• The MailBag
• More 2-Cent Tips
• The Answer Gang
• News Bytes
• Pl/Python and Cursors in Pl/Pgsql for PostgreSQL , by Mark Nielsen
• Red Hat and USB devices , by Mark Nielsen
• Configuring GDM 2.2 , by Mark Nielsen
• The Foolish Things We Do With Our Computers , by Mike Orr
• Qubism , by Jon "Sir Flakey" Harsem
• Wine: Raising a toast to your Windows Apps on Linux , by Gaurav Taneja
• My Guide To Linux Security , by Rob Tougher
• The Back Page

Linux Gazette Staff and The Answer Gang

Editor: Michael Orr
Technical Editor: Heather Stern
Senior Contributing Editor: Jim Dennis
Contributing Editors: Ben Okopnik, Dan Wilder, Don Marti

Linux Gazette, http://www.linuxgazette.net/
This page maintained by the Editor of Linux Gazette, [email protected]

Copyright © 1996-2002 Specialized Systems Consultants, Inc.

Send tech-support questions, Tips, answers and article ideas to The Answer Gang <[email protected]>. Other mail (including questions or comments about the Gazette itself) should go to <[email protected]>. All material sent to either of these addresses will be considered for publication in the next issue. Please send answers to the original querent too, so that s/he can get the answer without waiting for the next issue.

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 ever be answered, especially if not related to Linux.

Before asking a question, please check the Linux Gazette FAQ (for questions about the Gazette) or The Answer Gang Knowledge Base (for questions about Linux) to see if it has been answered there.

• Kylix
• netbooting Linux from network by using pppoe
• Tools for altering installed kernel
• usb pegasus driver vend/prod id

Kylix

Hola amigos :

Alguien sabe como Podria ejecutar un programa compilado en Kylix, fuera del entorno de Kylix?

Hi, friends. Does anybody know how to run a program that's compiled in Kylix, but without having the Kylix environment around at runtime?

!ah! Un comentario demonio (daemon )siguifica Dinamic access memory, estoy equivocado?

Ah! A daemon commentary means dynamic access memory, or am I mistaken?

Gracias por su tiempo. Octavio.

Thanks for your time. -- Octavio

Octavio-- Sorry, I've never used Kylix. I just ran a demo once. I don't understand your second question. Memory is hardware; a daemon is software. And what's a "daemon commentary"?

Octavio-- Lo siento, no he usado Kylix. Ejecute' un demo de e'l una vez, no ma's. No entiendo la segunda pregunta. La memoria es hardware, un demonio es software. Que' significa un "comentario demonio"?

-- Mike Orr

Hola amigos :

Espero que puedan ayudarme, resulta que en mi maquina instalé firebird, y luego cree una base de daatos, luego desde Kylix me conecte sin problemas.

De la misma forma quise hacer en otras máquinas que tienen redhat 7.2, copie el instalador firebirdCC....rpm, pero resulta que me sale un error :

Hi friends, I hope you can help me. I installed Firebird on my computer, and then created a database, which I can connect to from Kylix without problem.

I wanted to install it the same way on other Red Hat 7.2 machines. I copied the installer FirebirdCC RPM, but got the following error:

--------------------------------------------------------------------------
warning : Expected size : 2676232=lead(96)+sigs(68)+pad(4)data(2676064)
warning : actual size : 2676232
warning : Expected size : 2676232=lead(96)+sigs(68)+pad(4)data(2676064)
warning : actual size : 2259998
error : unpacking of archive failed on file /opt/interbase/lib/libgds.so.0
;3 d021bc6 ; cpio:need
--------------------------------------------------------------------------

Intente bajar de internet el mismo paquete pero el resultado para instalarlo es el mismo error.

(Heather: oboy, my spanish is rustier than Mike's, but I'll try.)
I intend to go under the internet to packets (maybe: download the package?) but the result of installing is an error.

Como puedo solucionar este problema ?

Gracias por su tiempo Octavio

What's the solution to this problem? Thanks for your time. Octavio.

netbooting Linux from network by using pppoe

Hello,

Hi!

I want to install a Linux on my PC. This PC has a Ethernet connection towards a DSL modem. Across this Ethernet I had to use PPPOE. Is their an image available with PPPOE support? The standard netboot.img has no support for PPPOE. This image recognize my Ethernet but thus not allow me to activate PPPOE across it.

I want to install Redhat 7.3 across the net. Thanks in advance for your answer.

Grt

Wim

I'm pretty certain that most, if not all rather new images include that, exactly why you ask - to get dsl up and running.
Robos

So if someone knows the hint Wlm needs, let us know, and we'll publish your Two Cent Tip. -- Heather

Tools for altering installed kernel

I am helping someone out on another list I am on and a have a query.

Does anyone know of a reliable utility to alter parameters on an installed kernel other than rdev.

In particular whether there is anything that will get rid of debugging in the kernel?

I would just recompile personally but if anyone knows of a tool that would be useful.

usb pegasus driver vend/prod id

Hi,

I have a USB ethernet adapter based on the Pegasus/Pegasus-II chipset. I tried to use the pegasus driver with a 2.4.3 kernel but the driver is not claiming the vend/prod id of the USB adapter. Unfortunately I am unable to recompile a more recent kernel for my system. I would like to know if there is a way to spoof the vend/prod id somehow (without flashing the USB adapter) so the pegasus driver claims the device. I am thinking there is perhaps some kernel mechanism to increase the set of devices claimed by a particular driver at runtime. I think a more recent kernel version would solve my problems but a recompile is not an option for me because of my particular setup. Any ideas?

Ebo

Don't use quoted printable with no fancy characters to defend.

Maybe one of our readers can suggest the right tricks for compiling modules that are only major-version dependent instead of minor version dependent. I think some people who use linmodems might know a Tip or two.

Note you still have to have the right symbols present in your kernel. If they aren't, you won't be able to use the module safely, even with insmod -f. -- Heather

• Mistake in December 99 Linux Gazette
• Re: Making executables smaller
• Is it possible to have a latest issue link?
• Linux gazette 79 article improvement
• Kudos
• Difference between LJ and LG
• Etiquette Wars -- the final salvo.
• re : The Complaint Department: Typos and Grammatical Errors
• Did you see that Fabor gets famous?

Mistake in December 99 Linux Gazette

Hi,

I'm a French student and I tried to compile a little program I found in your magazine in your "Linuxthreads programming" section of December 99 magazine. The programm is not working and I didn't find why. Could you help me please to make it work.

Thanks

Your best bet is to contact the author, Matteo Dell'Omodarme. His address is at the top of the article. But you'll need to say something more specific than "not working". See http://www.linuxgazette.net/tag/ask-the-gang.html and scroll down to "doesn't work". How exactly did it fail? -- Mike

Re: Making executables smaller

John sent us a 2 Cent Tip, so the Answer Guy wondered...

Are you the same John Fisk that originally started the Linux Gazette? -- JimD

Hello Jim,

Thanks so much for the note. And yes, it's me. Since the last submission (now a couple years ago) I've been rather busy finishing up medical training (Pathology and Medical Informatics at Yale) and my wife and I have adopted a little girl from China (with another one on the way). Thomas Adam (the new maintainer of the Weekend Mechanic column) and I just started corresponding and I took the opportunity to look over the latest edition of the LG. The folks at SSC have done a commendable job of keeping the LG alive and very active. I really appreciate the great job they've done.

cheers,
John

Is it possible to have a latest issue link?

Can we have something like a www.linuxgazette.net/latest link?

http://www.linuxgazette.net/current -- Mike

linux gazette 79 article improvement

Hi Krishnakumar R.

Your series of articles "Writing Your Own Toy OS" on Linux Gazette is the best ever.

1. http://linuxgazette.net/issue77/krishnakumar.html Part I
2. http://linuxgazette.net/issue79/krishnakumar.html Part II

I am enjoying it very much and I'm eager to learn something about the 80x86 protected mode.

I also have a suggestion. In part II, I think the code for write.c can be improved a little.

When reading sect2 with

   file_desc = open("./sect2", O_RDONLY);
   read(file_desc, boot_buf, 510);
   close(file_desc);

instead of reading only 510, you can actually read 512 bytes with no harm.

It doesn't hurt to be 510, but I think it would be more easy to understand it's 512, so that learners won't be thinking that the second sector also have to finish with the magic numbers x55 xAA, just like the first sector does.

I'd like to know what do you think about it and if you agree.

See you and thanks a lot, man!

Silvio Luis Leite Santana

[The article was changed at the author's request. -Iron.]

Kudos

Guess what - I got a job . A guy I worked with a few years back was reading the Linux Gazette, and saw my article.

In May's issue, http://linuxgazette.net/issue78/tougher.html -- Heather

He emailed me, and one lunch and two meetings later I was employed again. You definitely get the assist on that one.

I also credit your magazine for keeping me sane the last 8 months - writing for you has been a great outlet. I'll keep the articles coming.

Difference between LJ and LG

At our company there has been some discussion as to the differences of the Journal and the Gazette. Would you please respond with SSC's definitive description of the difference and is both being published at this time. Thereby we can put to rest any further discussion at our work place.

Regards,
Wyman Griffin

Linux Journal is a commercial print magazine. Linux Gazette is a free e-zine that SSC donates some employee time to. LG was started by an individual, John Fisk, then SSC took over responsibility for it when John no longer could.

LJ pays authors for their work. It has a stricter standard for what it will accept, does professional proofreading and technical editing, won't publish anything that's been published elsewhere (with occasional exceptions), and doesn't allow republishing without permission. Each LJ issue has a theme, and articles are solicited for that theme (although any issue will have lots of non-theme articles too). Space issues determine the number of articles and their length. (Because the printer prints on 32-page sheets, you have to add pages in groups of eight.) LJ also publishes several series of publicly-accessible web articles at http://www.linuxjournal.com, for which we pay the authors just like magazine articles. (The magazine articles are also available to the public after three months.) For specific questions about LJ, contact the Linux Journal Editor, [email protected].

LG does not pay authors, does less time-consuming proofreading, and publishes pretty much anything we have permission to publish that's about Linux, contains some significant content of a more or less permanent nature ("new information" or reference material), doesn't unfairly slam/slander anybody, and isn't a mindless advocacy rant. But we don't go looking for content, we let it come to us. LG issues do not have a theme, we just publish articles whenever they arrive. There is no particular number of pages to fill, so we don't pay attention to article count or article length, although we do try to keep the issue size to less than 2 MB compressed (occasionally 4 MB). LG does not accept advertisements, although we do have a sponsorship program that gets your logo on the home page. LG is published under the Open Publication License, so readers may copy and redistribute it (for free or profit) as much as they wish.

Etiquette Wars

the final salvo

Once upon issue 64 or so in the Mailbag, we pubbed a note from a cheeky fellow who decided to tell us off about our bad attitude. He also took the tack that we were a single person and that it was somehow our "fault" if a bunch of sensitive souls ever saw it. Obviously there are others in the world who think he was right, but Marko took umbrage with us for being cheeky enough ourselves, to post his message when we replied.

Scofflaws may enjoy reading the offending note and its reply together: http://linuxgazette.net/issue64/lg_mail64.html#mailbag/1 and a number of the Gang replying to Marko in issue 78: http://linuxgazette.net/issue78/lg_mail.html#mailbag/4 -- Heather

Dear Ben,

thanks for your reply, however I mastered etiquette course (sorry for misspellings) and know very well the difference between vulgar and etiquette.

Gazette is distributed under free licence and so when people reading it in a computer club (from 8 to 88) they should get a good viewpoint of gazette or bad view point?

And "vulgar" is a compliment when it comes to the Linux Gazette; we are indeed "of the common people".

re : The Complaint Department: Typos and Grammatical Errors

Boy, this topic is from the dusty shelf; http://linuxgazette.net/issue37/tag/23.html and http://linuxgazette.net/issue36/tag/67.html -- Heather

With all of that guy's complaints, I'm reminded of an old advertisement for learning shorthand:

u cn us unx.

Cheers, -- Jay R. Ashworth

Point being, that the informational difference between their/they're, or more appropriately, between "kernel core team has soundly reject suggestions that Linux adopt..." and "kernel core team has soundly rejected suggestions that Linux adopt..." as quoted the information content difference is nil, for a native English speaker. Don't let him get too down on you -- we just are pampered by having a MLA in the first place to standardize these issues.

Did you see that Fabor gets famous?

Famous? Obviously not famous enough for my name to get spelled correctly!

Hi all! Well, there is this "Is linux dead?" comment on /. and in the MSNBC article (http://www.msnbc.com/news/772215.asp) Fabor is quoted rather extensively. The /. news comment is really bad (doesn't fit at all) but Fabor comes along really nice.

Thansk for the compliment. When I first read the article, I was sounding like Chandler Bing's ex-girlfriend on "Friends"

<Janice>Oh - my - gawd!</Janice>

The article was, IMO, a back-handed compliment.

He should have mentioned TAG though

I think I did.

As a question to fabor: Why do you say (as the article quotes) "It's for geeks"? I mean, we're mostly geeks (ok, all) but those people who write us with questions are most certainly not geeks (most of them) since then they would probably figured out the thing themselves. These lusers might have some probs with "linux" but only because when they buy some win crap they wine to the support stuff of that firm, in GNU/linux they get all the tools at once and don't have such a technical support (suse and redhat for a short time at the beginning, ok..) to ask questions. So they come to us and thats what TAG is for. Bit I think that most luser get along with GNU/Linux pretty well given the fact that GNU/Linux is far more powerful and customizable. With most questions they come to either us or debianhelp for example, they wouldn't even ask those questions on win since there they wouldn't get the fix idea to run their own webserver just-for-fun since there it isn't that much free (as in beer) software to play with (that sentence is rather crap, granted, but I hope you get my general drift) -- Robos

I'll disagree to the extent that there is plenty of free-as-in-beer or shareware available for Windows, but to a certain degree you have to be geeky to know where to go looking for it. Been there, showing people cool stuff like virtual desktops and icon managers and replacement command shells. -- Heather

Well, you really need to hear the question I was asked! I was asked "Why is Linux popular in the enterprise and with upper management but not popular on home PCs?"

"It's for geeks and they thrive in the enterprise where the power of Linux is appreciated." Then I went on to mention about MS licensing practices taht forbid other OSes or changing of the boot sequesnce. I said THAT was why Linux isn't popular on the desktop. I even mention BeOS and Hitachi.

So, to make it clear: I think with a little help (about as much as you need in the beginning with windoze) and some distro like suse or mandrake a pretty normal user can now easily use linux and the accompained software (as long as they can and are willing to read).

I agree. And while my student/attendee, Dave Potter, did say those things, he came off alot different than the article sounds.

Anybody know of a course in "how to answer a journalists' questions without being misrepresented?"

-- Regards, Faber

What Robos had to say only works if you know what parts they are likely to misrepresent. Make them repeat it back. Squeeze 'em if they can't get it right. Unfortunately the cultural gap is likely to foster addiitonal assumptions based on whatever you say or do to try and keep matters straight.

If people don't want to understand, we can't make it happen. That's the real nature of freedom, folks. But we can say things our way in our own venue, and when they come looking for us, it'll still be here.

