong>Ben's fame to claim???</strong></a>
<li><A HREF="#mailbag/5"
></a>Re: Apropos question --or--
<br><A HREF="#mailbag/5"
><strong>Non-ASCII characters and LG</strong></a>
<li><A HREF="#mailbag/7"
><strong>Missed the toons</strong></a>
<li><A HREF="#mailbag/8"
><strong>email with multiple POP3 accounts</strong></a>
<li><A HREF="#mailbag/9"
><strong>Link fix needed</strong></a>
<!-- index_text ends -->
</UL>
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="mailbag/1"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Thinking of and Praying for you</FONT></H3>
Wed, 12 Sep 2001 22:54:08 +0200
<BR>Wiri (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20mailbag%20%231">wbr from online.fr</a>)
<P><STRONG>
Hello Linuxg@zette,
</STRONG></P>
<P><STRONG>
Please accept our expression of condolence for the terror that has struck your
country. God bless you and America !
</STRONG></P>
<P><STRONG>
Wilf and friends.
</STRONG></P>
<P>
Thank you very much, Wilf; I realize this isn't a Linux topic, but I didn't
want your message of support to just stand unanswered. Just a bit of military
historical perspective: at one point, Rome lost three <EM>legions</EM> and one of
their governors in a single ambush in the Teutoburger Forest. Never before had
they suffered a disaster of those proportions; nothing even close. The result?
Roman armies marched; and afterwards, there was not enough left of the tribes
that had attacked them to even bother Rome for *five centuries.*
</P>
<P><em>
"We have awakened a sleeping giant and filled him with a terrible resolve."
-- Admiral Yamamoto, after Pearl Harbor
</em></P>
<P>
Thank you again. And <EM>thank you</EM> to all of our friends who are with us in
compassion, caring, and spirit.
</P>
<P>
Ben Okopnik
<br>US Army veteran
</P>
<p><em>See also the <a href="lg_bytes71.html#legislation">News Bytes</a> and
<a href="lg_answer71.html">TAG</a> columns for some more words from
the <b>Linux Gazette</b> staff on this topic. -- Heather </em></p>
<!-- end 2 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="mailbag/3"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Ben's fame to claim???</FONT></H3>
Wed, 5 Sep 2001 22:31:20 +0100 (BST)
<BR>Thomas Adam (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20mailbag%20%233">The Weekend Mechanic</a>)
<P>
Dear Ben (and others),
</P>
<P>
I just thought that you and the rest of the team at
the LG, would like to know that I was flicking through
a friends copy of a British magazine called PCPlus.
Although this is mostly orientated towards Windoze
users, they do have a Linux section.
</P>
<P>
In this section the subject of shell scripting was
being taught. I was not impressed with their content.
The author of the article referred to shell scripting
as a "dos batch file" equivalent, but gave no mention
that BASH in fact has many boolean logic
control-structures. But that is by-the-by.
</P>
<P>
The real reason why this e-mail is being sent to you,
is that in one of the references, they pointed it to
Ben Okopnik's article on The basics of shell languages
(in issue 52). It is nice to know that the LG is used
in such a context.
</P>
<P>
Keep up the good work guys,
<br>Regards,
<br>Thomas Adam -- The Linux Weekend Mechanic
</P>
<P><em>
&lt;smile&gt; Always good to hear that somebody is getting good use out of this
stuff. Thanks for the note, Thomas!
-- Ben Okopnik</em></P>
<!-- end 4 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="mailbag/5"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Non-ASCII characters and LG</FONT></H3>
Wed, 26 Sep 2001 11:28:04 -0700
<BR>S&aacute;ndor B&aacute;r&aacute;ny (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20mailbag%20%235">bs@tud.at</a>)
<p><em>As frustrating as I find "quoted printable" or HTML attachments, they
are ways that foreign character sets can survive to get to me.
I'm pleased to say that since he is active on Debian mailing lists,
some of whose archives do not ruin his name, I was able to rescue
it from the Dread Question Mark Disease. The rest of our answer is
from Mike Orr. -- Heather</em></p>
<P><STRONG>
thank you very much for your answer about apropos. The solution you sent
works properly. I had myself something similiar; however I could not
imagine there is no built-in possibility for my problem which I have
overseen.
</STRONG></P>
<P>
An OS can never give you all the commands you want, especially since
they conflict with the commands someone else wants. What Unix gives
you is a comprehensive set of basic commands and the building blocks
to build higher-level custom commands. This is why shell scripts and
aliases are so highly valued by Unix enthusiasts, because they give
you the ability to make custom commands for anything the developers
might have forgotten.
</P>
<P><STRONG>
I crosschecked it again and my mailer inserts the proper headers:
Content-Type: text/plain; charset=iso-8859-2
</STRONG></P>
<P><STRONG>
Content-Transfer-Encoding: 8bit
</STRONG></P>
<P><STRONG>
I find it really very pity you do attempt any use of i18n in your
mailer. I am from Hungary, so I actually need the iso-8859-2 charcter
code when I use my mother language for mails; however, my name is within
the simple Western-Europe or ascii256 charset. If you US people insist
on using us-ascii then ther are plenty of guys on the world who do not
have any chance to see their name as in their personal documents. I have
recently run some circles around locales and gnome (which I prefer to
kde), and I have to tell you how much I was shocked by the fact how long
way is to go till we reach to the point Windows95 already had. I have
freefonts, ttfs, X fonts for several languages etc. but when I wanted to
print out proper hungarian characters I had to redirect the StarOffice
postscript output to file (was also forced to use elementary postscript
fonts), and drive it through 'ogonkify'. A large number of Linux users
can not live with us-ascii, so at a given point they are lost.
</STRONG></P>
<P>
The problem of representing multiple languages is acute, and I strongly
wish Linux was more advanced in that area. If editors and browsers
fully supported Unicode seamlessly across the board, we would switch to
it in an instant. However, 8-bit character sets continue to be better
supported. The limitation is that only one 8-bit character set can be
active at a time, meaning you can't properly display a document containing
English and Russian and German unless one of the languages is ASCII-ified.
This was a pain when I had Russian friends in Russia and Germany I sent
e-mail to and typed up text documents for.
</P>
<P>
LG has just thrown its hands up in the air and taken the
incorrect-but-easiest approach of using Latin-1 but pretending it's
ASCII. Most of the non-English mail we get uses Latin-1 characters.
I try to convert these to HTML entities when I see them, but I don't
make a time-consuming effort of it. Compounding this is the fact that
many of us use mutt as our mailreader, and mutt replaces non-ASCII
characters with "?". Then if you save the message or forward it, mutt
converts the placeholder "?" into real "?", and then the original character
is completely lost. With Romance/Germanic languages we can usually
guess what the original character was and substitute it back
(because "ma?ana" is clearly "ma&ntilde;ana", "K?ln" is "K&ouml;ln",
"Jos?" is "Jos&eacute;",
"Universit?t" must be "Universit&auml;t" because "Universit&ouml;t",
"Universit&uuml;t" and "Universit&szlig;t" don't exist, etc--unless
you want to say "Universit&ouml;t" is slang for "dead university"!);
however, with names from other languages we're at a total loss.
</P>
<P>
Perhaps someday we can come up with a more enlightened way to support
multiple languages, but this is what we have now.
</P>
<P><STRONG>
Last question: are you plan to publish on the <em>Linux Gazette</em>
page this new Answer-Gang mail address? Or
not publishing it is the proper way to avoid getting rid of off-topic
questions
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle">)
</STRONG></P>
<P>
The linux-questions-only address is at the top of the Mailbag page and The
Answer Gang index page, where we have always published it. The top of
the 2-Cent Tips page still has the gazette address, but I've asked Heather
to change it. In any case, I bounce everything to linux-questions-only that
was misaddressed to gazette.
</P>
<P>
If you see anywhere else (besides in back issues) where the gazette
address or the obsolete tag address is used, please let me know and
we'll change it.
</P>
<P>
I thought about putting the address on the home page but decided against
it, because people should at least have a look at what The Answer Gang
is about before they find out there is a submission address.
</P>
<P>
The problem of off-topic questions was not caused by Gazette readers.
It was caused by the fact that the tag address was published on many
webpages with no reference to LG. So people would type their question
into search engines, find the tag address, and send us questions, often
without even realizing Linux Gazette existed. Our off-topic questions
were easily 50% of the total. See the past several issues of The Back
Page for the more amusing ones, and issues of The Answer Gang before
that.
</P>
<P>
Since switching to the linux-questions-only address, our off-topic
rate has dropped to near zero, and we are also seeing fewer Linux
questions from people who don't even bother to read the FAQs and
documentation first but just expect us to hold their hand. LG believes
in helping those who help themselves.
</P>
<p>-- Mike
<!-- end 6 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="mailbag/7"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Missed the toons</FONT></H3>
Fri, 14 Sep 2001 10:06:26 +0530
<BR>Sudhakar . A N (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20mailbag%20%237">sudhakar.an from eximsoft.com</a>)
<p>
<STRONG>I miss the toons in your lates issue.</STRONG>
</P>
<P>
We miss them too. Shane Collinge has to
concentrate on paid employment for a while, so HelpDex is on hiatus.
Eric Kasten has his hands full doing whatever he's doing, so Tuxedo Tails
is also taking a break.
<P> Jon "Sir Flakey" Harsem is still going strong, so we have a new
installment of <A HREF="qubism.html">Qubisms</A> this month for your
cartoon fix. It was missing last month because I, um, forgot to include it.
Most Qubism cartoons are non-Linux but I'm including some of the funnier
ones anyway.</P>
<P> I originally told Eric Kasten we wanted only Linux cartoons,
but he said Linux is too specific a topic to come up with that many
cartoons about, so I've been publishing non-Linux Tuxedo Tails panels too.
</P>
<P>--Mike.</P>
<!-- end 7 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="mailbag/8"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">email with multiple POP3 accounts</FONT></H3>
Thu, 30 Aug 2001 11:33:54 +0800
<BR>Artemista - (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20mailbag%20%238">artemista from mail.com</a>)
<P>
Thanks to everyone who responded to my question. With everyone's advice, I was able to figure out a solution to the problem.
</P>
<P>
-- Artemista
</P>
<!-- end 8 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="mailbag/9"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/envelope.gif">
<FONT COLOR="navy">Link fix needed: http://www.linuxgazette.com/issue70/tag/9.html</FONT></H3>
Sat, 01 Sep 2001 21:56:10 -0600
<BR>Alvin Austin (<a href="mailto:gazette@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%20mailbag%20%239">alvin from crlogic.com</a>)
<P>
Hi Heather,
</P>
<P>
In the latest Linux Gazette online issue, the link to the "internet cafe" is set
to that of "Password aging" instead of:
</P>
<P><BLOCKQuote>
<A HREF="../issue70/tag/9.html"
>http://www.linuxgazette.com/issue70/tag/9.html</A>
</BLOCKQuote></P>
<P>
You will want to correct this.
</P>
<P>
Have a nice day,
</P>
<P>
Alvin Austin
</p>
<p><em>Ooops! Sorry about that! As Mike noted elsewhere, my conversion
script caught a bug last month, and I <b>mostly</b> managed to
clean up after it, but obviously, I missed another one.
-- Heather</em></p>
<!-- end 9 -->
<P> <hr> </p>
<!-- *** BEGIN copyright *** -->
<H5 align="center">This page edited and maintained by the Editors
of <I>Linux Gazette</I>
<a href="http://www.linuxgazette.com/copying.html"
>Copyright &copy;</a> 2001
<BR>Published in issue 71 of <I>Linux Gazette</I> October 2001</H5>
<H6 ALIGN="center">HTML script maintained by
<A HREF="mailto:star@starshine.org">Heather Stern</a> of
Starshine Technical Services,
<A HREF="http://www.starshine.org/">http://www.starshine.org/</A>
</H6>
<!-- *** END copyright *** -->
<H4 ALIGN="center">"Linux Gazette...<I>making Linux just a little more fun!</I>"</H4>
<HR> <!-- ******************************************* -->
<center>
<table cellpadding=7><tr><td>
<IMG SRC="../gx/bytes.gif" border=1 ALT="News Bytes">
</td><td>
<H3>Contents:</H3>
<ul>
<li><a HREF="#legislation">Legislation and More Legislation</a>
<li><a HREF="#links">Linux Links</a>
<li><a HREF="#conferences">Conferences and Events</a>
<li><a HREF="#general">News in General</a>
<li><a HREF="#distro">Distro News</A>
<li><a HREF="#commercial">Software and Product Announcements</a>
</ul>
</td></tr></table>
<STRONG>Selected and formatted by <A
HREF="mailto:michael.conry@softhome.net">Michael Conry</A> and <A
HREF="mailto:gazette@ssc.com">Mike ("Iron") Orr</A></STRONG> </center>
<P> Submitters, send your News Bytes items in
<FONT SIZE="+2"><STRONG>PLAIN TEXT</STRONG></FONT>
format. Other formats may be rejected without reading. You have been
warned! A one- or two-paragraph summary plus URL gets you a better
announcement than an entire press release.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<font color="green">
October 2001 <I>Linux Journal</I>
</font>
</H3>
<IMG ALT=" " SRC="misc/bytes/lj-cover90.png" WIDTH=200 HEIGHT=268
ALIGN="left" HSPACE="20">
<P>
The October issue of <A HREF="http://www.linuxjournal.com/"><I>Linux
Journal</I></A> is on newsstands now.
This issue focuses on Engineering. Click
<A HREF="http://www.linuxjournal.com/lj-issues/issue90/index.html">here</A>
to view the table of contents, or
<A HREF="http://www.linuxjournal.com/subscribe/index.html">here</A>
to subscribe.
<P>
<FONT COLOR="green">All articles through December 1999 are available for
public reading at
<A HREF="http://www.linuxjournal.com/lj-issues/mags.html">http://www.linuxjournal.com/lj-issues/mags.html</A></FONT>.
Recent articles are available on-line for subscribers only at
<A HREF="http://interactive.linuxjournal.com">
http://interactive.linuxjournal.com/</A>.
<BR CLEAR="all">
<a name="legislation"></a>
<p><hr><p>
<!-- =================================================================== -->
<center><H3><font color="green">Legislation and More Legislation</font></H3></center>
<P> <STRONG>Behold the debut of a new News Bytes section.</STRONG>
<P> This is the third month in
a row that the legal landscape surrounding Linux users and programmers has
been rapidly changing. We want to give adequate coverage to these
changes--new laws and proposed laws--around the world. Since we have
personal knowledge only of the US and Ireland, we'll need readers to <A
HREF="mailto:gazette@ssc.com">tell us</A> what's happening in their
countries. This is important because anything that gets enacted in one
country is often held up as an example to encourage similar legislation in
other countries.
<P> For any new law, one must ask: Who is pushing it? What will they
gain? Who will lose under it (re fines or jail time)? Why? Do the
proponents have a secret agenda to use the law in ways the legislature
didn't intend? Do they have a not-so-secret agenda to push for bigger laws
after this one is passed and accepted by the public? What unintended
effects will the law have that even its proponents did not predict?
We can't answer all these, but hopefully we can start asking the questions.
<P> Especially the last question. This section is partly an Ode to the Law
of Unintended Effects, because there are so many of them recently.
<HR NOSHADE WIDTH="20%"> <!-- ********************************* -->
LG reported in <A HREF="../issue69/orr.html">July</A>
and <A HREF="../issue70/lg_bytes70.html#dmca">August</A> about
the unexpected fallout from the
<STRONG>Digital Millenium Copyright Act (DMCA)</STRONG>.
Companies are using it to suppress criticism of their shoddy designs,
prevent customers from protecting themselves from the effects
of said shoddy designs, and even jail a foreign programmer for writing (in
his home country) a program that is legal in his home country. Now that
Dmitry is facing a possible sentance of 25 years, I guess a decline in
corporate profits is more serious than armed robberies--even if the decline
in profits is hypothetical or imagined. (Didja notice how in spite of
Napster, Gnutella and DeCSS, the sales of CDs and DVDs continue to go
nowhere but up?)
<P> Foreign programmers like Alan Cox (#2 Linux kernel developer and former
Usenix coordinator) are <A
HREF="http://lwn.net/2001/0726/letters.php3">avoiding the US</A> in order not
to fall into the same trap Dmitry did.
American programmers are
<A HREF="http://noframes.linuxjournal.com/articles/misc/0048.html#effects">
looking for jobs elsewhere</A> -- anywhere -- now that
normal and necessary practices in security development and security
certification are illegal. Not that there may be many
places to go: the major proponents of the DMCA (the five biggest
media-publishing and software-publishing conglomorates) are using the
established US law as an example to push for similar laws in Canada, Europe
and the FTAA (a possible future free-trade zone covering North and South
America), saying: "See, they did it, so you should too."
<HR NOSHADE WIDTH="20%"> <!-- **************** -->
In September, change went from "high gear" to "extremely
high gear" and then into "overdrive". The Big 5 publishers came back with an
even sweeter proposal, the son of DMCA. Aiming to plug the "loopholes" in
the DMCA (meaning the last bit of fair use the DMCA allows), the
<STRONG>Security Systems Standards and Certification Act</A> (SSSCA)</STRONG>
<A HREF="http://www.politechbot.com/docs/hollings.090701.html">[draft
text]</A>
<A HREF="http://cryptome.org/sssca.htm">[another draft]</A> would make it
illegal to "manufacture, import, offer to the public, provide or otherwise
traffic in any interactive digital device that does not include and utilize
certified security technologies that adhere to the security systems standards
adopted under section 104."
<P> "Security systems standards" means software that
enforces digital copyrights. Remember
<A HREF="http://www.theregister.co.uk/content/archive/17009.html">
CRPM</A>, the aborted effort to put
non-bypassable rights management into the firmware of all new IDE hard
drives? That was scrapped because too many customers would refuse to buy
such products. But SSSCA would make this or the equivalent mandatory.
<P> Linux Weekly News <A HREF="http://lwn.net/2001/0913">writes</A>,
"The definition of a 'digital device' is just as broad as it sounds -
essentially, anything--hardware or software--that is capable of moving
and storing bits. In particular, a computer running Linux is certainly
such a digital device, as is Linux itself or any of a number of other
free programs." Free-software advocates are concerned, because is it
even <EM>possible</EM> for Linux to be compliant? Linus could implement some
rights-management code in the kernel, but because it's open source, any
programmer could just comment it out. And the companies would presumably
want to keep their (shoddy?) rights algorithm secret, so it would be
available only in binary form. Would they even make a Linux version? If
they did, would Linus have to link a proprietary, binary-only library into
the standard kernel and change Linux's license to allow and mandate this?
Would the kernel have a new module "digirights.o" with the help text, "If
you are outside the United States, choose 'N' for maximum flexibility,
reliability, speed and security. If you are inside the US, be aware that
choosing 'N' may be a felony, and you should consult a lawyer before
proceeding."
<P> Another problem is that the technical standard is to be determined by
"representatives of interactive digital device manufacturers and
representatives of copyright owners". What about representatives of the
public? The constitutional right of copyright is a balance between the
author's interests (payment) and the public's interests (the "progress of
science and useful arts" by having everything become public domain after a
limited time, and fair-use rights in the meantime). But this law is
one-sided in favor not even of the authors, but of the big publishing houses.
<P> There is also a certain antitrust exemption in the bill.
<P> One concession to fair use remains: TV time-shifting. People will be
allowed to record a TV show if it's an "over-the-air broadcast, non-premium
cable channel or non-premium satellite channel". Recording a Showtime movie
would become illegal since it's on a premium cable channel. Note that there's
no provision for radio, webcasting or future technologies, so there would be no
fair use at all for those.
<P> The SSSCA is not law yet. In fact, as of early September it had not
even been introduced in Congress, just debated informally. More happened
later, but let's keep things chronological....
<HR NOSHADE WIDTH="20%"> <!-- ********************* -->
On September 11, the tragedy heard round the world. This has been
well reported elsewhere, so I will stick to the issues relating to Linux.
Suddenly, <A HREF="http://www.wired.com/news/politics/0,1283,46816,00.html">
crypto back doors</A> and crypto export limitations are fashionable
again. Congress is falling over itself trying to pass anti-terrorism
legislation as quickly as possible. Some of this legislation is good and
necessary. But lobbying groups and government agencies are finding a rare
window of opportunity to sneak long-desired unrelated topics into the
package, and they are not shy about exploiting it. It's a lobbyist's dream as
Congress is in a spending mood and eager to pass any legislation that purports
to hinder terrorism, without enough time to evaluate whether the actual effects
will be good or bad.
<P> Of course, there are the usual arguments against <STRONG>encryption back
doors</STRONG>:
<UL>
<LI> If encryption is outlawed, only outlaws will have encryption.
<LI> You want we should destroy our freedom in order to save it?
<LI> Even if our government and allied governments are good now, what if
one of them becomes bad? How will we invalidate the keys it holds, especially
for old messages in a fixed (unchangeable) format?
<LI> What about rogue employees in the government or keyholding service?
Especially those who might sell the information to marketers, or use it for
identity theft to raise $$ for their meth fix?
<LI> E-commerce will decline because nobody wants to trust their personal
information to something with a back door.
<LI> Strong encryption will continue to be developed overseas. Our competitors
and enemies will have an advantage.
<LI> Skilled tech workers will vote with their feet and move to countries where
they can work on projects unencumbered by restrictions.
<LI> Exports will decline because foreigners will laugh at the security of
American encryption products.
</UL>
<P> Exactly one week after the terror attacks, the Nimda worm/virus
appeared, the son of Code Red. The Justice Department
<A HREF="http://www.securityfocus.com/news/257">included</A> in
its Anti-Terrorism Act language that would <STRONG>define hackers,
virus-writers and web site defacers as "terrorists", eligible for life
imprisonment without parole.</STRONG> "Cracking a computer for the purpose of
obtaining anything of value, or to deliberately cause damage" would carry the
same penalties as assassinating a public official or dropping a chemical
weapon. The law would be retroactive to the beginning of time, so even
crimes committed long ago could be tried under it. Fortunately for Kevin
Mitnick, he's already received his sentance. But those who break into a
grocery store's web site and order a pack of gum for free had better watch
out. And those who provide "'advice or assistance' to cyber crooks, or
harbor or conceal a computer intruder" would receive the same punishment as
the intruders themselves. "DNA samples would be collected from hackers upon
conviction, and retroactively from those currently in custody or under
federal supervision. The samples would go into the federal database that
currently catalogs murderers and kidnappers."
<P> What happens if you cross an Anti-Terrorism Act with a Digital Millenium
Copyright Act? Answer: Dmitry goes to prison for life. No, that hasn't been
proposed. But watch out for that definition of "hacking" and see what
exactly it includes, and whether it expands later. Remember the law of
Unintended Effects.
<P> Larry Ellison, the head of Oracle, is
<A HREF="http://www.siliconvalley.com/docs/news/svfront/ellsn092301.htm">
calling for</A> <STRONG>national ID cards</STRONG>. This may sound like
merely the musings of a concerned citizen until you remember that an ID-card
system needs a database, and why not an Oracle database? Ellison is offering
to give the government the software for free, but still, what a PR bonanza for
Oracle it would be. (Like when Microsoft "gives" software to schools. Of
course, nowadays it "sells" software to schools....) Regarding identity cards
themselves <A
HREF="http://www.privacy.org/pi/activities/idcard/idcard_faq.html"> this
report</A> looks at countries that use them and countries that don't use them,
and notes the differences between what each country originially intended its
card for vs how it's being used now. (Again, the Law of Unintended Effects.)
<P> There is one bright side: Congress is considering splitting up the
omnibus Anti-Terrorism bill. That would allow it to pass the most urgent
portions right away, but hold off on the more controversial measures until
they can ascertain which ones would cause more harm than good.
<HR NOSHADE WIDTH="20%"> <!-- ******************************* -->
<P> In late September, the <STRONG>SSSCA</STRONG> was introduced in the
Senate. It has a long way to go before it becomes law, since it has not even
been introduced in the House yet. Most are predicting it has too many
critics to pass this year, but portions of it could crop up in future years.
<P> <I>Linux Journal's</I> Don Marti <A
HREF="http://www.linuxjournal.com/articles/conversations/0034.html">chided
Michael Eisner</A>, the Charman and CEO of the Walt Disney Company, for
planning a trip to Washington, DC, to "close the deal on a computer
censorship bill, the SSSCA, you're buying from Congress." He also
chided Senator Fritz Hollings (D-SC) under the headline, <A
HREF="http://www.linuxjournal.com/articles/conversations/0036.html">
"Senator Hollings Cheaper Than We Thought"</A>, saying that Eisner had paid
Hollings $18,500 to
get the bill introduced. (And not the $25,000 <I>LJ</I> had previously
reported.) Of course, the payment was in the form of
cumulative campaign contributions, not a direct bill payment (pun intended).
<P> The Register notes in <A
HREF="http://www.theregister.co.uk/content/4/21830.html">
"Copy-Control Senator Sleeps While Fair-Use Rights Burn"</A> that the Big 5
media companies are among the top 20 contributors to Hollings' election
campaigns: AOL Time Warner, the Murdoch-owned News Corporation, Viacom's CBS,
the National Association of Broadacsters, and Walt Disney Company.
If you type "senator hollings campaign contributions disney" into
<A HREF="http://www.yahoo.com/">Yahoo</A>, several other articles come up,
including <A
HREF="http://www.commoncause.org/publications/040297_rpt4.htm">this one</A>.
(Yes, you <EM>can</EM> try this at home. Type "senator &lt;NAME&gt; campaign
contributions" and see what comes up for your favorite Congresscritter. Or
"representative &lt;NAME&gt;" for members of the House.)
<P> Here's an article that looks at SSSCA from the manufacturer's
standpoint:
<A HREF="http://lists.essential.org/pipermail/am-info/Week-of-Mon-20010917/007186.html">
Bill Could Force Copy Control On IT Firms</A>. It says the SSSCA "could slow
the development of the technologies it seeks to regulate by shifting the
attention of the industry from product development to lobbying." One attorney
comments, "Telling us what systems to pay for and implement to protect someone
else's property doesn't make sense."
<P>
<A HREF="http://www.theregister.co.uk/content/6/21577.html">Another Register
article</A> says the
SSSCA "would close all the irritating little loopholes in the DMCA right
around the necks of consumers, where, the industry reckons, the pressure
rightly belongs." And, "Conveniently, and by design, the words 'fair use'
appear nowhere in the draft. The industry lobbyists never liked that
troublesome phrase in the DMCA, so now it's gone." The article also points
out that the SSSCA does not require new complient hardware to be
backward-compatible with older hardware, meaning another round of buying the
same content again.
<HR NOSHADE WIDTH="20%"> <!-- ******************************* -->
<P> The <STRONG>role of the
<A HREF="http://www.eff.org/">Electronic Frontier Foundation (EFF)</A>
</STRONG> emerged as a topic in activists' discussions.
Many people think of the EFF as a lobbying organization, but its mission is
actually to defend individuals who have been unjustly accused. Taking on
full-scale lobbying of Congresscritters would require significant changes to
EFF's structure, tarnish its reputation among those who raise their noses at
"lobbyists", place the organization in a different tax category, and distract
it from defending individuals.
<P> Thus, the free-software and "free Dmitry" groups are debating whether
they should start a lobbying organization themselves. Of course, one's first
knee-jerk reaction is to stay as far the h*ll away from Washington as
possible, but if we don't do it, who will? Of course, it would mean doing
some distasteful things. Like (gasp) making campaign contributions to
influence a Congresscritter's votes. Is the free-software community ready to
sponsor a PAC? (PAC = Political-Action Committee, a fancy term for "lobbying
group".) Even though freeniks have some of the highest noses and loudest
sneers against "lobbying scum"? Some are considering it, thinking
it's the only way make a dent in the rapidly-accelerating onslaught against
our rights. Obviously it's something that it will take a long time to come to
consensus on.
<HR NOSHADE WIDTH="20%"> <!-- ******************************* -->
There is another bright side, as pointed out in the IT article. The media
companies should watch what they wish for because they just might get it.
Perhaps the Law of Unintended Effects will end up applying to them. Especially
if enough people decide they can do without the Big 5's content.
<P> Or if artists
start giving away all their music for free. That would generate more
fans at shows, and bands receive much more money from one concert patron
($5-10, plus $10 if she buys a T-shirt) than they do from one CD purchase
(less than $1). And if she buys a CD at a show, they both win: she gets a
discounted price (often $10), and the band get a few dollars rather than the 25
cents they would get from a retail sale.
<P> Then we would see corporate profits drop.
<HR NOSHADE WIDTH="20%"> <!-- ******************************* -->
In conclusion, the DMCA was passed and nobody noticed. (A few people like
Richard Stallman <A HREF="http://www.gnu.org/philosophy/right-to-read.html">
sounded the alarm</A>, but everybody said it wouldn't get that bad.) Now when
it's too late, we are seeing the effects. We're also seeing DMCA-like laws
pushed in countries we thought were "safe". Then the publishers pull a rabbit
out of their hat with another law, and it doesn't take a rocket scientist to
see that it will also turn out to be more powerful than it appears when it's
passed (if it's passed), just like the DMCA.
<P> This, coupled with the crypto back door and hacking-considered-terrorism
proposals and others, foreshadow a society fifty years from now vastly
different than now, where everything is pay-per-view, fair use is forgotten,
all available computer hardware enforces this, and Linux has been illegal for
so long that nobody remembers what it was. But the biggest companies will
still have familiar names--AOL Time Warner, Walt Disney, Microsoft. The laws
give a competitive advantage to the companies that were dominant at the time of
the laws' adoption, since they can use the laws to sue everybody else out of
existence. (Why else do you think they pushed so heavily for the laws in the
first place?) Perhaps many people in today's computer field will drop out in
disgust and switch to other professions, and shun e-mail and the phone in favor
of face-to-face activities. Farfetched? Perhaps, but we've learned and not to
trust the CEOs and politicos any farther than we can throw them, and to expect
the worst because it will turn out worse than that.
<P> Of course, one wonders whether the needs of the publishers for
strong encryption and the needs of the FBI for weak encryption are on a
collision course. We've already seen that the needs of the FBI (to catch
bad guys) and the needs of e-commerce (to promote a healthy economy) are
opposite: that's why the Clinton administration weakened crypto export laws,
and why the FBI is now pushing back.
<HR NOSHADE WIDTH="20%"> <!-- ********************** -->
<STRONG>Other items of interest</STRONG>
<P> <A HREF="http://www.sciencemag.org/cgi/content/full/293/5537/2028">"Anticircumvention Rules: Threat to Science"</A> (Science magazine)
argues that the DMCA is a threat to all scientists, not just those in
computer security and encryption research. "Virtually all computer
scientists, as well as many other scientists with some programming skills, find
it necessary on occasion to reverse engineer computer programs. Sometimes they
have to bypass an authentication procedure or some other technical measure in
order to find out how the program works, how to fix it, or how to adapt it in
some way. The act of bypassing the authentication procedure or other technical
measure, as well as the making of a tool to aid the reverse engineering
process, may violate the DMCA. Although the DMCA also has an exception for
reverse engineering of a program, it too is narrow. It only applies if the sole
purpose of the reverse engineering is to achieve program-to-program
interoperability and if reverse engineering is necessary to do so. Trying to
fix a bug or understand the underlying algorithm does not qualify. Information
even incidentally learned in the course of a privileged reverse engineering
process cannot be divulged to any other person except for the sole purposes of
enabling program-to-program interoperability." The article also speculates
about a pharmaceutical company that "produces data to prove that a new drug is
safe but technically protects it so that only certain tests can be performed on
the data, all of which support the safety claim. A scientist who doubted the
safety claim and tried to process the data by additional tests would violate
the DMCA if he or she bypassed the access control system restricting use of the
data."
