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The Mailbag


HELP WANTED : Article Ideas
Submit comments about articles, or articles themselves (after reading our guidelines) to The Editors of Linux Gazette, and technical answers and tips about Linux to The Answer Gang.


2.6's constant complaining about untranslated keyboard keys

Mon, 14 Jun 2004 13:02:11 -0700 (PDT)
Bradley Chapman (kakadu_croc from yahoo.com)
atkbd.c: Unknown key released (translated set 2, code 0x7a on isa0060/serio0).
atkbd.c: This is an XFree86 bug. It shouldn't access hardware directly.
atkbd.c: Unknown key released (translated set 2, code 0x7a on isa0060/serio0).
atkbd.c: This is an XFree86 bug. It shouldn't access hardware directly.

Does anybody get this at all on their 2.6 Linux systems? I get it all the time and have just dismissed it, but now I'm curious if anyone has bothered to figure out why it happens.

Also, I've just got ahold of a Gmail account, but I haven't been able to decide what to do with it. Does anyone else have a similar dilemma? ;-)

Brad


getting email from an external server

Mon, 14 Jun 2004 14:30:12 -0400
sbasurto (sbasurto from playboyunderwear.com)

Good afternoon, My question is...

I setup an Internet server with debian the lastest version, I also configure a squid proxy 2.4 estable6 with squidGuard as redirector, a dhcp, a dns, and ipchains.

The configuration looks like:

            190.0.0.3
Workstation|---------|--|
                        |    eth0   --------------    eth1       -----
            190.0.0.4   |-|190.0.0.1|Linux Server|192.168.0.1|---|DSL|
Workstation|---------|--|           --------------               -----
                                         x.x.x.x                   |
                                      ---------------   Internet   |
                                      | Mail Server |--------------|
                                      ---------------

What I am expecting - Run send/recive email messages in what ever email client in a workstation within my lan and get the email from the external server or send email with the external server.

What is happening - Run send/recieve email messages in Outlook with the right configuration and it sends a "Conection Refused by the Server" or "Conection Timeout".I understand that maybe what I am looking for is a pop3 and smtp poxy server, nevertheless I install pop3.proxy and smtp.porxy servers in my linux box an it does not retrieve or send the email from workstation to the external server. I configure fetchmail too an it work but within the server, if I try to get email from a workstation it crash.

What I already did -

  1. I already run tcpdump in the eth where the internet conection is (In my case eth1). In this point I want to mention that in the output of tcpdump I never saw the header for the retrive of the email message from the client(Workstation) to the server, nevertheless the conection to Internet is working fine.
  2. I also stop my firewall because may be a misconfiguration of the firewall can block my email, but even without firewall, it crash.
  3. I installed a pop3 and smtp proxies, and get them run as an inetd service, but without sucess. I mean the proxy run but can retrieve email from workstation.
  4. Finally I had this configuration working with SuSE the problem is that I do not know exactly how I did it.

At this point I hope some one of you can help me or tell me what I am doing wrong. Or tell me whatever documentation where I can get an answer.

Regards

Sergio B.J


Scripting languages compared

Sun, 13 Jun 2004 08:34:47 +0100
Jimmy O'Regan (The LG Answer Gang)
[Jimmy O'Regan]
http://merd.sourceforge.net/pixel/language-study/scripting-language
sh wins, closely followed by Perl and Ruby.
Read that backwards, in terms of winning order and: \o/ -- Thomas
Well, he's wrong about "sh" not having a debugger, particularly since he's using Bash; "-x" certainly fits the bill. Step-by-step execution, no, but I think that would go under "full interpreter in debugger".
As to his length comparisons for different programs - certainly in regard to Perl - he had me cracking up. E.g., the Perl entry for 'env' has his actual home directory name spelled out...
The rest of it, I'm afraid, demonstrates his lack of knowledge of the several languages I can vouch for rather than being an accurate comparison of any sort (he did mostly OK with "sh", though. :) -- Ben
Ok, it's your chance, gentle readers. Would anyone like to take a more thorough and in-depth view about how the languages compare? We come not to flame Caesar, but to praise him... code samples maybe, but a fair treatment is called for at the very least. -- Heather

GENERAL MAIL


Compliments to you all.