Remind me to ask Faber's question in the press room at LWE though... -- Heather

• ask-the-gang

ask-the-gang

Compliments to Ben for continuing to make tag/ask-the-gang.html better and better.

Thanks much! I treat it as a serious resource, and try my best.

Gosh, this is twice I've complimented Ben in one week. I promise it won't happen again.

"I guess his heart just couldn't stand the shock - we've got syncope and V-fib. All right, lets give him the whole 200j. ... Sync off... CLEAR!" <BZZZZT!>

"OK, got paced rhythm and pulse. He'll prob'ly pull through if he doesn't get any more of those compliments..."

-- Ben

Too many compliments? Just stack them over there next to the groceries, and I'll add them to the virtual beer and munchies in the Answer Gang fridge. (See tag/members-faq.html for more about the fridge.) No fuzzybears were harmed in the writing of this document -- Heather

This page edited and maintained by the Editors of Linux Gazette Copyright © 2002
Published in issue 80 of Linux Gazette July 2002

HTML script maintained by Heather Stern of Starshine Technical Services, http://www.starshine.org/

• Fvwm Buttons
• Creating WAN "LAN' with one IP Address
• customized linux install cd?
• Ghostscript fails after printer driver install
• quick disaster recovery
• question
• checkinstall
• 'crypt' error !!
• demand dialing
• Modem speed and diald
• Exchange with Linux
• Grub vs LILO
• Email Linux To Windows - a simple solution for reference
• linuxconf setup
• Kernel Message: VM: Killing resource foo (bar)....
• Parsing Strings To Equations
• lpd/lpr problems with serial printer
• Getting files out of a .rpm file without installing it
• ramdisk and initrd fundamentals?
• Re: Making executables smaller
• Linux Journal's Weekly News Notes Tech Tips
  • sending Microsoft Word documents
  • Keeping a persistent session as you log in and out from different terminals
  • Outlook to Evolution
  • Mozilla port paranoia
  • Renaming a file that has a special character in the name
  • Have Ethernet cables, will travel
  • subscribe to LJWNN

Fvwm Buttons

This is in reply to Help Wanted #5, in issue 79. Thomas replied via the FVWM mailing list. More details about that can be found at: http://www.fvwm.org/mailinglist.html -- Heather

Hello,

In answer to your question as to why when you press a button on your panel, it stays depessed is to do with the way in which FVWM handles exec() a program via the $SHELL of the $USER.

If command is an fvwm Exec command, then the button will remain pushed in until a window whose name or class matches the quoted portion of the command is encountered. This is intended to provide visual feedback to the user that the action he has requested will be performed. If the quoted portion contains no characters, then the button will pop out immediately.

Note that users can continue pressing the button, and re-executing the command, even when it looks "pressed in."

There is a way around this, and I have found that if you append a "&" character at the end of your command that is bound to the button, then that sometimes solves your problem -- but not always.

Hope I have helped, Kind Regards,

Thomas Adam

-- "The Linux Weekend Mechanic" -- www.linuxgazette.com

Hi,

Thanks a lot for taking the time to answer my Q. I actually managed to sort it out some time ago, but you are right. I had some fiddle with the window name.

Best regards
Hans Borg.

Creating WAN "LAN' with one IP Address

If I'm given a network address 192.168.7 (Class C) and have to create a WAN with 5 routers, how do I do it?

I can Subnett but the 3rd router keep saying the Network address is already used, when i try to put the subnet address there.

How do i do it.
RURI!!

We have a very good piece on that sort of thing in the back issues. It's called "Routing and Subnetting 101" and is one of the longest postings ever written by Jim Dennis. Several professors have used it in their coursework and even though Linux was much younger then the principles are still valid.

It's in issue 36. A professor asked about it in issue 37's mailbag, and some followups appeared in issues 51 and 59. Of course you could have learned this by typing "Routing and Subnetting" into the Linux Gazette search page: http://www.linuxgazette.net/search.html

...and you can easily get to those articles by visiting the Answer Gang Knowledge Base: http://www.linuxgazette.net/tag/kb.html

customized linux install cd?

These are in reply to Help Wanted #1, Issue 79. -- Heather

Hi, I did about this on a RH7.2 but I don't think it'll change this drastically under RH 7.3. You can point your browser to

http://lcmpc10.epfl.ch:8080/Menu/Docus/RedHat%20CD

(sorry for the space in the url...) it even describes how you can add a kernel on your own and get it to run...

Ineiti

The easiest way to customise the install is with Kickstart. We have done it (and learned a few things on the way).

Haven't time for a comprehensive reply at present but, if kicksatart hasn't been covered, I could put something together.

Rgrds

Peter

Ghostscript fails after printer driver install

This is in reply to LG 79, Two Cent Tip #4. -- Heather

Hello,

Rich Price may want to try a Laserjet 4 driver instead of trying to figure out the Xt dependency.

I have the Samsung ML-1450 and it's quite happy pretending to be an HP Laserjet 4.

Matt Easton

quick disaster recovery

I may expand this into an article, but for the very common scenario of "no init found" "unable to open an initial console" (usually after hard crash) a couple of possible causes which I have not seen anywhere else

There is a fair chance that files on / have been corrupted wiped including /dev.

Solution (very Rpm specific)

So mount rescue media, check for files on /

if missing mount cdrom from install and do:

rpm -Uvh dev-<version>-rpm

to re-instate dev files

then progressively force re-install rpms until you can boot

Then when you have managed to boot do this:

rpm -Va|grep missing>filename

This will print to a file all the files that are missing from your system according to your rpm database.

Then for all the files given do rpm -qf <filename> which will give you the name of the rpm

Then re-install the rpms in turn.

This is best done manually so you can check whats missing.

Should only take around an hour in total at most.

Certainly preferable to doing a re-install.

I came across this on my own box a while ago after multiple power cuts in succession (I'm poor so no UPS)

The advantage is that your modifications are far less likely to be hosed as in a re-install.

question

To Whom It May Concern:

I went to ebay and found all these used laptops/notebook puters, but I

have no clue which one to select. For example, "Intel Pentium II=AE 366Mhz 290MB RAM 6.1GB HDD CDROM Sound Windows 98 Office 2000 ..."

What does all that mean? And how I go about finding a good, used laptop, like what trait(s) do I search for?

-Thanks ,
Desperately needing laptop

If your question aims at running linux on that thing, compare what http://www.linux-laptop.net has to say to the model you like.

checkinstall

I dont know whether anyone else on the list has used the utility checkinstall available at:

http://asic-linux.com.mx/~izto/checkinstall

What it is the solution to the problem of maintaining a rpm/deb based system with compiling programs from source

Basically what it does is runs make install and then makes a functional rpm and installs it.

It is not perfect but certainly works well enough to continued use

I regard it now as pretty much indispensible when | am following a project (eg: gnome2)

My feeling is that it ives the flexibilty of using source packages without losing package management

Hi!

Well, there was some coverage of that utility here in germany in the magazine (print) "linux-user". Seems to be quite nice, I've used it several times and it worked most of the times. Not always, but when it doesn't work you can still fall back to

./configure
make
make install

Robos

'crypt' error !!

I have got a peculiar problem in hand. Got this code compiled properly in red hat Linux 6.1(g++ compiler version 2.91.66 ) but giving error in red hat 7.1(g++ compiler version 2.96).But if compiled with red hat 7.1(gcc compiler version 2.96) , it is doing perfectly fine.

why this in-consistency ?

Source code: Server.c

Command:

g++ -lcrypt server.c

Error: 'crypt' undeclared

Since it seems nobody tried an answer yet I try to add some cents:

• first thing coming to my mind is probably a typo in the mail -- but server.c and Server.c might be different files....

You do the right includes (whatever they are, crypt.h problaby), do you? There might be a difference where crypt is stored for gcc and for g++ -- so gcc and g++ might behave differently. Also g++ might might have changed in default location or default behaviour of including C headers. Try to locate crypt.h (or wherever crypt is defined). Is there a g++ version of it? What happens if you put -I ad -L explicitly to the gcc crypt path?

Then crypt is probably compiled by gcc -- this has a different routine name mangling then g++, so you might have to call not crypt but '_crypt' or 'crypt_' or something like that (speaking from very little experience with how to use fortran subroutines in C -- and a peculiar problem lately: if I compiled a subroutine with gcc I got a "..." undefined from the linker. If I compile it with g++ everzthing works.

I would have expected "better" integration with gnu c and c++ -- but there you go.

K.-H.

demand dialing

This is in reply to LG 79, help wanted #7. -- Heather

There are two linux versions that I've used as a server for demand dialout for internet access, and both worked well. One is Coyote linux, which is a floppy disk boot version, and can be run on a 386 with numeric coprocessor or a true 486 (or 486sx with numeric coprocessor). I don't recall it's memory requirements. The other version that is good is the mitel (formerly e-smith) at www.e-smith.org. It requires a 586 class processor, but also setsup DNS, and other server functions.

Modem speed and diald

I've mainly been connecting to the internet using diald, but I've noticed that I'm only getting about 3.5 KBps , whereas on W98 I get about 5KBps. A little experimentation shows that dialling with kppp gives about 5KBps as well.

kppp seems to use an initialisation string of ATM1L1, but changing MODEM_INIT to "ATM1L1" in /etc/diald/connect, didn't improve the performance.

MODEM_INIT started out as "ATZ&C1&D2%C0". I changed "%C0" to "%C3" to ensure that compression was enabled, but this made no difference. I can't find an option in diald to log exactly what's sent to the modem and I can't see any conflicting options in the configuration for pppd.

Any suggestions for how to track down why kppp gets better performance than diald would be appreciated.

The modem is an MRI 56K internal modem.

I'm not sure how you would test this, but I suspect that it's not your PPP connection that's slowing you down - "diald" uses SLIP as a "fake interface" that's always up, which is why you don't get error messages from Netscape and such when you try to connect. It listens for requests, then makes the PPP connection "behind your back". It's been a long time since I've used it, and I'm rather fuzzy on the details, but ISTR that "diald" let you play around with SLIP settings... sorry I can't be of any more help, but that's pretty much the extent of what I remember. I also STR that "diald" had a good set of documents with it which I found very helpful in working around a problem that I had with it. Good luck.

Exchange with Linux

Hope this is the right address for answers as well as questions. Regarding Linux Exchange In my quest to use Linux without having to use Windows in our network I discovered a couple of simple solutions.

1. Most any email client will work with a default install of exchange if you enter your login as in the following:

domain/username

Of course all the group features will not work with this solution but simple email is no problem.

2. You can use a browser with a default install of exchange since it also installs IIS as a webserver. Various browsers will have different degrees of success since of course IE is the "prefered" browser. Type the following in your browser substituting your exchange servers correct IP address:

http://ipaddress/exchange

This will give you access to all the group features if your browser will render the Microsoft proprietary technology. Thanks for reading

John Helms

Grub vs LILO

Does anyone know what the Grub command is that replaces the LILO command append="hdb=ide-scsi"

It would be the same syntax, minus the "append=".

The append="" stuff is part of the Lilo syntax. Your grub.conf file should look something like:

default=1
timeout=10
splashimage=(hd0,0)/grub/splash.xpm.gz
title Example
        root (hd0,0)
        kernel /vmlinuz ro root=/dev/hda3 hdc=ide-scsi vga=1 console=/dev/tty2 CONSOLE=/dev/tty2
        initrd /initrd-2.4.18-whatever

where you are allowed to use "\" and the end of a line, to mean line continuation.

Email Linux To Windows - a simple solution for reference

1. Set up mail server on Linux with user ids as applicable (exim reads userids from linux box)
2. Set up fetchmail to poll server at isp
3. install and activate pop3 server on linux box
4. poll for mail by pop3 to the linux box account

a more detailed example is at:

http://linuxgazette.net/issue43/stumpel.html

linuxconf setup

This is in reply to LG 79 help wanted #3. Our reader wondered about setting up ACLs so he could access his Linuxconf remotely without letting everyone else in. -- Heather

http://www.redhat.com/docs/manuals/linux/RHL-7.1-Manual/custom-guide/linuxconf-lcinterfaces.html

That should help you Good luck

Kernel Message: VM: Killing resource foo (bar)....

Hi Gang,

Hello Thomas!

I am wondering if someone would be so kind as to expain to me why I get the following error messgae:

Grangedairy: kernel: VM: killing resource acroread

[ quickly find-grepping that in the kernel source tree ]

Ok, it's in "arch/i386/mm/fault.c". (Actually for 2.4.17 it's "killing process xxx" but I presume it doesn't really matter). It seems to occur whenever a process tries to read something from a memory page which is not accessible because of an out-of-memory condition.

The above message is brought about, by an abnormal exit of the adobe acrobat reader. For some reason, my computer will slow down to a snails pace when I am reading a pdf document,

That's when the system starts swapping out madly. Does it happen with any PDF document, or only really big ones? What if you disable "Use Page Cache" and/or "Allow Background Download of Entire File" in your Acroread preferences (assuming those are currently turned on)?

and then X will kill acroread without any warning.

X itself has nothing to do with the actual killing. It's the way the kernel preserves your system from a total crash. What amount of RAM do you have?

When I check my /var/log/messages file, I get the above message.

What causes this, and what does it mean???

OOM. Virtual memory exhausted.

I tried running "strace" on the "acroread" process, but the file ended up being 38.2MB, despite me telling it only to display a certain number of lines

So maybe your PDF document is a resource hog. Or there is some incompatibility between the version of Acrobat Reader installed on your system and your current set of libraries (even Acrobat 5 is dynamically linked, mmph... this has obvious advantages but since their reader is only distributed in binary form...) or some bug in Adobe's product turns it into an self-destructing madsoft.

It yeilded nothing useful, anyway from what I could see.

The kernel's divine intervention in such cases is kinda brutal. Expect the same sort of things as those resulting from a SIGKILL: perhaps the process was "innocently" trying to read() something then it just vaporized into limbo.

Thanks,

Well I hope this'll help you somewhat.

-- Didier Heyden.

Parsing Strings To Equations

Can anybody in this list suggest a method to parse a string into a mathematical equation and then compute the values according to the equation.I have to do this in C in Linux. Is there any such code available in C.

Is there a similar command in Linux.

I have tried myself a lot.It is getting more and more complex.This is going to the level of a compiler design.ie,the task is similar to "how a compiler reads the source code and manipulates it", i also have to do a somewhat similar task.

Yes. Maybe not as complex as a C parser, because the corresponding grammar will probably be much cleaner; but the part of the program which will be dedicated to the symbolic computation won't be easy to write. But if you try with tools such as `flex' and `yacc' (or `bison') the parser itself can be implemented in a relatively short time, at least once you have read enough documentation about those development tools, and thoroughly understood the basic concepts. The related `info' pages are most useful, and finding tutorials and likewise on the net is fairly trivial.

What's interesting with `bison'-based parsers is that one can more easily split such tasks into smaller, independent parts, i.e. separate completely the syntactical analysis of the source code from the rest. For the parser itself, the work essentially consists in writing a correct grammar for the corresponding developed language.