<P> Lawrence Lessig, who wrote _Code and Other Laws of Cyberspace_, is
<A HREF="http://lwn.net/2001/features/LawrenceLessig.php3">interviewed</A>
by LWN's Dennis Tenney. He gives his perspective on the
DMCA, Dmitry Sklyarov's case, Hailstorm, international jurisdiction,
etc.
<P> Background on the
<A HREF="http://www.informationweek.com/story/IWK20010711S0010">DeCSS case</A>.
<P> A <A HREF="http://slashdot.org/comments.pl?sid=21786&threshold=1&commentsort=0&mode=thread&pid=2358824#2364678">Slashdot post</A>
that describes some of the lesser-known provisions of the DMCA.
<P> Phil Zimmerman, creator of PGP encryption,
<A HREF="http://www.philzimmermann.com/news-Response_WashPost.shtml">explains</A>
how he was misrepresented by the Washington Post. The Post reported that he
was "overwhelmed with feelings of guilt" over the fact that the September 11th
terrorists may have used PGP in planning their attack. Zimmerman reiterates
that he thinks the public having access to strong encryption without back doors
is a good idea, and that PGP is a good tool for human rights around the world.
He also insists he will not allow any back doors in PGP.
<a name="links"></a>
<p><hr><p>
<!-- =================================================================== -->
<center><H3><font color="green">Linux Links</font></H3></center>
<P> <hr> <P>
<IMG ALT="Linux Focus" SRC="../gx/linuxfocus.jpg" WIDTH="143" HEIGHT="45">
<BR CLEAR="all">
The following articles are in the September-October issue of the multilingual
ezine <A HREF="http://www.linuxfocus.org/">Linux Focus</A>.
<UL>
<LI><a href="http://linuxfocus.org/English/September2001/article139.shtml">
XMRM : Morphing with Linux</a></LI>
<LI><A HREF="http://linuxfocus.org/English/September2001/article198.shtml">
Avoiding security holes when developing an application - Part 5: race conditions</A>
<LI> <A HREF="http://linuxfocus.org/English/September2001/article206.shtml">Using XML and XSLT to build LinuxFocus.org(/Nederlands)</A>
<LI> <A HREF="http://linuxfocus.org/English/September2001/article213.shtml">Analyzing your internet applications' log files</A>
<LI> <A HREF="http://linuxfocus.org/English/September2001/article214.shtml">Psionic Portsentry 1.1, the defender of the ports</A>
<LI> <A HREF="http://linuxfocus.org/English/September2001/article215.shtml">E-mail over UUCP: The professional solution for dialup users</A>
<LI> <A HREF="http://linuxfocus.org/English/September2001/article216.shtml">Shell Programming</A>
</UL>
<P> In case you missed some of
<a href="http://www.linuxjournal.com/">
Linux Journal's</a> technical web articles over
the past few months here are some links to
System Administration articles by Marcel Gagn&eacute;<br>
<ul>
<li>Your Network's Secret Life<br>
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0059.html">part 1</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0060.html">part 2</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0061.html">part 3</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0062.html">part 4</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0063.html">part 5</A>.
<li>Tux Knows It's Nice to Share<br>
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0051.html">part 1</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0052.html">part 2</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0053.html">part 3</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0054.html">part 4</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0055.html">part 5</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0056.html">part 6</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0057.html">part 7</A>,
<A HREF="http://noframes.linuxjournal.com/articles/sysadmin/0058.html">part 8</A>.
</ul>
<P><a href="http://www.linuxjournal.com/">
Linux Journal</a> also has an online
<a href="http://www.linuxjournal.com/articles/linux_review/0052.html">
Review</a> of the book
Linux Administration: A Beginner's Guide, Second Edition.
<p><a href="http://www.linux-mag.com/">
Linux Magazine</a> have an article on MySQL
<a href="http://www.linux-mag.com/2001-06/mysql_01.html">
performance tuning</a>.
Much of the information could be applied to any SQL database.
<p>
<a href="http://www.thedukeofurl.org">
The Duke of URL</a> has
<ul>
<li>A <a href="http://www.thedukeofurl.org/reviews/misc/applixware50">
review</a> of
Applixware Office 5.0.
<li>An <a href="http://www.thedukeofurl.org/reviews/misc/tamingbeast">
editorial</a> called
"Taming the Beast." It's all about Microsoft's latest attempts to
corner the market and even has a little history, as well.
</ul>
<p><a href="http://www.linuxports.com/">The Linux Review</a> have taken a
<a href="http://www.linuxports.com/entry.lxp?lxpe=104">
look</a> at the new KDE 2.2 and its applications. The review points out
missing features that allegedly make the corresponding Windows and Macintosh
applications superior (even MS Outlook!). There is also a
<a href="http://www.linuxports.com/entry.lxp?lxpe=106">
follow up</a>. Courtesy
<a href="http://www.lwn.net/">LWN</a>.
<P>
Could DMCA be
<a href="http://mail.nl.linux.org/humorix/2001-08/msg00016.html">
outflanked</a> by new cosmogeny and quest for meaning of life ;-).
<P>There is an
<a href="http://www.osnews.com/story.php?news_id=93">
interview</a> with the creator of MenuetOS over at
<a href="http://www.osnews.com/">OS News</a>.
<a href="http://www.menuetos.org/">
MenuetOS</a>
is a small assembly-language OS
that fits on a floppy with room for a few applications. The video
driver has 16.7 million colours.
<p>
Some links courtesy of <a href="http://www.slashdot.org/">Slashdot</a>:
<ul>
<li>
Congress Mulls
<a href="http://www.wired.com/news/politics/0,1283,46816,00.html">
Stiff Crypto Laws</a>
in response to terror attacks.
<li>
CmdrTaco
<a href="http://slashdot.org/articles/01/09/13/154222.shtml">
explains</a>
how Slashdot stayed up during their highest load ever
after the attacks. Comments about MySQL and static pages.
<li>
ZDNet
<a href="http://techupdate.zdnet.com/techupdate/stories/main/0,14179,2808791-1,00.html">
reviews</a>
12 Linux support services.
<li>
Guido has written a web page of
<a href="http://www.python.org/doc/Newbies.html">
resources</a> for Python newbies
<li>
<a href="http://www.ibm.com/">IBM</a> to
<a href="http://www.investors.com/editorial/tech.asp?v=8/28">
sell</a> Linux-based brokering software,
</ul>
<P>
In industry bad news,
<a href="http://lwn.net/">Linux Weekly News</a>
have
<a href="http://lwn.net/2001/0913/">
reported</a> that Great Bridge has closed its doors. Great Bridge was the
company that brought LG the article
<A HREF="http://www.linuxgazette.com/issue68/mitchell.html">The Opening of the
Field: PostgreSQL's Multi-Version Concurrency Control</A>.
<a name="conferences"></a>
<p><hr><p>
<!-- =================================================================== -->
<center><H3><font color="green">Upcoming conferences and events</font></H3></center>
<P> Listings courtesy <EM>Linux Journal</EM>. See <EM>LJ</EM>'s
<A HREF="http://noframes.linuxjournal.com/events/">Events</A> page for the
latest goings-on.
<!-- *** BEGIN events table [this line needed by Linux Gazette events.py *** -->
<table cellpadding=5 border=0 width=100%>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>Cluster 2001</b><BR>
<td valign=top>October 8-11, 2001<BR>Newport Beach, CA<BR>
<A HREF="http://www.cacr.caltech.edu/cluster2001/"
target=_blank>
http://www.cacr.caltech.edu/cluster2001/</A>
<BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>Linux Lunacy<br>Co-Produced by <i>Linux
Journal</i> and Geek Cruises</b><BR>
<td valign=top>October 21-28, 2001<BR>Eastern Caribbean<BR>
<A HREF="http://www.geekcruises.com/" target=_blank>
http://www.geekcruises.com</A><BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>LinuxWorld Conference & Expo</b><BR>
<td valign=top>October 30 - November 1, 2001<BR>Frankfurt, Germany<BR>
<A HREF="http://www.linuxworldexpo.de" target=_blank>
http://www.linuxworldexpo.de</A><BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>5th Annual Linux Showcase & Conference</b><BR>
<td valign=top>November 6-10, 2001<BR>Oakland, CA<BR>
<A HREF="http://www.linuxshowcase.org/" target=_blank>
http://www.linuxshowcase.org/</A><BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>Strictly e-Business Solutions Expo</b><BR>
<td valign=top>November 7-8, 2001<BR>Houston, TX<BR>
<A HREF="http://www.strictlyebusinessexpo.com/" target=_blank>
http://www.strictlyebusinessexpo.com</A><BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>LINUX Business Expo</b><BR>Co-located with COMDEX<br>
<td valign=top>November 12-16, 2001<BR>Las Vegas, NV<BR>
<A HREF="http://www.linuxbusinessexpo.com" target=_blank>
http://www.linuxbusinessexpo.com</A><BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
<tr><td valign=top>
<b>15th Systems Administration Conference/LISA 2001</b><BR>
<td valign=top>December 2-7, 2001<BR>San Diego, CA<BR>
<A HREF="http://www.usenix.org/events/lisa2001/" target=_blank>
http://www.usenix.org/events/lisa2001</A><BR>
</td></tr>
<tr><td colspan=2><HR size=5 width=100% noshade align=center></td></tr>
</table>
<!-- *** END events table [this line needed by Linux Gazette events.py *** -->
<a name="general"></a>
<p><hr><p>
<!-- =================================================================== -->
<center><H3><font color="green">News in General</font></H3></center>
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Python10 conference
</FONT>
</H3>
<P> The
<a href="http://www.python10.org">
Tenth International Python Conference</a> (Python 10) will be held on
February 4-7, 2002, at the Hilton Alexandria Mark Centre in Alexandria,
Virginia.
The Call for Papers for the Refereed Paper Track, and the Call for
Tutorials can be found at
<a href="http://www.python10.org/p10-callpapers.html">
www.python10.org/p10-callpapers.html</a>,
and
<a href="http://www.python10.org/p10-calltutorials.html">
www.python10.org/p10-calltutorials.html</a>,
respectively. The deadline for
submitting a paper to the Refereed Paper Track is Monday, October 8,
2001. The deadline for submitting a proposal for Tutorials Day is Monday,
October 1, 2001.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">LLNL Adds Linux Cluster Supercomputing Power to ASCI Project
</FONT>
</H3>
<P>SGI Federal, a
subsidiary of
<a href="http://www.sgi.com/">SGI</a>,
has
<a
href="http://www.linuxnetworx.com/news/8.28.2001.49-Lawrence_Liverm.html">
teamed up</a> with
<a href="http://www.linuxnetworx.com">
Linux NetworX</a> to win a bid to build three Parallel
Capacity Resource (PCR) Linux cluster computing systems totalling 472 Pentium
4 processors for the National Nuclear Security Administration's Accelerated Strategic
Computing Initiative (ASCI).
ASCI is a program to reach 100-trillion calculations per second by 2005
that will help scientists to maintain the
safety and reliability of the U.S. nuclear stockpile by simulating the
aging and operation of nuclear weapons. With a theoretical peak
performance of 857 gigaFLOP/s, the largest of the three systems with 252 Pentium
4 processors, named PCR P4A, will be one the fastest Linux clusters ever built.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Petroleum Penguins
</FONT>
</H3>
<P><a href="http://www.lgc.com/">
Landmark Graphics Corp.</a>, a wholly owned business unit of
Halliburton Company, today announced plans to offer its full
suite of integrated UNIX exploration and production applications on a range
of Linux platforms with rollout beginning in the fourth quarter of 2001.
This marks the most significant commitment to date by a major technology
provider in the oil and gas industry to support the "open source" Linux
operating system. Compaq, Dell, EMC, IBM, Intel and Network Appliance are
working with Landmark to offer a broad range of optimized Linux solutions,
including workstations, servers and storage.
<a name="distro"></a>
<p><hr><p>
<!-- =================================================================== -->
<center><H3><font color="green">Distro News</font></H3></center>
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Debian
</FONT>
</H3>
<a href="http://www.debian.org/News/weekly/2001/21/">
There are</a> a lot of orphaned (102) and up-for-adoption (35) packages out
there. Some of the packages include kicq, knews, mcvert (Mac to Unix file
converter) and several others. A list of packages is found
<a href="http://lists.debian.org/debian-devel-announce/2001/debian-devel-announce-200109/msg00003.html">
here</a>.
<p>
<hr width="20%" noshade>
<p>
Adam Di Carlo
<a href="http://lists.debian.org/debian-boot/2001/debian-boot-200109/msg00255.html">
announced</a> that version 3.0.14 of the boot floppies are
<a href="http://people.debian.org/~aph/debian/dists/woody/main/">
available</a> for testing for powerpc and
i386. Hammer on them and send reports, comments or praise to debian-boot@lists.debian.org.
<a href="http://www.debian.org/News/weekly/2001/22/">
Original story</a>.
<p>
<hr width="20%" noshade>
<p>
Debian Security is crucial to users and should be managed properly.
<a href="http://www.debian.org/News/weekly/2001/23/">
Recently</a>, to
help improve the situation, Joey Hess has
<a href="http://lists.debian.org/debian-security/2001/debian-security-200109/msg00225.html">
asked</a> for a Security Secretary, who
will
<a href="http://lists.debian.org/debian-security/2001/debian-security-200109/msg00299.html">
help</a> the Debian Security Team doing their work.
<p>
Reports taken from
<a href="http://www.debian.org/News/weekly/">
Debian Weekly News</a>.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">SuSE
</FONT>
</H3>
<P>From the end of August,
<a href="http://www.suse.de/en/">SuSE Linux</a>
<a href="http://www.suse.de/en/sles/">
Enterprise Server 7</a> will be available for Intel's 32-bit
architecture (x86), Intel's 64-bit architecture (Itanium processor family),
and IBM's mainframe platform S/390. Versions for IBM's iSeries,
pSeries, and zSeries will follow in late autumn.
Included in the purchase price, are maintenance services that make sure that
SuSE Linux Enterprise Server 7 is always up-to-date, stable, and tested.
SuSE regularly informs users by e-mail and makes the respective patches,
fixes, and updates available via FTP server.
For more information please refer to
<a href="http://www.suse.de/en/sles/">
http://www.suse.de/en/sles/</a>
<p>
<hr width="20%" noshade>
<P>SuSE Linux have also announced that
<a href="http://www.suse.de/en/produkte/solutions/database_server/index.html">
SuSE Linux Database Server</a>
combines the operating system platform of SuSE Linux Enterprise
Server with IBM's DB2 Database to form a complete solution for professional users.
In mid September, SuSE Linux will present an updated version of the solution package.
<a name="commercial"></a>
<p><hr><p>
<!-- =================================================================== -->
<center><H3><font color="green">Software and Product Announcements</font></H3></center>
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">New CPCI SBC from MEN Micro
</FONT>
</H3>
<P>
<a href="http://www.menmicro.com/">
MEN Micro</a> have released
a new CompactPCI single board computer (SBC). The SBC comes in three
versions, and each version includes a 300 MHz PowerPC XPC8245. The D3, as
the new SBC is designated, is a one-slot 6U CompactPCI board. In CompactPCI
systems it operates as a master system-slot board, but in embedded
applications it can also operate as a standalone processing unit without a
bus connection. As a computer, the D3 comes with up to 256K of DRAM in a
SODIMM slot, two megabytes (MB) of flash memory and an ATA-compatible
CompactFlash site, in addition to numerous other I/O features. The D3 can
run either the VxWorks or Linux operating systems. For more information on
the D3 including a data sheet, go to
<a href="http://www.men.de/products/press/">
www.men.de/products/press</a>.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Rackspace Named Best Dedicated Host
</FONT>
</H3>
<P>
<a href="http://www.rackspace.com/index.php">
Rackspace</a>, who hosts more than 2,500 Linux servers, has earned the title of
"Best Dedicated Host",
as judged by the editors of
Web Hosting Magazine,
because of their dedication to customer service.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">SAIR Linux and GNU Certification
</FONT>
</H3>
<P>
Recently, to assist in promoting the Linux+
certification effort,
<a href="http://www.linuxcertification.com">
SAIR Linux and GNU Certification</a> has released a version of its
Fundamentals course-ware, which doubles as preparation course-ware for
<a href="http://www.comptia.org/">
CompTIA's</a> Linux+ Certification exam.
SAIR Linux and GNU
was contacted by CompTIA<49> to aid in the development of CompTIA's
Linux+ Certification exam. The course title is SAIR Linux
and GNU Fundamentals/Linux+.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Linux Based Ethernet Compatible Set Top Box
</FONT>
</H3>
<P> <a href="http://www.vtmt.com/">
Media Technology</a> have launched their new product, the
<a href="http://www.vtmt.com/html/vt900.html">
VT900 Set Top Box</a>.
The VT900 enables Ethernet 10/100 data streams to be converted to composite
analog RF data streams or digital S-Video data streams compatible with all
standard TV sets. Over 250 channels of various forms of TV-format data
have been successfully tested with the VT900.
Implementing Linux, the VT900 incorporates a full browser, and supports all
plug-ins. Partnerships have been established with both Century Embedded
Software Inc., and Enreach Technology Inc, to further develop application
software.
The VT900 is designed using the National Semiconductor Geode processor in
conjunction with the Sigma Design EM8400 MPEG Decoder and the Macphyter
Ethernet adapter. Optionally available are DVD Player, CDRW, Floppy and
standard IDE Hardware.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Team ASA Announces NPWR SBC up-grade with Dual Gigabit Ethernet Ports
</FONT>
</H3>
<P> <a href="http://www.teamasa.com/">
Team ASA's</a>
NPWR is a Single Board Computer (SBC) designed for
manufacturers and OEMs in the Network Attached Storage (NAS), RAID,
and Personal Server marketplaces. It is
now available with dual Gigabit
Ethernet ports.
The NPWR is powered by the Intel XScale processor, the XScale is a
RISC CPU with clock rates reaching as high as 733 MHz. NPWR's
standard configuration includes 160 Mbytes per Second (LVD) SCSI
port, 8 Mbytes of FLASH ROM, 128 Mbytes of SDRAM and a Gigabit
Ethernet port.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">DocPro DocBook Tool Set
</FONT>
</H3>
<P><a href="http://www.commandprompt.com/">
Command Prompt, Inc.</a> is pleased to announce
<a href="http://www.commandprompt.com/products_DocPro.lxp">
DocPro</a>, the
"professional DocBook tool set".
DocPro is a compilation of tools designed to allow technical writers to
effectively process their DocBook SGML and XML layout. DocBook itself
is a powerful markup language. However, the tools are painful to compile,
configure and work with. Command Prompt, Inc. has eliminated the problems
associated with the integration of these tools into a production
environment. DocPro comes in Basic and Deluxe versions, and should work
with all RedHat 6.2 and later compatible distributions of Linux.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Tarantella Enterprise 3 Starter for Linux
</FONT>
</H3>
<P>
<a href="http://www.tarantella.com/">Tarantella, Inc.</a>
has announced the availability of
<a href="http://www.tarantella.com/products/e3/starter.html">
Tarantella Enterprise 3 Starter for Linux</a> software.
The product makes it possible to publish Windows, Web, Java, AS/400, Linux
and UNIX applications securely to client devices anywhere. It
can be used for a wide
range of tasks, such as remote system administration or accessing company
applications and services from home.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Embedded Open Motif
</FONT>
</H3>
<a href="http://www.ics.com/">
Integrated Computer Solutions</a> has announced a
version of Open Motif targeted at embedded and handheld devices with
limited displays, memory, and processing power.
<a href="http://www.motifzone.net/projects/?group_id=16">
Embedded Open Motif</a> has been ported to the Compaq IPAQ and the Agenda
VR3 from Agenda Computing. Both source code and binary packages are
available for free download from the
<a href="http://www.motifzone.net/">
MotifZone</a>.
Get more information online at:
<a href="http://www.motifzone.net/forum/forum.php?forum_id=140">
http://www.motifzone.net/forum/forum.php?forum_id=140</a>
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">WAP Opera
</FONT>
</H3>
<P><a href="http://www.opera.com/">Opera Software</a>
have
<a href="http://www.opera.com/pressreleases/20010905.html">
announced</a> that future versions of its browser will support the new and
improved Wireless Application Protocol (WAP) 2.0 standard.
<p>
<hr width="20%" noshade>
<p>
Opera Software have also opened the
revamped
<a href="http://my.opera.com/">
MyOpera</a> community and released the second edition of their popular
Opera Composer, inviting users to join an Opera community or create their
own. In this new version, users can customise their own Web browser for
the Linux platform as well as for Windows,
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">Alabanza
</FONT>
</H3>
<P>
<a href="http://www.alabanza.com/">
Alabanza</a> has
<a href="http://www.alabanza.com/pages/press_sitebuilder.html">
launched</a> version 4.1 of
of its Automated Web Hosting Software Suite, which was originally
built on and still runs on the Linux operating system. The latest version of the
software suite includes a new Web Site Builder tool it acquired from OnNet Web
Hosting. Version 4.1 automates administrative Web hosting tasks, empowers users to
update sites, provides for complete security and furnishes electronic commerce
services for small businesses.
Alabanza's Automated Web Hosting Software Suite 4.1 is the most proven, reliable
and secure solution on the market for hundreds of Web designers and developers,
systems integrators, Internet service providers and telecommunications carriers.
It allows end users to automate administrative tasks, manage content, and update
Web sites with a significant decrease in time and costs; all within a secure
environment.
<P> <hr> <P>
<!-- =================================================================== -->
<H3><IMG ALT=" " SRC="../gx/bolt.gif">
<FONT COLOR="green">BrainTAGS
</FONT>
</H3>
<P>
<a href="http://www.braintags.de/">
BrainT@GS</a>
has released NetRelay. This software-tool automates processes between web
client, server and databases. This includes automatic record creation,
deletion, display and up-date and integration of a template-engine. The
intelligent and structured architecture of NetRelay makes the development
of dynamic web applications more transparent and structured. NetRelay
creates a clear separation between logic and presentation and also
generates automatic XML documents, enabling easy data-transfer. NetRelay
is database independent. NetRelay runs on any server platform supporting
the JDK, and has been tested on Linux.
<!-- *** BEGIN copyright *** -->
<P> <hr> <P>
<H5 ALIGN=center>
Copyright &copy; 2001, Michael Conry and
the Editors of <A HREF="mailto:gazette@ssc.com"><I>Linux Gazette</I></A>.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 71 of <i>Linux Gazette</i>, October 2001</H5>
<!-- *** END copyright *** -->
<center>
<H1><A NAME="answer">
<img src="../gx/dennis/qbubble.gif" alt="(?)"
border="0" align="middle">
<font color="#B03060">The Answer Gang</font>
<img src="../gx/dennis/bbubble.gif" alt="(!)"
border="0" align="middle">
</A></H1>
<BR>
<H4>By Jim Dennis, Ben Okopnik, Dan Wilder, Breen, Chris, and the Gang,
the Editors of Linux Gazette...
and You!
<br>Send questions (or interesting answers) to
<a href="mailto:linux-questions-only@ssc.com">linux-questions-only@ssc.com</a>
</H4>
<p><em><font color="#990000">There is no guarantee that your questions
here will <b>ever</b> be answered. Readers at confidential sites
must provide permission to publish. However, you can be published
anonymously - just let us know!
</font></em></p>
</center>
<p><hr><p>
<H3>Contents:</H3>
<dl>
<dt><a href="#tag/greeting"
><strong>&para;: Greetings From Heather Stern</strong></A></dl>
<DL>
<!-- index_text begins -->
<dt><A HREF="#tag/1"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
><strong>Q: avoid getting answers from apropos in the man sections 3 and 3x</strong></a>
<dt><A HREF="#tag/2"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
><strong>"crypt" function in Linux</strong></a>
<dt><A HREF="#tag/3"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
></a>I think this would be a common problem at least is has been for me
--or--
<dd><A HREF="#tag/3"
><strong>Dependency Hell</strong></a>
<dt><A HREF="#tag/4"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
><strong>Is This a Good Book for Linux Programming?</strong></a>
<dt><A HREF="#tag/5"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
><strong>What ISPs Do We Use for Linux</strong></a>
<dt><A HREF="#tag/6"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
><strong>How to let the world find your Linux Server when using DHCP</strong></a>
<dt><A HREF="#tag/7"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
><strong>trouble w/ dual boot</strong></a>
<dt><A HREF="#tag/8"
><img src="../gx/dennis/qbub.gif" height="28" width="50"
alt="(?)" border="0"
></a>Any good resources on laptop hardware support? --or--
<dd><A HREF="#tag/8"
><strong>HOWTO find a good laptop</strong></a>
<!-- index_text ends -->
</DL>
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/greeting"><HR WIDTH="75%" ALIGN="center"></A>
<H3 align="left"><img src="../gx/dennis/hbubble.gif"
height="50" width="60" alt="(&para;) " border="0"
>Greetings from Heather Stern</H3>
<!-- begin hgreeting -->
<p> Ouch.
<p>
The world trade center in shambles. The financial community is still
mostly in shock. The airline industry is rightfully quite horrified.
I know <em>I'm</em> horrified...
<p>
What can we, members of the free software community, do?
<p>
I know a lot of sites have put up banners linking to various helpful
organizations, the Red Cross, funds for the families of all the
emergency personnel killed, and so on. So much in fact, that I wonder
how many charities will go short shrift of donations, clothes, and
other things, simply because this one presently has everyone's attention.
<p>
But that's what we do <em>as people</em>. As a <em>community</em> we
can do a lot more. <a href="http://www.slashdot.org/">Slashdot</a>
did great on keeping us all in tune with the news, when the routers
in front of almost every major news service were going into meltdown.
People used IRC and websites to find out if friends were alive and well,
I saw wikis, I saw email lists briefly stop talking about the topic
of the moment and reserve the day for traffic about who was okay. Now
this didn't just mean wondering whether anybody died in New York. For
instance, a friendly soul from the GNOME Usability Project was trapped
in China for 6 days longer than he expected... making it to our user
group meeting just in time, I might add, but I think it probably
dampened his enthusiasm for our chinese food.
<p>
We're an international community, and now an international problem that
has existed for a long time has been made more obvious. These people
that took these planes used little that was unavailable to Cro Magnon
Man. I'll update them to the Bronze Age because they found a cheat
sheet for how to not be followed - but we're still talking tribal
hunters, not 21st century "agents" from The Matrix.
<p>Yet there are these pushes to "wiretap" email. (See the Crypto-Gram
Newsletter, <a href="http://www.counterpane.com/crypto-gram-109a.html"
>http://www.counterpane.com/crypto-gram-109a.html</a>
for some details.) The ultra-protectionism
of Big Corporate copyrights continues (you think the
<a href="http://www.educause.edu/issues/dmca.html"
>Digital Millenium Copyright Act</a>, already passed
and being enforced, is bad? Look at the bill
"<a href="http://216.110.42.179/docs/hollings.090701.html"
>SSSCA</a>" up for attention. According to the EFF's Cindy Cohn
it makes the DMCA "look like the Bill Of Rights".) while frankly,
my ability as a real individual who writes about one tune every 2 years,
lyrics a little more often, and at least one article a month, to
continue to enforce my OWN copyrights and fair use rights under the
US Code, Title 17
(<a href="http://www4.law.cornell.edu/uscode/17/index.html"
>http://www4.law.cornell.edu/uscode/17/index.html</a>)
continues straight into the gutter.
My expectation of safety when I visit a foreign country obviously won't
be based on the idea that I was an invited speaker -- as far as I know,
anybody who was trapped in another city because all flights were grounded
has gotten home now, even the ones who took a taxi From Chicago to Los
Angeles -- but Dmitry Sklyarov, a Russian citizen, continues to live
trapped in the USA because eBooks can't be sold in Russia unless you
can make a backup of them, and he agreed to TALK about how the encryption
works on US soil.
<p>
<strong>NOW</strong> I'm terrified.
<p>Of course most of my email lives a very public life already. But let's
face it, a translucent dime store postcard written on in big black marker
has more privacy than the average internet Joe. It's not a federal
felony to hassle a small town ISP because they don't want to let you
wiretap all of their customers just because you have a warrant on one of
them. (We'll leave out whether the "up to something" they might
be up to is about real life-and-death matters or merely about someone
wanting to play Mom for us.) It's not a federal crime to impersonate
being someone important so that your spam gets into a victim's box.
Hey, I may dislike spam a great deal, but it's just a delete button,
okay? He's said his piece and I ignore it. We paint over graffiti
on the walls of small towns, no attention, no fanfare, and eventually
the spams die. End of story.
<p>
Soon, however, it may be a federal crime -- penalty, to lose most of
your rights of US citizenship forever -- to deface a website. HELLO
real world! This is about equivalent to "joyriding". Give 'em some
community service and get on with life. Goodness knows what level of
punishment they have in mind for someone who
believes that mail containing things about money matters really ought
to be in an envelope that can't be steamed open, even in the figurative
sense of cyberspace. (If you don't use PGP or
<a href="http://www.gnupg.org/">GnuPG</a> already, establish
the habit now. Free interoperable clients for MSwin and Mac:
<a href="http://www.pgp.com/products/freeware/default.asp"
>http://www.pgp.com/products/freeware/default.asp</a>)
Or that we have a reasonable expectation of privacy and freedom to
assemble as a group for any other reason. Or that the business
transactions of any US company are none of any other company's or
country's direct business,
unless some sort of model of trust exists between them.
Join the <a href="http://www.eff.org/">Electronic Frontier Foundation</a>
and keep up on other resources about what is going on. As a group we
have a better chance. (There are other privacy related groups out there
too. <a href="http://www.cato.org/">Cato.org</a>, the
<a href="http://www.aclu.org/">American Civil Liberties Union</a>,
and Europeans might consider checking out the Justis database,
<a href="http://www.justis.com/database/european_law.html"
>http://www.justis.com/database/european_law.html</a>. I'm sorry
I can't read other languages or surely I'd have more pointers...)
<p>
The electronic 'zines I'm subscribed to were singing the praises of the
IT staff who arranged for businesses to go onward regardless of the
chaos. They're only just starting to notice the drastic legislation
that's trying to come down the pipe on a wave of patriotism, duty, and
budget-grubbing. I work with and know a lot of sysadmins. I can tell
you that a lot of sysadmins right now don't like the idea of being
put in a tight spot: as a cop, with none of the legal defenses a cop
has for doing his job; as a carrier of bits, with none of the legal
defenses of a telphony Common Carrier for the fact that we are not the
origin of any of this information; as an implementor of company policy,
and a professional with special skills, but without the defense of
"client privilege" that other professions enjoy.
<p>A number of legislators are quite up in arms over the idea that they
are being asked to vote on these matters without enough time to read
all the horrid little details. However, some seem to want this extra
time so they have a chance to draft their own pet departments, see
<a href="http://dailynews.yahoo.com/htx/ap/20010920/us/attacks_terrorism_laws_3.html">http://dailynews.yahoo.com/htx/ap/20010920/us/attacks_terrorism_laws_3.html</a>. Call your reps now and make sure that whatever does finally get
drafted actually defends and supports <em>you</em>. I'm sad to say that
email probably isn't enough -- you can try it, but they get a ton, and it
carries little emotional power. Use a phone and <strong>talk</strong>
to these people.
<p>
While a proposed bill isn't exactly
"closed source" it is pretty much what something huge like OpenOffice
or the linux kernel is to someone uninitiated to the wizardry of C and
perhaps even deeply experienced in the same. Of course in <em>our</em>
scope we have all sorts of utilities to help us manage large projects
and sort through things. So what I'd love to see is some sort of
"pretty print" style parser that goes over proposed bills and exposes
the described crimes, regulations, penalties and so on to a bit of
serious debugging. The "sources" are readable by anyone on THOMAS,
<a href="http://thomas.loc.gov/">http://thomas.loc.gov/</a>;
although goodness knows if those are up to date with what is being
argued on the Congress floor, it's a start. I'm sure somebody out
there can give it a shot!