Fri, 4 Jun 2004 13:15:18 +0100
Steve Brown (sp_brown from hotmail.com)

Hi there,

I've just finished reading some of the June issue, I got the feeling that you are all a little dejected - don't be! You all produce a fantastic read, absolutely superb - much better than that other one (I did write and tell them they were crap, but they didn't reply funnily enough).

Thanks, Steve. I don't know that I'd call it dejection - it's more of a realization of a lot of work ahead, at least for me. Given that I enjoy it, though, that's no bad thing. -- Ben

I used to use an Amiga (still own it sans powerpack) and I spent hours and hours learing to program in C (very very simple stuff), shell scripts and the like. I loved the learning process and the usability of it all. I was forced into buying a PC (following the demise of the power pack) and it came complete with Win95, what a nightmare -I couldn't find out how any of it worked without paying for the information one way or another. Then I came across Mandrake 8, actually I was desperately looking for something other than Windows, and my little world changed. All the information I could ever want and then some.

One of my earliest discoveries was your good selves. My favourite Amiga mag was Amiga Shopper - a good mix of basic newbie stuff and more advanced information - programming, how the machine works and so on. It pandered to my newbie needs and as I grew in knowledge so I gained even more from the magazine.

Your magazine offers something similar, a good mix without pandering too much to the total newbie. So many magazines seem to offer a three monthly cycle of tutorials with little new material.

I was actually considering recycling a bit of our previous material. Jim Dennis' "Routing 101" is an evergreen that can definitely stand to be exposed to new minds; my own Perl and shell tutorials (it turns out that somehow one of the articles I wrote for it never got published!), too. Yes, people can find them in the old issues - but I suspect that many of our readers don't go trolling through the archives but just read us once a month.
(If anyone's got suggestions on a previous article that's worth dusting off, my mailbox is always open.) -- Ben

The only thing I'd like to see is how to build/design a program in for Linux, don't care what language, just how to design, program and test it, to give a good correct program.

[grin] See those very tutorials that I've mentioned. I suggest starting with shell scripting and climbing up from there. -- Ben

My Amiga programs were very simple, single user affairs, and I really don't get OOP and multi user stuff yet. I mean how do you prevent buffer over-runs and memory loss for example.

Those aren't an issue in the modern scripting languages (shell, Perl, Python, etc.) In C, well, see my response to Tom. Unless you really know what you're doing, C can be very dangerous indeed. -- Ben
[Tom Brown] Tip: If you want to learn how to program in OOP, spend a little time learning Borland's Delphi (it uses a Pascal variant). It has nearly all the power of C++, and is easier to use than Visual Basic. Once you get all the C++ syntax out of the way, you'll learn OOP in no time. Then you can move on to something like C++, Java, or C#. I had the same trouble you did, and that's what worked for me.
[Jimmy O'Regan] You mean Kylix, which is the Linux version. There's also the Lazarus IDE (http://www.lazarus.freepascal.org) for Free Pascal (http://www.freepascal.org).
I've snipped a bit of replies that were a sideline about programming details themselves - with the Gang chiming in, it might make a good thread or an article in upcoming months. -- Heather

In the meantime, I shall continue to enjoy your magazine.

Some other thoughts: Get more people to link to you and advertise your site more, most people would do it out of gratitude for all the good work you guys do.

Something like that is in process now; it's one of those things that I mentioned discussing with Heather. -- Ben

Find every occurence of the .com one and get a link to your site on there as well - surfers will compare sites and you'll win hands down!

Thanks. A couple of our people were doing just that, right after the separation. -- Ben

Take care and all the best,

Steve Brown

Note: I had to use a Hotmail account (yeuchh) as my dog took a fancy to copper cored wire and ate every single wire sticking out the back of my box, he only left me with a monitor lead. Next time I'm gonna leave it switch on.