Then I tried google search but didn't find any useful links in C.I haven't done an extensive search.

For symbolic computation LISP-like languages may prove more adequate than C.

Then I contacted you,the answer gang. I thought if somebody here has previously done a similar task..it would be helpful for me if they share it.. or just give me some links to some resources on the net having information about this...

Well, what I'm saying here is nothing more than one possibility among others. Keep in mind that whatever solution you choose, you'll have to invest a good deal of time to fully work it out.

regards sree

HTH,

-- Didier Heyden.

lpd/lpr problems with serial printer

This is in reply to LG 79, help wanted #6. Rather than solving the problem as asked, Doug suggests a different approach. -- Heather

I have only used lpr over a TCP/IP network. Would it be possible to connect the printer to a serial to ethernet print server (Intel and HP work with Linux)? Then network to the Linux box. And then have all devices/terminals use lpr/lpd.

Doug

Raul knows which software he should be using instead. -- Heather

Hi,

From the article:

I am using Mandrake 8.2. I have recently installed a serial printer using a Digi Classic-8 ISA card. . . . I can print to this printer by using 'cat {filename} > /dev/ttyS11' and this works just fine, however I cannot get lpr to print to this printer.

AFAIK, lpd does not come with mdk 8.2. IIRC, no up to date distribution ships lpd anymore. At least they have replaced it with LPRng or CUPS.

I don't use MDK, but I do use Cups which is the default printer system in MDK.

I have two serial printers (ttyS0 and ttyS1) working fine.

All you got to do is to log into http://localhost:631 and add a new printer. Select the proper Serial Port and the most important, set the correct values to the printer. My printers works at 9600 and 4800 only.

This should be more than fine to live test.

If you will keep with lpd, the /etc/printcap is the place to go. The man page for printcap will provide the right arguments for setting the ttyS printer.

Regards,

Raul Dias

Getting files out of a .rpm file without installing it

Ever wanted to get those files out of a .rpm without installing it? Ofcourse it's easier to just install it, but sometimes it is not possible because a newer version may already be present on the system.

In such cases, the utility "rpm2cpio" can be used to extract the files of the RPM into a cpio archive.

For example:

$ rpm2cpio < xmms-2.4.rpm > xmms.cpio

The files can then be extracted from the cpio file using the "cpio" command. For example:

$ cpio -i -d < xmms.cpio

In this case the files will be extracted with absolute paths into the present directory.

A good 2-cents' worth, Ashwin. However, you can do this even easier by selecting the RPM and pressing 'Enter' in Midnight Commander; all the files are under "CONTENTS.cpio", and you can explore the rest of the RPM structure at will. There are also two executable metafiles called "INSTALL" and "UPGRADE"; if you're viewing the file as root, you can do either one simply by scrolling down to them and pressing 'Enter'. The above functionality also applies to Debian's DEB files.

ramdisk and initrd fundamentals?

This is in reply to Issue 79, Help Wanted #4 -- Heather

{1st time at this, let's see what happens}

What documentation is available for ramdisk and initrd fundamentals?

When "initrd" is specified in "lilo.conf" and the Linux kernel is configured for ramdisk support, and the system is booted, what ramdisk image is loaded first or at all?

You also need to configure the kernel to do an "initrd" as well as a "Ramdisk" if this is what you wish to do.

The "initrd" image or the kernel ramdisk image?

"initrd" loads first. It loads from the bootloader (LiLo, Loadlin, etc.) while still in "real" mode using the PC's BIOS calls, and loads before the kernel loads. The purpose of the initrd is to provide what ever support files that the kernel might need to find its root file system. Typically people wishing to have a generic boot disk that will boot just about anything can put disk controller drivers, various filesystems, PC-Card drivers and even networking drivers in here. Then the kernel is set to attempt to load all of them, but of course only the ones that match existing hardware will actually load. After this process, the initrd can be destroyed to free up the memory (but I don't know how this is done) as the boot process continues to find the real root filesystem to boot from. This file system can reside on anything the kernel has a driver loaded for, which includes a "ramdisk". I'm not sure if something in initrd may be needed to set up the "ramdisk". After the kernel finishes booting, control is handed off to /sbin/init which then begins executing things in /linuxrc.

In summery: the initrd is loaded using only BIOS and simply saves you from having to compile all these drivers into the kernel, only to have many of them unused and take up memory in the running system. It also the only way to deal with PC-Card devices that might be needed to boot that are only availble as external modules

What programs are responsible for the loading the "initrd" and "ramdisk" root images (kernel or LILO boot.d).

"initrd": is loaded with the bootloader. For the ramdisk, I'm not sure if the kernel can do this automatically, I expect you have to wait until an "init" "rc" script residing in initrd can do it

Note that the Linux kernel does not need LILO in order to load a ramdisk from a second floppy using the same drive.

Right, LiLo is completely out of the picture by this time.

When is "pivot_root" an implicit process, and when must it be explicitly invoked?

Don't know

What is the difference between a LILO specified "initrd" and the kernel specified ramdisk loaded as root?

See the above lengthy paragraph

I have a fundamental problem understanding the relationships between an "initrd" image, ramdisk root image, and the use of /initrd, /linuxrc, and swap-root.

Sorry that I don't have all the answers. In fact I may be wrong in places since I have never really done this sort of thing before.

James


Linux is the one competitor Microsoft
can't buy,
can't intimidate, and
can't stop.

If Linux were an "it" I might agree with the "one" part, but if you just take Linux as the kernel, it's like saying rotary engines (the natural competitor to the cylinder style) are competing with Ford, and if you don't, then there are a lot of different brand name Linuxen (Linuces?) out here to choose from. Plus I don't think it's fair to forget all the freely usable BSD variants out there. They could make something with a BSD core but they can't force "customer lock-in".

They could "buy" Linux - in the sense of using it commercially - but they wouldn't pay the price we charge (freedom for derivitive works).

Of course since we have so many varieties - and any effort to mention how un-glitzy and unready that Linux thingy is just causes more people to notice it as a possibility - plus the fact that many Linux distros are non commercial and all the parts and then some are easier to get than your average blinkylight at Radio Shack, I have to agree with the last. Look out for that "Palladium" chip trick they're trying to pull though. It sounds just like the Clipper Chip of yesteryear. -- Heather

Did you look at the files ramdisk.txt and initrd.txt in the Documentation subdirectory of the kernel source itself? It may be obvious, but many of your questions seem to be answered here.

The Slackware-style ramdisk at startup (see file ramdisk.txt) is loaded by the kernel from a device (almost always a floppy) where the offset can be specified. This ramdisk remains the root file system throughout the lifetime of the kernel. You can boot the kernel directly from a floppy (just dd the image to /dev/fd0) without a boot loader and still use this type of ramdisk.

The initrd ramdisk is much more flexible, but you do need a real boot loader to use it. It is loaded into memory by a boot loader. All Linux boot loaders (LILO, LOADLIN, SYSLINUX and GRUB) can use this type of ramdisk. The file /linuxrc inside the initrd ramdisk is the first program to be executed. Linuxrc can do any of the following things:

• load additional modules (e.g. scsi host adapter drivers that the kernel needs to access the hard disk)
• prepare other file systems, e.g. on the hard disk or on different ram disk devices (/dev/ram2)
• temporarily mount other file systems (e.g to retrieve extra programs).
• set the real root device (by writing to /proc/sys/kernel/real-root-dev)

When linuxrc terminates, the real root device (possibly a different ramdisk on /dev/ram2) will be mounted as root and /sbin/init will be run as usual. So the initrd ramdisk will be the root file system only as long as /linuxrc is running. Using this approach you can forget about the older type of startup ramdisk.

Because it is loaded by the boot loader, an initrd ramdisk can be loaded from the floppy image on an El Torrito bootable CD-ROM, while the older type of startup ramdisk can't.

The kernel command line is passed to the kernel by the boot loader (e.g. LILO) as a pointer to a string in memory. The kernel parses various arguments on that command line for itself and can pass the rest as a command line to init.

Just some minor additions:

• I don't think that the boot loader passes the pernel command line as a pointer (I think it's at a fixed location), but it _is_ a string in memory that the kernel processes later.
• The boot loader loads any initrd ramdisk into RAM using the BIOS disk device (therefore it works from a disk image on a bootable CD-ROM) and places the command line also in RAM. Next it jumps to the setup.S part of the kernel From then on the boot loader's work is over.
• The kernel moves itself, the command line and the initrd disk image around in RAM, decompresses itself and initializes a lot of things.
• If there is an initrd ramdisk, the kernel can gunzip it (if it is compressed) and copies it to /dev/ram (internal ramdisk device). Next it does the temporary root device trick that I have already explained.

Further reading: kernel source tree:

• arch/i386/boot/bootsect.S (is only used when the kernel is booted directly from a floppy, is skipped by LILO and other boot loaders).
• arch/i386/boot/setup.S (real-mode initialization, entry point for LILO).
• arch/i386/kernel/head.S (protected mode initialization).
• anything in arch/i386/boot/compressed (see how the kernel decompresses itself).
• init/main.c initialization flow, including temporary initrd mount and starting of init.
• drivers/block/rd.c (ramdisk driver, also for initrd ramdisk, decompression etc). Almost all code (including initialization) is shared between the initrd and normal ramdisk.

-- Lennart

Re: Making executables smaller

Hello Gals and Guys,

I enjoyed reading the latest batch of 2 cent tips and thought I'd pass along one more small bit of information:

Besides using "strip" to reduce the size of an executable, if you're into compiling from source you can use the "-Os" optimization, which will optimize for size (should work with an respectably recent version of GCC). For the ultimate in downsizing, you can also link your apps against any of a number of libc derivatives. Check http://freshmeat.net for the latest versions of:

• diet libc: http://www.fefe.de/dietlibc
  this site also provides documentation and helpful links
• uClibc: http://www.uclibc.org
  designed specifically for embedded systems; additional links avail.

Several other similar projects are out there; these were the first to come to mind. Thanks so much.

cheers,
John

Linux Journal Weekly News Notes Tech Tips

sending Microsoft Word documents

If someone asks you for a file in Microsoft Word format, don't panic or start to do something dumb, like dual-booting. Just convert the file to HTML, do a cp file.html file.doc and send the ".doc" file. Microsoft Word will automatically import it.

Keeping a persistent session as you log in and out from different terminals

Here's the Ten-Second Guide to screen for people who just don't want to type stuff over when they lose their net connection.

1. ssh to the server you need to work on.
2. Type screen.
3. Do what you need to do. It will be inside a screen session.

When your connection fails:

1. ssh to the server.
2. Run screen -r to resume your session where you got cut off.

Joy!

Outlook to Evolution

Upgrading from Microsoft Outlook to Evolution? To free your address book from Microsoft's proprietary format, just sync it to a Palm Pilot then sync it back into Evolution. (If you have to borrow a friend's Palm Pilot to do this, back it up first with pilot-xfer, then restore when you're done.)

Source: Ari Jort, New York Linux Users Group

Mozilla port paranoia

You've just hooked up a cool web-administered device; you type in the device's IP address and port number, and Mozilla says, "Access to the port number given has been disabled for security reasons." What?

Fix it in Mozilla's all.js configuration file, which probably lives in usr/lib/mozilla/defaults/pref/all.js or somewhere like that. If the banned devices are on ports 1080 and 31337, add the line:

pref("network.security.ports.banned.override", "1080,31337");

to the all.js file.

Renaming a file that has a special character in the name

Help! I can't rename a file with a special character in its name!

If you have a file called important?file, and the ? is really some character you can't figure out how to type, try this:

ls | grep important?file

Make the pattern after grep long enough that it matches only one file. Then, when the above command matches only one file, go back up and edit the command:

mv `ls | grep important?file` important-file

And you've renamed the file without ever figuring out its true name.

Have Ethernet cables, will travel

The lightest, most compact way to be prepared to hook up to whatever Ethernet connection you find is to carry one regular cable, one crossover adapter and one RJ45 coupler.

             Plug                           Jack

Straight     none, or coupler +             straight cable
             straight cable


Crossover    coupler +                      crossover adapter +
             crossover adapter +            straight cable
             straight cable

This page edited and maintained by the Editors of Linux Gazette Copyright © 2002
Published in issue 80 of Linux Gazette July 2002

HTML script maintained by Heather Stern of Starshine Technical Services, http://www.starshine.org/

Contents:

¶: Greetings From Heather Stern

How to Investigate a System Lockup

How to send email without a DNS server?

Starting many X sessions

Playing CD Music Digital Output

need help! Mandrake 8.1 fd0 unknown device, and downloading pictures from a digital camera

How to optimize space usage for multiple files on multiple CDs

/dev/scd0 is not a valid block device?

Greetings from Heather Stern

The Answer Gang's Editor Gal

Hello all, and welcome once more to the lively world of The Answer Gang. I'd like to hand out a special thank you to all the readers who definitely read the posting guidelines before asking the Gang their question. It's helped my work a lot.

Almost the only spam that escapes Dan's traps anymore are those dratted conman scams telling me about how their late uncle / business partner / revered general or whatever left them a quadzillion dollars / francs or whatever and they can't get at any of it unless you as a friend / distant relative / confidant / conveniently uninvolved sucker open your bank account to help them launder it. Whereupon I presume they take you to the laundry, raid all your spare quarters and leave you in the giant tumble-dryer with no socks. So that's the Peeve of the month. Although I suppose I should mention that the useless use of HTML attachments fought really hard for second place. The Klez worm gets a distant third since infected people usually figure it out and fix themselves.

So I didn't get very far in my personal project of the month this time. After a foray into the space for some clients of mine, I'm starting to seriously look into decent IMAP setups. UW IMAP is easy to install, sort of like saying a tricycle is easy to drive. Any kid can do it but it just was never designed for anything beyond being the reference implementation for IMAP as far as I can tell. Beyond that it's somewhat well known for being full of bugs, and their attitude towards client side problems in the FAQ feels laced with a lot of "your client sucks, use pine." Cyrus I glanced at and it seems sturdy enough, I guess. But the clients asked after Courier-IMAP. Hmmm, nice. About ten times as fast as UW. Just don't use the MTA that comes with it. Ugh, whatta mess. Maybe in a year or two you'll be reading this and it will have grown up. We went back to sendmail. If there are any other IMAP daemons to speak of I couldn't find them all that quickly. Courier is sufficiently cool and maildir delivery makes people happy for other reasons.

Did I remember to say IMAP is cool? As I've been going to more conferences with less techie features available, the idea of having my mail on the server be willing to deal with two workstations and a laptop carrying the same mail around doesn't sound half bad at all. And most people can't take the other tactic that I've done, which is to get involved with setting up internet lounge space

Which reminds me, the ConJosé, the 60th World Science Fiction Convention is coming up at the end of August, in my area, and I expect it'll be a lot of fun. I can tell you there's gonna be some Linux around.

Linux World Expo will be in my area in August also. WIth any luck I'll get to meet some more members of the Answer Gang. Group photo, anyone?

Anyways, back to IMAP. It turns out there are email specific appliances out there running Linux and Cyrus under the hood. Not only nice but I don't have to tinker? Oboy! To be fair I'm good friends with the folks over at IMAP Partners and the people who make the appliances they use host the system for my local sysadmins group, BayLISA.

