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Contents: |
Date: Wed, 02 Jul 1997 22:30:26 -0700
From: Wood Ellis woodswrk@erols.com
Subject: Newbie Needs More Definitive Article on Parallel Port Tape Drives
The various leads which can be followed from the parport home page tend to indicate that it's just not worth all the hassle to try to operate a tape on the parallel port, unless you are an expert and maybe want to program it yourself. I just cannot believe that it is that difficult.
I would appreciate it if you were to provide an article which, in simple, newbie language, tells how to do it. The article should include definitive solutions for every brand of parallel port tape drive which is commonly available. Mine is an HP-1000 travan-1. My system is Redhat 4.1. One can imagine that some linux devotees enjoy the abstruseness of things new and difficult and exclusive. Contrary to that viewpoint, I believe that we all should strive to make linux easier and more available to the relatively uninformed. Probably you share my feeling. That's as close as I can come to a flaming request right now. I really appreciate all the good stuff in the Gazette.
Thank you,
Date: Sun Jul 6 16:35:46 1997
From: Takkala, takkala@highstar.com
Subject: Please help me....
Recently, ever since I upgraded to Slackware 3.2/Redhat 4.1, I have noticed that my modem has been behaving rather erratically. My modem is a Motorola ModemSurfr 28.8. Now, when I type 'ppp-on' to initiate a ppp session, many times, the modems TR led lights up, and then nothing happens, until the computer times out 45 seconds later and aborts the ppp session. Normally, when I type 'ppp-on' the modem almost immediately begins dialing up my isp, and connecting, but most of the time, it would just sit there, until I killed the process and tried again, it may take up to twelve or more tries for the modem to dial, but sometimes it will dial on the first try. This erratic behavior only began occurring (from what I can tell, I'm not sure) ever since I upgraded to redhat 4.1, and now slackware 3.2. My modem does work fine in windows 95, and also if I use DIP, or minicom to try and connect. So I was wondering if this may be a timing error somewhere in the ppp-on script. Has anyone else had similar problems? I myself tried tweaking some of the abort timeouts, but that didn't help.
Someone please help me!
Thanks for any help suggestions...
Jari
Date: Mon, 07 Jul 1997 01:00:35 -0700
From: Paul M., pmarcano@saltspring.com
Subject: Deluxe Paint IIe
Don't mean to come out of the blue but... I was searching the net for some reference to Deluxe Paint IIe for the PC and ended up here... Can you send me any information you can about how I might get a hold of a copy of this program which I assume is discontinued. I come from an Amiga background and still feel there are some redeeming features to this program that I would like to use on my PC...
Thanks for any information you can impart!
Paul Marcano
Date: Fri, 11 Jul 1997 16:57:33 -0300
From: Annette Sahores annette@invap.com.ar
Subject: Problem with adaptec 2940U
I'm trying to install linux red hat 2.0.x in a machine with an Adaptec 2940U host adapter an a scsi external 4x cdrom. The problem is that the bootdisk does not recognize the host adapter, so I can't set the linux and swap partitions. may be the problem is that the driver aic7xxx is old and doesn't work whith the 2940 ultra.
Thank You
Annette Sahores
Date: Tue, 15 Jul 97 15:01:00 PDT
From: Mark Mangolas mmango01@gsg.eds.com
Subject: Linux on a ThinkPad
Hello,
I am writing this in hopes that you can help me with my Linux
configuration. I have Linux Slackware 3.2 running on an IBM 760E Thinkpad
and I can't get X to run properly. It scrunches the screen when I fire up
X and then scrambles everything when I exit forcing me to reboot. I've
tried almost all of the video cards, chipsets, etc. in XF86Setup and
nothing helps. Any help would be greatly appreciated......thank you,
Mark Mangolas
Date: Wed, 16 Jul 1997 15:01:49 -0400
From: Scott Fowler scorpi04@earthlink.net
Subject: Pnp Modem and mouse
Help I have a plug and pray modem and mouse, actually my mouse is a ps/2 mouse, will the program isapnptools fix all the pnp problems?
Date: Sun, 20 Jul 1997 10:43:54 -0600
From: Doug Milligan, Red Hat Linux User doug@nwrks.com
Subject: Disk deferag?
I'm new to Linux, but like it very much having recently installed RedHat 4.2 via FTP. In looking through utility software I have not run accross any disk defragmentor programs nor have seen references to them in any Linux books that I have consulted. Is disk degragmentation not needed in maintaining a Linux file system?
Thanks,
Doug Milligan
Date: Sat, 19 Jul 1997 18:58:20 +0200 (SAT)
From: Abraham vd Merwe ixion@ilink.nis.za
Subject: Chown Problem
Hi!