[laugh] If you write it up and send it to me, it'll end up in "The Foolish Things We Do With Our Computers" column sometime soon. -- Ben
...and indeed, you can see it here! Any foolish things you've done to your computers? Send 'em in... -- Heather

Hi Ben, thank you for the reply.

I'll keep an eye out for those tutorials. I've got the O'Reilly Learning Perl Book and I'm still getting over the stage of "it looks like garbage", familiarity will sort all of that out no doubt. I seem to recall your one-liner articles, I found those fascinating as they demonstrated the problem solving methods you use, and gave a good insight in how to use what's already there.

[Ben] Actually, I was talking about my 5-part "Learning Perl" series. Take a look at http://linuxgazette.net/authors/okopnik.html .

Aahh, I'd forgotten about these gems, thank you.

I'm glad to see that buffer overruns etc. are not a problem in Perl or Python, I'll just avoid C, I'm most familiar with it as a language but it's some time since I actually used it. Thanks for the example program, I'm looking forward to looking at that and trying to work out why it isn't correct.

[Ben] As Thomas has already noted (something I originally missed due to being tired and mostly asleep), it's a buffer overflow due to strncpy not terminating the string - a truly idiotic design decision. From libc's info:
 - Function: char * strncpy (char *restrict TO, const char *restrict
          FROM, size_t SIZE)
     This function is similar to `strcpy' but always copies exactly
     SIZE characters into TO.

     If the length of FROM is more than SIZE, then `strncpy' copies
     just the first SIZE characters.  Note that in this case there is
     no null terminator written into TO.
no null terminator oh my.
At that point, as they say, the rest^H^H^H^Hsystem is history...

Nope, I would never have got this, I'll still run the example to see what happens 'first hand' though.

[Ben] The actual mechanism, which can be seen by disassembling the corefile, is a stack smash via a free() call overrun.
jail@Fenrir:~$ gdb -q -c core smash
Core was generated by `./smash
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libc.so.6...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
#0  0x40096acf in _int_free () from /lib/libc.so.6
(gdb) x/i $eip
0x40096acf <_int_free+191>:     mov    %eax,0xc(%edx)
(gdb) info reg eax edx
eax            0x34333231       875770417
edx            0x44434241       1145258561
(gdb)
Joel Eriksson did a very impressive demo of getting root with the above proglet in the vulndev forum. He used Solar Designer's shellcode, computed the EIP, and pushed the shellcode onto the stack; voila . This, of course, required the proglet to be SUID. Took ~20 lines of C.

I'm still challenged with a modem, I've got a HCF modem that refused to work correctly when I upgraded my motherboard, I'm going to dig it out and play with it some more [grin].

[Ben] http://linmodems.org :)

Yeah, my modem used to work, but I just upgraded from a Duron to Athlon XP on a new board and the modem didn't work correctly, as I had a spare external modem, although only 33.6 kbs, I used that instead, too lazy to sort it out. Now my dog's busy digesting big chunks of the power supply I'm forced to get HCF modem running.

Take care,

Steve Brown.


Re: Dual "Linux Gazette"?

Sun, 6 Jun 2004 13:49:40 -0400
Ben Okopnik (LG Technical Editor)
Question by God Rudy (Dpfrdtrky from netscape.net)

Hello Linux Gazette and Editor;

[Ben] Hi, Rudy -

I hope that this is the correct mailbox for my "old" question. About last december i noticed that "www.linuxgazette.com" changed it pages drasticaly, to the bad. Through a longer search, i found "linuxgazette.net" (the "old version").

What happend?

I was reading backissues of both versions trying to find some answers --> no much succes!

[Ben] The answer can be found in the cover article that I wrote when we separated from SSC (the hosts of LG.com) - take a look at http://linuxgazette.net/issue96/reborn.html . We've actually been trying to contact readers like yourself, trying to get the word out that the original Gazette and the original mission are still very much in operation and going full force; unfortunately, we have not had much success, particularly since SSC has acted very hostile indeed throughout the entire process and has supressed any mention of us in their pages.
We still have a large number of readers, mirrors, and translators, but I wish there was a way to notify people like yourself of the change. If you have any ideas on that score, please feel free to let me know.