<p><em>On a somewhat more local note, we had many more threads than this,
in fact I am amazed at the percentage of incoming questions that we
answered. But I just got all boiled up and had to let off the
above rant. On the plus side my scripts are doing better by
far than last month. So I have picked some highly juicy ones
and hope you'll forgive me the short list. We have new
<a href="tag/bios.html">Biographies</a>
for the Answer Gang, too, so you can get a sense of who answers
your questions here.</em></p>
<!-- end hgreeting -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/1"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 1 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>Q: avoid getting answers from apropos in the man sections 3 and 3x</H3>
<p><strong>
From S&aacute;ndor B&aacute;r&aacute;ny
</strong></p>
<p align="right"><strong>Answered By Mike Orr
</strong></p>
<BLOCKQUOTE>
Dear Answer Gang,
</BLOCKQUOTE>
<BLOCKQUOTE>
I am looking for a way to avoid getting answers to my apropos queries
from the man sections 3 and 3x (ie I want to see only command names and
no APIs). How can I do that without statically removing those man
sections?
</BLOCKQUOTE>
<BLOCKQUOTE>
Regards,
</BLOCKQUOTE>
<BLOCKQUOTE>
S&aacute;ndor B&aacute;r&aacute;ny
</BLOCKQUOTE>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
If you want to see only a certain section, you can pass that as the
second argument to "man". For instance, "crontab" has two pages.
"man 5 crontab" shows the file format, and "man 1 crontab" (or "man
8 crontab" on some systems) shows the command.
</blockQuote>
<blockQuote>
Apropos doesn't have any options, but man can be called as:
</blockQuote>
<blockquote><code><font color="#000033"><br>man -S 1:5:8 MyCommand
<br>man --sections=1:5:8 MyCommand
</font></code></blockquote>
<blockQuote>
to make it search only certain sections. In this case, it will display
the first file it finds.
</blockQuote>
<blockQuote>
The easiest way to do what you want would be to have a shell script or
function that greps the output of "apropos" to remove the unwanted lines:
</blockQuote>
<blockquote><code><font color="#000033"><br>#!/bin/sh
<br>apropos $* | fgrep -v '(3)
<br>(3X)'
</font></code></blockquote>
<blockQuote>
Or if you like regular expressions:
</blockQuote>
<blockquote><code><font color="#000033"><br>#!/bin/sh
<br>apropos $* | egrep -v '\((3|3X)\)'
</font></code></blockquote>
<!-- end 1 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/2"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 2 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>"crypt" function in Linux</H3>
<p><strong>From Ben Okopnik
</strong></p>
<p align="right"><strong>Answered By
<p></strong></p>
<BLOCKQUOTE>
Just a little while ago, I needed to use the "crypt" program, so
well-known in other Unices, to encode a text file (for those of you
unfamiliar with it, it encrypts the contents of a file using a password
that you supply. A fairly useful little utility when you want just a bit
of added security on a publicly-readable file.) Imagine my surprise when
I found that Linux does not have one! Once again, it's Perl to the rescue.
</BLOCKQUOTE>
<BLOCKQUOTE>
This version follows the syntax of the original "crypt", although
I'm certain that the algorithm is different. The encryption and the
decryption are symmetric, meaning that the same syntax is used for both
(with the obvious exception of the relevant filenames):
</BLOCKQUOTE>
<blockquote><code><font color="#000033"><br># This encrypts the contents of "mysecret.txt" using "iAMw0tIam" as the
<br># password and saves the results to "mysecret.encrypted".
<br>crypt iAMw0tIam &lt; mysecret.txt &gt; mysecret.encrypted
<br>
<br># This prints out the decrypted contents of "mysecret.encrypted" to the
<br># screen.
<br>crypt iAMw0tIam &lt; mysecret.encrypted
<br>
<br># This decrypts the contents of "mysecret.encrypted" and writes the results
<br># to "mysecret.decrypted".
<br>crypt iAMw0tIam &lt; mysecret.encrypted &gt; mysecret.decrypted
</font></code></blockquote>
<BLOCKQUOTE>
Long passwords are preferable to short ones for better security;
"crypt" accepts them without a problem, provided that any password
containing spaces or other "weird characters" is quoted (preferably
in single quotes).
</BLOCKQUOTE>
<blockquote><code><font color="#000033"><br> crypt 'Praeterea, censeo Carthaginem esse delendam.' &lt; file &gt; file.enc
</font></code></blockquote>
<BLOCKQUOTE>
As always, bug reports, comments, and piles of diamonds are welcome.
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle">
</BLOCKQUOTE>
<p align="center">See attached <tt><a href="../misc/tag/crypt.perl.txt">crypt.perl.txt</a></tt></p>
<BLOCKQUOTE>
Ben Okopnik
</BLOCKQUOTE>
<!-- end 2 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/3"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 3 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>Dependency Hell</H3>
<p><strong>From Andrew
</strong></p>
<p></strong></p>
<p align="right"><strong>Answered By Thomas Adams, Dan Wilder, Heather Stern
</strong></p>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Hello Gang,
</STRONG></P>
<P><STRONG>
Hope you don't minding me milking some knowledge from
you. One thing that has been bugging me for a while now is this.
</STRONG></P>
<P><STRONG>
I am running Redhat 6.1 with a recompiled kernel (2.2.19)..
</STRONG></P>
<P><STRONG>
This is the thing though. There are given programs that i may/do want to
install that need different libraries for them to work. Most of my upgrades
have been via rpm -U scenario (easy to keep track of what is on my system).
</STRONG></P>
<P><STRONG>
I need to install gcc which when i do the following i get this
</STRONG></P>
<pre><strong>[root@echelon /root]# rpm -ivh gcc-2.96-54.i386.rpm
error: failed dependencies:
cpp =3D 2.96 is needed by gcc-2.96-54
</strong></pre>
<P><STRONG>
so then i do this
</STRONG></P>
<pre><strong>[root@echelon /root]# rpm -q cpp
cpp-1.1.2-24
</strong></pre>
<P><STRONG>
so i better upgrade
</STRONG></P>
<pre><strong>[root@echelon /root]# rpm -U cpp-2.96-85.i386.rpm
error: failed dependencies:
libc.so.6(GLIBC_2.2) is needed by cpp-2.96-85
cpp =3D 1.1.2 is needed by egcs-1.1.2-30
cpp =3D 1.1.2 is needed by egcs-objc-1.1.2-30
</strong></pre>
<P><STRONG>
Mmmm i know GLIBC is pretty important so i get the version above &amp; do the
following
</STRONG></P>
<pre><strong>[root@echelon /root]# rpm -q glibc
glibc-2.1.3-22
</strong></pre>
<P><STRONG>
so ok lets upgrade this (or at least try to)
</STRONG></P>
<pre><strong>[root@echelon /root]# rpm -U glibc-2.2-12.i386.rpm
error: failed dependencies:
glibc-common =3D 2.2 is needed by glibc-2.2-12
glibc &gt; 2.1.3 conflicts with db3-3.1.17-4.6x
glibc &gt; 2.1.3 conflicts with rpm-4.0-6x
libdb.so.2 is needed by enlightenment-conf-0.15-9
libdb.so.2 is needed by pan-0.9.1-0_helix_1
libdb.so.2 is needed by ggv-0.95-0_helix_1
libdb.so.2 is needed by pygnome-1.0.53-0_helix_3
[ . . . about 70 more complaints . . . ]
libdb.so.3(GLIBC_2.1) is needed by perl-5.00503-6
libdb.so.3(GLIBC_2.1) is needed by pam-0.72-20.6.x
libdb.so.3(GLIBC_2.1) is needed by php-3.0.18-1.6.x
libdb.so.3(GLIBC_2.1) is needed by sendmail-8.11.0-1
libdb.so.3(GLIBC_2.1) is needed by openldap-1.2.9-6
</strong></pre>
<P><STRONG>
Do you see wehat i am getting at
</STRONG></P>
<P><STRONG>
How would you get around these issues it can become rather frustrating
</STRONG></P>
<P><STRONG>
Any advice on this would be great like always
</STRONG></P>
<P><STRONG>
Thanx guys n girls
</STRONG></P>
<P><STRONG>
Regards
</STRONG></P>
<P><STRONG>
Andrew
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Thomas]
Hi Andrew,
</blockQuote>
<blockQuote>
Yuck!! You have managed to expose one of the more
annoying features that the RPM format
brings....version dependant files.
</blockQuote>
<blockQuote>
Since every package (or nearly every) is linked to
another, you can imagine just how one package may be
needed by another.
</blockQuote>
<blockQuote>
To try and get arounf your problem, you can specify to
install an RPM file without looking for it's
dependencies, thus:
</blockQuote>
<blockquote><code><font color="#000033"><br>rpm -i --nodeps ./rpmfile-version-3.rpm
</font></code></blockquote>
<blockQuote>
But, one caveat with this, is that if you don't
have/install the dependencies, then the program might
not work.
</blockQuote>
<blockQuote>
Hope That Helps
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Dan]
It is a common problem. The common solution is to upgrade the
installation using the upgrade method provided by the
distribution. It may be time for you to upgrade across-the-board to
Redhat 7.1.
</blockQuote>
<blockQuote>
It is possible to upgrade a distribution piecemeal, but it becomes
more difficult (as you have observed) as the number of dependencies
increases.
</blockQuote>
<blockQuote>
The alternative is going off-distribution and building the specific
things you need from source, one at a time. This is more often not
worth the effort.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
Heh. Jim calls this "dependency hell". Every distro has it. <A HREF="http://www.debian.org/">Debian</A>
is pretty good about reducing the number of parts in the puzzle -- about
the time you're looking at upgrading glibc, they call it the next version
name, and a lot of people bust their butts to make the upgrade smooth.
Of course, unless you're using <A HREF="http://www.libranet.com/">LibraNet</A> or something, the install is a
bit rocky...
</blockQuote>
<blockQuote>
For staying with an older distro a bit longer (hey, it's not crashing,
why change it much, right?) my common solution is to remove the offending
rpms, use alien (a perl script) to transform deb files from the equivalent
Debian variant, and then use those to provide the libraries and so on, that
just my app needs. I've used this trick to introduce lynx-ssl to a number
of systems that otherwise only come with a non-SSL version, often a bit old.
</blockQuote>
<blockQuote>
Nonetheless, I agree with Dan -- once you've decided to upgrade glibc, it's
time to take your upgrade seriously, and make a new round of it. Distros
vary widely as to whether it's safer to upgrade or to just install
anew; with a good backup of all your personal files (don't forget odd things
like any tweaks you made to config files in <TT>/etc/</TT> or <TT>/usr/lib</TT>, notes about
hardware you have and need support for, etc.) you can try an upgrade, and
<EM>if</EM> it bombs, <EM>then</EM> install fresh.
</blockQuote>
<!-- end 3 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/4"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 4 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>Is This a Good Book for Linux Programming?</H3>
<p><strong>From Chris Gianakopoulos
</strong></p>
<p></strong></p>
<p align="right"><strong>Answered By John Karns, Faber Fedor
</strong></p>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Hello Gang,
I've mentioned that I am working on an embedded project that will use
Linux as its kernel. As a result, I am learning to write cool software
for the Linux platform.
</STRONG></P>
<P><STRONG>
The type of stuff that I have to do will be fork()s and exec()s (the "s"
indicates lots of <TT> fork()</TT> and <TT> exec()</TT> invocations), IPC stuff, signals (I
know -- that's IPC stuff, too). and pipes. I know that there will be
slight differences (for example, the <TT> spawn()</TT> function), but now for the
question.
</STRONG></P>
<P><STRONG>
There are lots of good guides (and of course, the man pages). I am also
presently reading a book entitled "Advanced Programming in the Unix
Environment" by Stevens.
</STRONG></P>
<P><STRONG>
Will that Stevens book lead me astray? It really is giving me lots of
good insight (what other insight could there be?), so I hope that you
tell me that it is good reading for learning to create complex software
systems in Linux.
</STRONG></P>
<P><STRONG>
Of course, I will read the man pages and guides, and I expect that some
header file may be in different places (I saw slight differences for
network programming).
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [J.Karns]
I've seen that book recommended for Linux programming on a LUG list I
subscribe to. Additionally, this one:
</blockQuote>
<blockQuote><BLOCKQuote>
The Design of the Unix Operating System, Pr. Hall, ISBN-0-13-201799-7
Moris J. Bach
</BLOCKQuote></blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Thanks for the confirmation. I've got the Bach book and read it years
ago. It is my reference for Unix internals.
I will read the Stevens book just for the sport of it since it applies
to my <A HREF="http://www.freebsd.org/">FreeBSD</A> system. I am happy that it also applies to Linux.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
Excellent book, IMO. I was re-reading it Friday night (yes, I need a
life
<IMG SRC="../gx/dennis/smily.gif" ALT=";-)"
height="24" width="20" align="middle"> and still learning new things.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
I claim to have a life -- my peers don't agree with me when I start to
talk about technical stuff. I'm almost finished with chapter 9 -- the
stuff that talks about session leaders and stuff. Soon I read about
signals -- almost like writing interrupt handlers only a little easier.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
I don't do the kind of programming that you do, but I think the
combination of the Stevens book and the kernel documentation
(usr/src/linux/Documentation assuming you've installed the kernel
sources) should do you well
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
It will be not quite like an embedded project. That's what makes it fun
because it will be more like standard Unix programming (which I have not
yet done). I'll have to deal with such issues as do I run various
servers as daemons? What if I want daemon-to-daemon communication -- do
I use named pipes?
</STRONG></P>
<P><STRONG>
As I learn and discover, I will pass this type of information as 2 cent
tips.
</STRONG></P>
<P><STRONG>
Thanks for that info, Fabor. I will keep that Linux Documentation stuff
in my mind. I know that I ramble whenever I talk about this project
that I am working on. Here's why, though.
</STRONG></P>
<P><STRONG>
When I was doing DSP (digital signal processor) programming, I would ask
myself questions like "I wish that I could use DMA for those A/D
samples." Then, I would turn around and discover that the feature
existed.
</STRONG></P>
<P><STRONG>
Linux is the same way. I'm architecting this system as I were designing
hardware to do the job. You want I/O? Use the messaging IPC. That
allows programming language independence with respect to server
implementation. Linux (and Unix) has all of these cool things that
provide for a concurrent implementation of the system.
</STRONG></P>
<P><STRONG>
And that stability. The things that people can do when they work
together!!
</STRONG></P>
<!-- end 4 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/5"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 5 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>What ISPs Do We Use for Linux</H3>
<p><strong>From Chris Gianakopoulos
</strong></p>
<p></strong></p>
<p align="right"><strong>Answered By Dan Wilder, Heather Stern, Thomas Adams, Faber Fedor, John Karns,
Ben Okopnik, Mike Orr
</strong></p>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Hello gang,
I am going to lose my Internet service provider at the end of this year
because they are going to disappear.
</STRONG></P>
<P><STRONG>
I am visiting various web pages for ISPs out there, but, I am clueless
about how to determine their (the ISPs) interoperability with Linux.
</STRONG></P>
<P><STRONG>
For example, I talked to the support staff at www.excelonline.com, and
they said that their ISP service should work with Linux.
</STRONG></P>
<P><STRONG>
I'm not sure what the failure mechanisms are, and I will probably do lots
more surfing of the web so that I can find a suitable replacement for my
current ISP (provided by www.gateway.net).
</STRONG></P>
<P><STRONG>
About Linux Friendly ISPs... What does friendly mean? Does it mean that
standard protocols are used?
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Dan]
The short answer is, "almost any ISP works with Linux, but don't
count on technical support from most of them."
</blockQuote>
<blockQuote>
With most ISPs, you'll have to know how to set up your PPP, dhcp,
whatever, yourself. Increasingly, people are going to DSL and cable,
and you need to watch out for the ones who want you to put the router
or modem inside your box. Some of these are unsupported in Linux.
Better to go with a provider who furnishes an external router or
modem.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
An external modem will be more expensive ($200), but is worth it because
it's "standard". My Cisco 678 connects to an ordinary Ethernet card, and
is configured via telnet or a null-modem cable (minicom/kermit).
(Actually, I could never get the telnet mode to work because I couldn't
figure out the device's IP address on its configuration network. So I
went the minicom way.) The modem is switchable between bridging and
routing. The telco said I have to use bridging mode, so I'm directly on
the ISP's network. The modem converts from Ethernet to DSL, then to ATM,
then back to Ethernet at my ISP. For those that use the telco's own ISP,
I hear they use routing mode over PPP.
</blockQuote>
<blockQuote>
The telcos/cablecos frequently have promotions where you get a free or
discounted modem. And my ISP (oz.net/theriver.com, covering Washington
and Colorado) has deals for ex-Covad customers now that Covad is
bankrupt: free setup and installation for their portion of the fees
and free first and last month. I expect other ISPs have similar deals.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Ben]
By now, it's "you name it, and I've used it." I have not yet run into an
ISP to which I couldn't connect (AOL is neither an ISP _nor_ anything that
I want to connect to; I'd hate to wash my modem out with soap...) I've gone
through, oh, at least a dozen ISPs - in the Bahamas, all over the Caribbean,
in Bermuda, and a number of different ones in the States. Come to think of
it, better make that around two dozen.
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle"> I've used Ethernet, PCMCIA/serial/
USB modems, both wired and radio, and I'm about to try it via a cell phone.
These days, I'm about to drop AT&amp;T, their support policies <EM>and</EM> quality of
service started from egregiously bad and took a sharp downward turn. And
the rates. Blechhh.
</blockQuote>
<blockQuote>
Anyway - trust me: if it's at all possible, Linux has a way to do it.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
Basically, yes. TCP/IP is TCP/IP and even Microsoft Exchange supports
SMTP and POP.
<IMG SRC="../gx/dennis/smily.gif" ALT=":-)"
height="24" width="20" align="middle">
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
[For connectivity itself] most dialup places that speak MSwin-only use PAP.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
Almost all services should work with Linux. Some might be a little more
difficult to deal with than others, but most ISP's today use chap <TT>/</TT> pap
and set things up to be compatible with the default MSW client internet
connection cfg. I have found wvdial to work in almost all cases. Here in
Bogota, virtually all ISP's are using w2k or other MSW platform servers,
with no login scripts, which seem to be a thing of the past - which means
less fuss for you. I have tried at least three different ones over the
past 3 yrs and all have worked. Although sometimes (not too often) I have
to try dialing more than once to get a connection due to PAP
authentication gotcha's; but I tend to think that it's more an issue of
telecommunications complications than anything else.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
PAP and CHAP authentication are conceptually similar to an ssh login
without a password prompt. It does send a login and password, but this
is part of the built-in handshaking process rather than something you
have to script. To troubleshoot, set PPP to debugging mode and watch
the handshake strings and error messages. I haven't used pppd for years,
but the most frequent errors I used to get were the one about the line
not being 8-bit clean (you have to escape more special characters), or
the mysterious "serial line loops back" or whatever, meaning it tries to
contact the remote host but reaches itself; I think that means some
client/server switch is wrong.
</blockQuote>
<blockQuote>
As they say, Microsoft loves industry standards so much that it never
saw a protocol it didn't embrace and extend. NT4 had PAP and CHAP, but
it was "Microsoft PAP and CHAP". pppd users had to install a patch,
which eventually made its way into the standard package. Each version
of NT/Win2000/WinXP may introduce similar subtleties.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
That's interesting (but not the least bit surprising) - I wasn't aware of
that.
</STRONG></P>
<P><STRONG>
Cool -- I partly understand things.
I noticed that my new ISP uses PAP. My (soon to be) previous ISP uses
CHAP.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
As Dan pointed out, just about any ISP will suffice, just don't expect
any technical support. If you do require technical support, be
preparedto switch over to Windows for the duration of the phone call.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
That's cool. I can live without the support --
It's more fun figuring things out myself (and with your
help -- of course).
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
I have found that either wvdial or xisp or (there's a k toy, is it kisp?
kdial? oh well, it was on freshmeat somewhere) work slightly differently,
so if one doesn't work for you try the others before even starting to stress
out. Jim does dialup. I haven't had to in years, though I can trouble
shoot a raw PPP connection if I really have to.
</blockQuote>
<blockQuote>
Between freshmeat and the debian packages listing there are so many
front-ends trying to make it easy to do dialup, it's hard to just pick one
to use
<IMG SRC="../gx/dennis/smily.gif" ALT=";P"
height="24" width="20" align="middle">
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
That's true. Sometimes, I feel more comfortable doing it the "hard"
way, just so I know how to set up the various ppp scripts. For my
<A HREF="http://www.freebsd.org/">FreeBSD</A> machine, I have two alternatives. I can use the pppd (our
daemon), or I can use a program called ppp (a user space process). The
latter is pretty cool, because, by turning on ip forwarding (with the
sysctl command), and passing "-nat" to the ppp program, I get ip
masquerading.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
An important part of the issue might be to tell them that you're running
Linux, and ask if they would have a problem providing answers to you
regarding such a platform. If they turn up their nose at you, look
elsewhere. I would maybe ask them what platform they are using for their
operation, and look for one which is using a *nix <TT>/</TT> non-MSW platform.
</blockQuote>
<blockQuote>
There should be a number of ISP's that (still) fit this category.
Another reason I would tend to avoid the MSW people would be that I would
assume the *nix people might be a little more savvy technically speaking,
as setting up a w2k <TT>/</TT> or NT box may done with a few mouse clicks - ok
maybe several.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Or does it mean that a bunch of advertising
stuff does not clog your display window when using, for example, Netscape?
</STRONG></P>
<P><STRONG>
For example, a friend told me that when you use America Online, you need
their special browser to interact with them. I thought that all browsers
used http over TCP for the communications mechanism.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
AOL is a proprietary network, with proprietary protocols. IMNSHO, AOL is
not an ISP (in terms of a center that whose primary purpose is to let
you gain access to the Internet) but a private networks which,
coincidentally, you can access the Internet through.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Now I see why this is so. ISPs I sort of understand. AOL, I did not
understand (since I do not see their protocols in the textbooks that I
read).
</STRONG></P>
<P><STRONG>
As far as email is concerned, I thought that POP and SMTP would be
supported by each and every ISP (possibly a misconception on my part).
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
Every regular ISP supports POP. Some may try to steer you toward IMAP
instead of POP because it's more "advanced". Of course, if you don't
need IMAP's features (which allow complex operations on messages stored
on the server, rather than downloading them to your PC and reading them
there), POP works just fine.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
As longas it's not a proprietary network like AOL or Delphi (is that one
still around? What about Bix?), then you should be okay. But check
with the ISP JIC.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Very cool! I just tried an experiment using a friend's ISP account with
the provider that I was interested in (with the friend's permission of
course, and we were not simultaneously using the service), and it works!
It was just a connectivity experiment -- not one to rob somebody's
bandwidth.
</STRONG></P>
<P><STRONG>
So, my goals were to discover if ISPs are somewhat generic in their
behaviors (it seemed logical that they should be). Thanks to your
responses, and my experiment, I am now confident to proceed.
</STRONG></P>
<P><STRONG>
If a few of you could respond to the question "Which dialup ISP do you use
with your Linux system", that would be cool. I'll go ahead and read the
HOWTOs and figure out all of that chap-secrets stuff and make it work for
my <A HREF="http://www.suse.com/">SuSE</A> Linux distribution.
</STRONG></P>
<P><STRONG>
I guess that I am sort of lost because I am not getting the information
that I want from the various ISP sites (due to my ignorance of course).
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Dan]
You didn't mention where you were.
</blockQuote>
<p>
... Not that this kept most of the Gang from jumping in, nor
that the results might not also be useful to you, dear readers ...
</p>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
How silly of me, Dan. I forgot to mention that I am in the Chicago, IL
area. Thanks for the ultra quick reply. I just tried an experiment with
www.excelonline.com using my sister-in-law's login using my FreeBSD
machine as a router. Therefore this particular ISP works with FreeBSD's
ppp user space program. Linux should be free sailing -- I expect.
</STRONG></P>
<P><STRONG>
I gotta log off because the use of her ISP account (with her permission,
of course -- she's sitting next to me) was only for experimental purposes.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
With a *nix acc't you might want to look for an ISP which offers
shell accounts. It's nice to be able to log in and read mail from their
server if need be, or place a .forward file to have your mail temporarily
forwarded somewhere else if you plan to travel to where there will be a
local email account available.
</blockQuote>
<blockQuote>
And, there might be more reliability with an ISP using a *nix-based
box. :-0
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
Good luck. Most ISPs consider shell accounts a security risk, generator of
most of their tech-support calls ("Can you install/upgrade this
mailreader/newsreader/ compiler/library?"), and not a marketing priority
(because most of their customers wouldn't know what to do with a shell
account if it bit them).
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
No doubt the shell acc'ts are rarer today than a few years ago. I admit
that I haven't shopped for an ISP shell acc't for about 3 years; but at
that time I did come across a few. Also, my Colorado ISP acc't which I've
had since about 1995 is still a shell acc't. They use a kerberos'd DEC
ultrix.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Dan]
In the Seattle area, where our offices are located, we have a number
of Linux-supportive ISPs, such as blarg.net, eskimo.com, serv.net,
zipcon.net, oz.net, speakeasy.net, and others to whom I no doubt do
an unjustice by not listing here. Some of these providers have points of
presence in other cities.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
My provider, Idiom.com, offers dialup. It's S.F regional and spreading, but
I don't think it's nationwide quite yet. The owner is a big BSD fan so it's
all free software under the hood, and an all-digital internal backbone. It
may be more expensive than others, but we like getting our DSL from someone
we can trust - not like those PacBell bozos...
</blockQuote>
<blockQuote>
For Jim and I, Idiom's dialup is mainly a backup for if we are out of town,
but it's still handy.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Thomas]
Hello. That is a shame that Gateway are cutting their
ties with providing Intenet Access. I know of a few
ISP's in the UK that are Linux "friendly":
</blockQuote>
<blockquote><pre>www.uklinux.net
www.f9.net.uk
www.vigin.net
</pre></blockquote>
<blockQuote>
All offer PPP support allowing you to dial in.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
I did find a good ISP. At least the tech support staff answered their
phone during a Saturday morning and afternoon. When I asked them if it
took 25 minutes to service my phone call because of their heavy service
load, they told me that there is only a few people around their on
weekends. I suspected something like that. I almost gave up waiting,
but, I decided to give them a fair shake (on the belief that they were
real busy). It was worth the wait! When I asked them if they knew if
their system would play well with Linux, they told me that they would
help me if I had any problems. They the fellow said "We're just a bunch
of computer geeks hanging around here" (or something like that). I saw
their coolness (I'm somewhat of a geek too), and decided to give their
site a try. They have a good staff at www.excel.com.
</STRONG></P>
<P><STRONG>
As things went, I had no problems setting things up on my FreeBSD
machine (using user-space ppp) and no problems using Linux (using
wvdial).
</STRONG></P>
<P><STRONG>
I'm rereading the HOWTO that
talks about ip masquerading for Linux, because I do tend to give my
FreeBSD machine and Linux machines equal treatment. It's making sense
now...
</STRONG></P>
<P><STRONG>
Thanks much to all of you that answered! You all, once again,
increased my confidence in this stuff. This is just like engineering --
lots of successes and lots of time me being humbled. There's always
something to learn in this protocol world (and Linux world). That's
what makes it so much fun.
</STRONG></P>
<P><STRONG>
Chris Gianakopoulos
</STRONG></P>
<!-- end 5 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/6"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 6 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>How to let the world find your Linux Server when using DHCP</H3>
<p><strong>From Jason Bailey
</strong></p>
<p align="right"><strong>Answered By
<p></strong></p>
<h4 align="center"><br> Abstract
</h4>
<BLOCKQUOTE>
Many of us have broadband connecting our Linux machines to the
Internet and would like to play around with our own webservers, but
for a variety of reasons are unable to get a static address. This
article should help you with publishing your Linux server's current
IP address to an ISP's web server.
</BLOCKQUOTE>
<h4 align="center"><br> Introduction
</h4>
<BLOCKQUOTE>
I've wanted to have my own web server for many years. Partly because
I'm a geek who has a need to do things just because I can. But more
importantly, I've wanted to do it because many ISPs don't let you
play with cool stuff like databases, perl, php, python, etc.
</BLOCKQUOTE>
<BLOCKQUOTE>
So what's the big deal? You say. Set up a Linux box and you are good
to go. Well, it is that easy if you don 't care about sharing this
website with anybody else. My ISP won't give me a static IP for my
cable modem. So I thought, what if I could create a webpage on my
ISP's web server which would point to my web server? The game was
afoot! I began searching google.com and pestering the members of my
LUG (Linux Users Group) for ideas.
</BLOCKQUOTE>
<BLOCKQUOTE>
One of the most helpful articles I found was written for Linux
Gazette several years ago by Henry H Lu. I have followed a lot of
his basic ideas, though I have reduced the number of files used and
I've standardized on shell script as opposed to using both shell
script and perl. Henry does have a nice example of how to make the
FTP portion work with Geocities if you happen to be using them.
</BLOCKQUOTE>
<h4 align="center"><br> Automating FTP
</h4>
<BLOCKQUOTE>
The file transfer protocol client interaction can be a bit difficult
to script if you are having to wait for prompts for username and
password. One way around these prompts is to use the .netrc file.
The layout for the file would be as follows:
</BLOCKQUOTE>
<BLOCKQUOTE><BLOCKQuote>
machine www.MyISP.com login JoeUser password Top$ecret
</BLOCKQuote></BLOCKQUOTE>
<BLOCKQUOTE>
Please note that you must change this file to read/write owner only
when you create it. For more information about the .netrc file and
its uses do a man netrc at you command prompt.
</BLOCKQUOTE>
<h4 align="center"><br> HTML File Template
</h4>
<BLOCKQUOTE>
I found that the easiest way to do this was create an HTML file
which has a placeholder everywhere I want the IP address to go. I
chose "~~~IP~~~" to be my placeholder since it stands out and I'd
never have it appear anywhere else in my document. The following is
an example of what you might use.
</BLOCKQUOTE>
<p align="center">See attached <tt><a href="../misc/tag/up.html_source.txt">up.html_source.txt</a></tt></p>
<h4 align="center"><br> The Shell Script
</h4>
<BLOCKQUOTE>
I'll first show the script and then explain what each part does.
</BLOCKQUOTE>
<p align="center">See attached <tt><a href="../misc/tag/dhcp-myip.sh.txt">dhcp-myip.sh.txt</a></tt></p>
<BLOCKQUOTE>
First, we find the IP address using ifconfig on our WAN device (depending on
your setup it may be eth0, ppp0, etc)
and parse out all information we do not want. If you are not sure if you are
using eth0, eth1, ppp0, ppp1, etc you can
type ifconfig to see which devices you are currently running and look for the
</BLOCKQUOTE>
<BLOCKQUOTE>
one with a valid Internet IP address.
</BLOCKQUOTE>
<BLOCKQUOTE>
We save the IP address in the variable MyIP and in an ASCII file. Then we com
pare a file that contains the
current IP address and one that contains the IP address which we had the last
</BLOCKQUOTE>
<BLOCKQUOTE><BLOCKQUOTE><CODE>
time the script ran. If these two
</CODE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE>
addresses are the same we are done. If they are different, we use take our up
.html_source file and replace ~~~IP~~~
with our current IP and store the results in up.html. Next we FTP th
e file
to our ISP. Finally, we copy our current IP to "MyIP.then" for future referen
ce.
</BLOCKQUOTE>
<BLOCKQUOTE>
Make sure you do a chmod +x to the script after you save it.
