SLUG Pearls #1 For 4 Jun 2000

By Jeff Waugh

Check out the Sydney Linux User Group ( !

Table Of Contents


Welcome to the very first edition of SLUG Pearls!

Thanks to Zack Brown of Kernel Traffic fame ( for his interest in seeing this happen, and the inspiration to do it in the first place.

Go read the Kernel Cousins, they're good for you!

Zack has kindly made the KC team's tools available to ease the production of other summaries such as this one - it would have been torture without them! :)

Thanks also to everyone who shared their ideas on the Best of SLUG thread - there was some really interesting stuff in there that we'll be working on.

This edition covers the SLUG mailing list from Friday, 26th May to Saturday evening, 3rd June. Future Pearls will cover Sunday to Sunday.

Hope this fills the gap!

- Jeff Waugh <>

1. May Meeting

27 May 2000 - 30 May 2000 (2 posts) Archive Link: "Free Software and Social Justice & IPv6"

People: Charlie BradyDanny Yee

During last month's meeting, Danny Yee gave us some insight into his work as a volunteer for Community Aid Abroad, and how he's promoting Free Software there on moral grounds - not just because it works better!

Check out Danny's (very cool) webpage ( for more info.

Later, Charlie Brady posted an update to the list, mentioning that Community Aid Abroad's web server - a lowly 486 with 16MB of RAM - happily pushes out around a gig a month:

And have a look at this:

[charlieb@www charlieb]$ uptime
12:28pm up 410 days, 22:12, 3 users, load average: 0.03, 0.03, 0.00
[charlieb@www charlieb]$

Anand posted some links regarding IPv6 ( and Jason's funky software for this month, BubbleMon ( , which Anand has packaged for Debianites here ( .

2. `export PATH=$PATH:.' considered harmful?

27 May 2000 (4 posts) Archive Link: "PATH=$PATH."

People: John FerlitoMinh Van

Minh Van wondered how to execute binary files and scripts in the current directory, asking why the inclusion of "." (the current directory) in the path was considered dangerous. John Ferlito replied (with a bit of editing from Ian Tester):

The main problem with having . in your path is of course security.

Best is example is if you have . in your path and I put a file named 'ls' in /tmp that looks like this

cd $HOME
rm -rf *

Then go cd into /tmp and run ls well pretty disastorous things are going to happen.

He suggested using $HOME/bin to make life easier and prevent problems at the same time.

3. The Genesis of SLUG Pearls

29 May 2000 - 1 Jun 2000 (43 posts) Archive Link: "Call for new list best-of-slug ?"

People: Anthony RumbleDavid KempeJeffrey BorgConrad ParkerJamie HonanMatt AllenJon BiddellAdam KennedyMatthew DaltonAnand KumriaJeff WaughTerry Collins

Anthony Rumble posted, " Does anyone feel it's time for a best-of-slug list? I'm missing important posts to the list, because of the signal to noise. Anyone else feel the same way? Who would volunteer to be the sacrificial lamb/s to do the moderating?"

...starting the longest thread of the week in the process!

There was a short on-topic debate about whether this would work. Jeff Waugh said that most new list requests never eventuated because no one could agree on a format, and there's always posting confusion. Anthony replied, "No, Thats not how it works. best-of-* lists have one or more people who "scan" the main list, and forward "good" posts to the best-of-* list. There are many high bandwidth lists that do this already.. like "ausrave" and the linux kernel lists."

Adam Kennedy suggested a mailing list summary - much like the Kernel Cousins, and as it turns out, there was some discussion about this at the recent meeting. Matt Allen volunteered to help out with the website, so Jeff asked for a bit of input into what everyone would like to see on the site.

Paul Robinson replied with a lengthy list of ideas, including:

There was no reply.

(ed. [] Paul, you may want to check out, who do a similar thing, plus more. Many mailing lists pipe their mail there as a simple way of doing most of what you've mentioned. Unless there have been any big changes, eGroups use Linux too!)


David Kempe brought up the notion of problem/solution pairs, and DIY moderation, where the posters of problems reply back to the list with the best solutions, "But for me, the signal is in the problem/solutions that come out of the list. You know, oh thats a neat way of doing that, oh shit I better patch that, or yeah im glad someone asked that stupid question. So I reckon the best of slug would be user contributed, to give the people who have problems a chance to put something back."

Sonam Chauhan suggested a Hypermail/SWISH combo to fulfil our long time need for a good, searchable archive, and a specially hacked version for the best-of-slug list. Anand Kumria replied, voicing the too-many-CC's argument when implementing a separate optional list. Terry Collins and Sonam worked on getting SWISH going for Terry's archive.