Rudy (just another garden variety God :-)

[Ben] Aren't we all? :)

Hello Ben;

Thanks.

Found it! I was expecting something with more "flags". I was just looking for the wrong thing :-)

Rudy


Re: Foolish things....

Sun, 13 Jun 2004 10:15:00 -0400
Charlie Pearce (cjp from linuxmail.org)

--- First thing I just want to say, thanks to yourself and the rest of the team past and present for producing the great thing that LG is. I've just discovered it and am enjoying reading through the archives finding many a gem.

Thanks, Charlie! I've forwarded your compliments to The Answer Gang; they deserve to share in the glory. :)

Anyway here's my foolish story, feel free to add it to a future issue if you wish:

[snip] Added to the upcoming issue - we've had enough responses to put one out this month. --Ben


Re: Linux Gazette Redux :)

Wed, 26 May 2004 13:57:13 +0200
Huibert Alblas (huibert_alblas from web.de)

Hello Ben (and the others)!

Thanks for your mail, "das hat mich wirklich gefreut" (sorry but I don't know how to translate this one to english, maybe Karl Heinz can help?)

Halb. Welcome home. :) -- Thomas
[Ben] Hey, Halb - great to see that my email has dragged you out of hiding! :)
According to http://babelfish.altavista.com it translates as "that really made me happy" - which is a very pleasant sentiment indeed. Thank you!
[Sluggo] That's the literal translation, and it works fine. More colloquially one might say, "It's a pleasure to hear from you."
As far as I know, wirklich means 'really' in the sense of 'truly' (not falsely), or perhaps 'indeed'. But in sentances like the one above, 'rally' means 'very much'. It comes out to the same thing, but does it in a different way. :)
'gefreut' also has a sense of rejoicing and perhaps relief. So it's more than just 'happy' as in "You gave me a flower and I was happy".

Haven't heard of you and the gang for a long time either.

I was a little bit confused when (over a year ago, as far as I can remember) I got a mail from (hmm, forgot his name) claiming he was the editor of the LinuxGazette, and that he was breaking up with TAG (or something)

Then I stop receiving mails from TAG, so I thought the Project was dead.

Never! -- Thomas
Nope, in fact if anything that's why we split - sure looked like the CMS was gonna kill it. -- Heather

I visited the LinuxGazette site a few times, but didn't realy like it.

[Ben] That would have been Phil Hughes. We broke away from SSC - I wrote a nice little blurb about it here:
http://linuxgazette.net/issue96/reborn.html
The old TAG list got shut down shortly after that; Phil wanted to convert the whole site to CMS, which in my opinion would have killed LG (and for his "version", it obviously has.)
Your experience, interestingly enough, represents my exact viewpoint of what's happened with many of our readers: those who did not catch news of the changeover - and if you, a member of TAG, missed it, what does that say about the average reader? - simply decided that the old LG was no more. One of the things I'd really like to do is somehow get through to those readers wherever possible, and in general get the word out that the Linux Gazette is alive, is publishing, and is better than ever.

Since then a lot has changed in my live, At the time of the TAG breakup I was without work, shortly afterwards I got a job offer at the Metro Group (one of the worlds largest trading companies)

I landet in a Team of 3 people doing Java/Oracle based Enterprise Portal and Backend Development, very interseting stuff, but a lot of new stuff to learn.

[Ben] [grin] In my opinion, that's how any job should be. If there's not a lot to learn, you're not moving forward. Nobody said that was easy - but then nothing worthwhile in life is.

I starting to help getting away from usnig winNT based development to debian. Opensource is definetly going strong in our litle corner of the company, Who knows where it will end.

I'm also getting maried next year :-)

[Ben] Wow. Felicitations to you and your bride, then. Please be sure to give us a URL to the photos. :)

Anyways, I just visited http://linuxgazette.net and saw the the site is "back to normal" (but looks better!)

[Ben] Thanks! A lot of credit is due to Rob Tougher who did a wonderful job of building the CSS. It's been tweaked a bit since then, but he's the man.