</BLOCKQUOTE>
<h4 align="center"><br> Repeating the Process
</h4>
<BLOCKQUOTE>
After you have tested out the script, you'll probably want to have it run eve
ry five to fifteen minutes. You can easily to this
by adding a cron job. It is important that you run the cron job as the user w
ho has the files in his home directory and has the
FTP server information in his .netrc file.
</BLOCKQUOTE>
<h4 align="center"><br> Conclusion
</h4>
<BLOCKQUOTE>
If you want to make your web server, which is on a dynamic IP address, easily
</BLOCKQUOTE>
<BLOCKQUOTE>
found by your friends and other. This script can
</BLOCKQUOTE>
<BLOCKQUOTE>
make it as easy for them to find your home server as going to <A HREF="http://www.MyIS"
>http://www.MyIS</A>
P.com/~JoeUser/ip.html. The scripts are easy
to reconfigure to suite your needs. My next step is to write a PHP script tha
t will ping my IP address and if it gets a
response it would send you to the server. If no response was received, it wou
ld give a page that explains that the site it
down. I hope you find this as useful and fun as I did.
</BLOCKQUOTE>
<BLOCKQUOTE>
Jason Bailey
</BLOCKQUOTE>
<HR width="10%" align="left"><BLOCKQUOTE>
When I'm not at work doing system admin stuff, at school pursuing my Computer Science degree, at a Susitna Linux Users Group meeting or off doing freelance computer work, you can find me hanging out in beautiful Palmer, Alaska with my wife and kids.
</BLOCKQUOTE>
<!-- end 6 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/7"><HR WIDTH="75%" ALIGN="center"></A>
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>trouble w/ dual boot</H3>
<p><strong>From Jeferson
</strong></p>
<p></strong></p>
<p align="right"><strong>Answered By Mike Orr, Heather Stern, John Karns
</strong></p>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
&lt;html&gt;&lt;head&gt;&lt;meta http-equiv='content-type' content='text/html;'&gt;
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
Aaaaargh
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle"> allow me to quote my favorite wimpy, but totally virus proof
mailer --
</blockQuote>
<blockQuote>
[text/html is unsupported, treating like TEXT/PLAIN]
</blockQuote>
<blockQuote>
(somewhat after the fact, I note that there can be good reasons to do
this - foreign character sets maybe - but leave plaintext plain, okay?)
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Hey guys, how r ya doing huh ?
</STRONG></P>
<P><STRONG>
I'm having a little problem here with my OS, I've installed
Conectiva Linux in the Master HD and I had the MS windows installed
ins the Maste Slave hd, what can I do to have a graphical interface
or even an easier way to boot in the system, without having to go
to the system setup and change the boot order ...
</STRONG></P>
<P><STRONG>
Can ya help me ???
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
Have you looked at the HOWTOs at www.linuxdoc.org?
<A HREF="http://www.linuxdoc.org/HOWTO/HOWTO-INDEX/howtos.html"
>http://www.linuxdoc.org/HOWTO/HOWTO-INDEX/howtos.html</A>
Search for "Windows" and "Win" in the text. There are several HOWTOs
about making Linux coexist with Windows.
</blockQuote>
<blockQuote>
Also poke around www.linuxnewbie.org for other information you might
find useful.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
I've already looked at the HOW-TOs and my problem is a bit different, there
is any way I can manage the boot, like... now I want to boot with Win32, I
just reboot the pc and choose MSWIN, later I'll be in a mood to boot with
Linux, then I reboot the system and choose LINUX, I've already tryied with
"system commander", the Grub... wait a second, isn't grub a graphical
interface for the LILO ? how can I change the configurations of the lilo,
where is it's configuration file?
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
<TT>/etc/lilo.conf</TT> is a text file that <TT>/sbin/lilo</TT> (a progam) uses to compose
LILO (the boot loader). It's usually quite well documented in <TT>/usr/share/doc</TT>
somewhere, in a directory named either lilo, or lilo with a version number.
And in 'man lilo' plus those HOWTOs that Mike mentioned.
</blockQuote>
<blockQuote>
grub is not a GUI for LILO particularly; it's a boot loader in its own right.
But you can use it to point at LILO as a second stage if you want.
</blockQuote>
<blockQuote>
GAG, the initials are for the spanish words of "Graphical Boot Manager",
is an entirely GUI bootloader, and it <EM>is</EM> its own configurator
- that sounds a bit more like what you are really asking for.
The link's quite slow for me but might be a bit closer to your ISP there
in Brazil:
</blockQuote>
<blockQuote><BLOCKQuote>
<A HREF="http://www.rastersoft.com/gageng.htm"
>http://www.rastersoft.com/gageng.htm</A>
</BLOCKQuote></blockQuote>
<blockQuote>
Gujin is another alternative bootloader, it's supposed to be smart enough
to look for bootable drives or kernels on its own, so it doesn't need setup:
</blockQuote>
<blockQuote><BLOCKQuote>
<A HREF="http://gujin.sourceforge.net"
>http://gujin.sourceforge.net</A>
</BLOCKQuote></blockQuote>
<blockQuote>
But if I misinterpreted what you want, there are GUI tools which run
under X to help you set up <TT>/etc/lilo.conf</TT> - among them Glilo (GTK), Klilo,
lilo-config, or BootRip.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
Also, later versions of lilo have a gui-like interface which offer a menu
with a 'point &amp; shoot' menu-bar. BTW, even the older lilo versions offer
a "menu" of sorts, if you press the '?' key at the boot prompt, which will
display a list of available choices; although you still have type the
selection rather than "point &amp; shoot". Even this can be minimized by
using a short label in your lilo.conf:
</blockQuote>
<p align="center">See attached <tt><a href="../misc/tag/jkarns.lilo.txt">jkarns.lilo.txt</a></tt></p>
<blockQuote>
If your machine is fast enough and has ample memory, you might also
consider installing VMWare, and avoid having to reboot. Although if
you're a gamer, it might not offer what you want. Anyway, they are
offering an "express" version for $50, which isn't so expensive. I've
been very happy with the software, but it's running on a 700 Mhz machine
with 128 MB of RAM. Even w2k runs fast enough to be satisfactory. I also
purchased a copy to run on a 500 Mhz <TT>/</TT> SCSI machine which is a bit slower,
but still tolerable. A 380 Mhz <TT>/</TT> IDE <TT>/</TT> 64 MB machine is also usable, but
a bit too slow to be pleasureable.
</blockQuote>
<blockQuote>
There are other products available both commercial (e.g., Win4Lin) and GPL
(Wine). Re: wine, it is indeed a formidable task to emulate an entire API
on a foreign OS. They deserve lots of credit for getting as far as they
have, but it's still alpha. I haven't looked at Win4Lin so can't comment,
except to say that I believe that VMWare is the most mature product in
this venue. BTW, they also offer a version for w2k <TT>/</TT> NT to host Linux,
but since I think that Linux is the more stable OS, it seems a better idea
to use Linux as the host
<IMG SRC="../gx/dennis/smily.gif" ALT="=:&lt;)"
height="24" width="20" align="middle">
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
Well if he <EM>is</EM> a gamer, I really think he ought to look at Transgaming
(<A HREF="http://www.transgaming.com"
>http://www.transgaming.com</A>)
and see if their <A HREF="http://www.winehq.com/">WINE</A> + ActiveX solution works for his games. I saw a demo
at LWE and it ran Diablo for MSwin directly; I was impressed.
</blockQuote>
<blockQuote>
Lilo also supports a value called "alias" and if you make it a single
character then you can even get one-tap loading. Here's about the
simplest example that works -- assuming you have the world's plainest
configuration, basically, C: at the start, "all one big slash" for the
second partition with a linux kernel named "vmlinuz" at its root,
your swap partition invisible at the end, and no framebuffers or other
hardware oddities requiring an "append=" line. <TT>/vmlinuz</TT> could be a symlink
to wherever you really keep your kernels, if you prefer.
</blockQuote>
<blockquote><pre>boot=/dev/hda2
single-key
image = /vmlinuz
label = linux
alias = 1
other = /dev/hda1
label = dos
alias = 2
</pre></blockquote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
PS: Sorry about the HTML
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
That's okay, now you know
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle">
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
</STRONG></P>
<P><STRONG>
Thankx
<br>Jeferson
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
You're welcome
</blockQuote>
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<A NAME="tag/8"><HR WIDTH="75%" ALIGN="center"></A>
<!-- begin 1 -->
<H3 align="left"><img src="../gx/dennis/qbubble.gif"
height="50" width="60" alt="(?) " border="0"
>HOWTO find a good laptop</H3>
<p><strong>From William Thornton
</strong></p>
<p></strong></p>
<p align="right"><strong>Answered By Heather Stern, Faber Fedor, John Karns, Mike Orr
</strong></p>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Just wondering if you can point me to any good web resources on what
laptop hardware is currently supported under linux. What I've been able
to find are how-to's (as in how to install linux on a laptop. And these
seem to be out of date. You can't even buy the models listed anymore.)
Any help would be greatly appreciated. Thanks.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
One of the originals - and most extensive - was Kenneth Harker's
"Linux on Laptops".
</blockQuote>
<blockQuote>
It was at utexas.edu, but that URL has since changed, and unfortunately
I don't have the updated one.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Faber]
</blockQuote>
<blockQuote><ul>
<LI>Go to <A HREF="http://www.google.com"
>http://www.google.com</A>.
<LI>Type "linux laptops" in the search field.
<LI>Click on the first link.
</ol></blockQuote>
<blockQuote>
For those of you watching at home, the link is, of course...
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
... Kenneth Harker's site full of links to personal testimony
and other resources:
<A HREF="http://www.linux-laptop.net"
>http://www.linux-laptop.net</A>
</blockQuote>
<blockQuote><DL><DT>
Or Werner Hauser's Mobilix:
<DD><A HREF="http://www.mobilix.org"
>http://www.mobilix.org</A>
</DL></blockQuote>
<blockQuote>
Alternatively you could cheat, and buy a laptop from a vendor that sells
laptops pre-loaded with Linux...
</blockQuote>
<blockQuote>
Distros have gotten better about being able to be installed on a laptop;
the rise of laptops with accessible CD bays has helped a lot too.
</blockQuote>
<blockQuote>
The important thing to know is that you should consider your parts of
hardware <EM>individually</EM> when looking at buying a laptop. Model names and
numbers themselves are immaterial, except that those may make it easier
to find fellow users of the same hardware. Yes, the same real manufacturers
sell through many vendors, with the exception of a few giants like Sony and
IBM that build their own stuff.
</blockQuote>
<blockQuote>
USB
</blockQuote>
<blockQuote>
pretty much no problem. The command 'lspci' can tell you if you have UHCI or OHCI,
then you can load up the right one and rock on.
</blockQuote>
<blockQuote>
Infrared
</blockQuote>
<blockQuote>
Find out what chipset it has (this is harder than it looks, just
"fast" doesn't cut it). Linux supports several but to get Fast IR
you need to know which kind, and it needs to be one of the small
handful we handle. Mobilix has good info.
</blockQuote>
<blockQuote>
Mouse
</blockQuote>
<blockQuote>
luckily most mice are just PS/2; there are a few synaptics style
touchpads out there, that have a PS/2 compatible mode anyway. Those
"jogdial" things Sony has need a special program, but we have one.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
... and now those of the USB variety are available. I have been using one
for the past few months, since I purchased a Dell Inspiron. This allows
using an external keyboard which helps to make the laptop a better
replacement for a desktop. That way I can use both an external mouse and
keyboard, and still have the serial port free for an external modem should
I choose to use one.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
Video card
</blockQuote>
<blockQuote>
If you're planning to slash the bleeding edge, you really have to
be sure on this one. It's one of the parts you cannot easily
replace! Note that some manufacturers throw their own cheap X
servers together - check into them further and see if they are
going the XFCOM route (which eventually leads to the source being
merged with XFree, when the card is yesterday's news) or staying
proprietary. And whether they need a kernel module to support GL
and/or acceleration. (hey, that'd be sweet. But I wouldn't bet
on finding that.) If you're a gamer, check if the video has proper
texturing support. Many don't.
</blockQuote>
<blockQuote>
Also, X 4.1 is getting there, but there still might be a few cards
better supported under X 3.3.6.
</blockQuote>
<blockQuote><DL><DT>
Driver Status for XFree86[tm] 4.1.0
<DD><A HREF="http://www.xfree86.org/4.1.0/Status.html"
>http://www.xfree86.org/4.1.0/Status.html</A>
</DL></blockQuote>
<blockQuote>
For libvga I always recommend trying the VESA setting before giving
up. And setting the VesaSave value to a different number can help
solve if it's coming out with a text mode that puts your cursor below
the screen
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle">
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
I had a rough time with the Inspiron - the only way I could get X to work
was by DL'ing the XF86Config file from the mfr's Internet site; and I have
yet to get it to work for other resolutions than 1400 x 1050. Even though
they offer several to cover various resolutions, they did a very poor job
- some were just duplicates under different names.
</blockQuote>
<blockQuote>
Be careful of the ATI r128 chip series. There are around 10 different
variations of that chip, designated as r128 SM, r128 RE, etc., and they
are not compatible; so check the X docs to verify that the chip is
supported - or better yet verify that the chip is indeed the same as one
of the models mentioned on one of the Linux laptop sites, i.e. that it
has not been changed by the mfr for the currently shipping models.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
ATI is actually rather infamous in the community for generating
new troubles with every minor BIOS and circuitboard revision.
That problem is not at all limited to laptops
<IMG SRC="../gx/dennis/unsmily.gif" ALT=":("
height="24" width="20" align="middle">
</blockQuote>
<blockQuote>
Your monitor
</blockQuote>
<blockQuote>
Sounds odd, but yes, this needs to be considered seperately.
</blockQuote>
<blockQuote>
Try to get X modelines from someone else who has the same screen.
They don't need to be from the same distro, and in fact, you can
steal modelines from an XF86Config that's meant for version 3 and
use them on version 4 just fine. You <EM>cannot</EM> steal the whole file
and use it though - the format has changed a bit. Put your modelines
in the Monitor section, in either case.
</blockQuote>
<blockQuote>
Sound
</blockQuote>
<blockQuote>
You actually have a pretty good chance here. So far lspci has always
been good for me at coughing up what chipset the sound is, and after
that it's easy to look up. (This doesn't work on older models that
have ISA sound, but you're talking about new machines here.) The
important tidbit is, there are three different ways to get sound
support working, and you only need one of them to work. In order of
preference, it can be a normal kernel module, the ALSA project
probably has drivers for you, or you can use OSS. <A HREF="http://www.suse.com/">SuSE</A> makes sound
setup easy. Your distro may vary.
</blockQuote>
<blockQuote>
<A HREF="http://www.alsa-project.org"
>http://www.alsa-project.org</A>
</blockQuote>
<blockQuote>
Ethernet
</blockQuote>
<blockQuote>
Usually isn't much of a problem. lspci should tell you what it is,
then just load the right module. In fact lspci is usually better
than the box for telling what's in it; many manufacturers are
licensing chipsets these days.
</blockQuote>
<blockQuote>
If you have a builtin modem...
</blockQuote>
<blockQuote>
Ouch. Most of these are winmodems, er, 'scuse me, "controllerless".
In other words they are born missing one or two of the three core
chips that make a real modem work. For anyone who's been under a
rock for the last few years, that means that they are "easily
upgradable" but also cheap and prone to breaking down under heavy
CPU load.
</blockQuote>
<blockQuote>
I list the ones mentioned at linmodems.org here, because many of
the projects have moved recently. The linmodems links still work
too.
</blockQuote>
<blockQuote>
Don't be afraid to buy a PCMCIA card to replace these. Nobody
will blame you. But <EM>do</EM> check the resources at linmodems before
buying a card - some folks have been burned by PCMCIA softmodems,
those pretty much don't work for us.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
In my case, I had to DL the pcmcia pkg from the 'net and install it
separately after installing SuSE 7.1 due to a quirk with the newer TI
PCI4451 PC card Cardbus Controller chip that the machine uses. Trying to
use the SuSE packaged version would hang the machine. This was explained
in one of the pages about my machine referenced from the harker site.
</blockQuote>
<blockQuote>
Also, one can check the docs that are pkg'd with the pcmcia stand-alone
pkg. There has in the past been a document included which lists the cards
known to work, with the caveat that card mfr's sometimes change the chips
inside the cards without changing the model designation - it's rare but
not unheard of, so you can find yourself with a card that doesn't work,
even though it's on the compatible list. I've had pretty good luck with
Xircom in the past - a CEM33/10 and a CEM56/100 which both have a full
modem implementation rather than a winmodem (the only people who 'win' are
the mfr and Microsoft
<IMG SRC="../gx/dennis/unsmily.gif" ALT=":-("
height="24" width="20" align="middle"> ).
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
</blockQuote>
<blockQuote><ul>
<LI>IBM Mwave works fine, they have a GPL'd project.
<A HREF="http://www-124.ibm.com/acpmodem"
>http://www-124.ibm.com/acpmodem</A>
<LI>Intel's HaM driver seems to have a BSDish license (yes, with source).
<A HREF="http://developer.intel.com/design/modems/support/license/r-333-5.htm"
>http://developer.intel.com/design/modems/support/license/r-333-5.htm</A>
<LI>For Motorola's SM56 they have shut down making softmodems, but still
provide the driver. They built it under RH 7.1 so use a 2.4 kernel.
You can consider this modem doomed, since it's a binary driver and
Linus has long since stated that binary only drivers will be allowed
to break and no kernel developer will ever cry a tear about it.
<A HREF="http://e-www.motorola.com/products/softmodem/support/software.html"
>http://e-www.motorola.com/products/softmodem/support/software.html</A>
<LI>Lucent's Microelectronics Group has been spun off to be called
Agere Systems, and they have a page with sources now, as well as
pointers to packages for a handful of distros. Use this for anything
calling itself an LTmodem, which may include some Xircoms. There are
also other projects playing with LTmodems as their target hardware (see
the linmodems page), so you have more than one thing to try too. At
least this modem will work.
<A HREF="http://www.physcip.uni-stuttgart.de/heby/ltmodem"
>http://www.physcip.uni-stuttgart.de/heby/ltmodem</A>
</ul></blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
These are perhaps the most ubiquitous of winmodems, and some say offer the
best chance of working under Linux.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
</blockQuote>
<blockQuote><ul>
<LI>PCTel's modem drivers have no source but they seem to be keeping
up via an unofficial site managed by Jan Stifter.
<A HREF="http://www.medres.ch/~jstifter/linux/pctel.html"
>http://www.medres.ch/~jstifter/linux/pctel.html</A>
<LI>Conexant used to be hopeless but some French company named Olitec came
up with something anyway. Binary, of course. And only for a few 2.2.x
kernels, no sign of a 2.4.x version. Sigh. (site in French)
<A HREF="http://www.olitec.com/pci56kv2.html"
>http://www.olitec.com/pci56kv2.html</A>
<LI>The linmodems page has drivers for the ESS and Ambient Tech chipsets.
<LI>3com/USR softmodems, as of this writing, are hopeless. I checked 3com's
site but it's painful to wander around in.
</ul></blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
Dell was shipping two versions which they were designating as mini-pci
3com ether combo cards. The one that was shipped in my machine is known
under the name of Actiontel, and has an LTModem paired with an Intel
eepro-100 ethernet chip - luckily for me both components are Linux
compatible; probably because they were offering machines pre-installed
with Linux. They have since changed their policy and are no longer
offering pre-installed Linux, except on their servers. Consequently they
are now shipping one of the modem chips mentioned above, which people
don't seem to having much luck with, and many have bought a pcmcia card to
use instead. However, there are two items of interest in this regard,
IMO:
</blockQuote>
<blockQuote><ol>
<LI>many of the pcmcia cards seem to run quite warm, even hot - especially
the ether / modem combos cards, which adds extra heat to your laptop, and
also means more battery drain.
<LI>many laptops are implementing the ether / modem combo cards for the
mini-pci slot connector which is also being offered on many desktop style
mobos. This connector very much resembles the one used for the type of
memory module (so)dimms currently being used. Thus if desired it is
possible to purchase one of these from an after market 3rd party and
replace an incompatible card with one that is Linux compatible.
</ol></blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
Did I miss anything?
</blockQuote>
<blockQuote>
Oh, probably. But if you have a feature listed that you're
wondering about, try Google! Linux (<A HREF="http://www.google.com/linux"
>http://www.google.com/linux</A>
- and do NOT put a slash on the end) and type in the buzzword
or chipset. Chances are good you'll find something on it.
</blockQuote>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [John]
... not too much!
</blockQuote>
<blockQuote>
Just one more thing. We need to make the hardware co's more Linux
cognizant. Be sure to mention that you're buying the machine because you
have reason to believe that it is Linux compatible, and if it wasn't you
wouldn't be purchasing from them! Also mention any items that you know
not to be compatible, such as the winmodem. Express your interest that
they consider increasing their Linux support in the future.
</blockQuote>
<P><STRONG>
<IMG SRC="../gx/dennis/qbub.gif" ALT="(?)"
HEIGHT="28" WIDTH="50" BORDER="0"
>
Wow! I thought I MIGHT get one answer to my question. Instead I get
three very good answers. The info at linux-laptops.net seems to be
much more up to date than what I'd been finding.
</STRONG></P>
<P><STRONG>
Thanks! I should be pretty well armed with info
for my next trip to the computer store.
</STRONG></P>
<blockQuote>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
Thanks for the encouragement.
</blockQuote>
<!-- end 8 -->
<P> <hr> </p>
<!-- *** BEGIN copyright *** -->
<H5 align="center">This page edited and maintained by the Editors
of <I>Linux Gazette</I>
<a href="http://www.linuxgazette.com/copying.html"
>Copyright &copy;</a> 2001
<BR>Published in issue 71 of <I>Linux Gazette</I> October 2001</H5>
<H6 ALIGN="center">HTML script maintained by
<A HREF="mailto:star@starshine.org">Heather Stern</a> of
Starshine Technical Services,
<A HREF="http://www.starshine.org/">http://www.starshine.org/</A>
</H6>
<!-- *** END copyright *** -->
<center>
<H1><A NAME="tips"><IMG ALIGN=MIDDLE ALT="" SRC="../gx/twocent.jpg">
More 2&cent; Tips!</A></H1> <BR>
<!-- BEGIN tips -->
Send Linux Tips and Tricks to <A HREF="mailto:linux-questions-only@ssc.com">linux-questions-only@ssc.com</A></center>
</center>
<UL>
<!-- index_text begins -->
<li>Tech tips from
<A HREF="http://noframes.linuxjournal.com/subscribe/lja-sub.html"
><I>Linux Journal's</I> Weekly News Notes</A>
<ul>
<li><A HREF="#tips/0a">Private domains</a>
<li><A HREF="#tips/0b">On-line dictionary</a>
<li><A HREF="#tips/0c">Telnet via http</a>
<li><A HREF="#tips/0d">Changing the title bar on an xterm</a>
<li><A HREF="#tips/0e">Running BIND as non-root</a>
<li><A HREF="#tips/0f">HTML Tidy</a>
<li><A HREF="#tips/0g">Moving Internet services among servers</a>
</ul>
<li><A HREF="#tips/1"
><strong>sendmail 2c TIP * 2</strong></a>
<li><A HREF="#tips/2"
><strong>About Converting Image Files</strong></a>
<li><A HREF="#tips/3"
><strong>While in hack mode...</strong></a>
<li><A HREF="#tips/4"
><strong>xshowrgb (xcolorsel replacement)</strong></a>
<li><A HREF="#tips/5"
><strong>re: kernel compilation error in issue 70</strong></a>
<li><A HREF="#tips/6"
><strong>Tarpit</strong></a>
<li><A HREF="#tips/7"
><strong>Monitoring log files in real time</strong></a>
<li><A HREF="#tips/8"
><strong>HSP Micromodem</strong></a>
<li><A HREF="#tips/9"
><strong>Query about Makefile</strong></a>
<li><A HREF="#tips/10"
><strong>Re: linux signwriting programs</strong></a>
<!-- index_text ends -->
</UL>
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/0"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">LJ Tech Tips</FONT></H3>
September 2001
<h4 align="center"><a name="tips/0a">Private domains</a></h4>
<P>
If you give an example hostname in documentation or as part of your
answer in an on-line forum, use one of the safe domains listed in RFC
2606. example.com, example.net and example.org are not assigned to
anyone, so you can safely use them in examples without someone's
actual server getting slammed if a reader takes you literally.
</P>
<HR width="10%" align="center">
<h4 align="center"><a name="tips/0b">On-line dictionary</a></h4>
<P>
When someone says you're "meretricious", that's a compliment, right?
Not necessarily. Save yourself a trip to the library with the
easy-to-use dict utility by Rik Faith, available on the dict.org web
site:
<A HREF="http://www.dict.org/links.html"
>http://www.dict.org/links.html</A>
</P>
<P>
The Dictionary Server Protocol is RFC2229
</P>
<P><DL><DT>
Or use Merriam-Webster's dictionary:
<DD><A HREF="http://www.m-w.com"
>http://www.m-w.com</A>
</DL></P>
<HR width="10%" align="center">
<h4 align="center"><a name="tips/0c">Telnet via http</a></h4>
<P>
If you can only do HTTP from work and want to send resum<75>s from your
shell account, check out GNU httptunnel. It encapsulates any TCP
connection in an HTTP connection, so it will work through an
application-level proxy.
</P>
<P>
(PPP over ssh over httptunnel is left as an exercise for those readers
who really want to give the corporate security pigs the finger.)
</P>
<P><DL><DT>
You can get more information from Nocrew.org:
<DD><A HREF="http://www.nocrew.org/software/httptunnel.html"
>http://www.nocrew.org/software/httptunnel.html</A>
</DL></P>
<P><DL><DT>
or from GNU.org:
<DD><A HREF="http://www.gnu.org/directory/httptunnel.html"
>http://www.gnu.org/directory/httptunnel.html</A>
</DL></P>
<HR width="10%" align="center">
<h4 align="center"><a name="tips/0d">Changing the title bar on an xterm</a></h4>
<P>
"xterm" isn't a very helpful window bar title for an xterm. You can
put extra information in the title bar, however, with escape
sequences. For example, this repeats your shell prompt both in the
title bar and the command line:
</P>
<P><BLOCKQuote>
export PS1="\[\033]0;$PS1\007\]$PS1"
</BLOCKQuote></P>
<P><DL><DT>
For more xterm title bar customization, see the Bash Prompt HOWTO by Giles Orr:
<DD><A HREF="http://www.shelluser.net/~giles/bashprompt/howto/xterm-title-bar-manipulations.html"
>http://www.shelluser.net/~giles/bashprompt/howto/xterm-title-bar-manipulations.html</A>
</DL></P>
<HR width="10%" align="center">
<h4 align="center"><a name="tips/0e">Running BIND as non-root</a></h4>
<P>
One of the main rules of security is "Don't run anything as root that
you don't have to." To run BIND as a non-root user, first create a
user and group "named", then add the -u (user) and -g (group) options
to the init script for BIND.
</P>
<P>
On some distributions the init script is called "bind" and on others
it's called "named".
</P>
<P>
For example, in <A HREF="http://www.debian.org/">Debian</A>, change the "start-stop-daemon" line in
<TT>/etc/init.d/bind</TT> to:
</P>
<P><CODE>
start-stop-daemon --start --quiet --exec /usr/sbin/named -- -g named -u named
</CODE></P>
<HR width="10%" align="center">
<h4 align="center"><a name="tips/0f">HTML Tidy</h4>
<P>
Got old web pages that are so messy you just stick a couple of extra
&lt;/table&gt; tags on the end and hope for the best? Try HTML Tidy, the
pretty-printer for HTML, available from the HTML Tidy web site:
<A HREF="http://www.w3.org/People/Raggett/tidy"
>http://www.w3.org/People/Raggett/tidy</A> or your favorite Linux packages
site.
</P>
<P>
HTML Tidy fixes common HTML mistakes and puts everything in an
easy-to-edit format. The author claims it does a good job of stripping
excess markup from Microsoft Word documents saved as HTML, too.
</P>
<HR width="10%" align="center">
<h4 align="center"><a name="tips/0g">Moving Internet services
among servers</a></h4>
<P>
To keep the flexibility of moving services from one system to another
without reconfiguring all the clients, it's a good idea to set up
CNAME records in your DNS. Some good examples are "pop", "smtp",
"news", "shell" and "webproxy"--that way you can move the outgoing
mail server or the Squid server to its own host without having to
reconfigure all the clients.
</P>
<P>
But with the increasing number of mobile users, don't make the mistake
of, for example, setting client software to only use "smtp" and "pop"
for their mail. Fully qualify the domain name, so that when they take
their laptops to the leetconference.com network, they don't end up
trying to send their mail through smtp.leetconference.com by mistake,
and get it bounced back for attempted spamming. Configure client
software for CNAMEs like smtp.internal.example.com.
</P>
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/1"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">(sendmail 2c TIP) * 2</FONT></H3>
Thu, 13 Sep 2001 18:50:56 -0700
<BR>Guy Milliron (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%231">The Answer Gang</a>)
<P>
2c TIP: Sendmail ignores everything after a plus symbol in a
username field of an email address. Hence if while cruisin the Wild
Wide Waste, you come across something that needs your email
address, you and put in <B>USER+comment@domain.com</B> When
you get mail/UCE/Spam to that address, you'll know who sold it, or
put it on a web page and a spider ran across it. Even works on
webpages when you want to put a "Mail Me" link. At least you
know a spider harvested your address.
</P>
<P>
Which leads into another 2c TIP. I use <TT>/etc/aliases</TT> file to control
my mail. Like I could alias "fubar" to my normal email account
"guy". If for some reason I get a lot of spam from that email
address "fubar" - I would just delete the alias "fubar" from the file,
and the "account" is gone, but my normal email address is intact
for my friends to use.
</P>
<P>
I do this with my clients that I host for. I inform them of the
benefits of aliasing, and then offer each account they have up to 3
aliases.
</P>
<P>
<EM>Smile</EM>
<br>--
<br>Guy Milliron
</P>
<!-- sig -->
<!-- end 1 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/2"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">A 2 Cent About Converting Image Files</FONT></H3>
Sat, 8 Sep 2001 18:04:03 -0500
<BR>Chris Gianakopoulos (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%232">The Answer Gang</a>)
<P>
Hello Answer Gang,
Sometime this week, I noticed that somebody was asking about how to
automating the Gimp so that it could convert image file formats from one
format into another from the shell command line.
</P>
<P>
I cannot remember who it was, because I lost the email, thus, I'll post
this message and hope that the person will see my posting.
</P>
<P>
The ImageMagick tools will do the trick. They have a utility called
"convert" that can do the necessary conversions from the command line.
</P>
<P>
I must give credit to the author of the article. Her name is Katja
Socher, and the URL is
<A HREF="http://www.linuxfocus.org/English/July2001/article211.shtml"
>http://www.linuxfocus.org/English/July2001/article211.shtml</A>.
Her article is entitled "Do magic with images on the shell". She
shows all kinds of cool things that can be done with ImageMagick.
</P>
<P>
I just stumbled on the article, and by coincidence, I was also trying to
find a tool to convert images from one format into another. Of
ImageMagick can do much more than convert images.