But I didn't get as far along as I wanted in my great project to determine which IMAP clients suck the least. Our loyal readers may recall that I have a rather cynical opinion about the usefulness of so-called "productivity' software and and regardless of my deep dependence on email, MUAs (mail user agents) are no exception. So I will probably have an article about that next month. Contributions welcome, of course.

With that, it's time for a picnic. This year's Independence Day issue is full of some juicy bits just waiting for you to throw some CDs on the roaster. Me, I'll be spending a happy 4th of July hanging out with my family down in L.A.

How to Investigate a System Lockup

From Chris Gianakopoulos

Answered By Didier Heyden, Breen Mullins, Ben Okopnik, Jim Dennis, John Karns
with tidbits by Robos, Heather Stern

Hi Gang,

[Didier] Hello, Chris!

[Robos] Hi

I was running X tonight (with the ICEWM window manager), I had a couple of xterms running (one with kermit running), and I was using Acrobat Reader Version 4.0.

As I was making a mouse movement, the my console locked up.

[Robos] Don't you have to reboot when you make a mouse-movement? Oh, wait, that's that other thing that claims to be an os...

No less than 4 other gang members chimed in with some version of a sigblock fortune cookie about this. -- Heather

I could not even get a response, via the Ethernet, when trying to ping my crippled Linux system.

Which log files could I look at to try to determine what the impending disaster could have been? I have included the tail portion of /var/log/messages. I have included extra stuff, I suspect. I'm curious what those entries that say "MARK" mean. Could that be related to my lockup?

[Didier] Nope. From the `syslogd' man page:

      -m interval
              The syslogd logs a mark  timestamp  regularly.  The
              default interval between two -- MARK -- lines is 20
              minutes. This can be changed with this option.

(However it seems that this feature is disabled in some versions of the syslog daemon -- maybe through a compile-time option?).

Okay. I'll investigate other stuff.

[Breen] At least on Red Hat it's through a run-time argument.

The init script for syslogd reads /etc/sysconfig/syslog for its arguments:

# Options to syslogd
# -m 0 disables 'MARK' messages.
# -r enables logging from remote machines
# -x disables DNS lookups on messages recieved with -r
# See syslogd(8) for more details
SYSLOGD_OPTIONS="-m 0 -r -x"

"-m 0" is the default; I added "-r -x" on this machine.

[Didier] Fairly redhat-ish, indeed. My own system is based on an antediluvian RH 5.2 distro. I'm usually not too impatient to upgrade with a full new distro install (preferring recompiling packages from source -- RPM'ed or not -- iff I can't no longer avoid it). Believe it or not, I haven't drowned yet in the resulting mess

By that time they just had no such configuration file, and the syslog daemon was run without any argument by default. But somehow the `-- MARK --' feature was... erm, is still in my case... totally disabled: whatever -m xx option I try no timestamp appears in the logs.

[JimD] Actually I think this was a bug. I reported it to the upstream maintainer a few years ago (when I was running RH5.2) and he pointed me to the updated version that worked.

Naturally I'd advise that you simply fetch the latest version (in source form if you don't want to get trapped in RPM dependency upgrade hell) and build/install that.

[Didier] Thank you very much for your suggestions, Jim. Now I know what package to download next.

Regarding the RPM dependency hell, IIRC I once experienced core dumps from the `rpm' program itself after having fiddled with the `--nodeps' option (I was supposed to know what I was doing The problem was (hopefully) fixed with this simple command:

rpm --rebuilddb

I'm not sure it would have worked in all situations, though. And unfortunately I don't remember the exact version that was then installed on my system. In fact this has most probably been fixed ages ago...

[Didier] Note that I also have a couple of problems with the associated `klogd' daemon, as indicated by the last two lines of the following excerpt:

Jun  4 14:13:56 wallace kernel: klogd 1.3-3, log source = /proc/kmsg started.
Jun  4 14:13:57 wallace kernel: Loaded 15309 symbols from /boot/System.map.
Jun  4 14:13:57 wallace kernel: Symbols match kernel version 2.4.17.
Jun  4 14:13:57 wallace kernel: Error seeking in /dev/kmem
Jun  4 14:13:57 wallace kernel: Error adding kernel module table entry.

The other weird thing is that that ancient kernel log daemon cannot be stopped by anything but a plain SIGKILL. Doesn't prevent me from having nice dreams, however.

[Didier] Unfortunately, when one experiences such brutal lockups, the logs are often not of much use: the whole system freezes before the daemon is given a chance to write anything in them -- even if some kernel oops actually occurred. The only way to see this happening would be to have the kernel writing directly to the console (assuming you're currently viewing the console output, but it won't do in a X session unless, maybe, console output has been redirected to a serial port at boot time?)

Upgrading your kernel might help, provided the lockup was not caused by some hardware (RAM?) failure.

[Ben] That's pretty much what I would suspect - hardware. The only times I've seen Linux hang has been hardware-related stuff. In one very annoying case, my laptop would hang for a number of seconds, several times per day - and I had to live with it, because the PCMCIA card causing it was my wireless modem which was on 24x7. AFAICT, it took a huge chunk of CPU when it switched channels (sometimes the CPU load meter would actually catch the spike before everything froze); fortunately, it didn't do that very often.

[Didier] Another example is an IDE cd-rom or cd-writer device buggy enough to suck up every possible CPU clock cycle whenever it fails to read or burn the medium, the system thus becoming almost unusable -- especially in the case where the application which makes use of it is run with a static real-time priority (cf. `cdrecord'). Actually I've never figured out whether some ill-written code in the IDE / IDE-SCSI driver could be held responsible for such a misbehavior or if it was simply inevitable on this kind of architecture.

Real-time constraints in a multi-tasking operating system are often very difficult to deal with anyway.

[Ben] <sigh> Hardware stuff like PCMCIA has root-level access - has to, to access privileged ports, etc. - and unfortunately I know of no way to mitigate that. I wish there was a "nice" utility for hardware...

[Heather] ACPI might like to be that, someday.

[Didier] I once read that running a shell with a posix real-time scheduling policy could help in some situations. Unfortunately I've never heard either of a `nice'-like utility which could be used to launch `bash', `csh', etc. this way. I assume that in fact you must have a special version of your favorite shell, containing direct calls to sched_setscheduler(), in order to do that -- but I'm not sure.

RAM is always a possibility. The system seems awful reliable, though. Maybe it IS time to upgrade to a new distro just for the fun of it. I say distro rather than kernel so that I can use XFree86 version 4.x. My friends at work keep offering SuSE 8.0. I believe that the S3 Trio64v+ is supported, so nothing is really stopping me from going to the new distro.

I am guessing that it is related to whatever applications might have been running under X in combination with Acrobat (if not a hardware problem). Dynamic systems are always the most difficult to troubleshoot.

See attached chrisg.logfile.txt

[John] Continuing on the kernel side of the issue, a thread on a related subject just came up on a LUG list I'm on:

Thank you all (there are so many names to list!) for your quick responses to my question. I'm gonna do some detective work. My perception was that the system locked up. The only thing that I really know is that the console and the network did not respond. I got two serial ports on my system. I dedicate one to the modem, and I use the other for kermitting around. I think that I am going to use my nonmodem serial port for a login session. Would it not be funny if the system was still running and only my network stuff failed as a result of an X lockup?

That would seem odd, though. Since I was running X via my local console (you know -- with the keyboard and display), I would expect Unix domain sockets to be used, thus, bypassing TCP (the network stream stuff).

You all gave me lots of good ideas, and thanks much again. This email response is like a broadcast thanks to all of you!

How to send email without a DNS server?

From Faber Fedor

Answered By John Karns, Mike "Iron" Orr, Mike Martin, Heather Stern, Ben Okopnik

Hi Gang!

A client of mine is discovering the Joy That Is Linux. He recently asked me if it was possible to send email from applications (written in JBASE, a PICK shell that runs on Linux). I mentioned that you could do this:

mail -s "Some Subject" [email protected] < output_from_app

and he was impressed. He has since come up with several time- and resource-savings applications of that simple redirection to the mail command.

He has raised an intersting (to me) question and although I can come up with two solutions, I'm looking for a better one. Also, it's generated a question that I can't answer, hence this posting.

The question is: How do you send mail between two linux boxen if there is no DNS server from which to query for an MX record?

Now, I'm not asking for the impossible here. The two boxen run sendmail/postfix and they are on the same internal network (the sender is 10.10.10.1 and the receiver is 10.10.10.2).

I could tell him to install a DNS server, which he would do (I love clients that listen to me but there should be a simpler solution. We could send the email to a local user on .1 and fetchmail the mail from .2, but that's too much of a kludge for my taste.

I've been through the HOWTOS and google and didn't find anything applicable (at this point Ben walks in, donning his mirrored sunglasses, executes a google search using 1.5 words (without quotes), finds The Canonical Page that answers this question and makes me look like a fool (again ).

Ideas?

[Ben] <mock growl> Don't do that, Faber; the fact that one of us has the answer _does not make the rest of us look like fools. Unproductive attitude there, sir. Me, I'm always happy when I see one of the other Gangsters come up with an answer to something I don't know (how d'you think I got this smart? - I get to learn stuff, which is a very good thing indeed.

[Heather] half a search word?

[Iron] mail [email protected]

Some mail transfer agents may balk at it, but I've found it to work most of the time.

[Heather] Works even better if the IP address is in brackets: remote_user@[10.10.10.2]

[Mike] Also, you can put the domain names in the poor man's DNS: /etc/hosts.

[Mike Martin] Assuming that the network is small with no server (as implied) /etc/hosts is the right idea

If you are sending externally you would need a DNS either locally or via the isp anyway

[Ben] "/etc/hosts", or maybe even a lightweight local (caching?) DNS. I'm coming to really like PDNSD; painless to install, dirt-simple to set up. Or, you could always use "ssmtp" to rotate the mail off the local hosts to the actual MTA, since it's local; that's my solution (farm the job out to the guy who's good at it.)

[Heather] Yes, you can use /etc/hosts, but it can't do an MX record lookup. Your smtp daemon will need some tweaking. In sendmail you can tell it that transport for a given named host will go through an explicit IP address host, and then it would never try an MX lookup, just use the burned in route.

[John] Depending on the distro, distro version, and MTA you're using ...

Using SuSE 7.x & sendmail, and a psuedodomain I use, I've come up with the following solution to that problem:

edit /etc/mailertable to add entries like the following

mylinuxServer1.my.domain		smtp:mylinuxServer1.my.domain
mylinuxServer2.my.domain		smtp:mylinuxServer2.my.domain

I don't have DNS setup, as the servers are isolated, but sendmail via dialup. I do have the hostnames listed in the hosts file on each server though. In this way, any mail addressed to [email protected] only goes out when connected to that server.

[Heather] The postfix equivalent to that is /etc/postfix/transports, although that's actually mentioned in /etc/postfix/main.cf to activate it, so you could name the file anything you like.

You can't use nullmailer for these even if it's only two boxes, because that won't accept mail for local deliveries. You could keep all the mail on only one of 'em and use nullmailer on the rest of the machines though. At that point the machine becomes a very tiny server and also needs to run a pop or IMAP daemon to allow mail pickup. At which point you may as well also set up a dummy local DNS, maybe for a silly domain name that won't be used by the outside world because there are no root servers for it, like fabershouse.local -- which would serve A and MX records for say... livingroom.fabershouse.local, den.fabershouse.local, etc.

You could skip mail and drop notes in a samba share at each other, or ssh in and share a kibitz session using your favorite text editor. Which means somebody becomes a server but may bother people a lot less.

Starting many X sessions

Answered By Ashwin M, Heather Stern, Jay R. Ashworth, Chris Gianakopoulos, Robos

[Ashwin] Hi,

I am a relative newbie to Linux, hence this tip may be common or may have been already published.

[Heather] This is a particularly clear description of it, and the thread turned a curious direction as well. Welcome to the pages of The Answer Gang, Ashwin.

[Ashwin] Yes! You can have more than one X session running at the _same time! By default your X session will be running on virtual terminal 7 (that is why you use Ctrl-Alt-F7 to get to it).

To start a new X session get to a terminal session (F1 - F6) and type "startx -- :1". A new X session starts up. Now to go back to the older X session, use Ctrl-Alt-F7. For the new X session use Ctrl-Alt-F8.

(For more X sessions use the next numbers after 1 like 2,3 and so on. They don't have to be in order like 1 next 2 and so on. No matter what number you use here the Ctrl-Alt-Fx number will be assigned the next available number after 7)

[Heather] Strictly speaking, the first available open terminal; on most major distro setups that's 7, after your 6th text console, but if you're an oddball like me who uses enough text consoles that you set up, say, 10, then it would show up on console 11 instead.

Of course if you do that too, make sure Xdm or its cousins don't think they are supposed to take a console used by a text getty.

[Ashwin] Now, why would anyone need another X session? Some reasons could be -

• To use different window managers at the same time like KDE and GNOME.
• To run X sessions logged in as different users.
• To try out things with the XFree86 system (like fonts and such)

You may think "why would I need this?". But, once you know this trick you will find new ways to use it for your work

Note: I found this not to work on some (very few) systems with old video cards and less VRAM.

thanks, Ashwin

[Chris G] That's a cool tip. I just tried it out, and it works with Version 3.3.6 of X.

[Heather] My favorite reasons to run multiple X sessions on the same machine are:

• Jim and I are both using the machine... so we want our own X session each. Since we're running in different chroot spaces (for an experiment) on one of the machines around here that's kind of handy.
• to have different native bit depths, also for experiment. Happily getting to be rare, but there is occasionally software that is happiest only at one color depth. If you're designing graphics for use at multiple color depths I swear this is the fastest way to tell which colors will wash out.

In the modern era you could also use Xnest to provide the reduced depth to the stupid app, but it's less confusing to do the above than to make sure you're running something inside the nest.

Not that it's hard mind you - make the nest's first client an xterm with a custom color fg and bg, then launch things you want in the nest from the special xterm.

[Robos] Well, I knew this, but did you know that the keyboard and mouse are bound to one? Meaning you can't - like I tried - run two xsessions on two grafik cards and share the keyboard between them. This is only possible if you use a ps/s keyboard and a usb version. I want to do that, but I haven't got the usb keyboard yet that I would like: small form factor (84 keys), english layout (I'm in germany) and usb...

[Jay] You are supposed to be able to do that.

And indeed, a quick test proves that you can.

RH 7.1, and whichever X ships with that. I did Ctrl-Alt-F1 to a text login, logged in as root, did 'startx -- :1', and was whisked over to tty8, where I got a KDE desktop as root (that being the default choice on my laptop).

Ctrl-Alt-F7 switched me right back to the desktop I'm on (KDE under KDM, logged in as myself), and I could C-A-F8 right back to the other one; mouse and keyboard worked in both.

And indeed they should: X switches to a free vt before it binds the hardware, and what it gets is the virtualization of the hardware that it produced by the multi-console driver. It doesn't bind directly to the hardware.