I will subscribe to list, but only if it stays below 50 mails/day, before my subscription was cut there was a lot of noise on the list from people talking (mainly) to each other.

Then you should be ok -- but bear in mind things fluctuate.
Well, there is a lot of spam, but we're looking into fixing this. And as for the chatter -- that was due to the move from SSC. There is a bit of chatter here at the moment, most of which is not Linux related, I should add. -- Thomas
One of our threads this month actually was a technical aside to a line of chatter that began off-topic. You never can tell with the Gang, til it's all said and done! But, not 50 plus a day, no. -- Heather

Don't get me wrong, I have nothing against people having fun communicating, but I won't have the time to keep track of another 50+ mails/day.

I will install the current Gazette on my palm to read on the way home.

Back on topic: Articles.

Yes, we need articles. Please, put fingers to keyboard and type away! :) -- Thomas

Have Fun!

Huibert Alblas

You'll be seeing Halb's article soon :D -- Heather
[Ben] Right now, I'm actually looking for ideas on how to get the word out and the direction in which to take LG; having become the Editor-in-Chief, I now have to take care of the baby - and I'm a fussy babysitter. :) The ideas that have been proposed so far - making LG a bit more professional to involve the corporate crowd and advertising in other Linux-related media, as well as a number of other specific things to do - sound really good to me; however, I'm still open to input.
You read it here. Gentlefolk, if you've ideas - let us know! -- Heather


Linux Gazette article in issue 103

Mon, 07 Jun 2004 12:51:10 -0400
C. Numan (anonymous)
Regarding the PopupALT article. -- Heather

Jimmy:

I read your article on extensions for Mozilla. Thanks for highlighting some! I get more and more impressed with what you can do with Mozilla / FireFox.

I noticed you wondered this at one point:

PopupAlt Popup ALT does exactly what is says on the tin: it provides a popup of an image's ALT tag when the mouse is placed over it. This feature, which was present in Netscape 4, was removed from Mozilla for some unknown reason.

I believe it was taken out since the correct HTML spec says the alt tag is only to be displayed if the browser can not display images. It is not supposed to be a "pop up" info. I couldn't find it, but I think there is some tag to display a pop up when the mouse hovers.

[Ashwin N.] The "title" attribute in the "img" tag is shown as popup text by most browsers when the mouse cursor is hovered over the image.
<img src="your_image.jpeg" title="This should show up when you hover your mouse over this">

Anyways, it is a cool extension to show the information, but Mozilla as default is now more correctly rendering the page. In fact, the W3 says that the alt tag should be used very carefully, and I've seen some really long alt tags - this causes problems if your browser translates to voice or braille, which is the purpose for the alt tag. See: http://www.w3.org/TR/html401/struct/objects.html#alternate-text

Just thought you might be interested in some of the history.

C.


linuxgazette.net down......

Thu, 3 Jun 2004 22:50:02 +0200
Martin Bock (mbock-stade from t-online.de)

Hi folks,

you've asked for it, you'll get it: A few thoughts of my own about missing mail to TAG.

  1. The "average" PC user today differs from the average PC user three or five years ago. Today there are a lot of more people using computers at work or at home. The majority of these peoples are interested in doing stuff like writing mails and letters, surfin' the web and other non-sophisticated stuff like this. Most of them feel no need to find out why things work for them and how they could could customize or improve something.
  2. There are a lot of distributions around, which install with a few mouse clicks a usable system. There is no need to think (and ask) about partitions, filesystems, configuration and so on. In most cases there is no need to edit files e.g under '/etc/ppp/' - it's all done by ${install-tool} with drop-down- and dialog-boxes.
  3. Linux is grown up -- there are lots of information around (at? on? I dunno) the internet. Best of it: They are only one "google" away.

I appreciate the project "Linux Gazette" (hey, there are all issues from the beginning on my workstation's and my laptop's hard disks). But: I feel, nowadays Linux Gazette shouldn't focus on basic- and newbie-support, but should do more stuff one ore two steps further.