</P>
<P>
Chris Gianakopoulos
</P>
<!-- sig -->
<!-- end 2 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/3"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">While in hack mode...</FONT></H3>
Sat, 15 Sep 2001 15:28:55 +0000
<BR>Ben Okopnik (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%233">The Answer Gang</a>)
<P>
Back in LG#60, one of our readers ("Roy") posted a little Tcl/Tk script
to TAG - in effect, this thing pops up a little 'sticky note' with a
message, and goes away when it's clicked. I saved it, and put it to use
occasionally - it's a rather useful toy. A few minutes ago, however,
I happened to glance at the code, and noticed that there was a "dead"
section in there, code that was supposed to execute but didn't. So,
having fixed it and added a usage message, here's the 'New and Improved'
version of the script I called "3m" for semi-obvious reasons:
</P>
<p align="center">see attached
<a href="misc/tips/sm.tcl.txt">misc/tips/sm.tcl.txt</a></p>
<P>
Contrary to the original author's statement, "funny characters" (shell
metacharacters) can indeed be used in the message; simply enclose the
entire message in single quotes.
</P>
<P><CODE>
# This displays the message and saves it with a timestamp
<BR>3m - Lunch with Liana, 1:00-2:00pm Sunday &amp;
</CODE></P>
<P><CODE>
# Oh-oh - here come those funny characters!
<BR>3m 'Watch out for <EM>Larry</EM>, &amp;Moe&amp;, and %Curly%!!!' &amp;
</CODE></P>
<P>
Tcl/Tk will simply display the quoted text enclosed in curly braces.
Also, note the (unquoted) '&amp;' at the end of the line - this puts
the process in the background, and allows you to continue using your
xterm... perhaps to launch more 'sticky notes'.
<IMG SRC="../gx/dennis/smily.gif" ALT=":)"
height="24" width="20" align="middle">
</P>
<!-- end 3 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/4"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">xshowrgb (xcolorsel replacement)</FONT></H3>
Mon, 17 Sep 2001 15:52:11 +1200 (NZST)
<BR>Ryurick M. Hristev (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%234">r.hristev from phys.canterbury.ac.nz</a>)
<P>
Hello,
</P>
<P>
For your 2c Tips page:
</P>
<P><BLOCKQuote>
Attached is an perl script as a xcolorsel replacement
(xcolorsel doesn't work on X11R6).
</BLOCKQuote></P>
<P>
Require the perl-Tk package
(RedHat users may find it on the Developer Module Archive disk).
</P>
<p align="center">see attached
<a href="misc/tips/xshowrgb.perl-tk.txt">misc/tips/xshowrgb.perl-tk.txt</a></p>
<P>
Cheers,
<br>--
<br>Ryurick M. Hristev
</P>
<p><em>I usually use xcolors or gcolorsel, myself. With the caveats that
xcolors creates a <b>huge</b> window and gcolorsel requires GNOME, they're
enough for me to get a quick eyeball on the named color I want to use.
-- Heather</em></p>
<!-- end 4 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/5"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">re: kernel compilation error in issue 70</FONT></H3>
Tue, 11 Sep 2001 00:12:55 -0400
<BR>Kenneth Veith (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%235">kencv from coil.com</a>)
<P>
Hi,
</P>
<P>
I ran into similar problems. The following, from RedHat's
site, fixed the problem for me.
</P>
<h4>
7.1 Compiling a kernel from source in <A HREF="http://www.redhat.com/">Red Hat</A> Linux 7
</h4>
<P>
For various reasons, gcc is no longer able to compile the kernel from
source because it uses the 2.96 version of the GNU C
Compiler. However, it is still easy to compile your kernel, as version
2.91.66 of the egcs C compiler has been included with the
distribution. Please note that the details involved with compiling a
kernel are not covered here. For more information please read
the Linux Kernel HOWTO at
<A HREF="http://www.redhat.com/mirrors/LDP/HOWTO/Kernel-HOWTO.html"
>http://www.redhat.com/mirrors/LDP/HOWTO/Kernel-HOWTO.html</A>. This document
is assuming
you have a basic grasp of what is necessary to compile a kernel and
simply cannot get the @$&amp;%@$@*% thing to compile in Red
Hat Linux 7. This information only applies to pristine source,
downloaded from a site such as kernel.org, as the changes necessary
to compile have already been made to the source from the
kernel-source-2.2.16-22.i386.rpm package.
</P>
<P>
After downloading and extracting the source in <TT>/usr/src</TT>, cd
to/usr/src/linux and open the Makefile in your favorite editor. You will
need to look for a line similar to this:
</P>
<Pre>
CC =$(CROSS_COMPILE)gcc -D__KERNEL__ -I$(HPATH)
</Pre>
<P>
This line specifies which C compiler to use to build the kernel. It
should be changed to:
</P>
<Pre>
CC =$(CROSS_COMPILE)kgcc -D__KERNEL__ -I$(HPATH)
</Pre>
<P>
for Red Hat Linux 7. The kgcc compiler is egcs 2.91.66. From here you
can proceed with the typical compiling steps.
</P>
<DL><DT>
The url for this is
<DD><A HREF="http://www.redhat.com/support/docs/gotchas/7.0/gotchas-7-7.html#ss7.1"
>http://www.redhat.com/support/docs/gotchas/7.0/gotchas-7-7.html#ss7.1</A>
</DL>
<P>
Hope this helps.
<br>Kenneth Veith
</P>
<!-- end 5 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/6"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">Tarpit</FONT></H3>
Thu, 20 Sep 2001 11:03:21 -0700
<BR>Mike Orr (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%236"><em>LG</em> Editor</a>)
<P>
Here's a tar pit program that sits on unused IP addresses and plays
with Internet worms.
</P>
<P>
<A HREF="http://www.threenorth.com/LaBrea"
>http://www.threenorth.com/LaBrea</A>
</P>
<P>
Courtesy <A HREF="http://www.slashdot.org/">Slashdot</A>.
-- Mike
</P>
<!-- end 6 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/7"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">Monitoring log files in real time</FONT></H3>
Thu, 20 Sep 2001 13:06:48 -0700
<BR>Mike Orr (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%237"><em>LG</em> Editor</a>)
<P>
When you're debugging a program that writes error messages to a log
file, run "<tt>tail -f LOGFILENAME</tt>" in another
window. You'll see the error messages immediately when they
occur.
</P>
<P>
If it's hard to distinguish the lines referring to the latest error,
press Enter a few times in that window. That won't affect the file,
but it will put a few blank lines on the screen. Then it will be easy
to see where the next error message starts.
</P>
<P>-- Mike
</P>
<!-- end 7 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/8"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">HSP Micromodem</FONT></H3>
Mon, 10 Sep 2001 21:58:22 -0500 (COT)
<BR>John Karns (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%238">The Answer Gang</a>)
<P>
JJ asked:
</P>
<P><STRONG>
Pie ChartsHi all,
I'm desperately looking for a driver for my HSP56 Micromodem, a device
integrated on my Mainboard.
Could you suggest some site to download it?
</STRONG></P>
<P>
Try searching for "linmodem" with your favorite search engine - I usually
favor google for Linux related searches. There is a site dedicated to
information regarding setting up modems under Linux, and is called
something like www.linmodem.org. I can't remember whether it's .org or
.net, or something else.
</P>
<P>
-- John Karns
</P>
<dl><dt>It's plural, and .org ...
<dd>if anything calls itself an "HSP"
"HSF" or "HCF" modem, this is the place to see if linux hates
it or can deal with it. -- Heather
<dd><tt><a href="http://www.linmodems.org/">http://www.linmodems.org/</a></tt>
</dl>
<!-- end 8 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/9"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">Query about Makefile</FONT></H3>
Tue, 18 Sep 2001 22:10:39 -0500
<BR>Chris Gianakopoulos (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%239">The Answer Gang</a>)
<P>
Amol wrote:
</P>
<P><STRONG>
Hello everybody ,
</STRONG></P>
<P><STRONG>
I am new to this Linux field . I just want to
know all information about Makefile concept used for
compling and configuring Linux kernel .
Where can I get good resource about Makefile ?
</STRONG></P>
<P><STRONG>
amol
</STRONG></P>
<P>
Hi Amol,
I read a book entitled "Mastering Make, A Guide to Building Programs on
DOS, OS/2, and Unix Systems" by Tondo, Nathanson, and Young. The ISBN is
ISBN 0-13-121906-5.
I suspect that the O Reilly book about make is also good.
</P>
<P>
Hope that helps,
<br>Chris Gianakopoulos
</P>
<!-- end 9 -->
<!-- .~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~.~~. -->
<P> <A NAME="tips/10"><HR WIDTH="75%" ALIGN="center"></A> <P>
<H3><IMG ALIGN=BOTTOM ALT="" SRC="../gx/lil2cent.gif">
<FONT COLOR="navy">Re: linux signwriting programs</FONT></H3>
Tue, 4 Sep 2001 10:11:42 -0700
<BR>Mike Orr (<a href="mailto:linux-questions-only@ssc.com?subject=%20Re%3A%20%5BLG%2071%5D%202c%20Tips%20%2310"><em>LG</em> Editor</a>)
<P>
Steve Gosden wrote:
</P>
<P><STRONG>
PLEASE SEND ME TO A SITE WHERE I CAN DOWNLOAD A SIGNWRITING PROGRAM THAT
USES LINUX.
<br>REGARDS STEVE
</STRONG></P>
<!-- sig -->
<P>
The 'banner' program prints large ASCII banners. On <A HREF="http://www.debian.org/">Debian</A> it's
<TT>/usr/games/banner</TT>, part of the standard 'bsdmainutils' package.
</P>
<P>
If that program isn't suitable, tell us more about what kinds of signs
you're trying to make.
</P>
<P>
Do any Answer Gang members have recommendations for making signs with
colors or signs with graphics?
</P>
<p><em>You could try one of these:</em></p>
<em>
<ul>
<li>AAType - like banner, only uses AAlib and truetype fonts to make it
look cool:
<br><tt><a href="http://w1.520.telia.com/~u52013156/aatype.html"
>http://w1.520.telia.com/~u52013156/aatype.html</a></tt>
<li>gozer - another truetype text banner thingy:
<br><tt><a href="http://linuxbrit.co.uk/gozer/"
>http://linuxbrit.co.uk/gozer/</a></tt>
<li>figlet is especially handy, it comes with most distros:
<br><tt><a href="http://ianchai.50megs.com/figlet.html"
>http://ianchai.50megs.com/figlet.html</a></tt>
<li>and if he means "normal" signs ... as long as your printer is up to
it, there is OF COURSE my favorite, The Gimp. Pretty darn easy to
tell it you want 250 point fonts. It isn't trying specially to be
"Print Shop Deluxe" ... aiming more for Photoshop really ... but
you can do just about anything with it.
<br><tt><a href="http://www.gimp.org">http://www.gimp.org</a></tt>
<li>If it was one of those banner/greeting card/calendar etc. programs
you wanted then maybe Chilliware's IceSculptor would work for
you. As far as I can tell Chilliware itself is unreachable
(were they bought by someone?) but it's pretty easy to find their
boxed product in various e-stores, at least right now. I can't
give you any info about how easy it is to install, etc.
</ul>
</em>
<p><em>-- Heather</em></p>
</em>
<P>
Long ago on the VAX/VMS mainframes we used to make ASCII-art signs that showed
Snoopy holding a sign with your text on it. Since the printer used that
tractor-fed paper, it was easy to make a wide sign. The program might have
been called 'banner'.
</P>
<p><em>We had them in my old PDP-11 days, certainly. -- Heather</em></p>
<!-- end 10 -->
<P> <hr> </p>
<!-- *** BEGIN copyright *** -->
<H5 align="center">This page edited and maintained by the Editors
of <I>Linux Gazette</I>
<a href="http://www.linuxgazette.com/copying.html"
>Copyright &copy;</a> 2001
<BR>Published in issue 71 of <I>Linux Gazette</I> October 2001</H5>
<H6 ALIGN="center">HTML script maintained by
<A HREF="mailto:star@starshine.org">Heather Stern</a> of
Starshine Technical Services,
<A HREF="http://www.starshine.org/">http://www.starshine.org/</A>
</H6>
<!-- *** END copyright *** -->
<H4 ALIGN="center">
"Linux Gazette...<I>making Linux just a little more fun!</I>"
</H4>
<P> <HR> <P>
<!--===================================================================-->
<center>
<H1><font color="maroon">A Need for Documentation</font></H1>
<H4>By <a href="mailto:matthiasarndt@gmx.net">Matthias Arndt</a></H4>
</center>
<P> <HR> <P>
<!-- END header -->
<H2><A NAME="SECTION00010000000000000000">
Contents</A>
</H2>
<!--Table of Contents-->
<UL>
<LI><A NAME="tex2html15"
HREF="#SECTION00020000000000000000">1 Introduction</A>
<LI><A NAME="tex2html16"
HREF="#SECTION00030000000000000000">2 Why should I write documentation?</A>
<LI><A NAME="tex2html17"
HREF="#SECTION00040000000000000000">3 What aspects of my project/program should I document?</A>
<LI><A NAME="tex2html18"
HREF="#SECTION00050000000000000000">4 How do I write documentation?</A>
<LI><A NAME="tex2html19"
HREF="#SECTION00060000000000000000">5 What formats should I use for my documentation?</A>
<UL>
<LI><A NAME="tex2html20"
HREF="#SECTION00061000000000000000">5.1 File formats suitable for documentation</A>
<LI><A NAME="tex2html21"
HREF="#SECTION00062000000000000000">5.2 Source code documentation</A>
</UL>
<LI><A NAME="tex2html22"
HREF="#SECTION00070000000000000000">6 Documentation formatting with HTML</A>
<LI><A NAME="tex2html23"
HREF="#SECTION00080000000000000000">7 Use LyX</A>
<LI><A NAME="tex2html24"
HREF="#SECTION00090000000000000000">8 What about PDF?</A>
<LI><A NAME="tex2html25"
HREF="#SECTION000100000000000000000">9 Conclusion</A>
</UL>
<!--End of Table of Contents-->
<P>
<H2><A NAME="SECTION00020000000000000000">
1 Introduction</A>
</H2>
<P>
Giving everything a GUI has become a popular trend in the Linux community.
This implies that more and more program authors tend to use a GUI-based
configuration dialog.
<P>
However, you lose an important thing when GUIs are used for everything:
documentation. People who can point-and-click
are often the one who think: ```Why should I read the programs
documentation? I simply point-and-click--and it works.''
<P>
But it would be better to encourage people to read documentation.
In fact, the better the documentation, the simpler it is to use
a program. Take the Apache web server for example, it comes
with heavy documentation. As a result, anybody who can understand a little
English is able to use Apache and configure it--without using a
point-and-click interface.
<P>
This article tries to encourage programmers to document their projects,
as well as to provide ideas and tips on doing so.
<P>
<H2><A NAME="SECTION00030000000000000000">
2 Why should I write documentation?</A>
</H2>
<P>
Lots of reasons! More documentation means easier usage. More documentation
means better add-on modules. More documentation means happier users.
As soon as a user gets stuck trying to get a program feature to work, he
or she starts to read that program's documentation. Imagine, therefore,
creating well-structured and well-written documentation that will make it
easy for the user to get that feature to work.
<P>
<H2><A NAME="SECTION00040000000000000000">
3 What aspects of my project/program should I document?</A>
</H2>
<P>
In general the following aspects of a program or project should be
documented:
<P>
<OL>
<LI>Basic usage is mostly covered in a man page.
</LI>
<LI>More advanced usage can be achieved by listing ALL configuration
options in the documentation and giving examples on how to use them
(take the very good Apache documentation for example).
</LI>
<LI>Source code, of course, because somebody may want to add features
to the program.
</LI>
<LI>Examples of usage to supply a working basic configuration file
and document it heavily.
</LI>
<LI>Installation of the program, because not all programs work with <B>./configure
&amp;&amp; make &amp;&amp; make install</B>.
</LI>
<LI>User interface, especially if it is not a common point-and-click
one.
</LI>
</OL>
This list can be extended further. But in general a well-documented
program will cover at least these, and it will do so in a readable
fashion.
<P>
<H2><A NAME="SECTION00050000000000000000">
4 How do I write documentation?</A>
</H2>
<P>
Use your favourite text editor, as the formats I propose here can all
be written using a text editor.
<P>
Style is worth mentioning as well. Write your documentation in an
easy-to-read style. Do not try to use poetry.
<P>
The preferred language for documentation is plain English, as almost
anyone who uses a computer is able to understand it. You can always
add documentation in your native language as well. But keep in mind
that not everyone speaks German or Russian. At least include English
documentation for the most basic parts of your project. Someone who
cannot understand the simplest parts of the documentation will not read
it, and in many cases he will not use that program.
<P>
The rest is up to you. Always keep in mind that writing the documentation
is the ugliest part of developing.
<P>
<H2><A NAME="SECTION00060000000000000000">
5 What formats should I use for my documentation?</A>
</H2>
<P>
<H3><A NAME="SECTION00061000000000000000">
5.1 File formats suitable for documentation</A>
</H3>
<P>
Use a standard one, nobody likes proprietary file formats. This
effectively kills MS Word, StarOffice or anything like that for documentational
purposes.
<P>
The most simple format is plain text. It can be read everywhere, and
everyone can use his or her favourite pager or editor.
<P>
If you want your documentation to be printable, L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X is a good
choice. It is relatively easy to use, at least for writing a documentation
file. Advantages of using L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X are the system-independent
output format and a stylish formatted document. You can even export
it to HTML.
<P>
The most preferred choice nowadays is HTML. It is hypertext, there
are readers for all platforms available, and it can be distributed
on the project's homepage for on-line reading.
<P>
You can also use an SGML- or XML-based format such as DocBook or
LinuxDoc/SGML. These formats provide the most flexibility for converting
to many other output formats (including formats which haven't been invented
yet), or parsing as structured text (for automated text-processing tools),
but require a learning curve similar to
L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X.
<P>
<H3><A NAME="SECTION00062000000000000000">
5.2 Source code documentation</A>
</H3>
<P>
Source code can simply be documented by heavy use of comments and
suitable variable names. API descriptions in an external file is important,
especially if you're writing a library or something else that can
be extended.
<P>
<H2><A NAME="SECTION00070000000000000000">
6 Documentation formatting with HTML</A>
</H2>
<P>
Always use the most common subset of HTML. Do not use frames or Javascript
in documentation. Simply use &lt;H1&gt;&lt;/H1&gt; to &lt;H6&gt;&lt;/H6&gt; for sections and
&lt;P&gt;&lt;/P&gt; for paragraphs. Read your favourite HTML-Howto for more detail.
<P>
<H2><A NAME="SECTION00080000000000000000">
7 Use LyX</A>
</H2>
<P>
This my personal tip for writing program documentation. It features
what-you-see-is-what-you-mean input and result formatting in L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X,
as well as export to ASCII and HTML. Think of it as some sort of GUI frontend
for L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X. Always keep in mind that LyX is not a WYSIWYG
text processor</B>.
<P>
LyX comes with most Linux distributions, with its own
documentation file. Give it a try--it's easy to use and the results
are stunning.
<P>
The export features of LyX make it well-suited for our purpose.
You can create a .dvi file of your documentation that can be printed
on almost all Linux boxes configured for printing. So even
the distribution of a printable manual is easy.
<P>
<H2><A NAME="SECTION00090000000000000000">
8 What about PDF?</A>
</H2>
<P>
PDF is an extended version of Postscript. Its main disadvantage for
documentation is it requires a graphic display or a printer to
be viewed properly.
<P>
PDF is also less reliable on Linux. HTML files and man pages "just
work". L<SUP><SMALL>A</SMALL></SUP>T<SMALL>E</SMALL>X files work if you
install the software correctly. But there are incompatibilities between
the various PDF-authoring tools and viewers, and you may end up
distributing a document that somebody can't open or that has some of the
text showing up blank in various viewers.
<P>
PDF files are also huge, especially if you include pictures and tables.
Displaying PDF files is slow compared to HTML, DVI or plain
text. You may use it--but I do not recommend PDF for project documentation.
<P>
<H2><A NAME="SECTION000100000000000000000">
9 Conclusion</A>
</H2>
<P>
Writing documentation can be fun if you use the right tools. Always
remember that the documentation should be written so that anyone
can read it.
<P>
Now, go do it--good documentation is worth the effort.
<!-- *** BEGIN bio *** -->
<SPACER TYPE="vertical" SIZE="30">
<P>
<H4><IMG ALIGN=BOTTOM ALT="" SRC="../gx/note.gif">Matthias Arndt</H4>
<EM>I'm a Linux enthusiast from northern Germany.
I like plain old fifties rock'n'roll music, writing
stories and publishing in the <i>Linux Gazette</i>, of course.
Currently I'm studying computer science in conjunction with
economics.</EM>
<!-- *** END bio *** -->
<!-- *** BEGIN copyright *** -->
<P> <hr> <!-- P -->
<H5 ALIGN=center>
Copyright &copy; 2001, Matthias Arndt.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 71 of <i>Linux Gazette</i>, October 2001</H5>
<!-- *** END copyright *** -->
<H4 ALIGN="center">
"Linux Gazette...<I>making Linux just a little more fun!</I>"
</H4>
<P> <HR> <P>
<!--===================================================================-->
<center>
<H1><font color="maroon">Code Optimization Using the GNU C Compiler</font></H1>
<H4>By <a href="mailto:rahulj@veritas.com">Rahul U Joshi</a></H4>
</center>
<P> <HR> <P>
<!-- END header -->
<p>
<i>
This article describes some of the code optimization techniques used by the
GNU C Compiler, in order to give the reader a feel of what code optimization is
and how it can increase the efficiency of the generated object code.
</i></p>
<h2>Contents</h2>
<OL>
<LI><a href="#sect1">Introduction</a>
<LI><a href="#sect2">Assembly Language Code for a C Program</a>
<LI><a href="#sect3">Constant Folding</a>
<LI><a href="#sect4">Common Subexpression Elimination</a>
<LI><a href="#sect5">Dead Code Elimination</a>
<LI><a href="#sect6">Strength Reduction using Induction Variable</a>
<LI><a href="#sect7">Conclusion</a>
<LI><a href="#sect8">Acknowledgments</a>
<LI><a href="#sect9">References</a>
</OL>
<h2><A NAME="sect1">1. Introduction</A></h2>
<p>
As we all know, a compiler is a program that reads the source program in
a high-level language and translates it into (typically) machine language. This
is a complicated process involving a number of stages. If the compiler is
an <i>optimizing compiler,</i> one of these stages "optimizes" the
machine language code so that it either takes less time to run or occupies
less memory or sometimes both. Of course, whatever optimizations the compiler
does, it must not affect the logic of the program i.e. the optimization must
preserve the meaning of the program. One might wonder what type of optimizations
the compiler uses to produce efficient machine code? Since in no case the
meaning of the program being compiled should be changed, the compiler must
inspect the program very thoroughly and find out the suitable optimizations
that can be applied. As we may wonder, such a thorough analysis of the program
and then finding and applying suitable optimizations is a complex and time
consuming process, the details of which are beyond the scope of this article.
</p>
<p>
What I am going to describe in this article are a few type of code
optimizations that the GNU C Compiler uses so that we can understand how the
code is optimized and appreciate the complexity of the optimization process.
The GNU C Compiler is a sophisticated optimizing C compiler that uses a large
array of optimization techniques to produce efficient code. It may not be
possible to describe all of them, so I have chosen some that are interesting
and also easy to understand. A complete list of the optimization techniques
that are used by the GNU C compiler is available at <a href="http://www.redhat.com/products/support/gnupro/gnupro_gcc.html">http://www.redhat.com/products/support/gnupro/gnupro_gcc.html</a>.
Instead of simply describing what a particular optimization technique does,
I will describe them using the assembly language code that is generated by
the GNU C Compiler. This method will also enable the readers to further
explore code optimization carried out by the compiler and also the advanced
optimization techniques, in case they are interested.
</p>
<h2><A name="sect2">2. Assembly Language Code for a C Program</A></h2>
<p>
The GNU C Compiler (called GCC henceforth) reads a C program source file and
translates it into an object program that contains the machine code for the
program in binary form. However, it can also produce assembly language source
code for the program instead of the object code, so that we can read it and
understand how the assembly language program looks. We will be generating such
assembly language files to see the optimizations being used by the compiler,
so it would be beneficial if we see how the assembly language code for a simple
C program looks like. However, also note that we need not understand <i>each</i>
assembly language statement in the generated code, so some statements that are
not crucial towards understanding the code optimization will not be explained
for simplicity. To generate the assembly language code, create a file
<tt>test1.c</tt> as shown below and give the following command:</p>
<PRE>$ gcc -c -S test1.c</PRE>
<p>
This will generate a file <tt>test1.s</tt>, which has the assembly language listing of
the generated code for the C program. The file <tt>test1.c</tt> along with the assembly
language code is shown below.</p>
<PRE><TT>
1 : /* test1.c */
2 : /* This first file simply demonstrates how the assembly program that the
3 : compiler produces looks like and some peculiarities of the GNU
4 : assembler that follows some different conventions from MASM/TASM.
5 : */
6 : #include &lt;stdio.h&gt;
7 :
8 : int main()
9 : {
10 : printf("Hello, World\n");
11 : return 0;
12 : }
13 :
14 : /* end test1.c */
15 : /* ----------------------------------------------------------------- */
16 : /* generated assembly language file */
17 : .file "test1.c" /* some assembler directives to be */
18 : .version "01.01" /* ignored */
19 : gcc2_compiled.:
20 : .section .rodata /* this segment has read-only data */
21 : .LC0:
22 : .string "Hello, World\n"
23 : .text
24 : .align 4
25 : .globl main
26 : .type main,@function
27 : main: /* main function begins */
28 : pushl $.LC0 /* push parameter for printf() on stack */
29 : call printf /* call the function */
30 : addl $4,%esp /* clear the stack */
31 :
32 : xorl %eax,%eax /* make EAX = 0, functions use register */
33 : jmp .L1 /* EAX to return values */
34 : .p2align 4,,7 /* this is an alignment directive */
35 : .L1:
36 : ret /* return from main, done */
37 : .Lfe1:
38 : /* other assembler directives to be ignored */
39 : .size main,.Lfe1-main
40 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
41 : /* end of the generated assembly language file */
42 : /* ---------------------------------------------------------------- */
</TT></PRE>
<p>
In case you know about the architecture
of the 80386 or higher microprocessors and have experience with assembly
language programming, you will find that the assembly language that is produced
is only partly familiar to you. This assembly language follows the AT&amp;T
assembler syntax that is different from the Intel/Microsoft
Assembler/Turbo Assembler syntax that most of us are probably familiar with.
Let us go through the assembly language code. We will ignore the assembler
directives as they are not crucial towards understanding the generated code.
On line 20 a read-only data segment has been defined with the string <tt>"Hello,
World\n"</tt> in it. A label <tt>.LC0</tt> has been assigned to the string. On line 27, the code for the <tt>main()</tt>
function begins. As we know, in C language the parameters to functions are
passed by pushing them on the stack, and the parameters are pushed in the
reverse order i.e. the last parameter is pushed first on the stack. In this
case, the <tt>printf()</tt> function is being called with a single parameter, the
string <tt>"Hello, World\n"</tt>. The statement <tt>pushl $.LC0</tt> pushes the address of the
string <tt>"Hello, World\n"</tt> on the stack. The "<tt>l</tt>" in <tt>pushl</tt> stands for "long" as we
are dealing with 32 bit variables. In all the assembly language programs that
we will see, the mnemonics will be followed by an "<tt>l</tt>" to indicate that we are
dealing with 32 bit variables. The "<tt>$</tt>" preceding <tt>.LC0</tt> means the address of the
string. The next statement calls the <tt>printf()</tt> function. After the <tt>printf()</tt>
function finishes execution, we need to cleanup the stack, so we need to add 4
to ESP. (Why 4? That's because we pushed 4 bytes on the stack before calling
<tt>printf()</tt>.)
To do so, we would normally write, <tt>ADD ESP, 4</tt>. The Intel convention is
<tt>&lt;instruction&gt; dest, src</tt>. However, the AT&amp;T convention is <tt>&lt;instruction&gt; src, dest</tt>, so you can
see that the instruction on line 30 is <tt>addl $4, %esp</tt>. Immediate operands like
4 are prefixed by a $ and register names are prefixed by a %. This convention
was followed to maintain compatibility with the BSD assembler. The next
statement XOR's EAX with itself so that EAX = 0 afterwards. This is because
the return value from a function is stored in the EAX register. After that,
you will see a jump instruction and an alignment directive. These will not be
explained and it will suffice to know that <tt>main()</tt> function will return back at
this point. Now that we understand how the assembly language code looks like,
let us move towards the optimizations.</p>
<h2><A name="sect3">3. Constant Folding</a></h2>
<p>
Constant folding is the simplest code optimization to understand. Let
us suppose that you write the statement <tt>x = 45 * 88;</tt> in your C program. A non-optimizing
compiler will generate code to multiply 45 by 88 and store the
value in x. An optimizing compiler will detect that both 45 and 88 are
constants, so their product will also be a constant. Hence it will find 45 *
88 = 3960 and generate code that simply copies 3960 into x. This is
<i>constant folding</i>, and means the calculation is done just once, at
compile time, rather than every time the program is run. To illustrate this,
create the file <tt>test2.c</tt> as shown below. Generate the assembly code
for this program as was shown earlier. Since by default, GCC does not
optimize the program, you will see that the assembly code is a
straightforward translation of the C program (Lines 18 to 62).</p>
<PRE><TT>
1 : /* test2.c */
2 : /* Demonstration of constant propagation */
3 : #include &lt;stdio.h&gt;
4 :
5 : int main()
6 : {
7 : int x, y, z;
8 : x = 10;
9 : y = x + 45;
10 : z = y + 4;
11 : printf("The value of z = %d", z);
12 : return 0;
13 : }
14 : /* end of test2.c */
15 :
16 : /* ---------------------------------------------------------------- */
17 : /* assembly language file without any optimizations */
18 : .file "test2.c"
19 : .version "01.01"
20 : gcc2_compiled.:
21 : .section .rodata
22 : .LC0:
23 : .string "The value of z = %d"
24 : .text
25 : .align 4
26 : .globl main
27 : .type main,@function
28 : main:
29 : pushl %ebp /* save EBP register on stack */
30 : movl %esp,%ebp /* EBP = ESP */
31 : subl $12,%esp /* Create stack frame. 3 variables x 4 bytes */
32 :
33 : /* x = 10; */
34 : movl $10,-4(%ebp) /* x = 10. x is topmost on the stack */
35 :
36 : /* y = x + 45; */
37 : movl -4(%ebp),%edx /* EDX = x */
38 : addl $45,%edx /* EDX = EDX + 45 */
39 : movl %edx,-8(%ebp) /* y = EDX. y is second from top of stack */
40 :
41 : /* z = y + 4 */
42 : movl -8(%ebp),%edx /* EDX = y */
43 : addl $4,%edx /* EDX = EDX + 4 */
44 : movl %edx,-12(%ebp) /* z = EDX. z is third from top of stack */
45 :
46 : /* printf("The value of z = ", z); */
47 : movl -12(%ebp),%eax /* EAX = z */
48 : pushl %eax /* push EAX(=z) as first parameter of printf */
49 : pushl $.LC0 /* second parameter for printf */
50 : call printf
51 : addl $8,%esp /* clear stack */
52 :
53 : /* return 0; */
54 : xorl %eax,%eax /* for return 0 */
55 : jmp .L1
56 : .p2align 4,,7
57 : .L1:
58 : leave
59 : ret
60 : .Lfe1:
61 : .size main,.Lfe1-main
62 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
63 : /* end of assembly language code */
64 : /* ---------------------------------------------------------------- */
65 :
66 : /* ---------------------------------------------------------------- */
67 : /* generated assembly language code after optimization */
68 :
69 : .file "test2.c"
70 : .version "01.01"
71 : gcc2_compiled.:
72 : .section .rodata
73 : .LC0:
74 : .string "The value of z = %d"
75 : .text
76 : .align 4
77 : .globl main
78 : .type main,@function
79 : main:
80 : pushl %ebp /* Save EBP register on stack */
81 : movl %esp,%ebp /* EBP = ESP */
82 :
83 : /* by constant propagation, z will always be 59 */
84 : /* printf("The value of z = %d", z); */
85 : pushl $59 /* first printf parameter */
86 : pushl $.LC0 /* second printf parameter */
87 : call printf
88 : /* no need of cleanup, we are exiting anyway */
89 : /* return 0; */
90 : xorl %eax,%eax
91 : leave
92 : ret
93 : .Lfe1:
94 : .size main,.Lfe1-main
95 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
96 : /* end of assembly language code */
97 : /* ----------------------------------------------------------------- */
</TT></PRE>
<p>
There are some new things in the assembly code that we need to
understand. First of all, the <tt>main()</tt> function defines 3 local variables for
whom space will be allocated on the stack. Also, to access these variables, we
will be using the indexed addressing mode and we will be using EBP for that.