[Robos] Well, a misunderstanding and a wrong memory on my part (I run memtest86 later on me, it always takes so long...). I meant that I wanted to run two xservers on two graphic cards and have two keyboards too. My motivation: Running quake3 and chatting with my pals in irc at the same time. Thought about either two xservers or one xserver and one mga framebuffer. But, as said, no usb keyboard yet.

[Jay] What is hard is having two X servers on different physical display adapters with separate keyboards. Hard, but often very useful.

[Robos] And cheaper than two computers, not to mention the noise reduction.

[Heather] While I had interpreted this confusion as wanting both X servers to listen to the keystrokes in tandem, implying that they'd both be grabbing keyboard events from the same pool. Which given his usage example, of course is not what you'd want I could see some vague reason why somebody might want to do it (test the same app on two video cards at once) and I can certainly imagine the USB model of how devices work being much better for handling it.

X 4 lets you designate entirely different screen layouts to be stored in its config file, and you can specify which one to use by passing -layout "layout[1]" (or whatever ID you named it) down to X. Of course your usual methods of starting X may try to protect you from doing this, but with startx it's pretty easy: startx -- -layout secondhead :2

With X 3.3.x you probably have to just keep seperate config files.

If anyone out there is crazy enough to be trying this, let us know how it works out for you. And then there's always the Linux Terminal Server Project: http://www.ltsp.org

Or better yet the K-12 Linux Terminal Server Project: http://k12ltsp.org/contents.html

Playing CD Music Digital Output

Questions From Bill Parks, Mithra

Answered By Lennart Benschop, Dave Maxwell, Serkan Akdag, Rob McMeekin, Robos

This thread is in response to Issue 79, Help Wanted #2 and all of these people sent in Tips. I'm sure there's really at least a quarter's worth here; that'd be Two Bits instead of Two Cents -- Heather

I purchased an eMachine to run Linux on. It came with (sorry) XP which I used to check out the hardware. It plays music CD's fine but uses digital data over the IDE buss rather than a cable from the CD drive to the sound input.

Loaded Red Hat 7.3 and it plays sounds fine but it won't play music CD's...the player just runs and the CD spins along.

How do I configure the CD/sound system to pick up the digital sound data on the IDE buss to play the music?

Thank You, Bill Parks

[Lennart] Linux does have a program that can play a CD by reading the digital data over the IDE bus, it's cdda2wav, included with most Linux distributions.

cdda2wav -D /dev/cdrom -t 1 -eN

will play track 1, if the KDE sound system isn't keeping /dev/dsp busy. The -eN options cause cdda2wav to echo the data to the soundcard and not write the ridded data to a file.

You can also try to connect an analog cable between the CD-ROM drive and the sound cards, as most PC's have.

[Dave] There is a plugin for XMMS that does this. It can be downloaded at

ftp://mud.stack.nl/pub/OuterSpace/willem

The version numbers are a little confusing. The latest version is:

xmms-cdread-0.14a.tar.gz

The one labeled 0.9a is not it. XMMS comes with a cd player plugin that is supposed to do this but it didn't work for me. To play a cd, start XMMS and open your /dev/cdrom device or whichever device the cdrom drive actually is. I'm currently playing a cd from a drive without it's audio cable so I suppose that means it works . Come to think of it, if you add an audio cable from your cd to your sound card then the player you attempted to use will work as well. The audio from this plugin will be cleaner as it passes through one less analog stage.

Another nice thing about this plugin is it will pull title data from Freedb and let you play individual tracks by name. The stock plugin won't do this.

Oh yeah! Be sure to disable the stock plugin before attempting to use this one. Right click on XMMS and choose Preferences.

[Serkan] Hello, You will need to enable the "Enable Digital Sound" from one of the configuration options of KDE and/or Gnome. There is an option like that somewhere but I can't remember but I am sure its in X and not the console. Also, you could type audio:/ at the KDE browser to view your CD-Player contents and open a multimedia player like XMMS and drag the files in the browser to the playlist of XMMS and play that way. It should work.

[Rob] Hello. I have an IDE CD-ROM drive and an IDE CD-RW drive. The CD-ROM has audio cables attatched to the Sound Card while the CD-RW does not. The CD-RW would not play compact discs until I configured it for writing (enable SCSI-Emulation). I'm not an expert. I don't know if this is supposed to be the case. It could just be a fluke, but it worked for me.

And, since someone may also want to play other sorts of fun noise with their player, and most easily find this thread instead... -- Heather

[Mithra]

Hai,

I use Caldera Linux . i Would like to watch movies in my syatem. But There is no s/w that would play .Dat file for me. Can any one suggest me a downloadable s/w that can Play .dat files.

[Robos] Try mplayer, it can do this. Url is http://www.mplayerhq.hu.

Mandrake 8.1 fd0 unknown device, and downloading pictures from a digital camera

Questions From F F, Mike "Iron" Orr

Answered By Chris Gianakopoulos, Ben Okopnik, Mike "Iron" Orr, Heather Stern

I can't read the FLoPPY disk! both cd roms works properly, but there's no way to access the flp! (Yeah, it is! in the drive)

Does someone have the solution?

[Chris G] I know that this question might sound silly, but, is your floppy drive one of those LS-120 drives? If the answer is yes, then, it looks like an IDE hard drive, and you mount it like a hard drive.

If it is a regular floppy, and you know that the floppy works, I would check the bios settings on your computer and see if the floppy controller is enabled.

Also type "dmesg" and see if a floppy controller has been detected. If the floppy controller was detected, I would check the cables to the floppy drive and its power connector.

The last resort -- swap the floppy drive with another known good drive.

I hope that this helps.

[Ben] I guess it depends on whether the querent is running Linux, Chris; if so, he hasn't mentioned it. In case he is, a simple "mount" command might help.

Hmm. I'm going to try something that might be useful here. The idea behind this is "how would I phrase the querent's question if I was having this kind of a problem?" The question, when properly phrased, should contain the solution - as they very often do. Perhaps modeling clueful behavior may be a useful thing...

[Heather] Of course, if they knew enough to say all this, they probably wouldn't ask us anything... and it's much easier for an utter newbie to assume we will somehow know what he's talking about, since we've seen so much before. Bravo for answering in true Answer Guy style - if need be, use your own sense of autocompletion to upgrade an interesting question to readability, then answer the result. At least somebody will get a good answer from it

I have to remind the Answer Gang to read subjects as well as messages. though. It usually isn't much but every clue is something.

I note that if you have a bad /etc/mtab then just running 'mount' to ask the system what is mounted can provide strange and wrong results. To be sure you're getting the real info, ask the proc filesystem: cat /proc/mounts

[Chirs G] Right you are, Ben! I have not answered any Answer Gang questions for a while, and, it would seem that I forgot how!! I don't know what was up in my mind. For some reason, I must have been looking at a previous Linux question, and I connected "F F"'s email with that question.

Thanks for that constructive input, Ben.

Congrats to Ben for an excellent answer. And maybe one that belongs in ask-the-gang.html somewhere. -- Mike

[Ben] Thanks. I thought it might be a good way to model something useful; I don't know that there's a good way of adding it to "ATG", but I'll try doing it that way a few more times (I don't think we're going to run short of poorly-phrased queries anytime soon), and maybe the idea will get propagated just due to its exposure to the LG-reading crowd. I like the idea of folks being effective at asking questions; if I can contribute to even a small increase in cluefulness in the general population, I'm happy.

It's easy to assume the querent is having the same problem you've had before. And since I have used Linux exclusively for several years ... I forget what kind of assumptions Windows users make. So you are not the only one who answers an ambiguous question with a Linux answer and doesn't even realize it. -- Mike

[Chris G] It's gotten automatic now. I used to use Microsoft Outlook for reading my email. Once I set up Sendmail and Mutt, I use Windows for playing network Doom with my kids. I remember, though, if the question is ambiguous, answer with a Linux solution. I like Ben's example, though.

I also forgot to suggest to the querent to try booting off of the floppy using a dos-based disk. I had a similar problem when helping a coworker install a SuSE distribution on a Compaq DeskPro computer. I noticed that the system would not boot from the floppy drive, and, upon closer inspection, I realized that the floppy drive was an LS-120 drive. As a result, the mtools stuff did not work. We went ahead and looked at /etc/fstab and saw an entry that corresponded to the LS-120 drive.

[Ben] Hmm, that's odd. I've got an LS-120 in my desktop PC, and it boots just fine. However, you're right about "mtools" freaking out about it: that 120MB capacity fries its little brain... I was never able to find a combination of switches for "superformat" that would let me do anything with it, even to the extent of creating a 1.7MB floppy. Kinda sucky.

[Chris G] Maybe there was something about the bios settings of the Compaq computer. I recall that we could not do anything with the bios setup because we did not have the password to the thing. Soooo..., you can boot off of an LS-120. Cool.

[Heather] I have found that I could boot from LS-120s and as I recall I could work with 1.44 disks. What I don't remember, because it was a pain, is whether I could format them after some setup tweaks, or if I could dd them. I recall I could only do one and not the other, and I couldn't make 1.722 disks using the tomsrtbt setup. Very annoying, but possibly also the victim of Tom using an older floppy formatting program because it was smaller. I considered the whole thing fitful and use my trusty laptop to cough floppies. Except that it can't mount floppies directly very well, so I 'dd' images of the floppy off, and loopback mount them. Raw access works fine, it just seems to be a timing thing. But I'm not complaining, because the loopback mounted images are much faster than a floppy, anyway, and the diskette is safe from being scrambled unless I deliberately copy the image back out.

Mandrake 8.1 fd0 unknown device, and digital camera

From Mike 'Iron' Orr

Answered By Ben Okopnik

And since I have used Linux exclusively for several years (except a few times a year to download pics from my digital camera), ...

[Ben] I got myself a FlashPath "floppy" to bypass all that. Stick the SmartCard into the gadget, use the modified version of "mtools" to read it (standard "mtools" functionality plus FlashPath capability), and all is good. Besides, the various camera interface utils (GPhoto, etc.) are getting pretty darn hot these days.

The camera is a Canon Elf S100, which uses compact flash memory. It was working with gphoto2 command-line mode at one point. Then the USB device entry disappeared in the middle of a download. Usually that meant the battery went dead and I try it again with a recharged battery. But the last time, it wouldn't acknowledge the device at all. Then in Windows it stopped recognizing the device too, so I figured the camera's USB interface was defective, because the card works fine in the camera.

So I bought one of those little USB card readers. Not only do you not have to worry about batteries, but supposedly the card shows up like a removable disk drive, with ordinary files, bypassing the ideosyncracies of each camera driver. But Windows wouldn't mount the card, it just said "invalid filesystem format" or something like that.

[Ben] Right - despite the "ordinary files", etc. advertisements, it does not look like a standard floppy even to Wind*ws - a special driver is required (at least this is true for SmartDisk FlashPath 'floppies'.) The same is true for Linux; hence the special version of "mtools" (it's a binary-only driver - there is a source tarball, but I was unable to compile it, and the author himself says to use the RPM with the binary.)

So I hooked up the camera to Windows again, and this time it recognized the camera. For software I had the Kodak Imaging program that came with the camera, and Photoshop. Photoshop's "import..." menu option was disabled for some unknown reason even though I had used it before. So I tried the Imaging program. But that program is too horrible to use. It takes a lot of clicks to download each picture, and I had 150 of them. And it kept trying to save in TIFF format, taking forever to save one image and insisting on using TIFF format, which is big, and somehow it used all 100 MB of free disk space and I had to kill the program, and every time I tried to save it did something similar. So that was useless.

So I downloaded kernel 2.4.18 and was delighted to see there's a USB driver for my card reader. I'm hoping when I try it out it will work, and that it will recognize the card's filesystem.

[Ben] I suspect that it won't. The "tweaked mtools" author is a guy name of Jason McMullan ([email protected]) (Jim, Heather - somebody you know?); the version that I have is "mtools-3.9.7-7fp.i386.rpm". I renamed it to "mtools-9.9.7-7fp.i386.rpm" before running alien; that way, the version info shows a high number and updating Debian doesn't overwrite my version.

Is there a floppy reader for compact flash?

[Ben] ISTR that SmartDisk makes one, but I'm not 100% certain. Worth looking into, though; I like my little gadget.

I found gphoto and gphoto2 to be a total pain. My camera was only in gphoto2, which was an unreleased development version at the time so there was no Debian package. Of course, the usage instructions I had were for the old version, and the GUI front end had been replaced by something else that I think was missing something. Maybe it's better now. But having the images appear as files is really what I want to do anyway.

Update some time later

I finally got my pictures out. I compiled a new kernel with the basic USB stuff in, and used Debian's gphoto 2.0 final. To download all photos:

gphoto2 --camera "Canon PowerShot S100" --port usb --get-pictures

gphoto2 --camera "Canon PowerShot S100" --port usb --list-files >files
gphoto2 --camera "Canon PowerShot S100" --port usb --get-picture 5-10

I had less luck with the Lexar card reader although it did download some images. For this, you need not only the kernel USB support but also SCSI "generic device" support (not just SCSI disk support). You also need the USB Storage module. With all this in place, when you stick the Compact Flash card in the reader, it shows up as a SCSI disk, /dev/sda1, which you can mount as an msdos filesystem or use (the ordinary) mtools on. (The mtools configuration line is, 'drive c: file="/dev/sda1"'.) But the problem with this is that after twenty-five pictures at the beginning (or after three or even one picture later), the light on the card reader would go off and it would play dead. This isn't a battery problem because the reader gets its power from the USB bus. The processes would be in "D" state ("uninterruptable sleep" in the ps listing) so they can't be killed. Also, they make the system unable to shut down cleanly: 'halt', 'reboot' and the vulcan nerve pinch just hang at "Sending processes the TERM signal" until you ctrl-C and continue. So I have to do a cold boot with the power switch. To prevent disk corruption, I upgraded my ext2 partitions to ext3 (journalled):

tune2fs -j /dev/hdc10

But it was satisfying seeing my card reader more compatible with Linux than with Windows 2000/XP. Windows would try to mount the card reader and give up silently or say "invalid filesystem format". Take that, Windows!

How to optimize space usage for multiple files on multiple CDs

From Michiel van Leening

Answered By Thomas Adam (The LG Weekend Mechanic), Ben Okopnik, Karl-Heinz Herrmann

With our kind thanks to Michiel for granting publication permission -- Heather

Hi Gang,

I've got a bunch of files which will roughly fill up 12 CDR's. My question is, how can i best optimize the space used for these files, so as to use as little CD's as possible?

[Thomas] Assumming that you are not fussed as to which files appear on which CDR, and assuming that these files reside in a single common directory, then you could write a script that will take the largest files.

[Ben] Actually, that's an NP-Complete problem, i.e. you can't get an actual solution before the Universe ends. Sad but true. However, there are a number of "close enough" approximations you can do. I've never heard of anyone scripting this kind of a thing, although I would imagine every CS student out there has played with the concept.

Here's a reasonable one: sort your files. Grab the largest one, subtract that from MAX_SIZE; now, find the largest file that will fit in the remaining space. Iterate until the remaining space is smaller than your smallest file. Repeat the above process for every one of your CDs. You're done - and in linear time, too.