Jon Biddell not only wanted a searchable SLUG archive, but SLUG HOWTO's as well! There was a bit of discussion about the quality and audience of HOWTO's, ending with Jon's link to the venerable Irish Linux Users Group ( website.

Jeffrey Borg came up with a unique solution to the problem:

What would be useful is a yahoo style listing of specific linux related questions that could be compiled by flagging any new threads with a category.

So to look for something specific the archives would have categories for questions and then the subjects of the 1st message in the thread which should lead the answers about that question to be read.

I can not give any examples of this because I haven't seen it anywhere! It sort of like a cross between yahoo directory but instead of being for the web it's for a email list.

Matthew Dalton posted the obligatory "Use Google!™" response, but also mentioned Search Linux ( , an archive of Linux usenet posts.

David Kempe didn't think that an online archive was the magical solution we're all looking for, and that it just required a bit of nous to discern the signal from the noise.

Conrad Parker agreed,

yep. Throwing crappy '90s technology at the problem isn't going to fix it. The problem is not with the medium, its with the truckloads of messages.

Perhaps (as you suggest) all we need is a culture where people say:

"Here's my problem, tell me what to do and I'll summarise to the list"

... and then they actually go on and summarise the responses. The only way to get that culture is for people to start doing it ...

Sonam obviously really wanted a threaded archive, and also an automated FAQ. Jeff replied that there was in fact a threaded view for our archive at ProgSoc ( and that the FAQ was on its way. Anand asked for input on the format of the list, and decided to test swish++ after finding out it was Free Software.

Jeff volunteered to do at least the first SLUG Pearls, though there was some "debate" about the name. Suggestions included Pearls, Pellets, Pullets, Trails and Entrails, with Jamie Honan somehow implying a Bjelke-Peterson connection!

Yes pellets.

Shades of Bjelke-Peterson feeding the 'chooks' (these were his press conferences).

Going further, if we used pearls, then they would be cast before swine. Thus the choice between the pighouse and the chookhouse.

(Now Jamie, back to your monitor like a good chap. Here's a nice C program for you to maintain.)

Perhaps a vote is in order. ;)

4. Formatting and Copying Partitions

29 May 2000 - 30 May 2000 (6 posts) Archive Link: "wiping a HDD clean"

People: Doug StalkerRick WelykochyChuck D

Doug Stalker asks, " Using linux, how do I wipe a HD completly clean and then verify it has no bad sectors? Also, what is the best way to produce an exact copy of a HDD? (Assuming they are the size size/format drive and they are both connected to teh one system)"

Rick Welykochy solved the formatting and testing side of things:

To format: man mke2fs

e.g. mke2fs -c /dev/whatever

but this installs the ext2 fs as well.

Also: man badblocks

whilst Chuck D covered mirroring:

dd if=/dev/hda of=/dev/hdb

will mirror from one drive to another. Probably best to boot from a floppy to do this.

or to create an image of your disk as a file that you can later restore or put on another drive:

dd if=/dev/hda of=filename

You can copy an image to a drive of different size as long as it is larger. You then lose the extra space.

5. Copying a CD and Loopback Mounting

29 May 2000 - 30 May 2000 (5 posts) Archive Link: "Mking copy of the borg's stuff"

People: Terry CollinsJohn Ferlito

Terry Collins wondered if he could copy CDs for backup purposes,

Is this possible under linux?

Is it as simple as including -I and -J options of mkisofs?

Still complains about ~sbs, ~anaimations, ~help, ~images ~source

John Clarke posted a user-friendly script ( that prompts you though the process of copying a CDROM, and Jason gave the following solution:

The easiest way (I use this and it works) is to:

1. Put the CD to be duped into the drive.

2. Make an image:

dd if=/dev/cdrom of=/opt/cd.img bs=8092
This will spit a couple of errors at the end of the CD - but it doesn't matter. From here you can write the image to another CD using CDRecord or similar, or mount it via the loopback interface:
losetup /dev/loop0 /opt/cd.img
mount -t iso9660 /dev/loop0 /mnt/cdrom
Note - remember to remove the loopback interface when it is not required:
umount /mnt/cdrom
losetup -d /dev/loop0

John Ferlito added that the extra losetup commands were unneccesary if you mount the file using: " mount -t iso9660 -o loop /opt/cd.img /mnt/cdrom "

6. Overqualified Linux Users

30 May 2000 - 31 May 2000 (5 posts) Archive Link: "Bulletin story (fwd)"

People: Jamie HonanTerry CollinsPeter Samuel

Conrad posted an email from a journalist looking for Linux users, "unsophisticated when it comes to computers but maybe tried Linux because they were curious to learn more about it." Jamie had an example he prepared earlier, " Would my ten year old daughter who uses hotmail, plays web games, X based games and railroad tycoon qualify?"