So the first statement saves the current value of EBP onto the stack. Then
the stack pointer ESP is copied into EBP (note that the source ESP is first)
so that EBP can be used for accessing the local variables. Finally, we need
to create space for three 4-byte variables on the stack, so we subtract 12
from ESP; i.e., we grow the stack by 12 bytes. <tt>x</tt> will be the
bottom-most stack element and at an offset of -4 from EBP. See the diagram
below.</p>
<pre><tt>
EBP-----> ---------------
| x | 4 Bytes
---------------
| y | 4 Bytes
---------------
| z | 4 Bytes
ESP-----> ---------------
| |
| |
^ | |
| ...
Address increases | | |
as we go up | 0 ---------------
</tt></pre>
<p>
Similarly, the offset of y from EBP is -8 and that of z is -12. Now consider the
assignment <tt>x = 10;</tt>. The statement to implement it on line 34 is
<tt>movl $10, -4(%ebp)</tt>. The indexed addressing mode is written as
<tt>&lt;offset&gt;(&lt;base register&gt;)</tt>. Thus the above statement will copy the constant 10
to the address (EBP - 4) i.e. the address of <tt>x</tt> on the stack. In a similar
manner, <tt>-8(%ebp)</tt> is used to access <tt>y</tt> and <tt>-12(%ebp)</tt> is used to access <tt>z</tt>. Lines
37, 38 and 39 evaluate <tt>x + 45</tt> and assign the result to <tt>y</tt>. To do so, the value
of <tt>x</tt> is first copied into the EDX register, 45 is added to it and the result
which is in EDX is copied to <tt>y</tt>. The code for <tt>z = y + 4</tt> is similar. In line 47
the parameters for <tt>printf()</tt> are pushed on the stack. The last parameter (<tt>z</tt>) is
pushed first and then the address of the string is pushed. In line 51, we
cleanup the stack by adding 8 to ESP. I guess that since we pushed two 4-byte
parameters, we had to add 8 to ESP. In the first example, we pushed only one
parameter and hence we had to add just 4 to ESP. The rest of the code is easy
to understand.</p>
<p>
Now if we look at the above program, when we evaluate <tt>x + 45</tt>, the
value of <tt>x</tt> is always going to be 10 because of the assignment <tt>x = 10</tt>.
Therefore <tt>x + 45</tt> will always evaluate to 55. So the statement always assigns
55 to <tt>y</tt>. Similarly, when evaluating <tt>y + 4</tt>, the result will always be 59. If
the optimization is enabled, the compiler will be in a position to detect
this. To enable optimization, use the -O2 option. Enter the following command:</p>
<PRE>gcc -c -S -O2 test2.c</PRE>
<p>
The assembly code generated with optimization enabled is shown in lines 69 to
95. Notice that on line 85, the compiler directly pushes the constant 59 on
the stack followed by the address of the string and calls <tt>printf()</tt>. Thus, by
constant folding, the compiler evaluates the various expressions in the
program only once and plugs the final value into the generated code. One more
interesting thing to observe is that after constant folding, there is no need
of the variables <tt>x</tt>, <tt>y</tt> and <tt>z</tt>. Therefore no space for them is allocated on the
stack, thus reducing the memory requirement of the program. This brings out
the fact that one optimization may lead to another one. In the above case
constant folding lead to a decrease in run time (since all the computations
are done at compile time) and also to a decrease in the space requirements.</p>
<h2><a name="sect4">4. Common Subexpression Elimination</a></h2>
<p>
Many a times, it happens that the same expression is evaluated at
different places in the same program and the values of the operands in the
expression do not change in between the two evaluations of that expression.
For example, the program may evaluate say <tt>a * b</tt> at the beginning and at the
end. If the values of <tt>a</tt> and <tt>b</tt> do not change in between these two evaluations
of <tt>a * b</tt>, then instead of evaluating <tt>a * b</tt> again at the end, we can save the
result of the evaluation of <tt>a * b</tt> at the beginning in some temporary variable
and use it at the end. This will help eliminate redundant computations in the
program. This optimization is called as <i>common subexpression elimination</i>.
Consider the following program that demonstrates it.</p>
<PRE><TT>
1 : /* test3.c */
2 : /* common subexpression elimination, and also of constant propagation */
3 : #include &lt;stdio.h&gt;
4 :
5 : int main()
6 : {
7 : int a, b;
8 : int x, y, z;
9 : scanf("%d %d", &amp;a, &amp;b);
10 : x = a * b;
11 :
12 : if(b &gt;= 4)
13 : {
14 : y = a * b;
15 : z = 0;
16 : }
17 : else
18 : {
19 : z = a * b * 4;
20 : y = 0;
21 : }
22 :
23 : printf("x = %d, y = %d, z = %d\n", x, y, z);
24 : return 0;
25 : }
26 : /* end of test3.c */
27 :
28 : /* ----------------------------------------------------------------- */
29 : /* generated unoptimized assembly language code */
30 : .file "test3.c"
31 : .version "01.01"
32 : gcc2_compiled.:
33 : .section .rodata
34 : .LC0:
35 : .string "%d %d"
36 : .LC1:
37 : .string "x = %d, y = %d, z = %d\n"
38 : .text
39 : .align 4
40 : .globl main
41 : .type main,@function
42 : main:
43 : pushl %ebp /* save EBP */
44 : movl %esp,%ebp /* EBP = ESP */
45 : subl $20,%esp /* Create space for 5 variables */
46 :
47 : /* scanf("%d %d". &amp;a, &amp;b); */
48 : leal -8(%ebp),%eax
49 : pushl %eax /* push address of b on stack */
50 : leal -4(%ebp),%eax
51 : pushl %eax /* push address of a on stack */
52 : pushl $.LC0 /* push address of string */
53 : call scanf
54 : addl $12,%esp /* stack cleanup after scanf */
55 :
56 : /* x = a * b; */
57 : movl -4(%ebp),%eax /* EAX = a */
58 : imull -8(%ebp),%eax /* EAX = EAX * b = a * b */
59 : movl %eax,-12(%ebp) /* x = EAX = a * b */
60 :
61 : /* if( b &gt;= 4)... */
62 : cmpl $3,-8(%ebp) /* compare b with 3 */
63 : jle .L2 /* else part at label .L2, if follows */
64 :
65 : /* y = a * b; */
66 : movl -4(%ebp),%eax /* EAX = a */
67 : imull -8(%ebp),%eax /* EAX = EAX * b = a * b */
68 : movl %eax,-16(%ebp) /* y = EAX = a * b */
69 : /* z = 0; */
70 : movl $0,-20(%ebp)
71 : jmp .L3 /* jump over the else part */
72 :
73 : .p2align 4,,7
74 : .L2:
75 : /* else part begins here */
76 :
77 : /* z = a * b * 4; */
78 : movl -4(%ebp),%eax /* EAX = a */
79 : imull -8(%ebp),%eax /* EAX = EAX * b = a * b */
80 : leal 0(,%eax,4),%edx /* EDX = EAX*4 + 0 */
81 : movl %edx,-20(%ebp) /* z = EDX */
82 : /* y = 0; */
83 : movl $0,-16(%ebp)
84 : .L3:
85 : /* if..else is over here */
86 :
87 : /* printf("x = %d, y = %d, z = %d\n", x, y, x); */
88 : movl -20(%ebp),%eax
89 : pushl %eax /* push address of z on stack */
90 : movl -16(%ebp),%eax
91 : pushl %eax /* push address of y on stack */
92 : movl -12(%ebp),%eax
93 : pushl %eax /* push address of x on stack */
94 : pushl $.LC1 /* address of string */
95 : call printf
96 : addl $16,%esp /* stack cleanup after printf */
97 :
98 : /* return 0 */
99 : xorl %eax,%eax
100 : jmp .L1
101 : .p2align 4,,7
102 : .L1:
103 : leave
104 : ret
105 : .Lfe1:
106 : .size main,.Lfe1-main
107 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
108 : /* end of unoptimized assembly language code */
109 : /* --------------------------------------------------------------- */
110 :
111 : /* --------------------------------------------------------------- */
112 : /* generated optimized assembly language code */
113 : .file "test3.c"
114 : .version "01.01"
115 : gcc2_compiled.:
116 : .section .rodata
117 : .LC0:
118 : .string "%d %d"
119 : .LC1:
120 : .string "x = %d, y = %d, z = %d\n"
121 : .text
122 : .align 4
123 : .globl main
124 : .type main,@function
125 : main:
126 : pushl %ebp /* save EBP */
127 : movl %esp,%ebp /* EBP = ESP */
128 : subl $8,%esp /* space for just 2 variables on stack */
129 :
130 : /* scanf("%d %d", &amp;a, &amp;b); */
131 : leal -4(%ebp),%eax
132 : pushl %eax /* push address of b on stack */
133 : leal -8(%ebp),%eax
134 : pushl %eax /* push address of a on stack */
135 : pushl $.LC0 /* address of string */
136 : call scanf
137 :
138 : /* x = a * b; */
139 : movl -4(%ebp),%eax /* EAX = b */
140 : movl %eax,%edx /* EDX = EAX = b */
141 : imull -8(%ebp),%edx /* EDX = EDX * a = b * a = a * b */
142 :
143 : addl $12,%esp /* delayed stack cleanup */
144 : /* if( b >= 4).... */
145 : cmpl $3,%eax /* compare EAX = b with 3 */
146 : jle .L17 /* else part from label .L17 */
147 :
148 : /* y stored in ECX, z in EAX, x in EDX */
149 : /* y = a * b; */
150 : movl %edx,%ecx
151 : /* z = 0; */
152 : xorl %eax,%eax
153 : jmp .L18 /* jump over the else part */
154 : .p2align 4,,7
155 : .L17:
156 : /* z = a * b * 4; */
157 : leal 0(,%edx,4),%eax /* LEA EAX, [EDX*4]+0 */
158 : /* y = 0; */
159 : xorl %ecx,%ecx
160 : .L18:
161 : pushl %eax /* push value of z */
162 : pushl %ecx /* push value of y */
163 : pushl %edx /* push value of x */
164 : pushl $.LC1 /* push address of string */
165 : call printf
166 : /* stack cleanup after printf not necessary */
167 :
168 : /* return 0; */
169 : xorl %eax,%eax
170 : leave
171 : ret
172 : .Lfe1:
173 : .size main,.Lfe1-main
174 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
175 : /* end optimized assembly code */
176 : /* -------------------------------------------------------------- */
</TT></PRE>
<p>
This program has an example of a common subexpression. On line 10, the expression
<tt>a * b</tt> is evaluated the first time, and then again on lines 14 and 19. The last two evaluations
of <tt>a * b</tt> are redundant since the value of neither <tt>a</tt> nor <tt>b</tt> changes after the first evaluation.
Thus these two evaluations are common subexpressions that can be eliminated. Lines 30 to 108
show the unoptimized assembly code that is a straightforward translation of the C code and
should be easy to understand. Now consider the optimized assembly language code from lines 113
to 176. The first thing to notice is that now only variables <tt>a</tt> and <tt>b</tt> are stored on the stack,
hence a stack of just 8 bytes is required as opposed to a 20 byte stack for the unoptimized
version. You may wonder what's so special about variables <tt>a</tt> and <tt>b</tt>. The specialty is that the
address of variables <tt>a</tt> and <tt>b</tt> is used in the program (for <tt>scanf()</tt>) and variables that reside in
the registers cannot have a memory address. Hence the compiler is unable to put them inside
the registers. The registers that the compiler chooses for other variables are as follows:
<tt>x</tt> in EDX, <tt>y</tt> in ECX and <tt>z</tt> in EAX. Statements 139 to 141 evaluate <tt>a * b</tt> and the value is stored
in EDX (which holds <tt>x</tt>). Also, the value of <tt>b</tt> is available in the register EAX.
One more thing to notice is the delayed cleanup of stack after the call to
<tt>scanf()</tt> on line 143. May be there is some advantage in doing so, I don't know.</p>
<p>
Next starts the <tt>if</tt> statement. In the <tt>if</tt> part, the expression <tt>a * b</tt> is reevaluated and
we expect that the compiler will use the value stored in EDX. That is exactly
what the compiler does. For the statement <tt>y = a * b</tt>, the generated code on
line 150 simply copies the value of <tt>a * b</tt> in register EDX into the register
ECX (which holds <tt>y</tt>). In the <tt>else</tt> part again, there is a common subexpression
in the statement <tt>z = a * b * 4</tt>. Thus we expect that the compiler will take
the value of <tt>a * b</tt> in EDX, multiply it by 4 and then store the result in EAX
(which holds <tt>z</tt>). Now there are many ways in which this can be done. One is
to use a sequence of <tt>movl</tt>, <tt>imull</tt> instructions as in</p>
<pre><tt>
movl %edx, %eax /* EAX = EDX = a * b */
imull $4, %eax /* EAX = EAX * 4 */
</tt></pre>
<p>
The second choice is to use a shift (<tt>sall</tt>) instead of <tt>imull</tt> in the above
sequence of instructions. However, it turns out that the GCC uses an obscure
speed trick to optimize the code. It uses the instruction</p>
<pre><tt>
leal 0(,%edx,4), %eax
</tt></pre>
<p>
This instruction uses the scaling and indexing capabilities of the 80386
processors. The above instruction takes EDX as the index register, 4 as the
scale and 0 as the offset, calculates the effective address and stores it
in the EAX register. Thus the register EAX gets a value EDX(=a*b)*4 + 0 i.e.
<tt>a * b * 4</tt>. The <tt>leal</tt> instruction always executes in 2 clock cycles on an 80386,
whereas a simple shift will take around 7 clock cycles. We see
that the compiler knows about processor peculiarities and uses
it when it generates the code.</p>
<p>
Thus it can be seen that common subexpressions save a lot of computations and also
space that is used up by the code for these redundant computations. At this stage, one can
understand that the compiler when analyzing the program for optimization must keep a track
of how and when the variables change, the expressions that are evaluated and also
which registers are allocated to variables. In general such a kind of analysis that the
compiler performs on the program is called as <i>data flow analysis</i>.</p>
<h2><a name="sect5">5. Dead Code Elimination</a></h2>
<p>
Dead code is the code in the program that will never be executed for any input or other
conditions. A common example is an <tt>if</tt> statement. If the compiler finds out that the condition
inside the <tt>if</tt> is never going to be true, then the body of the <tt>if</tt> statement will never be
executed. In that case, the compiler can completely eliminate this dead code, thus saving the
memory space occupied by the code. The following program demonstrates dead code elimination.</p>
<pre><tt>
1 : /* test4.c */
2 : /* demonstration of dead code elimination */
3 : #include &lt;stdio.h&gt;
4 :
5 : int main()
6 : {
7 : int x;
8 :
9 : scanf("%d", &amp;x);
10 :
11 : if(x &lt; 0 && x &gt; 0)
12 : {
13 : x = 99;
14 : printf("Hello. Inside the if!!!");
15 : }
16 :
17 : return 0;
18 : }
19 : /* end of test4.c */
20 :
21 : /* --------------------------------------------------------------- */
22 : /* optimized assembly code */
23 : .file "test4.c"
24 : .version "01.01"
25 : gcc2_compiled.:
26 : .section .rodata
27 : .LC0:
28 : .string "%d"
29 : .LC1:
30 : .string "Hello. Inside the if!!!"
31 : .text
32 : .align 4
33 : .globl main
34 : .type main,@function
35 : main:
36 : pushl %ebp /* save EBP on stack */
37 : movl %esp,%ebp /* EBP = ESP */
38 : subl $4,%esp /* create space for x on the stack */
39 :
40 : /* scanf("%d", &amp;x); */
41 : leal -4(%ebp),%eax
42 : pushl %eax /* push address of a on stack */
43 : pushl $.LC0 /* push string on stack */
44 : call scanf
45 :
46 : /* the entire body of the if and the condition checking is dead code */
47 : /* return 0; */
48 : xorl %eax,%eax /* no stack cleanup, we are exiting anyway */
49 : leave
50 : ret
51 : .Lfe1:
52 : .size main,.Lfe1-main
53 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
54 : /* end optimized assembly code */
55 : /* ---------------------------------------------------------------- */
</tt></pre>
<p>
Since the unoptimized assembly language code serves no purpose and also its easy
to understand, I have omitted it. In the program, the condition on line 11 is <tt>x &lt; 0 &amp;&amp; x &gt; 0</tt>,
which can never be true. The compiler finds this and concludes that the body of the <tt>if</tt>
statement forms dead code, so it does not generate any code for that. One interesting
thing to notice is that after the body of <tt>if</tt> has been eliminated, the string
<tt>"Hello. Inside the if!!!"</tt> is no longer needed and hence can be eliminated from the read-only
data section. However, detection of such things probably will increase the complexity of the
compiler and hence is not done.</p>
<h2><a name="sect6">6. Strength Reduction using Induction Variable</a></h2>
<p>
One type of code optimization is strength reduction in which a "costly" operation is
replaced by a less expensive one. For example, the evaluation of x<SUP>2</SUP> is much more efficient if
we multiply x by x rather than call the exponentiation routine. One place where this optimization
can be applied is in loops. Many times in a loop, one variable changes in synchronization with
the loop variable. Such a variable is called as <i>induction variable</i>. Induction variables give
the compiler a chance to apply strength reduction, as can be seen from the following program.</p>
<PRE><TT>
1 : /* test5.c */
2 : /* demonstration of induction variable elimination */
3 : int main()
4 : {
5 : int i, j;
6 :
7 : for(i = 0; i &lt; 10; i++)
8 : {
9 : j = i * 7;
10 : printf("i = %d, j = %d", i, j);
11 : }
12 : return 0;
13 : }
14 : /* end test5.c */
15 :
16 : /* --------------------------------------------------------------- */
17 : /* optimized assembly language code */
18 : .file "test5.c"
19 : .version "01.01"
20 : gcc2_compiled.:
21 : .section .rodata
22 : .LC0:
23 : .string "i = %d, j = %d"
24 : .text
25 : .align 4
26 : .globl main
27 : .type main,@function
28 : main:
29 : pushl %ebp /* save EBP on stack */
30 : movl %esp,%ebp /* ESP = EBP */
31 :
32 : pushl %esi /* ESI will hold 'j' */
33 : pushl %ebx /* EBX will hold 'i' */
34 : xorl %ebx,%ebx /* both are initialized to zero */
35 : xorl %esi,%esi
36 : .p2align 4,,7
37 : .L5:
38 : /* printf("i = %d, j = %d", i, j); */
39 : pushl %esi /* push value of j */
40 : pushl %ebx /* push value of i */
41 : pushl $.LC0 /* push address of string */
42 : call printf
43 : addl $12,%esp /* stack cleanup */
44 :
45 : /* instead of saying j = i * 7, its efficient to say j = j + 7 */
46 : addl $7,%esi
47 : incl %ebx /* i++ */
48 : cmpl $9,%ebx /* is i &lt;= 9, then repeat the loop */
49 : jle .L5
50 :
51 : /* return 0; */
52 : xorl %eax,%eax
53 : leal -8(%ebp),%esp
54 : popl %ebx
55 : popl %esi
56 : leave
57 : ret
58 : .Lfe1:
59 : .size main,.Lfe1-main
60 : .ident "GCC: (GNU) egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)"
61 :
62 : /* end optimized assembly code */
63 : /* ----------------------------------------------------------------- */
</TT></PRE>
<p>
Here <tt>i</tt> is the loop variable whereas <tt>j</tt> is the induction variable as <tt>j</tt> always changes
in lock step with <tt>i</tt>. In the generated assembly language code, the compiler has decided to
use registers to store both <tt>i</tt> and <tt>j</tt> with <tt>i</tt> in EBX and <tt>j</tt> in ESI. Line 34 initializes EBX(=<tt>i</tt>) to
zero, as is indicated in the initialization part of the for loop. The compiler sees that during
the first pass, <tt>j</tt> will be assigned a value of 0, so it also initialized ESI to 0 in line 35.
The loop starts at line 37 and continues till line 49. Since <tt>j</tt> already has its value assigned
to it, the first thing the compiler does inside the loop is to call the <tt>printf()</tt> function. Here,
the compiler has adjusted the order of the statements in the loop so as to enable it to use
strength reduction. After analyzing the program, the compiler sees that inside the loop,
the value of <tt>i</tt> is always going to increase by 1 and since <tt>j</tt> is an induction variable, its
value is always going to increase by 7. Therefore, instead of multiplying <tt>i</tt> by 7 (which is costly),
it adds 7 to the old value of <tt>j</tt> before going on to the next iteration. Thus a costly operation
of multiplication has been replaced by addition which is cheaper (in terms of time).</p>
<h2><a name="sect7">7. Conclusion</a></h2>
<p>
In this article we have seen some very basic code optimization techniques that the
GNU C Compiler uses to optimize the generated code. From these optimization techniques and
the various pieces of information that are required to apply them, the reader can appreciate
the type of sophisticated and complex analysis that the compiler must carry out on the
program. It has to keep track of various things like variables, their storage places (memory
or registers), expression evaluations, constant expressions, dead code etc. It is because of
this high complexity of the process that the compiler takes much longer to compile a program
with optimization enabled. There are many details that are involved in code
optimization and code generation that I have not explained and that I don't know.
Code optimization is a field of active research and interested
readers can refer to [1] for additional information.</p>
<h2><a name="sect8">8. Acknowledgments</a></h2>
<p>
I would like to thank my Bachelor's project guide Dr. Uday Khedker for creating my
interest in compilers and code optimization. I would also like to thank the <i>Linux
Gazette, Linux Documentation Project, PC Quest</I> and the <i>Pune Linux User's Group</i>
(<a href="http://www.pluggies.org">http://www.pluggies.org</a>)
which have earlier accepted and published my contributions that inspires me to write more.
</p>
<h2><a name="sect9">9. References</a></h2>
<OL>
<LI><i>Compilers: Principles, Techniques, and Tools</i>, A.V.Aho, Ravi Sethi and J.D.Ullman, Addison Wesley.
<LI><i>Systems Programming and Operating Systems</i>, D.M.Dhamdhere, Tata McGraw-Hill.
<LI><A HREF="http://www.linuxdoc.org/HOWTO/Assembly-HOWTO/index.html"><i>Assembly HOWTO</i></A>, Franois-Ren Rideau, Linux Documentation Project.
<LI><i>Advanced 80386 Programming Techniques</i>, James L. Turley, Osborne McGraw-Hill.
</OL>
<!-- *** BEGIN bio *** -->
<SPACER TYPE="vertical" SIZE="30">
<P>
<H4><IMG ALIGN=BOTTOM ALT="" SRC="../gx/note.gif">Rahul U Joshi</H4>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<EM>I have recently joined Veritas Software India Pvt. Ltd. as an Associate
Software Engineer. I have worked on a research project entitled "Node Listing
Based Global Data Flow Analysis" during my Bachelor's degree. I am interested
in compilers, programming languages, operating systems and parallel/distributed
processing. I have contributed articles to Linux Gazette about
parallel processing and about optimizing C.</EM>
<!-- *** END bio *** -->
<!-- *** BEGIN copyright *** -->
<P> <hr> <!-- P -->
<H5 ALIGN=center>
Copyright &copy; 2001, Rahul U Joshi.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 71 of <i>Linux Gazette</i>, October 2001</H5>
<!-- *** END copyright *** -->
<H4 ALIGN="center">
"Linux Gazette...<I>making Linux just a little more fun!</I>"
</H4>
<P> <HR> <P>
<!--===================================================================-->
<center>
<H1><font color="maroon">The Foolish Things We Do With Our Computers</font></H1>
<H4>By <a href="mailto:gazette@ssc.com">Mike "Iron" Orr</a></H4>
</center>
<P> <HR> <P>
<!-- END header -->
On September 6, I, um, dropped a fork on my hard drive while it was running.
I asked The Answer Gang and Nick Moffitt what other foolish things they've done
with their computers, and here are the responses.
<H2>The Case of the Dropped Fork</H2>
<P> I keep my computer's
cover open to avoid overheating. A fork fell off my desk, through the
computer case and landed on the hard drive. The other half of the fork landed
on the, um, power supply. Fortunately not *in* the power supply.
<IMG ALT=":)" SRC="../gx/dennis/smily.gif" WIDTH="20" HEIGHT="24">
I extracted the fork--being glad I didn't get a shock--and then discovered I
couldn't save my nedit files ("read-only file system"). The disk light stayed
on continuously. I ran 'mount' and got an input/output error. Suspecting the
drive was fried, I wrote down all the changes I'd made to my Python files in
the nedit windows. I tried "su -c mount /Backups" to mount my backup partition
on the other drive, but it wouldn't do anything. I got most of the way through
writing down my changes when nedit aborted. I closed what I could and tried to
quit the X session, but the computer froze. I pressed Reset, but it wouldn't
get past the BIOS. I turned off the computer, waited a bit, and turned it back
on. This time it booted OK.
<IMG ALT=":)" SRC="../gx/dennis/smily.gif" WIDTH="20" HEIGHT="24">
<IMG ALT=":)" SRC="../gx/dennis/smily.gif" WIDTH="20" HEIGHT="24">
<P> The computer ran for a couple days, then then it started crashing in
the middle of the night and on bad days I would get two Oopses a day.
My roommate
strongly hinted I fix my computer, because he works at night and depends on it
being the Internet gateway for his Windows boxen. I wanted to install <A
HREF="http://www.rocklinux.org">ROCK Linux</A> and try it out, so this gave me
an excuse. But I couldn't get through the installation routine without an
Oops. It didn't matter whether both HDs were connected or only one. Thinking
something unknown might be wrong with the computer besides just the hard drive,
I got the parts to build another computer: AMD Duron 800 (more than twice as
fast as my K6 350 woohoo!), the cheapest brand-name HD (10 GB), and a PCI
Ethernet card and sound card (because my new motherboard didn't have ISA
slots), and an ATX case. Next month, I'll write about my adventures
installing ROCK.
<HR NOSHADE WIDTH="80%"> <!-- ************************* -->
<H2>The Viking Ship</H2>
By <A HREF="mailto:nick@zork.net">Nick Moffitt</A>
<P> I haven't got any blunder stories for you, but here's
something we used to do with computer hardware back in high school:
<P> My brother's school at the time had a bunch of surplus IBM
model Bs (predecessor of the XT I think) that I took home. I only had
so many outlets in my room (I had used up all the plugs I dared, and
was using oil lamps to light the place, but that's another story), so
I had no use for most of them myself.
<P> My friend Jason had a bunch of clock-chip crystals from some
card that ran at 66MHz or something. He probably got them from Boeing
Surplus, where you can buy drill bits by the pound, hard hats for a
dollar, and Ultrasparc pieces as-is. At least, that was the way it
used to be.
<P> So we built a crude Viking ship out of spare plywood and set
a model B atop it. I ran an extension cord out into the yard to power
it, Jason inserted the crystal, and we watched, entranced, as the poor
4.77MHz chip slowly slagged itself. It smelled to high heaven, and
the boat didn't catch on fire, so we resorted to setting flaming peeps
adrift in his bathtub for our Viking funerals.
<P> "What do you suppose the reaction will be once they reach
Valhalla?" Jason asked.
<P> "OLAF LOOK! BUN-NY!" &lt;stomp&gt; &lt;squish&gt;
<H4>Iron writes:</H4>
When I worked at an ISP, we got our servers from the Boeing Surplus. The owner
would buy ten of them at once, whatever model they were selling at $30 each
including monitor. The first time, it was these miscellaneous stray 386s. Two
years later, it was Dell 486s.
<P> At Bumbershoot (a multi-arts festival every Labor Day weekend), in the art
exhibit was a set of ferry-boat models made out of driftwood with scrounged
parts, with white Christmas lights inside. They actually looked pretty cool.
<HR NOSHADE WIDTH="80%"> <!-- ************************* -->
<H2>Upgrade Hell</H2>
By <A HREF="mailto:stern@starshine.org">Heather Stern</A>
<P> Gosh, so many years in computing, hard to think what was the dumbest
thing... oh yeah, we can narrow it down to just Linux.
<P> Heh.
<P> I think the dumbest thing I've done with my laptop is upgrade it all in
one day before I needed it for something... but doesn't everyone do THAT?
Face it, upgrades are dangerous.
<P> But you know, if you ate whole herrings like Tux you wouldn't have had that
fork bomb.
<P> &lt;badum Ching!&gt;
<HR NOSHADE WIDTH="80%"> <!-- ************************* -->
<H2>I/O Cards</H2>
By <A HREF="mailto:pilolla@gateway.net">Chris Gianakopoulos</A>
<P> My dumbest computer act was unplugging and reinserting I/O cards in my
S-100 (CP/M) system because I didn't want to wait that long 3-second
duration for CP/M to reboot when I was fixing my hardware. After about 40
Acts of Boldness, I finally plugged in the I/O card not quite so straight
into the socket and there were lots of sparks.
<P> I just took it apart, and after two weeks (front panel dangling on the
floor), I decided to fix the thing. One killer, though. The computer
would randomly crash and the front panel lights (it was an Altair 8800
with an 18-slot motherboard), would just light up. After 4 months, when
it got in one of its moods, I got a frequency counter and saw that the
system clock was superposed where it should not have been. Looking up the
signal definitions and the connector pinouts, I saw that there was a piece
of copper (from my hot-swapped I/O card connector fingers) shorting the
system clock to some other pin (I cannot remember the signals except that
one of them was the bus clock). Yes I was electronically oriented (a real
computer hacker), and that's what made me so careless.
<P> Not only that, but I was unplugging and reinserting the
I/O card without removing power from the computer. How cool I was!
<H3> <A HREF="mailto:jkarns@csd.net">John Karns</A> writes:</H3>
Hmm, you just dated yourself [about the Altair 8800]--and to join you, I'll
admit that I remember those! I think it was the same model Altair that one of
my college classes was assigned to write a low-pass filter algorithm
for--assembler debugging was a bear, as programming tools were non-existent--at
least for us.
<H3> Chris writes:</H3>
Those were the days of CP/M. But, now we have Linux, so that we have
those days and more!
<H3>Iron writes:</H3>
Especially with all those emulators Linux has.
<H3>John writes:</H3>
<P> I still have a 486 / 100 on which I ran Slackware. Although I haven't used
it in a while, it actually runs X tolerably well, thanks to the SCSI HD.
<P> I just wish they would offer SCSI on laptops - every time my system does a
disk buffer flush, there's a short and noticeable pause if I happen to be
moving the cursor around the screen to remind me that I'm running an IDE
HD. IMO, using a SCSI HD yields a gain similar to having ample RAM in
the machine - helps smooth things out.
<H3>Iron writes:</H3>
What does "superposed" mean? [Regarding the system clock that was
superposed where it should not have been.]
<H3>Chris writes:</H3>
<P> I read too many linear systems books. Some books will call the term
superposed, and other books will call the term superimposed (more
intuitive). Anyway, it means one mathematical function algebraically
summed with another mathematical functions. For example, you might have
a 5 volt DC signal with a 240 millivolt sinusoidal signal riding on top
of the 5 volt signal. So, you would have a sine wave with an amplitude
of 240 millivolts and a DC offset of 5 volts.