I've tried just looping through all the files and as long as the sum of the already seen files stays below the CD size limit, the file is added to a list.

[Ben] Erm... a 20MB file followed by a 631MB file, and you've got a CD with 20MB on it. Not a reasonable compromise. Even if you sort them first, 326+325, and you've wasted half a CD.

As soon as a file goes above the size limit, it starts a new list with filenames. These list are then used to burn the CD's with either mkisofs or Gcombust.

[Thomas] Is the limit 650 MB, in which case:

See attached fill-it-up.bash.txt

I'd actually like a program to figure out the best spread of files over the CD's (eg. CD1 has files 3,5,8 and CD2 has files 1,2,4 and CD3 has files 6,7,9) so as to minimize wasted space. What i've programmed myself has the disadvantage that if the next file in line is big enough to cross the size limit, it is put on the next CD, thereby wasting space on the current CD.

[Thomas] I'll work on this at home Might even put it in my LWM article next month

Now i could go and program such a thing, find out afterwards that something like this exists and tear my hairs out in frustration. So, does a program exist that can do this? Maybe someone has a script lying around. Ofcourse intensive Googling for a week hasn't turned up anything.

Thanks for any input on the matter.

[Ben] As I've mentioned, I haven't heard of anything (although any CompSci department has seen thousands of attempts), but it shouldn't be all that hard to script an approximation. The algorithm I suggested would only take a few lines of Perl, and even a shell script wouldn't be all that bad.

[Thomas] Hey Ben....you and I could work on this one Whadaya reckon -- I'm sticking to bash !!

[Ben] <dryly> The actual scripting is left as an excercise to the student. Gotta let folks do _something on their own, dude!

Now, all I've got to do is figure out the purpose of your script, above... what it does is obvious, why you'd care about the result (if there _was any) isn't.

[K.-H.] Actually there is already a script which served me quite nicely. It's already tied in with cdrekord and mkisofs and seems to handle special files correctly (i.e. uisng cpio or something to dump them).

see:

http://www.joat.ca/software/cddump.html

That's excatly what i was looking for. Thanks a lot.

[Ben] Cool; I figured somebody somewhere did it. Interestingly enough, he uses pretty much the algorithm I suggested:

    @todo = sort { ${$b}[2] <=> ${$a}[2] } @todo;

    ...

    foreach $file (@todo) {
        if ($thissize + ${$file}[2] < $remaining) {
            $thissize += ${$file}[2];
            push(@{$thisdo[${$file}[0]]}, ${$file}[1]);

It's not a bad approximation; the only degenerate case is where you have no-to-few small files and lots of large ( > MAX_SIZE/2 ) ones. If you have an average file spread, it works well.

/dev/scd0 is not a valid block device?

From Simeon Nevel

Answered By Mike Martin, Neil Youngman, Heather Stern

With our kind thanks for publication permission. -- Heather

Dear Answer Gang,

I'm trying to get my cd and cdrw working in RH7.3. I've read through both articles on CD Writing in issue 57 and looked at the CD-Rom HOWTO as well.

I've got to proper invocation in grub:

title Red Hat Linux (2.4.18-3)
   root (hd1,0)
   kernel /vmlinuz-2.4.18-3 ro root=/dev/hdb7 hdc=ide-scsi hdd=ide-scsi
   initrd /initrd-2.4.18-3.img

lsmod shows that the various ide-scsi modules are loaded:

 Module                  Size  Used by    Not tainted
  [other modules snipped for brevity]
  sr_mod                 16920   0  (autoclean) (unused)
  autofs                 12164   0  (autoclean) (unused)
  ide-scsi                9664   0
  scsi_mod              108608   2  [sr_mod ide-scsi]
  ide-cd                 30272   1
  cdrom                  32192   0  [sr_mod ide-cd]

[Mike M.] not sure whether ide-cd should be getting loaded you may want to experiment by unloading the scsi modules and reloading in turn (sg and sd may be an idea)

[Neil Youngman] Is this bit from the CD-Writing HOWTO relevant?

Example configuration for /etc/modules.conf from

http://www.tldp.org/HOWTO/CD-Writing-HOWTO-2.html

If that doesn't help then have a look at the output from dmesg and see if it offers any clues.

[Heather] autofs is unrelated. Unless you also have another ATAPI CD which is not supposed to be handled by scsi, you definitely have too many modules loaded.

The kernel support notes (very easy to read in "make menuconfig", a little plainer in /usr/src/linux/Documentation/Configure.help) make it clear that:

For my IDE/ATAPI cd-recorder, I don't have any of these loaded automatically. I do have the append line (in my case, 'hdd=ide-scsi'). When I:

	modprobe ide-scsi

then I run:

	cdrecord -scanbus

it says (sorry if hascii, Joerg has his name spelled properly here):

Cdrecord 1.11a05 (i686-suse-linux) Copyright (C) 1995-2001 J�rg Schilling
Linux sg driver version: 3.1.22
Using libscg version 'schily-0.5'
scsibus0:
        0,0,0     0) 'SAF     ' 'CD-RW2224       ' '2.06' Removable CD-ROM
        0,1,0     1) *
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *

And the drive becomes addressable as scd0, recordable in theory as sr0 but in practice I give the dev by host and lun number:

	cdrecord dev=0,0 speed=4 some-random.iso

At least I hope speed 4 works, because it takes ages to make them at lesser speeds. I do have to wonder if something in my setup is slowing it all down horribly, but hey, I'm not a big CD pressing house, I just wanna burn a CD once in a while ... and that's what I get for having had a cd writer for so long, the newer ones are faster.

Looking at that list again, maybe I've got too many modules involved. Maybe I've got some sort of conflict?

I've changed the links in /dev:

lrwxrwxrwx 1 root root   9 May 29 21:39 /dev/cdrom0 -> /dev/scd0
lrwxrwxrwx 1 root root   9 May 29 21:44 /dev/cdrom1 -> /dev/scd1

 brw-rw----    1 root     disk      11,   0 Apr 11 07:25 /dev/scd0
 brw-rw----    1 root     disk      11,   1 Apr 11 07:25 /dev/scd1

I've got the mount points defined in /mnt:

 drwxr-xr-x    2 root     root        4096 May 12 04:39 cdrom
 drwxr-xr-x    2 root     root        4096 May 29 21:47 cdrom0
 dr-xr-xr-x    1 root     root        2048 Nov 20  1999 cdrom1

but whenever I try to mount either of the cd-rom devices like so:

 mount -t iso9660 /dev/scd0 /mnt/cdrom0

or

 mount -t iso9660 /dev/cdrom0 /mnt/cdrom0

I get:

  mount: /dev/scd0 is not a valid block device

also, "cdrecord -scanbus" doesn't seem to find anything.

[Heather] Then it's right, ide-scsi did not turn them into SCSI hosts. ATAPI cdrom support is being favored, and the IDE stuff doesn't directly lead to writing under Linux. (cdrecord doesn't speak ATAPI. It only speaks SCSI.)

Although in theory if your CD writer is really DVD capable too, you may be able to write UDF filesystems to the disc (as hdc and hdd). I've never tried that, and only UDF support on another machine would let them read the disc. So it probably wouldn't be useful unless all your friends have DVD bays.

What am I doing wrong? I'm sure it's probably something really stupid, but I just can't see it.

A clue would be vastly appreciated.

adTHANKSvance!

Simeon

[Mike M.] this is seriously from memeory but try

first cat /proc/devices (I think)

[Heather] It may be interesting to see this, but a fresh boot where you didn't try to load the ide cdrom support would be more useful. Approximately -

• You need the IDE interface itself, because that handles the IDE controller.
• You -probably- need IDE standard hard disk support for your main drives so you can boot. Unrelated to the cd bays, except for being on the IDE controllers too.
• You -do not- want IDE cdrom services.
• IDE floppy services (those would be for LS-120 bays) or IDE tape services have no effect either way on ATAPI CD-RW's.
• You -do- need ide-scsi, and from the scsi subsection you need sg (scsi generic) support. sg gets autoloaded when ide-scsi behaves correctly and cdrecord is asked to scan the bus. At least from my setup it doesn't appear that SCSI-cdrom is used at all either.

-=: gemini :=- ~ # mount /dev/scd0 /mnt/cd
mount: block device /dev/scd0 is write-protected, mounting read-only
-=: gemini :=- ~ # lsmod
Module                  Size  Used by
sg                     28352   0  (autoclean)
ide-scsi                7312   1

(and a whole bunch of sound card modules. working, as far as my dings and talking-computer noises can tell )

[Mike M.] mount /dev/sd0 /mnt/cdrom0

[Heather] sd0 would be a scsi hard drive; compact discs would be scd0 so after his symlink the request is correct. He just needs to untangle that mess of modules.

For the record the system this is on is SuSE 7.3, but I'm using a locally built kernel - this answer is totally distro independent.

[Mike M.] I remember I had to do a bit of fiddling around when I did it a while ago

[sig block] If you're not outraged, you're not paying attention

[Heather] Hmm, well tell your congressmen and representatives that supporting the overly extended copyrights of MPAA and numerous corporations is against the principle that the entire country is supposed to eventually benefit from all of these works... great or otherwise... and a heavy infringement on the right of individuals to make (and copy, and change, and redistribute) works of our own invention.

(But, this isn't a politics thread. Don't get me started. If this bothers you too go help the EFF, http://www.eff.org.)

/dev/scd0 is not a valid block device?

From Simeon ben Nevel

Answered By Mike Martin

Hmm,

> > options ide-cd ignore=hdb         # tell the ide-cd module to ignore hdb

I thought the Grub/lilo incantation of hdc=ide-scsi & hdd=ide-scsi would take care of this?

> > alias scd0 sr_mod                    # load sr_mod upon access of scd0

Would I also have to to "alias scd1 sr_mod" ?

I've read on several occasions that if you have 2 cd-rom devices on the same ide interface, you really have to set them both up with the ide-scsi modules.

> > pre-install sg     modprobe ide-scsi # load ide-scsi before sg
> > pre-install sr_mod modprobe ide-scsi # load ide-scsi before sr_mod
> > pre-install ide-scsi modprobe ide-cd # load ide-cd   before ide-scsi

I did, indeed forget the modules.conf magic but I want to let you know that my problem vanished when I rebooted my machine even without having made the suggested changes.

[Mike M.] Out of curiousity - could you post the output of lsmod

I have a strong suspicion that on reboot the module loading was corrected.

Just that if anyone searches for the same problem you had it is nice to see the solution as well as the problem

<sigh>

As much as I enjoy learning more about my linux system, it often seems that the solution to various problems involves magical spells of one sort or another.

Anyway, thanks again for taking the time to lend me a hand.

Sincerely,

Simeon ben Nevel

This page edited and maintained by the Editors of Linux Gazette Copyright © 2002
Published in issue 80 of Linux Gazette July 2002

HTML script maintained by Heather Stern of Starshine Technical Services, http://www.starshine.org/

"Linux Gazette...making Linux just a little more fun!"

Contents: Legislation and More Legislation Linux Links Conferences and Events News in General Distro News Software and Product News

Selected and formatted by Michael Conry

Submitters, send your News Bytes items in PLAIN TEXT 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. Submit items to [email protected]

July 2002 Linux Journal

All articles through February 2002 are available for public reading at http://www.linuxjournal.com/magazine.php. Recent articles are available on-line for subscribers only at http://interactive.linuxjournal.com/.

Palladium

Back in January, we mentioned that Microsoft had been granted a patent claim for a `Digital rights management operating system'. It appears their plans are developing further. A recent article at MSNBC/Newsweek provides an "exclusive first look" at the new technology. It begins:

"An exclusive first look at Microsoft's ambitious-and risky-plan to remake the personal computer to ensure security, privacy and intellectual property rights. Will you buy it?"

The Register has published a some excellent articles on Palladium, by John Lettice, Richard Forno and Thomas C Greene. The third of these focuses specifically on what effect Palladium could have on the Linux community, and the indications are not good (unsurprisingly, given that it would mean a large part of the hardware industry could end up dancing almost exclusively to Microsoft's tune). Indeed, as Robert Cringely has written, Palladium could be bad news for the entire infrastructure of the internet.

If you want more information on Palladium, and DRM (digital rights management) technology in general, cryptome has some useful links along with the text of the original MS DRM OS patent. Of particular interest is Ross Anderson's TCPA / Palladium Frequently Asked Questions (TCPA=Trusted Computing Platform Alliance).

Governments and Linux

The BBC has reported that Germany has signed a contract with IBM and SuSE for a large public sector Linux-based computer contract. Among the reasons for the decision given by German representatives were cost and security. The BBC article gives quite a nice background to the story also, which is worth reading. Also of interest is SuSE's press release, and other reports of this news at The Register and at Slashdot.

In other good news, it has been reported by DesktopLinux.com and by LinuxToday that Finnish MP's have signed a bill requesting national and local agencies to migrate their IT systems to the Linux operating system. This could be part of a trend. Slashdot has reported a similar development in Taiwan, which "...will start a national plan to jump-start the development and use of Free (libre) Software". IDG.net has published a survey of countries which making moves toward open-source software and attempting to reduce dependence on Microsoft.

The following articles are in the July/August issue of the E-zine LinuxFocus:

• A Hardware watchdog and shutdown button
  
• Securing a heterogeneous network with free software tools
  
• Plugins and Mozilla 1.0
  
• Receiving faxes with efax.
  
• Bookreview: Beginning Databases with MySQL
  
• Compile your own Linux kernel
  
• Light, Camera, Action... Kino!
  

Article at IBM.com on installing and configuring CVS for Linux.

Interview with RMS. Among other topics, this deals with UnitedLinux.

Salon describes how FCC decisions are allowing a few big ISPs (the ones owned by the cable companies and telcos) to squeeze out all the little ones. Gives an analysis of what this will mean for the market.

Some stories from the The Register related to the Linux world:

• A look at NSA and SELinux
• Apache admins ambushed by premature vuln report.
• Ralph Nader recommends US Federal Government should develop software alternatives.
• NY Times sicks FBI on MSNBC journalists in hacking investigation, neglects press freedoms.
• How to read Xbox security key, legally apparently, and maybe even get Linux in there.
• US courts rule against library net censorship filters.
• Ruling on BT hyperlink patent expected soon.
• MS Passport as arbiter of public decency
• EasyGroup uses heavy handed tactics to acquire domain names.

Links from the O'Reilly stable of websites

• Trojaned networking tools, and other security information.
• Getting the most out of one computer by running multiple operating systems on it. Looks at WINE, DOSEMU, Bochs and User-Mode Linux.
• Open Source Bibliography.
• Tracking changes in CVS, a look at the functions and commands used in CVS.
• A look at the new GNU/Linux based Sharp Zaurus SL-5500 palmtop computer

Some Linux Journal web article that might be of interest:

• Learning to Use X11: A simple example program with a line-by-line walk through that explains key concepts for programming with X11.
• Doc Searls on GeekPAC and its mission to save the Net from Hollywood and other corporate interests.
• An introduction to the arch Version Control System.
• Review of four open-source accounting packages: Emma, GnuCash, jGnash and QHacc.
• Maddog visits the 20th anniversary of the Swiss Open Systems Group in Zurick, gives a talk, takes pictures, drinks the water (it's fresh).