We widely agreed that she was overqualified, with Peter Samuel asking for a resume. Terry was worried about more important matters, "I hope she is too young to come to the games fest.
It's bad enough loosing my pocket money to the 8year old next door in fish, but loosing at computer games - sheesh. {:-)"

...and the challenge is on?

7. Partition Panic

30 May 2000 - 31 May 2000 (4 posts) Archive Link: "lost link between /boot and /"


Ben Donohue's kernel had a panic when he deleted a partition between distant /boot and / partitions. DaZZa knew what was going on:

By deleting the partition in the middle, you have changed the numbers of the existing partitions - for example, in a situation like this

/dev/hda1 - boot
/dev/hda2 - extended
/dev/hda5 - Windows
/dev/hda6 - Linux

removing /dev/hda5 will turn /dev/hda6 into /dev/hda5.


I'd grab partition magic and move the Linux partition to the start of the available space, so it remains /dev/hda5 forever {or until you delete it}, then use Tomsrootboot or similar to fix lilo - but that's another story.

This solution worked fine.

8. Linux Notebooks

31 May 2000 (12 posts) Archive Link: "Recommendations - Laptop / Notebook Running Linux (RH62)"

People: David SaintyJon BiddellMatt Allen

David Sainty was looking for Linux notebook, and was after one which:

- Can be bought without Windoze pre-loaded?
- Can be bought with Linux pre-loaded?
- Works well in Linux (with XFree86 3 or 4, sound, modem, etc)?
- Has support from the manufacturer w.r.t. Linux?

Why is it that buying a decent notebook with Linux still isn't _easy_? <sigh> One day. :-)

Matt Allen was very happy with both his Dell notebook, and their service. Jon Biddell had a good story about his experience with Gateway:

I was about to plonk down a sizable slab of discretionary income for a Gateway 9300XLS (15.3" screen, 18Gb HD, 256Mb RAM) and had an argument with them about the old Windows licencing agreement - their comment was that it's too hard, and removing Windows would only drop $10 off the price because of their licencing agreement with TSOS (The Spawn Of Satan).

I was, on a matter of principle and because I refused to accept the licence agreement, prepared to accept the miniscule reduction in price, but the Gateway store at Castle Hill wouldn't hear of it. When I told them that they had just blown an $8k+ sale (and even showed them the $$$ to prove it !!), they had the hide to say "... your attitude is wrong - all you Linux nuts are the same, you want something for nothing".. How he reached that conclusion is still a mystery.

Most agreed that they were very happy with their Dell machines, and there were more Gateway experiences, all negative.

David is sticking to his principles and looking for a Dell.

Terry wondered Toshiba notebooks could handle Linux, saying that he could sell them sans "The Microsoft Tax" - and luckily for us, they can handle the penguin!

9. Powersaving Monitors Under X

30 May 2000 - 31 May 2000 (4 posts) Archive Link: "Making xset permanent?"

People: Simon RumbleJeffrey Borg

Simon Rumble asked:

I want my monitor to be friendly to our power bill when I walk away from it so I run:

xset dpms 600 600 600

How do I get this to run whenever my X server starts? What file do I stick it in? In what format?

Del offered:

My /etc/X11/XF86Config file says:

Section "Screen"


BlankTime 10
SuspendTime 10
OffTime 10


To which Jeffrey Borg added,


Section "Device"


Option "power_saver"


to enable DPMS

10. Tax with Tux

1 Jun 2000 (20 posts) Archive Link: "tax, damn them"

People: Conrad ParkerDavid SaintyGraeme MerralTerry CollinsAnthony Rumble

As if we didn't love the Australian Tax Office enough already, David reported that he received a "Gates Hegemony"-only tutorial CD, hoping they'd subsidise a computer on which he could run it.

Graeme Merrall wondered if Win4Lin would suffice, which both Anthony Rumble and Jason Rennie assumed to be the case. If Office runs...

David Sainty brought up GnuCash, asking if it were GST compliant, and whether there was an Australian OS project to add the functionality. Terry Collins informed that GnuCash wasn't really up to the task, but another piece of Free Software - GNU Enterprise - was building up to it rapidly.