<P> I suspect that you understand what I just said. You were probably
wondering where the heck I concocted a word such as "superpose".
Usually the word is used in the context of superposition with respect to
a linear system. I'm not gonna start talking about superposition,
because you will probably kill me for rambling (again).
<P> Anyway, I saw a 1-MHz signal appearing where it
shouldn't have been.
I'm sorry -- I talk so much. Get me talking about science and stuff and
I ramble......
<H3>Iron writes:</H3>
<P> I figured it meant the same thing as superimposed. I just couldn't,
with my puny understanding of electronics, figure out how a system
clock could "superimpose" itself somewhere, or why it would matter.
<H3>Chris writes:</H3>
<P> Oh, now I understand. Utilizing my puny mind, I got bold and was
unplugging circuit boards (and plugging them back into the motherboard)
with the power on the computer! After fixing my fried computer, every
now and then, I could not boot up the computer. All of the front panel
lights, on the Altair 8800 computer, just lit up (abnormally). When I
finally fixed the problem, I saw that there was a piece of copper
short-circuiting the system clock signal to an adjacent pin inside one
of the card edge connectors (These were 100-pin connectors - thus, the
S-100 bus).
<P> The piece of copper was a portion of foil that got sort of torn off
from the edge connector of the I/O card that I was constantly removing
and plugging into the computer.
<HR NOSHADE WIDTH="80%"> <!-- ************************* -->
<H2>Cold Therapy</H2>
By <A HREF="mailto:guy@gmnow.net">Guy Milliron</A>
<P> I do this (Sorta) all the time with my PCs (currently). I have only one
floppy drive. So when I need to use it on any system (Linux systems or my
OS-challenged systems), I just hot-swap it in.. power, I/O cables and all!
<P> Reason: Just like you, I don't want to wait. The Challenged OS takes 7
minutes to boot, linux only takes like less than two (But I lose my uptime
longevity).
<P> The most foolish thing I've done? Has got to be when I had a 386 CPU that
would overheat and crash the system due to my power supply fan had gone out.
So three or four times daily I would take 2 zip lock bags and fill them with
ice cubes and put them IN the computer right on top of the CPU. It actually
worked very well until I was able to buy a new system.
<P> BTW, I still have that same 386/33 motherboard. Was going to make it a
Linux Router, till I found the LinkSYS router.
<H3>Iron writes:</H3>
That takes the cake! If I could draw, I'd make a picture of a computer with
melting ice cubes in it.
<HR NOSHADE WIDTH="80%"> <!-- ************************* -->
<H2>Leaky Laptop</H2>
By <A HREF="mailto:jkarns@csd.net">John Karns</A>
<P> As recently as this past Spring I put my laptop into a backpack to bring
to a friend's house along with some other things, one of which was ... a
water bottle. Well, the top wasn't really screwed onto the bottle very
securely, and ... you can guess what happened. When I arrived at my
destination and pulled the backpack out of the car, I noticed that the
seat was very damp. Upon checking the contents of the backpack and
removing the laptop, water sort of dripped out of the side of the machine
as I held it sideways / vertical.
<P> I took it inside and disassembled it partially, and left it on a table
with a fan blowing into it. The important thing to remember in such cases
is not to turn on the machine (or other electronic device)! After I took
it home I removed the mobo and left it over-night. Luckily, the machine
survived the ordeal, without damage to the HD. The screen showed a few
white spots, but those went away after a few weeks - sigh of relief. I
was just glad that it was the older laptop and not the one I had just
bought a week before.
<H3>Iron writes:</H3>
That's another picture I'd draw: a laptop with water dripping out the side.
<P> <EM>If you would like to tell us about the most foolish thing you've done
with your computer, maybe we'll publish it.
<A HREF="mailto:gazette@ssc.com">gazette@ssc.com</A> </EM>
<!-- *** BEGIN bio *** -->
<SPACER TYPE="vertical" SIZE="30">
<P>
<H4><IMG ALIGN=BOTTOM ALT="" SRC="../gx/note.gif">Mike Orr</H4>
<EM>Mike ("Iron") is the Editor of <I>Linux Gazette</I>. You can read what he
has to say in the Back Page column in this issue. He has been a Linux
enthusiast since 1991 and a Debian user since 1995. He is SSC's web technical
coordinator, which means he gets to write a lot of Python scripts.
Non-computer interests include Ska and Oi! music and the international language
Esperanto. The nickname Iron was given to him in college--short for Iron Orr,
hahaha.</EM>
<!-- *** END bio *** -->
<!-- *** BEGIN copyright *** -->
<P> <hr> <!-- P -->
<H5 ALIGN=center>
Copyright &copy; 2001, Mike "Iron" Orr.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 71 of <i>Linux Gazette</i>, October 2001</H5>
<!-- *** END copyright *** -->
<H4 ALIGN="center">
"Linux Gazette...<I>making Linux just a little more fun!</I>"
</H4>
<P> <HR> <P>
<!--===================================================================-->
<center>
<H1><font color="maroon">Qubism</font></H1>
<H4>By <a href="mailto:sirflakey@core.org.au">Jon "Sir Flakey" Harsem</a></H4>
</center>
<P> <HR> <P>
<!-- END header -->
<P>
<IMG ALT="qb-10th-s.jpg" SRC="misc/qubism/qb-10th-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-longday-s.jpg" SRC="misc/qubism/qb-longday-s.jpg"
WIDTH="600" HEIGHT="257">
<BR CLEAR="all">
<IMG ALT="qb-rsync-s.jpg" SRC="misc/qubism/qb-rsync-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-wordprocessor-s.jpg" SRC="misc/qubism/qb-wordprocessor-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-worms-s.jpg" SRC="misc/qubism/qb-worms-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-iiscrack-s.jpg" SRC="misc/qubism/qb-iiscrack-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-leanbeef-s.jpg" SRC="misc/qubism/qb-leanbeef-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-stuffed-s.jpg" SRC="misc/qubism/qb-stuffed-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<IMG ALT="qb-xonipaq-s.jpg" SRC="misc/qubism/qb-xonipaq-s.jpg"
WIDTH="600" HEIGHT="240">
<BR CLEAR="all">
<!-- *** BEGIN bio *** -->
<SPACER TYPE="vertical" SIZE="30">
<P>
<H4><IMG ALIGN=BOTTOM ALT="" SRC="../gx/note.gif">Jon "SirFlakey" Harsem</H4>
Jon is the creator of the Qubism cartoon strip and current
Editor-in-Chief of the
<A HREF="http://www.core.org.au/">CORE</A> News Site.
Somewhere along the early stages of
his life he picked up a pencil and started drawing on the wallpaper. Now
his cartoons appear 5 days a week on-line, go figure. He confesses to
owning a Mac but swears it is for "personal use".
<!-- *** END bio *** -->
<!-- *** BEGIN copyright *** -->
<P> <hr> <!-- P -->
<H5 ALIGN=center>
Copyright &copy; 2001, Jon "Sir Flakey" Harsem.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 69 of <i>Linux Gazette</i>, August 2001</H5>
<!-- *** END copyright *** -->
<H4 ALIGN="center">
"Linux Gazette...<I>making Linux just a little more fun!</I>"
</H4>
<P> <HR> <P>
<!--===================================================================-->
<center>
<H1><font color="maroon">Numerical Workbenches, part III</font></H1>
<H4>By <a href="mailto:cspiel@hammersmith-consulting.com">Christoph Spiel</a></H4>
</center>
<P> <HR> <P>
<!-- END header -->
<p>Parts&nbsp;I and II of this little series on numerical math workbenches on
GNU/Linux have covered rather dry subjects like matrix manipulations and <em>
for</em>-loops. This part brings more color to the screens as it turns to the
graphical capabilities of GNU/Octave, Scilab, and Tela. It will deviate from
the previous way of presenting the three applications, because the differences
of the graphical backends are far too big to allow for a uniform treatment
with only a few explanations on the differences.</p>
<p>The article starts with an introduction applicable to all programs. To give
the reader maximum benefit, all applications have to solve the same three real
life <a href="#problems">problems</a>. This simplifies the comparison despite
the differences of the implementations. In the last part, <a href="#octave">
Octave</a>, <a href="#scilab">Scilab</a>, and <a href="#tela">Tela</a> have to
tackle the given tasks.</p>
<h2><a name="introduction">Introduction</a></h2>
<dl>
<dt><strong><a name="item_Discrete_Data_Only">Discrete Data
Only</a></strong><br>
</dt>
<dd>As all three applications are designed to work with vectors and matrices,
their graphics backends only understand this kind of data. Doh! For the user
this means that the graph of a mathematical function like
<pre>
{ sin(x)/x for x &lt;&gt; 0
y := f(x) = {
{ 1 for x == 0
</pre>
<p>cannot be drawn from the above expression, but the function has to be
transformed into discrete pairs&nbsp;(<em>x(i)</em>,&nbsp;<em>y(i)</em>). This
transformation is called sampling. To sample <em>f(x)</em>, we pick
values&nbsp;<em>x</em> where we are interested in <em>f(x)</em> and compute
<em>f</em> for the given <em>x</em>. Any reader who has followed the earlier
parts, will immediately recognize that this involves a vector operation.</p>
<pre>
### GNU/Octave code
</pre>
<pre>
function y = f(x)
if x == 0.0
y = 1.0;
else
y = sin(x) ./ x;
endif
endfunction
</pre>
<pre>
x = linspace(0.0, 4*pi, 50);
y = f(x);
</pre>
<p><em>linspace(start, end, n)</em> returns a vector from <em>start</em> to
<em>end</em>, whose <em>n</em>&nbsp;elements are evenly spaced. The
vectors&nbsp;<em>x</em> and <em>y</em> can be passed to an appropriate
plotting function.</p>
<p>If data already are in vectorized form, they can be displayed
immediately.</p>
</dd>
<dt><strong><a name="item_Complexity_at_Large">Complexity at
Large</a></strong><br>
</dt>
<dd>How do we actually display a graph? This question leads us to the
fundamental problem all applications run into when it comes to graphical
output of data: either complicated or many simple function calls! Let us first
consider the complexity for the user of a call to solve a system of linear
equations
<pre>
x = a \ b # Octave, Scilab
</pre>
<p>or</p>
<pre>
x = linsolve(a, b) // Tela
</pre>
<p>Even if we try hard to artificially complicate the calls (yet leaving them
useful), we hit the end of the road at</p>
<pre>
x = linsolve(a, b, "CompletePivoting", "DoIterativeRefinement")
</pre>
<p>This is, with the two additional parameters -- pivoting strategy and
iterative refinement of the solution -- the user completely controls <em>
linsolve()</em>. All other ``decisions'' can reasonably be taken by the
workbench itself, for example, what algorithm to use if matrix&nbsp;<em>a</em>
has a special form.</p>
<p>Contrast this with the 2d-graph of</p>
<pre>
x = [2.25, 2.27, 2.42, ...]
y = [0.363, 0.360, 0.337, ...]
</pre>
<p>What options can we think of?</p>
<ul>
<li>Draw isolated data points or connect data points with straight lines.</li>
<li>Which symbol to draw at each data point? A dot, star, circle, or asterisk?
What color should the data points be?</li>
<li>Which kind of line to draw between the data points? Continuous, dashed,
dotted, or dash-dotted? What line thickness and what color is the line?</li>
<li>Scale the plot to fit within the plotting window?</li>
<li>Draw coordinate axes? Linear or logarithmic <em>x</em> or <em>y</em> axis?
Both axes logarithmic?</li>
<li>Graduate or annotate the axes?</li>
<li>...</li>
</ul>
<p>Many more reasonable options are conceivable. The point is: we cannot
expect plotting to be as simple to use as is for example solving a system of
linear equations -- not because the applications are badly written, but
because the topic is inherently more complicated on the user's side. Hence,
nobody should be surprised if she ever needs 20 or more lines to define a
publication quality plot in Octave, Scilab, or Tela.</p>
</dd>
</dl>
<h2><a name="problems">Problems</a></h2>
<p>To make the competition interesting, I put up problems, which are not too
far away from the Real World(tm). Each of the three applications will have to
cope with three different types of plots:</p>
<ol>
<li><strong><a name="item_2D_Plot_of_Discrete_Data">2D Plot of Discrete
Data</a></strong><br>
<p>Display three sets of data (<a href="misc/spiel/l1.ascii">l1.ascii</a>, <a
href="misc/spiel/l2.ascii">l2.ascii</a>, <a href="misc/spiel/l3.ascii">
l3.ascii</a>) on a single page. The sets have a different number of data
points.</p>
<p>The data are stored as two columns, column&nbsp;1 holds the <em>
x</em>-value, and column&nbsp;2 the <em>y</em>-value:</p>
<pre>
0.2808 3.419E-07
0.3711 3.459E-07
0.4882 3.488E-07
...
</pre>
<p>The graph must show title, axes captions, and legend. The <em>x</em> and
<em>y</em> ranges are supplied by the user.</p>
</li>
<li><strong><a name="item_3D_Plot_of_a_Function">3D Plot of a
Function</a></strong><br>
Plot Rosenbrock's function (in two dimensions)
<pre>
f(u, v) = 100*(v - u^2)^2 + (1 - u)^2
</pre>
<p>as a 3d-surface in the parameter ranges -3&nbsp;&lt;=&nbsp;<em>
u</em>&nbsp;&lt;=&nbsp;3 and -2&nbsp;&lt;=&nbsp;<em>
v</em>&nbsp;&lt;=&nbsp;4.</p>
<p>Annotate the plot with title and axes captions.</p>
</li>
<li><strong><a name="item_Contour_Plot_of_a_Function">Contour Plot of a
Function</a></strong><br>
Plot function
<pre>
g(u, v) = exp(u) * (4*u^2 + 2*v^2 + 4*u*v + 2*v + 1)
</pre>
<p>with contours, this is, <em>f(u, v) = z</em> for given <em>z</em> in the
parameter ranges -4.5&nbsp;&lt;=&nbsp;<em>u</em>&nbsp;&lt;=&nbsp;-0.5 and
-1&nbsp;&lt;=&nbsp;<em>v</em> &lt;=&nbsp;3.</p>
<p>The iso-lines are defined by a user-specified ``weight'' function.</p>
<pre>
( z - z_0 ) 3
z_iso = (z_1 - z_0) * ( --------- ) + z_0
( z_1 - z_0 )
</pre>
<p>where <em>z_0</em> and <em>z_1</em> are the minimum and maximum values of
<em>g(u, v)</em> in the plot's range.</p>
<p>Again, annotate the plot with title and axes captions.</p>
</li>
</ol>
<p>All graphics must be rendered for two devices,</p>
<ul>
<li>X11 terminal and</li>
<li>Postscript printer.</li>
</ul>
<h2><a name="octave">Octave</a></h2>
<p>You know Gnuplot? Then learning to use GNU/Octave's plot functions will be
a piece of cake. All you need to do is precede the Gnuplot commands with a
``<code>g</code>'' to reach at the Octave equivalent. -- Oh, you haven't tried
Gnuplot yet? Then I will guide you through the examples. However, having a
Gnuplot manual (online or dead-tree edition) ready may be helpful.</p>
If you do not want to download Gnuplot's manual, you can use one of the <a
href=
"http://pi3.informatik.uni-mannheim.de/staff/mitarbeiter/westmann/gnuplot.html">
publicly accessible versions</a>.
<h3><a name="octave: 2d discrete data plot">Octave: 2D Discrete Data
Plot</a></h3>
<p>For an easier discussion, I have split the code into blocks. Each block
gathers commands that belong together. The blocks are labeled with numbers in
square brackets, to allow for referencing them in the text.</p>
<pre>
### [1] Read data set_i into N_i-times-2 matrices
set1 = load("l1.ascii");
set2 = load("l2.ascii");
set3 = load("l3.ascii");
</pre>
<pre>
### [2] Reset Gnuplot
graw("reset;");
clearplot;
</pre>
<pre>
### [3] Define decorations and plot area
gset title "Comparison of sets L1, L2, and L3";
gset xlabel "Temperature / K";
gset ylabel "Voltage / V";
gset key top left;
gset xrange [0 : 100];
gset yrange [8e-8 : 2e-6];
</pre>
<pre>
### [4] Plot data
hold on;
gplot set1 title "Set L1" with points;
gplot set2 title "Set L2" with points;
gplot set3 title "Set L3" with points;
hold off;
</pre>
<pre>
### [5] Switch to PostScript output and plot into file
gset terminal push;
gset terminal postscript;
gset output "oct1.eps";
replot;
gset terminal pop;
gset output;
</pre>
<p><img height="450" alt=
"[Graphics: The Gnuplot window that has been opened by Octave's graphics commands shows the three data sets. The data points are drawn with blue, green, and red markers. The markers themselves have different shape. The plot has a title. Both axes show the annotations as defined by the gset-commands.]"
src="misc/spiel/oct1.png" width="600"> The output to the Postscript terminal,
block&nbsp;[6], produced a <a href="misc/spiel/oct1.eps">printable version
(eps)</a> of the graphics.</p>
<p>Block&nbsp;[1] should be clear from the previous articles. The first
interaction with Gnuplot happens in [2], where Gnuplot is reset to a known
state and the X11-plot window gets cleared. A known state is helpful when
still experimenting with Gnuplot's options. In our case reseting is
unnecessary, but it does not hurt.</p>
<p>The block of <code>gset</code> commands, [3] is self explaining except</p>
<pre>
gset key top left
</pre>
<p>which means: ``put the legend (or key) inside the plotting area at the
north-west corner''. <code>xrange</code> and <code>yrange</code> with their
special interval syntax set the width and height of the plot range.</p>
<p>Now, the actual data can be rendered into the plot window [4]. Because the
data sets have different sizes, they cannot be gathered in a single matrix.
Hence, each data set must be plotted by itself, and Gnuplot must be told --
with <code>hold on</code> -- that it should collect all <code>
gplot</code>&nbsp;commands until the last plot of the set is completed and
<code>hold off</code> is called. The calls to <em>gplot</em> essentially
contain the data matrix</p>
<pre>
gplot set1
</pre>
<p>The title, which shows up in the plot's legend, is assigned in the call to
<code>gplot</code>, too.</p>
<p>Block&nbsp;[5] is specific to the way Gnuplot works. For each plot it uses
a <em>terminal</em> and an <em>output</em> file (remember that in UN*X
everything is a file, as for example is the console). When Gnuplot is running
under X, the terminal type defaults to X11 and output file defaults to
Gnuplot's X11-graphic window. Both, <em>terminal</em> and <em>
output</em>&nbsp;file can be changed independently with <code>gset</code>
commands. Thus, to get the same graphics in a different format, we switch from
the current terminal to Postscript, and put an ordinary file's name at the
output. Function&nbsp;<code>replot</code> replays all plot commands for us, we
do not have to write them again. After that the terminal and output settings
are undone, which is optional, but helpful if the user wants to twiddle some
more <code>gset</code>'s and repeatedly check their influence on the graph's
appearance.</p>
<h3><a name="octave: 3d function plot">Octave: 3D Function Plot</a></h3>
<pre>
### [1] Define function
function z = f(u, v)
## truncated Rosenbrock function
z = 100.0*(v - u.^2).^2 + (1.0 - u).^2;
zv = z(:);
zv(find(zv &gt; 100.0)) = 100.0;
z = reshape(zv, size(z));
endfunction
</pre>
<pre>
### [2] Sample function f()
x = linspace(-3, 3, 40);
y = linspace(-2, 4, 40);
[xx, yy] = meshgrid(x, y);
z_splot = splice_mat(xx, yy, f(xx, yy));
</pre>
<pre>
### [3] Reset Gnuplot
graw("reset;");
clearplot;
</pre>
<pre>
### [4] Define decorations and viewing direction
gset data style line;
gset title "Rosenbrock Function";
gset xlabel "u";
gset ylabel "v";
gset view 30, 160;
gset hidden;
gset nokey
gset parametric;
</pre>
<pre>
### [5] Plot
gsplot z_splot;
</pre>
<pre>
### [6] Switch to PostScript output and plot into file
gset terminal push;
gset terminal postscript;
gset output "oct2.eps";
replot;
gset terminal pop;
gset output;
gset noparametric;
</pre>
<pre>
system("gzip --best --force oct2.eps");
</pre>
<p><img height="450" alt=
"[Graphics: The Gnuplot window shows a red-mesh that is 'deformed' according to function f(u, v). The whole plot looks like the imprint of a boomerang.]"
src="misc/spiel/oct2.png" width="600"> A <a href="misc/spiel/oct2.eps.gz">
printer-ready version</a> (eps.gz) is available, too.</p>
<p>Again the first block, [1], should be easy to understand for anyone who has
read Part&nbsp;1 and 2 of this series for it only uses known functions. In
contrast, [2] introduces two new functions. Out friend <em>linspace()</em>
quickly generates two vectors which will define where <em>f(u, v)</em> will be
evaluated: from vectors&nbsp;<em>x</em> and <em>y</em>, a grid is constructed,
this is, two matrices&nbsp;<em>xx</em> and <em>yy</em>, where each pair of
matrix elements <em>(xx(i,&nbsp;j),&nbsp;yy(i,&nbsp;j))</em>,
1&nbsp;&lt;=&nbsp;<em>i</em>,&nbsp;<em>j</em> &lt;=&nbsp;40, define a (grid-)
point at which function&nbsp;<em>z&nbsp;=&nbsp;f(u, v)</em> will be evaluated.
The matrix of all <em>z</em>-values at the grid points then simply is <code>zz
= f(xx, yy)</code>. However, we are not done at this point, because Octave
requires to pass a specially formatted matrix to the 3d-plot
function&nbsp;<em>gsplot</em>.</p>
<p>The user-defined function <a href="misc/spiel/splice_mat.m">
splice_mat()</a> does exactly the needed operation: collect the grid data <em>
xx</em> and <em>yy</em> along with the <em>z</em>-values in matrix&nbsp;<em>
z_plot</em>. Matrix&nbsp;<em>z_plot</em> can be handed over to <em>gsplot</em>
without further ado (given Gnuplot is in parametric mode. (we will be in
parametric mode and for the given kind of problem parametric mode is the only
way to go (and I don't want to introduce another level of parenthesis
(really!))))</p>
<p>Block&nbsp;[4], a collection of <code>gset</code>s, looks almost familiar.
Some new settings are</p>
<ul>
<li><strong><a name="item_gset_data_style_line">gset data style
line</a></strong><br>
Join adjacent mesh-points with (by default: red) lines.</li>
<li><strong><a name="item_gset_view_x_angle%2C_z_angle">gset view x_angle,
z_angle</a></strong><br>
Rotate the view point around the <em>x</em>-axis by <em>x_angle</em> degrees,
then rotate around the new <em>z</em>-axis by <em>z_angle</em> degrees.</li>
<li><strong><a name="item_gset_hidden">gset hidden</a></strong><br>
Suppress invisible mesh lines. The back side of the mesh is drawn differently
(green in the X11-window and with dashed black lines in the
Postscript&nbsp;terminal).</li>
<li><strong><a name="item_gset_nokey">gset nokey</a></strong><br>
Suppress any legend.</li>
<li><strong><a name="item_gset_parametric">gset parametric</a></strong><br>
See GNU/Octave's documentation. (<code>help -i gsplot</code> from Octave, or
<code>info octave --node='Three-Dimensional Plotting'</code> from the
shell.)</li>
</ul>
<p>After so much preparation, the actual plot command, <code>gsplot
z_splot</code> in [5] looks trivial.</p>
<p>The Postscript block&nbsp;[6] is similar to [5] in Section <a href=
"#octave: 2d discrete data plot">``Octave: 2d discrete data plot''</a>. The
only additional job [6] does is gzipping the eps-file. In general <em>
system(``shell-commands'')</em> executes <em>shell-commands</em> in a
sub-shell. Obviously, this is extremely useful when interacting with an
external application, like gzip(1).</p>
<h3><a name="octave: contour function plot">Octave: Contour Function
Plot</a></h3>
<pre>
### [1] Define function
function z = g(u, v)
z = exp(u) .* (4.0*u.^2 + 2.0*v.^2 + 4.0*u.*v + 2.0*v + 1.0);
endfunction
</pre>
<pre>
### [2] Define weight function for iso-line distances
function y = pow_weight(x, n)
## Map interval X onto itself, weight with N-th power.
d = max(x) - min(x);
y = d*((x - min(x))/d).^n + min(x);
endfunction
</pre>
<pre>
### [3] Sample function g()
x = linspace(-4.5, -0.5, 40);
y = linspace(-1.0, 3.0, 40);
[xx, yy] = meshgrid(x, y);
zz = g(xx, yy);
z_splot = splice_mat(xx, yy, zz);
</pre>
<pre>
### [4] Compute iso-line distances
iso_levels = pow_weight(linspace(min(min(zz))*1.01, ...
max(max(zz))*0.99, 12), 3.0);
il_str = sprintf("%f,", iso_levels);
il_str = il_str(1 : length(il_str)-1); # remove last ","
</pre>
<pre>
### [5] Reset Gnuplot
graw("reset;");
clearplot;
</pre>
<pre>
### [6] Define decorations and viewing direction
gset data style line;
gset title "Contour Plot of g(u, v)";
gset xlabel "u";
gset ylabel "v";
gset contour base;
gset nosurface;
gset view 0, 0;
eval(sprintf("gset cntrparam levels discrete %s", il_str));
gset parametric;
</pre>
<pre>
### [7] Plot
gsplot z_splot;
</pre>
<pre>
### [8] Switch to PostScript output and plot into file
gset terminal push;
gset terminal postscript;
gset output "oct3.eps";
replot;
gset terminal pop;
gset output;
gset noparametric;
</pre>
<p><img height="450" alt=
"[Graphics: The Gnuplot window shows 12 iso-lines each with a different color. The plot exhibits a saddle point of g(u, v) in the right third of the image.]"
src="misc/spiel/oct3.png" width="600"> A <a href="misc/spiel/oct3.eps">
printable version (eps)</a> is available, too.</p>
<p>After working through the 2d discrete and the 3d function plot examples,
the top three blocks&nbsp;[1-3] of the contour function script should not
raise many questions. In block&nbsp;[4] however, I have to prepare a trick,
which I must play at the end of block&nbsp;[6]. The job is to plot contour
lines with a user-defined function. The values of this function and therefore
the positions of the iso-lines are not known in advance.</p>
<p>Gnuplot offers several ways to define iso-lines, for example, automatic
computation of a given number of (linearly spaced) contours or defining a
minimum and a maximum contour value with a fixed increment between two
adjacent contours. Our problem requires a more general solution because the
iso-lines are not equally spaced along the <em>z</em>-axis. For completely
arbitrary iso-line values, as the third way if specifying contour lines,
Gnuplot has the following <code>gset</code> command</p>
<pre>
gset cntrparam discrete z1, z2, ..., zN
</pre>
<p>where <em>z1</em>, <em>z2</em>, ..., <em>zN</em> are the <em>z</em>-values
of the iso-lines given as <em>floating point literals</em>. Thus,</p>
<pre>
gset cntrparam discrete 0.2, 0.4, 0.8
</pre>
<p>is a perfect call, whereas</p>
<pre>
z1 = 0.2
z2 = 0.4
z3 = 0.8
gset cntrparam discrete z1, z2, z3
</pre>
<p>is nothing but a syntax error as would be</p>
<pre>
gset cntrparam discrete iso_levels
</pre>
<p>Remember, <code>gset</code> needs floating point literals!</p>
<p>We are stuck unless we apply a bit of magic. If we present a complete
<code>gset</code> line to Octave, one where the values of vector <em>
iso_levels</em> are ``interpolated'' into (Perl programmers do this all day
long), the race is won. Here is how the trick is played:</p>
<pre>
# Convert iso_levels to comma-separated string. Octave reuses
# the format specifier list if there are more items to print than
# there are format specifiers. Don't try this with C's printf :-)
il_string = sprintf("%f,", iso_levels)
</pre>
<pre>
# Remove comma past last contour value in the string.
il_string = il_string(1 : length(il_string)-1)
</pre>
<pre>
# Play interpolation trick a second time
gset_string = sprintf("gset cntrparam levels discrete %s", il_string);
</pre>
<pre>
# Execute the command which is stored in the variable gset_string
eval(gset_string);
</pre>
<p>For readers who do not like abstract descriptions, this is a transcript of
a session (where long lines have been edited to fit):</p>
<pre>
octave:10&gt; il_string = sprintf("%f,", iso_levels)
il_string = 0.583444,0.592029,0.652120,0.815224,1.132847,1.656497, \
2.437679,3.527900,4.978667,6.841486,9.167864,12.009307,
octave:11&gt; il_string = il_string(1 : length(il_string)-1)
il_string = 0.583444,0.592029,0.652120,0.815224,1.132847,1.656497, \
2.437679,3.527900,4.978667,6.841486,9.167864,12.009307
octave:12&gt; gset_string = sprintf("gset cntrparam levels discrete %s", \
il_string)
gset_string = gset cntrparam levels discrete 0.583444,0.592029, \
0.652120,0.815224,1.132847,1.656497,2.437679,3.527900, \
4.978667,6.841486,9.167864,12.009307
</pre>
<p>In the script, no temporary variable&nbsp;<em>gset_string</em> has been
introduced, but <em>sprintf()</em> sends its output directly to <em>
eval()</em>.</p>
<p>Block&nbsp;[6]: Gnuplot does not excel in plotting contours. In fact the
GNuplot user-manual suggests not to use it directly. Anyhow, we proceed,
because the out approach is easier to understand. The following three <code>
gset</code>s switch Gnuplot into contour-mode:</p>
<pre>
gset contour base # draw contours in the xy-plane
gset nosurface # do not draw the surface's mesh
gset view 0, 0 # view the xy-plane from above
</pre>
<p>Blocks&nbsp;[7] and [8] closely resemble those we have already seen in
Section <a href="#octave: 2d discrete data plot">``Octave: 2D Discrete Data
Plot''</a> and <a href="#octave: 3d function plot">``Octave: 3D Function
Plot''</a>.</p>
<p>More demo plots of Gnuplot can be found at <a href=
"http://www.gnuplot.org/gnuplot/gpdocs/all2.htm">
http://www.gnuplot.org/gnuplot/gpdocs/all2.htm</a></p>
<h2><a name="scilab">Scilab</a></h2>
<p>And now for a rather different approach ...</p>
<p>Scilab goes a different way to cope with the complexity, which we have
discussed in Section <a href="#complexity at large">Complexity at Large</a>.
In contrary to Gnuplot, Scilab does not strictly separate plotting and
setting, but offers a plethora (buckle up, then try: <code>apropos
plot</code>) of different plot commands to produce different kinds of plots.
Furthermore, the plot functions themselves take many arguments that change the
plots' appearances. Some of the arguments are so cryptic that you almost
certainly will want to have the appropriate man-page within sight.</p>
<p>For the reader who wants to look at the on-line help, but does not have
Scilab installed, the <a href=
"http://www.num.uni-sb.de/~ehrhardt/Ue_PraMa/scilab/doc/html/manual/docu023.html">
Scilab manual</a> is available online.</p>
<h3><a name="scilab: 2d discrete data plot">Scilab: 2D Discrete Data
Plot</a></h3>
<pre>
// [1] Read data set_i into N_i-times-2 matrices
set1 = read("l1.ascii", -1, 2);
set2 = read("l2.ascii", -1, 2);
set3 = read("l3.ascii", -1, 2);
</pre>
<pre>
// [2] Clear plot window's contents
xbasc();
</pre>
<pre>
// [3] Plot data; 1st plot command defines plot area
plot2d(set1(:, 1), set1(:, 2), -1, "011", ..
rect = [0, 8e-8, 100, 2e-6]);
plot2d(set2(:, 1), set2(:, 2), -2, "000");
plot2d(set3(:, 1), set3(:, 2), -3, "000");
</pre>
<pre>
// [4] Define decorations
xtitle(["Comparison of sets", "L1, L2, and L3"], ..