BTW: The link on my site points to your (true[tm]) Linux Gazette.

Keep on rollin ...

Nice Regards

Martin Bock


GAZETTE MATTERS


Asking 2c-tips of TAG

Mon, 24 May 2004 20:37:26 +0100
Thomas Adam (thomas_adam from bonbon.net)

I am a little bit concerned the people here (especially those that are more established) don't fully understand what constitutes a 2c-tip. A 2c-tip is just that -- something that is short and easy and can be done in a few steps. Asking whether it is appropriate (Neil!) just causes us more grief to wade through meta questions!

This might be in the form of a configuration tweak, or a minuture program that performs a given task, etc. Often though, larger tips are turned into TAG column entries -- and vice versa.

Often what would be flagged by Heather and I as a TAG entry might well form off-shoots to 2c-tips if the quality of the thread in question is not worthy.

But we will publish anything not only explicitly marked as a 2c-tip, but also what we deem appropriate to be one. We certainly don't filter out sent in tips -- only vary rarely. The only thing I will say to you is that don't always expect to submit one and see it in the preceeding release of LG. Heather and I decide which tips get published when.

[jra] If you can figure out how to publish tips in an issue of LG that's already gone out, my hat's off to you, Thomas.
[Ben] The method is covered in Jim's "Retro" series. It's based on that capability of Linux that Linus talked about, executing an infinite loop in three seconds...
[Jason Creighton] Yes, it's quite a clever method. Instead of going to all the work of updating every copy of the LG everywhere, we just insert the tips in the past before all the mirrors pick up the issue.
The one problem is that executing an infinite loop in three seconds can only place information in the future. In order to place it in the past, we must use a Windows box, which, as everyone knows, takes an infinite amount of time to execute a three second loop.

Send them in.... you know you want to.

-- Thomas Adam


Author FAQ...

Wed, 23 Jun 2004 09:11:30 -0400
Ben Okopnik (LG Technical Editor)

...is now updated:

http://linuxgazette.net/faq/author.html

Thanks to Jimmy for doing a lot of the preparatory proofreading.
Comments, corrections, and ideas welcome.


Licensing

Fri, 18 Jun 2004 08:47:35 -0400
Ben Okopnik (LG Technical Editor)
[Ben] OK, I've done my bit of research and rewrite, etc., etc., etc. - thank you, Rick and Jimmy, for contributing to my knowledge of the topic.
If you readers think that discussion might be interesting to you, let us know. Most of the Gang here found it rather dry. -- Heather
[Ben] I've decided that the OPL is a good license for us to stick with, as long as the optional stuff is not asserted; consequently, I've updated our <http://linuxgazette.net/copying.html> page - it was a) in the "old" LG format and b) showed the draft version of the OPL. Both are now fixed. Starting with the next issue, the front page will now explicitly state
All content released under the Open Publication License v1.0 (options A and B not applied)
and the individual articles will be tagged with
Copyright  2004, [author_name]. Released under the Open Publication license
Comments, as always, are welcome.


[LG 101] mailbag #2 - Stephen Bint

Mon, 7 Jun 2004 11:22:35 +1000
Peter Maxwell (peter.maxwell from anu.edu.au)
Question by gfa2c (gfa2c from gmx.net)

Stephen Bint died in February. I wouldn't have known except that back then google turned up his sister's web log:

http://www.livejournal.com/users/smaoineamh/2004/02/27

http://www.livejournal.com/users/smaoineamh/2004/03/06

Apologies is this is old news (after all you published the question 2 months ago) but I guess it is just possible that no regular Linux Gazette readers were able to help.

-- Peter Maxwell

We sorrow that he's gone, but he stuck to his principles. There's plenty to be said for that. -- Heather

This page edited and maintained by the Editors of Linux Gazette
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Copyright © 2004, . Released under the Open Publication license unless otherwise noted in the body of the article. Linux Gazette is not produced, sponsored, or endorsed by its prior host, SSC, Inc.

Published in Issue 104 of Linux Gazette, July 2004

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