Conrad provided more info on GnuCash:

It's worth noting that [rumour has it] GnuCash have some pretty good financial backing, hence people are working on it steadily. It's certainly not suitable for business use in 2000/2001, but perhaps it will be ready by next year. They do have one of the most extensive and detailed todo lists I've ever seen ;)

[first thing to do: make sure the "au" locale works so that "cheque" is spelt correctly ....]

11. How long is your script?

1 Jun 2000 (25 posts) Archive Link: "Script needed"

People: Simon BryanAdam KennedyTony CookMatthew DaltonJames MorrisAnthony RumbleJohn FerlitoHerbert XuDoug BalmerRick Welykochy

Simon Bryan set the scene for one of SLUG's favourite pastimes: Obfuscated, Efficient & Esoteric Scripting 101, asking:

I am looking for some kind script wizard to help me out. I have a file of:


I want to be able to regularly generate a file from this of just the usernames, that is strip off the ':password'. Could some kind person pointme at the Perl (or other commands) to do this?

Our first contestant is Adam Kennedy:

perl -e 'print grep { s/^(\w+)\:.*$/$1/; 1; } <>' < inputfile > outputfile

What I of course SHOULD be saying is RTFM

Who gets points for a quick flame, but none for his looong solution! :) Other Perl devotees included Rodos:

perl -F: -ane 'print "$F[0]\n";' < inputfile > outputfile

Lets hope this does not turn into an obfcated (sp?) contest. Awk is better at this problem. As Larry says, awk has to be better at something.

Sorry, Rodos - too late! Obfuscation is the name of the game! :) Tony Cook also responded to Adam's entry:

If you're going to use perl:

perl -F: -anle 'print $F[0]' </etc/passwd


Oh I like the l option, it saved the quotes and the \n. Very nice.

Who says you can't learn anything from these things? Fancy a bit of sed? Matthew Dalton:

cat input | sed -e '/slug-pearls/s/:.*' > output

James Morris:

And if you're short of cats:

sed -e '/slug-pearls/s/:.*' < input > output

Next up, Anthony Rumble with awk:

This is a job for.. <tada> AWK.

cat thefile.txt | awk -F: '{print $1}'

Done.. easy..

Quickly plumbed for efficiency by John Ferlito:

Bah that forks two processes and a pipe how wasteful :)

awk -F: '{print $1}' thefile.txt

But the most impressive entry of all was from Herbert Xu:

cut -d : -f 1

Which floored everyone... Anthony Rumble:

Proving yet again.. theres always at least 15 ways of skining a cat on Unix :)

Doug Balmer was obviously stunned:

how cool.


My god... someone else who knows about the cut command. I'm truly amazed.

But Herbert had another trick up his sleeve: A shell-only solution!

while read LINE; do
    echo ${LINE%%:*}

But was Simon happy with the responses?

> Thanks everyone I think I now have three different ways of doing it!!

Gulp make that three hundred, so I guess it was an easy question. By the way I have RTFM a number of times but just can't seem to get my head around some of this stuff!

Thanks everyone....

Perhaps we should leave the end of the thread to Rick and Matt:

> Looks like we've got a lotta sysadmins crying out for
> something challenging to do :)

Naaah... they just want to show who's got the biggest... er... shortest script.

12. Win4Lin & VMWare Again

1 Jun 2000 (7 posts) Archive Link: "Win4Lin vs VMWare"

People: Anand KumriaJohn Ferlito

John Ferlito was interested in finding out the differences between the two products, having found VMWare to be quite slow. Anand gave the best description:

Here is how I think it is - someone correct me if I am wrong.

VMWare: attempts to virtualise the PC by providing software simulations of most hardware (bar the CPU) and emulates a CPU running in protected mode by trapping various calls. Fairly slow.

Wine: attempts to map Win32 functions to their X/Linux equivalent. Fairly fast as it does minimal CPU emulation (it does some because not all registers are available in user space under Linux)

Win4Lin: provides a set of drivers so that Windows ends up accessing a standard X screen/keyboard/mouse. CPU stuff isn't touched; probably in between Wine and VMWare in terms of speed.







Sharon And Joy

Kernel Traffic is grateful to be developed on a computer donated by Professor Greg Benson and Professor Allan Cruse in the Department of Computer Science at the University of San Francisco. This is the same department that invented FlashMob Computing. Kernel Traffic is hosted by the generous folks at All pages on this site are copyright their original authors, and distributed under the terms of the GNU General Public License version 2.0.