"Temperature / K", "Voltage / V");
legends(["Set L1 ", "Set L2 ", "Set L3 "], [-1, -2, -3], 2);
</pre>
<pre>
// [5] Save plot window's contents to file; convert file to PostScript
xbasimp(0, "sci1.xps");
unix("scilab -save_p sci1.xps.0 Postscript");
</pre>
<p><img height="447" alt=
"[Graphics: Please see the image caption of '2D Discrete Data Plot' in the Octave section.]"
src="misc/spiel/sci1.png" width="600"> The <a href="misc/spiel/sci1.eps">
Encapsulated Postscript output</a> is available, too.</p>
<p>Block&nbsp;[1] reads the data from disk-files into matrices.</p>
<p>Block&nbsp;[2] clears the graphics window (if it exists). Even more
important, <em>xbasc()</em> deletes all graphics commands that have been
recorded for the window. The mnemonic for <em>xbasc()</em> is x-bas-c for
<strong>x</strong>11-function, <strong>bas</strong>ic level, <strong>
c</strong>lear.</p>
<p>Tip: When playing with Scilab's plot functions, preceding the plot function
call with a clear command often saves keystrokes</p>
<pre>
xbasc(); plot2d(...);
</pre>
<p>in one line can be recalled for editing with a single C-p and replayed with
a single hit of the return-key.</p>
<p>In Block&nbsp;[3] the enigma raises its head! What in the world does</p>
<pre>
plot2d(set1(:, 1), // vector of x-values
set1(:, 2), // vector of y-values
-1, // style index
"011", // decoration control
rect = [0, 8e-8, 100, 2e-6]); // plot dimensions
</pre>
<p>do? I have added a comment for each argument, yet, to what does a ``style
index'' of -1 refer to? A badly dressed hacker? And what does the string in
``decoration control'' mean?</p>
<dl>
<dt><strong><a name="item_Style_index">Style index</a></strong><br>
</dt>
<dd>controls the kind of marker to draw for each data point or the color of
the line that joins the data points. A positive value&nbsp;<em>i</em> means:
draw a line with color&nbsp;<em>i</em>, a negative value means: use marker
type&nbsp;<em>abs(i)</em>. Note that <em>plot2d()</em> draws either markers or
lines, never both. If markers and lines are required for the same data set,
two plots with different style indices are necessary.</dd>
<dt><strong><a name="item_Decoration_control">Decoration
control</a></strong><br>
</dt>
<dd>always is a string of length&nbsp;3. Each character of the string controls
a certain aspect of the plot's decorations.
<dl>
<dt><strong><a name="item_Character_1">Character 1</a></strong><br>
</dt>
<dd>Toggle display of the plot caption. '<code>0</code>' is no caption,
'<code>1</code>' tells Scilab to display a caption.</dd>
<dt><strong><a name="item_Character_2">Character 2</a></strong><br>
</dt>
<dd>Control how the size of the plot is computed. Valid characters range from
'<code>0</code>' to '<code>8</code>'. Please see <em>plot2d()</em>
documentation for details.
<p>Here, we use '<code>1</code>' for the first plot and '<code>0</code>' for
all others. '<code>1</code>' lets the user explicitely specify the plot range
in the <code>rect</code>&nbsp;argument to <em>plot2d()</em>. If <em>
plot2d()</em> is called with '<code>0</code>', the size of a previous plot is
used and no size computation is done.</p>
</dd>
<dt><strong><a name="item_Character_3">Character 3</a></strong><br>
</dt>
<dd>Set the type of axes drawn around the plot. The user can choose from six
different values. We choose '<code>1</code>' for the first plot, which gives
axes on the bottom and the left hand side. The following plots use
'<code>0</code>', which means nothing is drawn around the plot.</dd>
</dl>
</dd>
</dl>
<p>Gee, that is quite a mouthful! Block&nbsp;[4] will give us some rest.</p>
<pre>
xtitle([title_line1; title_line2; ...], x_label, y_label)
</pre>
<p>Puts a possibly multi-line title into an existing plot and optionally
decorates the <em>x</em> and <em>y</em>-axis with labels.</p>
<pre>
legends([legend_1, legend_2, ...], [style_1, style_2, ...], position)
</pre>
<p>Places a legend in a plot where the position is given by <em>position</em>.
<em>position = 1</em> refers to the north east corner. The remaining corners
are enumerated counter-clockwise, this is, <em>position = 2</em> will put the
legend in the north west corner. The <em>style_i</em> parameters refer to the
same numbers that we have used as style indices in the <em>plot2d()</em>
calls. They determine which kind of marker or line is drawn right next to the
legend's text. The text is given by <em>legend_i</em>.</p>
<p>Finally, Block&nbsp;[5] converts the data in the graphics window to a
Postscript file.</p>
<pre>
xbasimp(0, "sci1.xps")
</pre>
<p>Replays all graphics commands for window&nbsp;0 (our only graphics window)
into <em>sci1.xps</em>. The function's name has nothing to do with a
X11-daemon named ``bas'', but has its stem from <strong>x</strong>11 and
<strong>bas</strong>ic level as <em>xbasc()</em>. The ``<strong>imp</strong>''
comes from the French word ``imprimer'', which means ``to print''. From which
language does ``fsck'' come from? N vcls, I guess.</p>
<p>File&nbsp;<em>sci1.xps</em> almost contains valid Postscript, but not
quite. The contents must be processed by Scilab</p>
<pre>
scilab -save_p sci1.xps.0 Postscript
</pre>
<p>adding the correct Postscript header and repositioning the graphics on the
page. The external Scilab is called by the <em>
unix(``shell-commands'')</em>&nbsp;function.</p>
<h3><a name="scilab: 3d function plot">Scilab: 3D Function Plot</a></h3>
<pre>
// [1] Define function
function z = f(u, v)
// truncated Rosenbrock function
z = 100.0*(v - u.^2).^2 + (1.0 - u).^2
z(find(z &gt; 100)) = 100;
endfunction
</pre>
<pre>
// [2] Define sampling grid for f()
x = linspace(-3, 3, 40);
y = linspace(-2, 4, 40);
</pre>
<pre>
// [3] Clear plot window's contents
xbasc();
</pre>
<pre>
// [4] Plot
fplot3d(x, y, f, 65, 1.5);
</pre>
<pre>
// [5] Define decoration
xtitle("Rosenbrock Function", "u", "v");
</pre>
<pre>
// [6] Save plot window's contents to file; convert file to PostScript
xbasimp(0, "sci2.xps");
unix("scilab -save_p sci2.xps.0 Postscript; " ..
+ "gzip --best --force sci2.eps");
</pre>
<p><img height="447" alt=
"[Graphics: Please see the image caption of '3D Function Plot' in the Octave section.]"
src="misc/spiel/sci2.png" width="600"> Here is the gzipped <a href=
"misc/spiel/sci2.eps.gz">Encapsulated Postscript version</a> (eps.gz) of the
graphics.</p>
<p>After so much new stuff in Section <a href="#scilab: 2d discrete data
plot">Scilab: 2D Discrete Data Plot</a> the only unknown here hides in
Block&nbsp;[4]:</p>
<pre>
fplot3d(x_vector, y_vector, function_of_x_and_y, alpha, theta)
</pre>
<p>The vectors&nbsp;<em>x_vector</em> and <em>y_vector</em> define the grid on
which <em>function_of_x_and_y</em> is evaluated. Comparing <em>fplot3d()</em>
with Octave's <em>gsplot</em> we notice, that Scilab generates the grid for
us. Function&nbsp;<em>fplot3d()</em> is a convenience function, built on top
of</p>
<pre>
plot3d(x_vector, y_vector, z_matrix, alpha, theta)
</pre>
<p>which resembles <em>gsplot</em> (and Tela's <em>mesh()</em>).</p>
<p>The parameters <em>theta</em> and <em>alpha</em>, define the elevation of
the view point and the rotation around the <em>z</em>-axis respectively.</p>
<h3><a name="scilab: contour function plot">Scilab: Contour Function
Plot</a></h3>
<pre>
// [1] Define function
function z = g(u, v)
z = exp(u) .* (4.0*u.^2 + 2.0*v.^2 + 4.0*u.*v + 2.0*v + 1.0)
endfunction
</pre>
<pre>
// [2] Define weight function for iso-line distances
function y = pow_weight(x, n)
// Map interval X onto itself, weight with N-th power.
d = max(x) - min(x)
y = d*((x - min(x))/d).^n + min(x)
endfunction
</pre>
<pre>
// [3] Define sampling grid for g()
x = linspace(-4.5, -0.5, 40);
y = linspace(-1.0, 3.0, 40);
</pre>
<pre>
// [4] Evaluate g() at points defined by X and Y
z = eval3d(g, x, y);
</pre>
<pre>
// [5] Compute iso-line distances
iso_levels = pow_weight(linspace(min(z)*1.01, max(z)*0.99, 12), 3.0);
</pre>
<pre>
// [6] Clear plot window's contents
xbasc();
</pre>
<pre>
// [7] Set format of iso-line annotation and plot
xset("fpf", "%.2f");
contour2d(x, y, z, iso_levels);
</pre>
<pre>
// [8] Define decoration
xtitle("Contour Plot of g(u, v)", "u", "v");
</pre>
<pre>
// [9] Save plot window's contents to file; convert file to PostScript
xbasimp(0, "sci3.xps");
unix("scilab -save_p sci3.xps.0 Postscript");
</pre>
<p><img height="447" alt=
"[Graphics: Please see the image caption of 'Contour Function Plot' in the Octave section for the image's description.]"
src="misc/spiel/sci3.png" width="600"> The output is available as <a href=
"misc/spiel/sci3.eps">printer-ready version</a> (eps), too.</p>
<p>Remember the difficulties we had with the user-defined iso-lines in
Octave/Gnuplot? The problem can be solved in Scilab without any tricks, magic,
or bribery. As with <em>plot3d()</em>, Scilab defines a convenience
function</p>
<pre>
fcontour2d(x_vector, y_vector, function_of_x_and_y, levels)
</pre>
<p>as a wrapper around</p>
<pre>
contour2d(x_vector, y_vector, z_matrix, levels)
</pre>
<p>However, as we must know the maximum and minimum value of <em>g(u, v)</em>
on the grid, <em>fcontour2d()</em> would not save us anything. Thus, Block [4]
computes <em>g(u, v)</em> on the grid defined by <em>x</em> and <em>
y</em>:</p>
<pre>
z = eval3d(g, x, y)
</pre>
<p>In Block&nbsp;[7], we use <em>z</em> and <em>iso_levels</em> from
Block&nbsp;[5]. The <em>xset()</em> call sets the <strong>f</strong>loating
<strong>p</strong>oint <strong>f</strong>ormat (``fpf'') to
``<code>%.2f</code>'', which is a C-printf format specifier that forces all
contour line numbers to have two digits after the decimal point.</p>
<p>All other blocks only use functions already discussed in the other
plots.</p>
<p>More demo plots of Scilab are found at <a href=
"http://www-rocq.inria.fr/scilab/doc/demos_html/node183.html">INRIA's Scilab
site</a>.</p>
<p>Scilab has much more to offer than the functions we have seen right above.
For example, it supplies</p>
<ul>
<li>Low-level functions to draw points, lines, polygons, etc.</li>
<li>
<p>Surface facets which are the building blocks for 3d-environments. (See for
example Enrico Segre's amazing <a href=
"http://www.polito.it/~segre/scigallery.html">Scigallery</a>)</p>
</li>
<li>High-level GUI-interface for rapid development of tailor-made Scilab
applications.</li>
<li>Feedback functions that allow passing back information from any graphics
window to Scilab.</li>
</ul>
<h2><a name="tela">Tela</a></h2>
<p>In the sections on <a href="#octave">Octave</a> and <a href="#scilab">
Scilab</a>, we have seen that both applications save auxiliary ``state'' of
the plot window. Gnuplot does so to the max: <code>gplot</code> or <code>
gsplot</code> have almost no parameters. The state is controlled by <code>
gset</code> commands. Scilab stores some state of the plot window as, for
example, the legend and title.</p>
<p>Tela uses the external application PlotMTV to display graphs. With PlotMTV,
Tela is located on the other side of the spectrum: its plots have no state,
and all information about the plot has to go into the call to the actual
plotting function. The advantage of Tela's approach is that multiple plots do
not interfere (unless we force them to do so by calling <code>hold(on)</code>
or <code>hold(off)</code> as we will see soon). The downside is that the calls
to plotting functions can get rather long.</p>
<p>As has been in the discussions of the other plotting applications, it is
helpful to have a PlotMTV manual within reach.</p>
<h3><a name="tela: 2d discrete data plot">Tela: 2D Discrete Data Plot</a></h3>
<pre>
// [1] Read data set_i into N_i-times-2 matrices
set1 = import1("l1.ascii");
set2 = import1("l2.ascii");
set3 = import1("l3.ascii");
</pre>
<pre>
// [2] Define plotting function
function do_plot(d1, d2, d3)
{
hold(on); // postpone actual plotting until hold(off)
</pre>
<pre>
// render set 1
plot(d1[:, 1], d1[:, 2],
"linestyle", 0,
"markertype", 2,
"linelabel", "Set L1",
// Define decorations
"toplabel", "Comparison of sets",
"subtitle", "L1, L2, and L3",
"xlabel", "Temperature / K",
"ylabel", "Voltage / V",
// Define plot area
"xmin", 0,
"xmax", 100,
"ymin", 8e-8,
"ymax", 2e-6);
// render set 2
plot(d2[:, 1], d2[:, 2],
"linestyle", 0,
"markertype", 3,
"linelabel", "Set L2");
// render set 3
plot(d3[:, 1], d3[:, 2],
"linestyle", 0,
"markertype", 4,
"linelabel", "Set L3");
</pre>
<pre>
hold(off); // plot!
};
</pre>
<pre>
// [3] Plot to X11 window
do_plot(set1, set2, set3);
</pre>
<pre>
// [4] Plot into a postscript file
plotopt("-o tela1.eps -printcmd 'cat' -noxplot -print");
do_plot(set1, set2, set3);
</pre>
<p>Hmm, this script looks differently! It does -- because I have to play
another trick that has to do with the statelessness plot functions. As Tela
``forgets'' the parameters after displaying graphics in an X11-window, I would
have to retype everything with output redirected to a Postscript file. Well,
code duplication is known to be the root of many (not all) evil. Thus, the
Tela plots are wrapped into a function. The further strategy is displaying the
plot in an X11 window, changing the output file and type, which is somewhat
analogous to Gnuplot, and then plotting again into an eps-file:</p>
<pre>
do_plot(...); // display plot in X11 window
plotopt("-o foo.eps -printcmd 'cat' -noxplot -print"); // redirect output
do_plot(...); // render plot in Encapsulated Postscript file foo.eps
</pre>
<p><img height="800" alt=
"[Graphics: Please see the image caption of '2D Discrete Data Plot' in the Octave section.]"
src="misc/spiel/tela1.png" width="600"> <a href="misc/spiel/tela1.eps">
Encapsulated Postscript version</a> of the graphics.</p>
<p>Function&nbsp;<em>do_plot</em> in Block&nbsp;[2] takes care of all output
by using function&nbsp;<em>plot()</em>. The general structure of Tela's <em>
plot()</em>, in fact all Tela plot functions, is first passing the mandatory
data arguments as vectors or matrices followed by optional key-value
strings.</p>
<pre>
plot(x_vector, y_vector // data
"option_key1", "option_value1", // option 1
"option_key2", "option_value2", // option 2
...
"option_keyN", "option_valueN"); // option N
</pre>
<p>Note that putting one key-value pair per line enhances the readability of
the whole call.</p>
<p>The key-value strings themselves are self-explaining. Non-obvious
associations like linestyle&nbsp;=&gt;&nbsp;0 (= invisible line) or
markertype&nbsp;=&gt;&nbsp;2 (= plus sign) must be looked up in the manual or
in a reference plot which shows all available line styles.</p>
<h3><a name="tela: 3d function plot">Tela: 3D Function Plot</a></h3>
<pre>
function v = linspace(a, b; n)
{
if (isdefined(n)) nn = n else nn = 100;
v = a + (0 : nn - 1) * (b - a) / (nn - 1)
};
</pre>
<pre>
// [1] Define function
function z = f(u, v)
{
// truncated Rosenbrock function
z = 100.0*(v - u^2)^2 + (1.0 - u)^2;
z[find(z &gt; 100.0)] = 100.0;
};
</pre>
<pre>
// [2] Sample function f()
x = linspace(-3.0, 3.0, 40);
y = linspace(-2.0, 4.0, 40);
[xx, yy] = grid(x, y);
zz = f(xx, yy);
</pre>
<pre>
// [3] Define plot function
function do_plot(x, y, zz)
{
mesh(zz,
"xgrid", x,
"ygrid", y,
"toplabel", "Rosenbrock Function",
"xlabel", "u",
"ylabel", "v",
"hiddenline", "true",
"eyepos.z", 2.0)
};
</pre>
<pre>
// [4] Render plot into X11 window
do_plot(x, y, zz);
</pre>
<pre>
// [5] Plot into a postscript file
plotopt("-o tela2.eps -printcmd 'cat' -noxplot -print");
do_plot(x, y, zz);
system("gzip --best --force tela2.eps");
</pre>
<p><img height="800" alt=
"[Graphics: Please see the image caption of '3D Function Plot' in the Octave section.]"
src="misc/spiel/tela2.png" width="600"> An gzipped <a href=
"misc/spiel/tela2.eps.gz">Encapsulated Postscript version</a> (eps.gz) of the
plot is available, too.</p>
<p>Tela has no built in <em>linspace()</em>&nbsp;function, so I quickly define
one.</p>
<p>Block&nbsp;[2] resembles Block&nbsp;[2] in Section <a href="#octave: 3d
function plot">``Octave: 3D Function Plot''</a>, where Octave's <em>
meshgrid()</em> has been replaced by Tela's <em>grid()</em>.</p>
<p>The 3d-mesh plotting function <em>mesh()</em> takes a matrix of <em>
z</em>-values as its first argument; the grid-specification is given in the
options:</p>
<pre>
mesh(z_matrix,
"xgrid", x_vector,
"ygrid", y_vector);
</pre>
<p>Of course, the sizes of <em>z_matrix</em>, <em>x_vector</em>, and <em>
y_vector</em> must be compatible.</p>
<h3><a name="tela: contour function plot">Tela: Contour Function Plot</a></h3>
<pre>
function v = linspace(a, b; n)
{
if (isdefined(n)) nn = n else nn = 100;
v = a + (0 : nn - 1) * (b - a) / (nn - 1)
};
</pre>
<pre>
// [1] Define function
function z = g(u, v)
{
z = exp(u) * (4.0*u^2 + 2.0*v^2 + 4.0*u*v + 2.0*v + 1.0)
};
</pre>
<pre>
// [2] Define weight function for iso-line distances
function y = pow_weight(x, n)
{
// Map interval X onto itself, weight with N-th power.
d = max(x) - min(x);
y = d*((x - min(x))/d)^n + min(x)
};
</pre>
<pre>
// [3] Sample function f()
x = linspace(-4.5, -0.5, 40);
y = linspace(-1.0, 3.0, 40);
[xx, yy] = grid(x, y);
zz = g(xx, yy);
</pre>
<pre>
// [4] Compute iso-line distances
iso_levels = pow_weight(linspace(min(zz)*1.01, max(zz)*0.99, 12), 3.0);
il_str = sformat("``", iso_levels);
il_str = il_str[2 : length(il_str)];
</pre>
<pre>
// [5] Define plot function
function do_plot(x, y, zz, iso_levels_str)
{
contour(zz,
"xgrid", x,
"ygrid", y,
"toplabel", "Contour Plot of g(u, v)",
"xlabel", "u",
"ylabel", "v",
"contours", iso_levels_str)
};
</pre>
<pre>
// [6] Render plot into X11 window
do_plot(x, y, zz, il_str);
</pre>
<pre>
// [7] Plot into a postscript file
plotopt("-o tela3.eps -printcmd 'cat' -noxplot -print");
do_plot(x, y, zz, il_str);
</pre>
<p><img height="800" alt=
"[Graphics: Please see the image caption of 'Contour Function Plot' in the Octave section for the image's description.]"
src="misc/spiel/tela3.png" width="600"> Also available is an Encapsulated
Postscript <a href="misc/spiel/tela3.eps">printer version</a>.</p>
<p>Tela requires us to play a similar trick on PlotMTV as we had to when
convincing Octave to pass the contours' values to Gnuplot. However, the trick
in Block&nbsp;[4] is not as involved. Again, the first step is to compute the
vector&nbsp;<em>iso_levels</em>. Function&nbsp;<em>sformat()</em> works
analogously to Octave's <em>sprintf()</em>, though the vectors are differently
formatted as the transcript shows (<em>il_str</em> has been edited to fit the
line).</p>
<pre>
&gt;il_str = sformat("``", iso_levels);
&gt;il_str
"#(0.583444, 0.592029, 0.65212, 0.815224, 1.13285, 1.6565, \
2.43768, 3.5279, 4.97867, 6.84149, 9.16786, 12.0093)"
</pre>
<p>PlotMTV does understand a vector that is enclosed in parenthesis, but the
leading sharp-sign must go</p>
<pre>
il_str = il_str[2 : length(il_str)];
</pre>
<p>In this form, <em>il_string</em> can be passed as value to the option key
<code>contours</code> in function&nbsp;<em>contour()</em>.</p>
<p>More demo plots of PlotMTV can be found at <a href=
"http://csep1.phy.ornl.gov/cornell_proceedings/tutorials/Plotmtv/overview.html">
ORNL</a> and at <a href=
"http://www.hammersmith-consulting.com/plotmtv-us-g.html">HSC</a>.</p>
<p>By the way, PlotMTV suits perfectly as graphical backend for home grown
scripts and programs. The PlotMTV manual consistently helps the reader to
develop programmatic interfaces for her own applications.</p>
<h2><a name="closing comments on graphics">Closing Comments on
Graphics</a></h2>
<p>We have seen how to get publication ready data and function plots from
GNU/Octave, Scilab, and Tela. Sometimes the solutions have been intricate,
because of implementations' restrictions. However, all <a href="#problems">
problems</a> could be solved.</p>
<p>The effort in creating pleasantly looking graphs appears to be high and
almost independent of the chosen application.</p>
<!-- *** BEGIN bio *** -->
<SPACER TYPE="vertical" SIZE="30">
<P>
<H4><IMG ALIGN=BOTTOM ALT="" SRC="../gx/note.gif">Christoph Spiel</H4>
Chris runs an Open Source Software consulting company in Upper Bavaria/Germany.
<EM>Despite being trained as a physicist -- he holds a PhD in physics from Munich
University of Technology -- his main interests revolve around numerics,
heterogenous programming environments, and software engineering. He can be
reached at
<A HREF="mailto:cspiel@hammersmith-consulting.com">cspiel@hammersmith-consulting.com</A>.</EM>
<!-- *** END bio *** -->
<!-- *** BEGIN copyright *** -->
<P> <hr> <!-- P -->
<H5 ALIGN=center>
Copyright &copy; 2001, Christoph Spiel.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 71 of <i>Linux Gazette</i>, October 2001</H5>
<!-- *** END copyright *** -->
<H4 ALIGN="center">
"Linux Gazette...<I>making Linux just a little more <STRONG>SCARY!</STRONG></I>"
</H4>
<P> <hr> <P>
<H1><font color="maroon">The Back Page</font></H1>
<ul>
<li><a HREF="#wacko">Wacko Topic of the Month</a>
<li><a HREF="#nottag">Not The Answer Gang</a>
<li><a HREF="#spam">World of Spam</a>
</ul>
<a name="wacko"></a>
<P> <hr> <P>
<!--====================================================================-->
<center><H3><font color="maroon">Wacko Topic of the Month</font></H3></center>
<P> <hr> <P>
<!--====================================================================-->
<H1><FONT COLOR="#CC0000">
<IMG ALT="" SRC="misc/backpage/redbat.png" WIDTH="89" HEIGHT="61">
<IMG ALT="" SRC="misc/backpage/redbat.png" WIDTH="89" HEIGHT="61">
Red Bat Linux
<IMG ALT="[bat.png]" SRC="misc/backpage/redbat.png" WIDTH="89" HEIGHT="61">
<IMG ALT="" SRC="misc/backpage/redbat.png" WIDTH="89" HEIGHT="61">
</FONT></H1>
<P> <FONT COLOR="#CC0000">Red Bat--The Halloween Edition.</FONT> The only
distribution with a SUI (spooky user interface). Voted most
popular distribution in Transylvania. Distributed under the GNU ("Goblins,
Newts and Undertakers") Public License. Featured packages:
<UL>
<LI> SATAN
<LI> kill, killall, terminate
<LI> Dracula Web Server
<LI> BTP (Blood Transfer Protocol)
<LI> alien
<LI> bastille (get rid of your enemies quick)
<LI> bob (watch Bill Gates bob for apples)
<LI> croff (like cron, but run events at random times)
<LI> curses (cast curses on your enemies. The curse will contain words like tail, toe, head, touch, finger, gawk, gnome, frog)
<LI> dungeon (the rattling of ipchains, bind and whiptail, and ringing of bells)
<LI> espell (evil spellchecker, with interesting "suggestions" for words. A companion to <A HREF="../issue51/collinge.html">VI-agra</A>.)
<LI> exorcise
<LI> fork (a good way to <A HREF="orr.html">destroy your hard drive</A>)
<LI> fortune, palmreader (used to extract data from Palm Pirates)
<LI> frankenpotato (dress a genetically-modified potato. Inspired by the KDE Potato Guy. See a <A HREF="misc/backpage/frankenpotato.jpg">screenshot</A>.)
<LI> ghostscript
<LI> gibberish
<LI> goblin (gobble input. Same as "cat >/dev/null 2>&1".)
<LI> hell (crash your neighbor's computer)
<LI> insane (drive another user insane)
<LI> ipmasqadm (plan a masquerade ball)
<LI> konquest, kruler (KDE World Domination games)
<LI> mc (Midnight Commander)
<LI> mkzombie
<LI> replicator
<LI> scare (same as "fortune | write $VICTIM")
<LI> setiathome (search for extraterrestrial life)
<LI> shadow
<LI> spellcaster (cast a variety of spells. Use with the kernel's IP Multicasting feature for extra effect.)
<LI> stormpkg (Storm Package Manager with an embedded game of Risk)
<LI> tar+feather
<LI> threaten
<LI> tmpreaper
<LI> trickortreat (a port scanning tool)
<LI> who (make a sound like an owl)
<LI> witch (call up a witch in six easy keystrokes including the newline)
</UL>
<SMALL>
(For those who didn't get the "bob" joke, Microsoft Bob was a "family-oriented
interface for Microsoft Windows" that utterly failed in the marketplace. The
pages are gone from Microsoft's web site, but here's a
<A
HREF="http://www.gratefuldad.com/twinsoft/products/msbob/msbob.html">product
summary</A> from a third-party sales site and a <A
HREF="http://www.strategymag.com/articles/magazine/19950123/10078.html">Canadian
prelaunch announcement</A>.)
</SMALL>
<P>
<IMG ALT="[skull &amp; crossbones]" SRC="misc/backpage/kill.jpg">
<BR CLEAR="all">
<a name="nottag"></a>
<P> <hr> <P>
<!--====================================================================-->
<center><H3><font color="maroon">Not The Answer Gang</font></H3></center>
<P> <HR> <P>
<!--======================================================================-->
<P>
<H3 ALIGN="center">Help me crack my school</H3>
<p align="right"><FONT COLOR="#000000"><strong>Answered By Iron, Heather Stern
</strong></FONT></p>
<STRONG>
just wondering how I can get into my schools computer? Its not like I am
going to do anything with it but I was just wondering if there is a way to
hack into the network system and well u know....
</STRONG>
<P>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Iron]
<P> If you read past issues of The Answer Gang, you'll see that we do not
offer help for cracking networks. But you will find much of entertainment,
and may learn a thing or two about Linux.
<P> If you type "hack,hacking,hacker" (that's "hack OR hacking OR hacker")
in the LG search engine, you will see several articles about hacking.
[Note: the search engine was changed after this was written, and comma-OR
no longer works.] But you
will discover that the word has a different meaning than how you are using it.
Hacking means spending long hours at the computer doing trial-and-error
experiments, and making new discoveries about how the system works or creating
new generally-useful programs. Breaking into somebody else's computer is a
whole different activity, and the term for this is "cracking".
<P> Of course if you're in the US, there's a bill in Congress now that would
<A HREF="lg_bytes71.html#legislation">equate cracking with terrorism</A> and
land you life in prison.
<P>
<IMG SRC="../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Heather]
<P>
<BLOCKQUOTE>
just wondering how I can get into my schools computer?
</BLOCKQUOTE>
Wait for the teacher to let you into class, turn it on, then wait for him
or her to tell you all the class login ID.
<BLOCKQUOTE>
Its not like I am going to do anything with it but I was just wondering
</BLOCKQUOTE>
...why I paid so much for community college (gosh I could go to the movies
a few times or buy some great clothes) when I hate computers, but then I
remember someone saying there's a bunch of money in computers, so I really
ought to get into one.
<BLOCKQUOTE>
if there is a way to hack into the network system and well u know....
</BLOCKQUOTE>
After I get all the money out of this computer I plan to shake any loose
change out of that ethernet hub too.
<H3 ALIGN="center">2-Cent Tip</H3>
<P>
<PRE>
rm -rf /bin/laden
</PRE>
Do it now and often!
<P> -- <BR>
BanDiDo is powered by Mandrake Linux and beer!
<BLOCKQUOTE><EM>
[You can also make this a nightly cron job. -Iron.]
</EM></BLOCKQUOTE>
<a name="spam"></a>
<P> <hr> <P>
<!--====================================================================-->
<center><H3><font color="maroon">World of Spam</font></H3></center>
<P> <HR> <P>
<!--======================================================================-->
<P>
<H3>Custom Made Theatrical/Costume Fangs</H3>
From: Killer Fangs!! &lt;shmuck@loser.com&gt;
<P> Have you been looking for a really good set of fangs? Are you trying to
achieve a certain look, be it from your favorite movie, or your worst
nightmare? Your search is over! Each set of our fangs meet standards of
quality as well as aesthetic appearance and will offer you that special "look"
you want. We offer custom fit, custom colored, and hand carved fangs tailored
to your specifications.
<P> Don't wait too long to start your fangs for Halloween!
<H4>Ben Okopnik writes:</H4>
Not much Linux content, though.
<H4>Chris G. writes:</H4>
Unless we can transmute our daemon processes into vampires by attaching
those fangs to them.
<HR> <!-- ************************************************************** -->
<P> Happy Linuxing!
<P> Mike ("Iron") Orr<br>
Editor, <A HREF="http://www.linuxgazette.com/"><i>Linux Gazette</i></A>, <A
HREF="mailto:gazette@ssc.com">gazette@ssc.com</a>
<BR CLEAR="all">
<!-- *** END Not Linux *** -->
<!-- *** BEGIN copyright *** -->
<P> <hr> <P>
<H5 ALIGN=center>
Copyright &copy; 2001, the Editors of <I>Linux Gazette</I>.<BR>
Copying license <A HREF="../copying.html">http://www.linuxgazette.com/copying.html</A><BR>
Published in Issue 71 of <i>Linux Gazette</i>, October 2001</H5>
<!-- *** END copyright *** -->
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