The Linux Buyer's Guide is a service provided by Linux Journal; it lists software (both commercial and free), hardware, distributions, books, etc. There are ten major categories and dozens of subcategories, and a search page for searching names, descriptions and price ranges. The service is always free to users, and vendors likewise can list their products for free. (Vendors can also sign up for paid premium services; e.g., banner ads.) Entries are added by the vendor through the web, so they reflect which vendors have visited the site and chosen to list their products. Free software developers are invited to register as "vendors" and list their software, so that the public can comparison shop between free and commercial items. Just designate one person to be the Buyer's Guide contact, who will update the product listing as the product changes. (All listings must be updated or verified at least once a year or they will be dropped; this prevents stale listings from remaining.)

Some links from Slashdot that should appeal to you:

• Ransom Love answers questions from Slashdot readers about UnitedLinux. Love was Caldera's CEO at the time of the interview, but now he's full time with UnitedLinux.
• A Fictional story in Popular Science magazine about how much information an average Joe leaves about himself during the course of a day.
• European commission sponsors Linux audio distribution
• A map of spam. Who sends it, who advertises through whom, and how the bulk of them interrelate.
• Broadband by the bootstraps: How a group of neighbours built their own high-speed network

Joel Spolsky has written a well thought out article outlining his theories on the economics underlying open source software. This was discussed on Slashdot. While on the theme of economics, Linux Journal have an article entitled A Successful Linux/Open-Source Business Model which might be worth looking through.

LWN

Linux Weekly News has a new look, "making light use of style sheets", which you should take a look at. There are further changes and enhancements including a more dynamic front page, login-preferences, and article talkbacks (which you will see at the bottom of the announcement of the new look). The old LWN site and content is available as old.lwn.net.

Of course, not only does LWN have a new and attractive style, it also has lots of good content! The following are some highlights of the past month that might interest you:

• Jon Corbet's report from the 2002 Kernel Developers' Summit. Has lots of information on where the Linux Kernel project actually is, and where it is heading.
• Commentary on the contradictions in how Disney's policies and aims interact with Linux.

Listings courtesy Linux Journal. See LJ's Events page for the latest goings-on.

O'Reilly Open Source Convention (O'Reilly)	July 22-26, 2002 San Diego, CA http://conferences.oreilly.com/
USENIX Securty Symposium (USENIX)	August 5-9, 2002 San Francisco, CA http://www.usenix.org/events/sec02/
LinuxWorld Conference & Expo (IDG)	August 12-15, 2002 San Francisco, CA http://www.linuxworldexpo.com
LinuxWorld Conference & Expo Australia (IDG)	August 14 - 16, 2002 Australia http://www.idgexpoasia.com/
Communications Design Conference (CMP)	September 23-26, 2002 San Jose, California http://www.commdesignconference.com/
IBM eServer pSeries (RS/6000) and Linux Technical University	October 14-18, 2002 Dallas, TX http://www-3.ibm.com/services/learning/conf/us/pseries/
Software Development Conference & Expo, East (CMP)	November 18-22, 2002 Boston, MA http://www.sdexpo.com/

Simile.D

A better bet is to read Robin "Roblimo" Miller's article at NewsForge: "One of the great defects in Linux compared to Windows is that it is not infected by cool viruses."

HP, Oracle and Red Hat Combine Engineering Expertise to Further Develop Linux Solutions for the Enterprise

HP have announced that it has combined engineering resources with software company Oracle, and Red Hat, to certify and deliver Red Hat Linux Advanced Server on an 8-Node Oracle9i Real Application Clusters environment running on ProLiant DL580 servers from the new HP.

More information on HP's Linux initiatives is available at www.hp.com/linux

This move has had some press coverage. Siliconvalley internet.com has interpreted it as a move to unseat IBM as the dominant Linux vendor. IDG has characterised the development as a reaction to the UnitedLinux development. Don Marti has also commented on the role Oracle's favouring of RedHat will have on the distribution market.

United Linux

One of the biggest earthquakes in the Linux Distribution landscape in a long time was the announcement by Caldera, SuSE, Turbolinux and Conectiva that they were going to team up to form UnitedLinux. Speculation about what exactly this development will mean for Linux began even before the announcement was formally made. RedHat, which would be an obvious target of the newly formed UnitedLinux, has made little comment on the development and is reported to be cautiously optimistic. However Dennis Powell, writing at Linux and Main, sees this as the beginning of a larger battle between UnitedLinux on one side and Dell Red Hat and Oracle on the other.

Among the features of UnitedLinux which have attracted attention are the refusal to distribute free binaries, and talk of per seat licensing. It would appear that not all details in these areas have yet been worked out.

Alexis de Tocqueville Institution

One of the most contentious happenings of the past month was the release by the Alexis de Tocqueville Institution of a whitepaper entitled Opening the Open Source Debate. Among the points made in this document was that

Terrorists trying to hack or disrupt U.S. computer networks might find it easier if the federal government attempts to switch to "open source" as some groups propose.'

Happily, for those of us who believe free and open software is a good thing, it appears that these contentions are not being blindly accepted. Indeed there have been some very well considered rebuttals of the whitepaper's theories. David F. Skoll at the Sydney Morning Herald has made detailed arguments (also at Roaring Penguin) against the specific points raised as has Thomas C. Greene at The Register and Karl O. Pinc at NewsForge,

Some commentators such as Michelle Delio at Wired have suggested that Microsoft may have paid to have the paper written. Whoever were the original funders of the paper, if you want to read it, you will have to stump up $5.29, as reported by NewsForge. It is possible to download the original version from a non-ADTI server, which was linked from the Slashdot report on this story. Apparently, the main differences between the different versions of the document are in spelling and grammar (Anthony Awtrey at Linux and Main goes through them in detail).

For a more positive analysis of the role of open/free software in government and military applications, you could look at the MITRE paper on the subject. Finally, for the ultimate irony, NewsForge had the pleasure of reporting that the ADTI's own website runs Apache.

MobiliX wins Against Obelix

In a recent court hearing in Germany, the owners of the name Mobilix have defeated a challenge brought against them by Les Éditions Albert René, owners of the popular Asterix comic book series. The Asterix comic features a character named Obelix, and it was the contention of lawyers representing Les Éditions Albert René that the name Mobilix was a violation of their trademarks. Mobilix is a website devoted to Mobile Unix (in particular Linux and BSD on laptops, PDA's, cell phones, etc.,). The court eventually ruled that there was little chance of the names being mixed up, especially given the very different markets they are aimed at.

The documentation of the case is available online (also in German), and includes letters from MobiliX lawyers Jaschinski Biere Brexl.

Debian

Debian Weekly News have reported the availability of preliminary XFree86 4.2.0 Packages. Branden Robinson and Ishikawa Mutsumi's announcement is available here. Werner Heuser has set up a Mini HOWTO about Debian-XFree86 v4.2. Download from a mirror if possible.

Also reported by DWN was the availability of updated Woody MiniCD images for alpha, i386, m68k, and PowerPC.

Gentoo

Gentoo Linux 1.2 was released June 10.

Phat

The fourth release of Phat Linux has arrived on FTP servers. It includes updates such as Ximian GNOME and a 2.4.18 kernel. Phat aims to be installable on a Windows computer without repartitioning.

Slackware

Slackware has announced the release of Slackware 8.1. Highlights of this release include KDE 3.0.1, GNOME 1.4.1 (with new additions like Evolution), the long-awaited Mozilla 1.0 browser, support for many new filesystems like ext3, ReiserFS, JFS, and XFS, and support for several new SCSI and ATA RAID controllers. You can buy it at store.slackware.com, or download it from one of many mirrors. The new release has been reviewed by Linux Planet, and also reported by Slashdot.

SuSE

SuSE plans a developers' release of UnitedLinux, and won't have a per-seat license. This does not directly affect the other distributions participating in UnitedLinux.

SuSE Linux have announced the mid-June availability of SuSE Linux Pro-Office CD with Sun Microsystems' StarOffice 6.0. Additionally, the Pro-Office CD for SuSE Linux 8.0 features the latest edition of the ultimate desktop environment KDE 3.0.1, as well as important patches for the SuSE Linux 8.0 operating system. With the Pro-Office CD, SuSE Linux users can equip their home computers with state-of-the-art Linux desktop technology.

SuSE Linux have also announced the release of an updated version of the SuSE Linux Groupware Server. The interweaving of the Linux operating system with the newly released Lotus Application Server 5.0.10 makes the SuSE Linux Groupware Server a powerful Lotus solution for Intel and AMD 32-bit processors.

Mozilla 1.0

Few can have missed this particular piece of news, but just in case you have been living under a rock all June, Mozilla 1.0 has been released.

Note that there are a few contributors to the project who still need to be contacted before Mozilla can be made 100% GPL. Maybe you can help track them down.

Linux Game Publishing: Majesty

Linux Game Publishing have released the first screenshot from the Linux version of Majesty. Majesty is a real-time strategy game currently in development at LGP.

Faximum Announces New Fax Software for Linux and Windows

Faximum Software, a developer of fax server software, has announced a major new release of its Fax Messaging Server (FMS) product. FMS 2 runs on Linux, integrates with an organisation's existing email server, and enables Windows, Mac, and Linux users to send and receive faxes as easily as (and using the same tools as) email. It is possible to try out the software running on one of Faximum's servers at www.faximum.com/demo.

Mammoth PostgreSQL Free Evaluation Now Available

Command Prompt, Inc. is pleased to announce the immediate availability of an evaluation version of Mammoth PostgreSQL for RedHat Linux 7.2/7.3. The release contains a 5 connection Mammoth PostgreSQL, LXP the XML application server for PostgreSQL and Mammoth Browser a GUI based data management application.

The product is available for immediate electronic distribution by visiting the Command Prompt, Inc. website at www.commandprompt.com.

Cylant IDS Upgrade Announced

Cylant, a provider of host-based intrusion detection and rejection systems for the Linux and FreeBSD server platforms, have announced the release of version 1.2.3 of CylantSecure. CylantSecure applies a preventative, behavioural approach to security, utilising kernel monitoring to detect attacks without needing continual signature or rule-set updates.

Benefits of CylantSecure's new version 1.2.3 include:

• Improved instrumentation for better kernel level behavioural measurement.
• More flexible IP profiling for superior recognition of port scans and connection hijacking attempts.
• Watcher performs faster over previous versions.
• Includes new self-training mandatory access control system.

Reliaty Announces New Data Protection Product

Reliaty, a provider of advanced data protection, have introduced Reliaty Backup, a data protection software developed on a Network Data Management Protocol (NDMP) foundation. This allows backup and recovery of data from any point within a storage environment to any device, regardless of the server and storage platforms or location of the connections. Reliaty Backup offers this seamless methodology for multiplatform environments, creating a new level of cost savings, ease-of-use, and faster data recovery. This standards-based software can be used with Network Attached Storage (NAS) devices, and also with UNIX, Linux, and Windows systems even if NAS is not present.

Pricing for Reliaty Backup starts at $2500. The software will be available in July.

IBM Linux Center

In response to growing customer demand for Linux solutions, IBM have announced the opening of the first center in New York City to help the financial services industry deploy Linux. The Linux center, which will be based in Manhattan, will include hardware, software and services from IBM as well as its partners, designed to help financial services customers evaluate and plan Linux implementations. SunGard, JD Edwards,Veritas, and Sybase are among the premier partners whose technologies will be available in the IBM Linux Center.

Arkeia Announces Plasmon Tape Library Certification

Arkeia Corporation, a Southern California-based supplier of the Arkeia network backup software, has completed compatibility tests with Plasmon automated data storage libraries. Arkeia 4.2 tested compatible with Plasmon V-Series devices, as did the Beta version of the soon-to-be-released Arkeia 5. Philippe Roussel, CEO of Arkeia Corp. said that this "...brings to Plasmon libraries new perspectives in the Linux and Unix environments."

Plug `n' Play Security Blade Appliance

Developed by OmniCluster Technologies of Boca Raton, Florida (an IBM spinoff), the SlotShield 1000 and SlotShield 3000 blade servers are redefining the security appliance market. OmniCluster has partnered with Check Point Software Technologies, to develop a security appliance integrating Check Point's VPN-1/FireWall-1 with OmniCluster's SlotShield appliance blade technology. Both products are plug n play security solutions that are PCI compatible and can be installed within minutes inside any industry standard server system. The SlotShield 3000's plug-n-play capabilities enable installation as easily as replacing a server's Network Interface Card. The SlotShield 3000 supports any server running Windows NT service pack 6, Windows 2000, Windows XP and Linux kernel 2.2x and 2.4x.

OmniCluster currently offers three variations in its blade security appliances. They include:

• Single-server firewalls
• High availability firewalls (HAFW) for server "farms
• Multiple applications for URL, virus screening, email screening, intrusion detection

New PXI Systems from MEN Micro

MEN Micro; a company that designs, manufactures and sells board-level industrial real-time and embedded computer products; has announced the release of two new PXI systems. MEN's new PXI systems come in two sizes, a 19-in. 7U rack with as many as 21 PXI slots and a 4U high rack with seven PXI slots. Pentium-based 6U and 3U MEN F7 PXI controllers are at the heart of the processing platform for these PXI systems. By the end of 2002, MEN plans to release a Pentium IV-based PXI system controller. The MEN product lines support the most widely used operating systems, including Windows NT, VxWorks, OS-9, QNX and Linux.

Wolfram Research Announces Release of Mathematica 4.2

Wolfram Research, have released Mathematica 4.2. New packages, XML functionality, and Java connectivity have been added in this release.

Other software

The Samba Team is proud to announce the release of Samba 2.2.5, the latest stable release of Samba

Galeon 2.5 was released on June 8. Features Mozilla 1.0 compatibility.

Copyright © 2002, Michael Conry and the Editors of Linux Gazette.
Copying license http://www.linuxgazette.net/copying.html
Published in Issue 80 of Linux Gazette, July 2002

"Linux Gazette...making Linux just a little more fun!"

1. Purpose
2. Compiling PostgreSQL
3. Executing Pl/Python and Pl/PgSQL with Cursors
4. Suggestions for Future
5. Conclusion
6. References

Purpose

NOTE: I am using Red Hat 7.2 as a base for this article. Things will be different with your version of Linux.

Compiling PostgreSQL

1. Edit src/pl/plperl/Makefile.PL and comment out lines 14 through 34.
2. Edit src/include/pg_config.h.in and change
   #define INDEX_MAX_KEYS 16
   to
   #define INDEX_MAX_KEYS 512
3. Use this command to compile PostgreSQL:
   adduser postgres
   mkdir /usr/local/pg72
   ./configure --prefix=/usr/local/pg72 --with-libraries=/usr/lib/perl5/5.6.0/i386-linux/CORE/libperl.a --with-perl --with-python
   make
   make install
   chown -R postgres /usr/local/pg72
   mkdir /home/postgres
   chown postgres /home/postgres
   su -l postgres

1. 
   PATH=/usr/local/pg72/bin:$PATH
   export PATH
   LD_LIBRARY_PATH=/usr/local/pg72/lib
   export LD_LIBRARY_PATH
   export PGDATA=/usr/local/pg72/data
   export PGLIB=/usr/local/pg72/lib
2. initdb
3. /usr/local/pg72/bin/pg_ctl -D /usr/local/pg72/data -l /tmp/pg_logfile start
4. createlang plperl template1
5. createlang plpython template1
6. createlang plpgsql template1
7. createdb postgres

Executing Pl/Python and Pl/PgSQL with Cursors

Execute these commands:

\c postgres

drop table contact;
create table contact (
first text, last text, phone text, address text,
city text,state text, zip text
);

drop function replace_e_to_a(text);
CREATE FUNCTION replace_e_to_a(text) RETURNS text AS
'
import re
Text1 = re.sub(''e'', ''a'',args[0])
return Text1
'
LANGUAGE 'plpython';

drop function replace_numbers_to_z(text);
CREATE FUNCTION replace_numbers_to_z(text) RETURNS text AS
'
import re
Text1 = re.sub(''[0-9]'', ''z'',args[0])
return Text1
'
LANGUAGE 'plpython';

insert into contact values ('Mark','Nielsen','123-123-1234',
  '1234 Somewhere St.', 'Some City 123', 'TX','12345-1234');
insert into contact values ('Mark','Nielsen2','123-123-1234',
  '3456 Somewhere St.', 'Some City 444', 'MI','12345-1234');
insert into contact values ('Mark','Nielsen3','123-123-1234',
  '5678 Somewhere St.', 'Some City 654', 'AX','12345-1234');

select first, last, address  from contact;

drop function select_contact();
CREATE FUNCTION select_contact () RETURNS refcursor AS '
DECLARE
    cursor1 CURSOR FOR select replace_e_to_a(first)as first, 
                        replace_e_to_a(last) as last,
                        replace_numbers_to_z(address) as address
            from contact;
BEGIN
 open cursor1;
 return (cursor1);
END;
' LANGUAGE 'plpgsql';

begin;
select select_contact();
FETCH cursor1; FETCH cursor1;FETCH cursor1;
end;

DROP
CREATE
DROP
CREATE
DROP
CREATE
INSERT 255188 1
INSERT 255189 1
INSERT 255190 1
 first |   last   |      address       
-------+----------+--------------------
 Mark  | Nielsen  | 1234 Somewhere St.
 Mark  | Nielsen2 | 3456 Somewhere St.
 Mark  | Nielsen3 | 5678 Somewhere St.
(3 rows)

DROP
CREATE
BEGIN
 select_contact 
----------------
 cursor1
(1 row)

 first |  last   |      address       
-------+---------+--------------------
 Mark  | Nialsan | zzzz Somewhere St.
(1 row)

 first |   last   |      address       
-------+----------+--------------------
 Mark  | Nialsan2 | zzzz Somewhere St.
(1 row)

 first |   last   |      address       
-------+----------+--------------------
 Mark  | Nialsan3 | zzzz Somewhere St.
(1 row)

COMMIT

Suggestions for Future

1. Procedures seem to be able to only return one "item'. It can't return two items. For me, I would like to be able to return at least two items -- a cursor and a flag saying if the cursor is good or not. Cursors DO NOT make procedures return more than one value, they return the cursor which you can consider to be a reference to many items, not the items themselves. The way I compile my procedures is that they can take upto 512 variables of input, but they can only return one "item". I am dumbstruck as to why that is. I tried to read of the discussions on the mailing lists and docs, but I got lost.
2. There doesn't seem to be very many things you can do to cursors, like see how many entries there are, if there are any entries left, if there are any entries at all, if it executed correctly, etc. Cursors need to be advanced some more. Perhaps I just don't have enough experience with cursors to comment on them.
3. Procedures can't return rows of data. Besides the fact it can only return one item, it can't return rows of one items or rows which contain multiple items. Being able to return multiple rows with multiple fields would be cool. Even if we only want to return one row of data, it would be nice to return a cursor as one item, and then its status (good, bad, how many, etc) as well. If you can return more than one item, you might as well make it unlimited or limited by a compile-time number (like inputs are).

This isn't really a complaint of cursors, but of DBD:Pg for Perl, and possibly other interfaces to PostgreSQL -- cursors really aren't supported, as far as I can tell. Thus, if Pl/PgSQL could return multiple rows of multiple items, it would take care of this problem.

The only other way I know to store data from a procedure is into a temporary table which can be accessed after the procedure has finished. To me, that is a bit extreme for 99% of the data I want to get. It is extreme because usually I just want one row of data and creating a table just for one row of data isn't worth the effort.

Conclusions.

The sad thing is, my version of DBD::Pg for Perl and my Python interface don't support cursors, and so, it is useless for me to the most part, but at least it is getting better. I found some things at http://developer.postgresql.org/todo.php which look promising. Since cursors really aren't supported in the programming languages I use, if I truly need to store lots of data, I will probably have to use temporary tables. I still don't understand why a procedural language can't return data like you can in a normal sql command. Whatever the limitation is, it would be nice to overcome.

References

1. Standard Database Setup with Perl and PostgreSQL: Part 3
2. Part 2: PostgreSQL: Perl procedures with PL/pgSQL
3. Part 1: PostgreSQL: Perl procedures with PL/pgSQL.
4. An older article setting of Web and Database Servers.
5. Branden Williams articles on PostgreSQL.
6. http://techdocs.postgresql.org/oresources.php
7. http://techdocs.postgresql.org/
8. Some links which have nothing to do with this article, but I am considering for future articles.
   • http://authpg.sourceforge.net/.
   • http://www.digitalstratum.com/pglogd/
   • http://www.giuseppetanzilli.it/mod_auth_pgsql/
   • http://www.zort.ca/postgresql/ -- very nice and I will use this. I tried it, and it grouped all my tables together, so I had to ungroup it and separate out the tables.
   • http://www.brasileiro.net/postgres/cookbook/
9. If this article changes, it will be available at http://www.gnujobs.com/Articles/26/nielsen.html

TitleBar=true
Browser=true

LockPosition=false
SetPosition=true
PositionX=0
PositionY=700

#!/bin/sh

/usr/X11R6/bin/xsetroot -solid "#363047"

    ### This next item is a huge security risk. 
    ### It basically sets up an xterm with the user "mark". 
xterm -r -fn 6x12 -geometry +0+25 -e '/etc/X11/gdm/mark.sh' &
#xterm -r -fn 6x12 -geometry +0+25 -e '/etc/X11/gdm/dummy.sh' &
    ### This puts a picture on the background.
/usr/bin/xsri -geometry 500x500+600+300 /etc/X11/gdm/im000048.jpg
    ### This puts xeyes on the screen to watch your mouse pointer.
xeyes -geometry +800+650 -bg white -fg green -outline blue &
    ### Christmas all year round. 
xsnow -santaspeed 10 -santa 2 -snowflakes 1000 -whirl 4 -windtimer 30 &
    ### A clock down to the second. 
xclock -digital -geometry +600+650 -update 1 &

    ### The popular mine game. Sorry, doesn't seem like you can position it. 
    ### it just pops up in the middle of the screen.
gnomine &

  ### Maelstrom is pretty cool. 
Maelstrom &
   ## xboard pops up behind GDM, so we can't use it. 
#xboard &
  ### Chromium is a cool arcade-like old fashioned game. 
chromium-setup &
  ### Look at the light shining on the earth.
kworldclock -geometry +750+0 &
  ### A silly creature for your desktop. 
amor &

#!/bin/bash

trap "" HUP
trap "" INT 
trap "" QUIT
trap "" KILL
trap "" TSTP

su -l mark
exit
exit

#!/bin/bash

trap "" HUP
trap "" INT
trap "" QUIT
trap "" KILL
trap "" TSTP

chroot /chroot/dummy su -l dummy
exit
exit

gunzip Wine-20020411.tar.gz
tar -xvf Wine-20020411.tar
cd wine-20020411
./configure
make depend
make
make install

export CVSROOT=:pserver:[email protected]:/home/wine
cvnpres login

cvs -z 3 checkout wine

cp documentation/samples/config ~/.wine/config

cd /c
mkdir -p windows/system
mkdir -p windows/Start\ Menu/Programs

Com1=/dev/ttyS0
Com2=/dev/ttyS1
Com3=/dev/modem,38400
Com4=/dev/modem

Remember the Windows Registry ? 

programs/regapi/regapi setValue < winedefault.reg

SPAM: -------------------- Start SpamAssassin results ----------------------
SPAM: This mail is probably spam.  The original message has been altered
SPAM: so you can recognise or block similar unwanted mail in future.
SPAM: See http://spamassassin.org/tag/ for more details.
SPAM: 
SPAM: Content analysis details:   (16.2 hits, 5 required)
SPAM: Hit! (2.2 points)  BODY: As seen on national TV!
SPAM: Hit! (1.5 points)  BODY: Asks you to click below
SPAM: Hit! (0.2 points)  BODY: No such thing as a free lunch (1)
SPAM: Hit! (-0.1 points) BODY: Claims you can be removed from the list
SPAM: Hit! (2.1 points)  BODY: Talks about opting in
SPAM: Hit! (3.0 points)  URI: Uses a dotted-decimal IP address in URL
SPAM: Hit! (0.1 points)  URI: Uses non-standard port number for HTTP
SPAM: Hit! (3.5 points)  URI: URL of page called "remove"
SPAM: Hit! (-0.8 points) BODY: JavaScript code which can easily be executed
SPAM: Hit! (-0.5 points) BODY: HTML mail with non-white background
SPAM: Hit! (1.8 points)  BODY: Tells you to click on a URL
SPAM: Hit! (3.2 points)  HTML-only mail, with no text version
SPAM: 
SPAM: -------------------- End of SpamAssassin results ---------------------

SPAM: Hit! (0.6 points)  Invalid Date: header (wierd month)
SPAM: Hit! (0.5 points)  BODY: A WHOLE LINE OF YELLING DETECTED
SPAM: Hit! (3.0 points)  URI: Uses a dotted-decimal IP address in URL
SPAM: Hit! (-0.8 points) BODY: Image tag with an ID code to identify you
SPAM: Hit! (-0.4 points) BODY: Contains a line >=199 characters long
SPAM: Hit! (1.8 points)  BODY: Tells you to click on a URL
SPAM: Hit! (3.2 points)  HTML-only mail, with no text version
SPAM: Hit! (2.0 points)  Received via a relay in relays.osirusoft.com
SPAM:                    [RBL check: found 148.167.27.64.relays.osirusoft.com., type: 127.0.0.4]
SPAM: Hit! (3.0 points)  DNSBL: sender is Confirmed Spam Source

SPAM: Hit! (1.0 point)   From: ends in numbers
SPAM: Hit! (0.5 points)  Subject has an exclamation mark
SPAM: Hit! (0.4 points)  Subject has lots of exclamation marks
SPAM: Hit! (-0.5 points) BODY: Contains 'Dear Somebody'
SPAM: Hit! (2.7 points)  BODY: Nigerian scam key phrase ($NN,NNN,NNN.NN)
SPAM: Hit! (2.4 points)  BODY: Nigerian scam key phrase
SPAM: Hit! (4.3 points)  BODY: Nigerian Bank or Petroleum scam, cf http://www.snopes2.com/inboxer/scams/nigeria.htm
SPAM: Hit! (2.2 points)  BODY: Risk free.  Suuurreeee....
SPAM: Hit! (-0.4 points) BODY: Contains a line >=199 characters long

SPAM: Hit! (4.3 points)  Reply-To: is empty
SPAM: Hit! (2.4 points)  'Message-Id' was added by a relay (2)
SPAM: Hit! (2.2 points)  From: has a malformed address
SPAM: Hit! (1.5 points)  Message-Id is not valid, according to RFC-2822
SPAM: Hit! (1.3 points)  Message-Id has no @ sign
SPAM: Hit! (0.5 points)  Possibly-forged 'Received:' header found
SPAM: Hit! (2.1 points)  BODY: FONT Size +2 and up or 3 and up
SPAM: Hit! (3.2 points)  HTML-only mail, with no text version

SPAM: Hit! (1.0 point)   From: ends in numbers
SPAM: Hit! (0.5 points)  Subject has an exclamation mark
SPAM: Hit! (0.4 points)  Subject has lots of exclamation marks
SPAM: Hit! (0.9 points)  URI: Filename is just a '\#'; probably a JS trick
SPAM: Hit! (-0.8 points) BODY: JavaScript code which can easily be executed
SPAM: Hit! (0.0 points)  BODY: Includes a URL link to send an email
SPAM: Hit! (3.2 points)  HTML-only mail, with no text version
SPAM: Hit! (1.9 points)  Subject is all capitals

SPAM: Content analysis details:   (6.2 hits, 5 required)
SPAM: Hit! (1.1 points)  BODY: Contains a large block of hexadecimal code
SPAM: Hit! (-0.6 points) BODY: Frame wanted to load outside URL
SPAM: Hit! (1.8 points)  No MX records for the From: domain
SPAM: Hit! (1.9 points)  Subject is all capitals
SPAM: Hit! (2.0 points)  Subject contains a unique ID number

SPAM: Content analysis details:   (10.1 hits, 5 required)
SPAM: Hit! (1.2 points)  Valid-looking To "undisclosed-recipients"
SPAM: Hit! (0.5 points)  Subject has an exclamation mark
SPAM: Hit! (0.4 points)  Subject has lots of exclamation marks
SPAM: Hit! (0.2 points)  BODY: Contains at least 3 dollar signs in a row
SPAM: Hit! (0.2 points)  BODY: No such thing as a free lunch (1)
SPAM: Hit! (2.3 points)  BODY: List removal information
SPAM: Hit! (1.9 points)  BODY: List removal information
SPAM: Hit! (1.0 point)   BODY: No such thing as a free lunch (3)
SPAM: Hit! (0.5 points)  Forged hotmail.com 'Received:' header found
SPAM: Hit! (1.9 points)  Subject is all capitals

SPAM: Content analysis details:   (12.6 hits, 5 required)
SPAM: Hit! (2.0 points)  From: contains numbers mixed in with letters
SPAM: Hit! (1.0 point)   From: ends in numbers
SPAM: Hit! (0.6 points)  From: does not include a real name
SPAM: Hit! (2.7 points)  BODY: Claims you can be removed from the list
SPAM: Hit! (1.9 points)  BODY: List removal information
SPAM: Hit! (0.1 points)  BODY: List removal information
SPAM: Hit! (1.3 points)  URI: Includes a link to a likely spammer email address
SPAM: Hit! (-0.4 points) BODY: Contains a line >=199 characters long
SPAM: Hit! (0.5 points)  Forged hotmail.com 'Received:' header found
SPAM: Hit! (1.0 point)   Received via a relay in orbs.dorkslayers.com
SPAM:                    [RBL check: found 17.98.187.210.orbs.dorkslayers.com.]
SPAM: Hit! (1.9 points)  Subject is all capitals

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--------------------------------------------------------------------------------
 
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