You can make anybody the owner of your files right? At least that is w hat I always thought, but take a look at this:
% whoami ixion % cat /dev/null > ChownTest ; chmod 0777 ChownTest ; ls -l ChownTest -rwxrwxrwx 1 ixion users 0 Jul 19 18:10 ChownTest % cat /etc/passwd | grep fakeuser fakeuser:x:1005:100:Nobody:/home/fakeuser:/bin/bash % chown fakeuser ChownTest chown: ChownTest: Operation not permitted
I've tried it on various systems and it turns out that I can't make an ybody the owner of my files when I'm a user (root obviously can). Why? I'd b e very grateful if you can explain how to do it or if not possibly, at l east why I can't do it...
Thanks
Abraham
Date: Sat, 19 Jul 1997 04:40:56 +0100
From: Emmet emmet@indigo.ie
Subject: Firewire and DV
Hi,
I've nearly got my brother converted to Linux, except he's interested
in using firewire cards and whatever software to edit video from
a DV camera. After some web-searching, and a several sites, it
seems that there are no firewire drivers or spiffy DV software for
Linux.
Even worse, Adaptec, who manufacture what appears to be becoming a very popular card, are only supporting MS and Mac platforms. To add insult to injury, their FAQ, in response to a question about the possibility of drivers for Un*x, etc., contains the single word "No", no explanation or euphemisms, just "No".
At this point in time, horror of horrors, it looks like I'm going to wind up with my brother using NT. Frankly, I'd rather have a sister in a whorehouse than a brother using NT. Check out Mitch Stone's excellent site at http://www.vcnet.com/bms for why.
Does anybody know different? Are there any plans afoot in this direction? Maybe somebody in a position of influence could lean on some firewire card manufacturers to make their driver software available for porting to Linux? Maybe the Linux community could email sales@adaptec.com or support@adaptec.com asking them to reconsider making drivers available?
Any information about the possibility of DV editing software or firewire drivers would be most appreciated. I'll help if I can.
Thanks,
Emmet.
Date: Wed, 23 Jul 1997 22:24:44 -0500
From: Ben and Nick nbwbolen@bstream.com
Subject: cpu Speed
I was wondering if you could tell me where I could get a listing of
bogomites? bogomytes? on different cpu's and computers?
Thanks Ben
Date: Wed, 23 Jul 1997 15:56:49 -0400 (EDT)
From: Jon Lewis jlewis@inorganix5.fdt.net
Subject: Linux Uptimes
Do you have any idea what the longest uptime on a linux system is? I have a system with over 14 months of uptime, and am wondering if its heading for some kind of record. I've been told that with the 1.2.x kernels, uptimes longer than about 16.4 months are thought to be impossible due to jiffy counter wrap.
Date: Thu, 3 Jul 1997 19:12:36 -0700 (PDT)
From: Greg Roelofs newt@pobox.com
Subject: Re: Changing video modes
A friend of mine wants to know how to change video modes without restarting X, and I noticed you say you can do that on your Linux page. How can this be done? (I'm using XFree86, he's using MkLinux)
Just changing *modes* is easy: use ctrl-alt-gray+ and ctrl-alt-gray- to cycle between the resolutions defined in your XF86Config file. I have the following defined:
Modes "1280x1024" "1536x1152" "1600x1200" "640x480" "800x600" "1024x768"To run multiple X servers is a little trickier, and I've been meaning to write up a Linux Gazette or Linux Journal article on that. Assuming you use startx instead of xdm, the basic trick is to do something like this:
startx -- :4 -bpp 32 &My default (16-bit mode) command is this:
startx -- :1 -bpp 16 &You can switch between them via ctrl-alt-F7 through F10, typically-- F1 through F6 tend to be normal text-mode Linux consoles.
It's really best to alias these things and make sure the screen numbers (:0 or :2 or whatever) don't collide; if they do, the second X server will "steal" the number from the first, and you won't be able to start any more windows or even restart the window manager under the first server.
The special 320x200 game mode is even more complicated, and I won't even try to explain that here. It can be done with a second XF86Config or with additional lines in the main one under some circumstances.
I don't know how AccelX and XiGraphics and MetroX handle these things.
Date: Mon, 07 Jul 1997 10:27:46 -0700
From: James Gilb p27451@am371.geg.mot.com
Subject: *2+ Processing
Check out the Linux SMP page at http://www.uk.linux.org/SMP/title.html and get a new distribution. I think that SMP became part of the standard kernel at 2.0, so 2.0.?? might be a good choice (check out the SMP page, I think some patch levels are broken with respect to SMP).
If you are pretty good a Linux installs (and from the multiplicity of your OS's is sounds like you are), you could pick up a RedHat distribution for less than USD $10. I can't help you with availability in Sweden, but check out Caldera, RedHat, Craftworks, SuSE and Yggdrasil (sp?), I think most of them support SMP. If you need pointers to their web pages, try http://www.linuxmall.com, http://www.linux.org, or http://www.ssc.com/ (had to put a plug in for the sponsor of the excellent LG).
Date: Tue, 8 Jul 1997 09:10:32 -0700
From: Robert Christ rchrist@mcis.washington.edu
Subject: Spam Counter Attack
In Linux Gazette #19 you say:
SPAM Counter Attack! If you'd like to have your voice heard regarding
SPAM mail, why don't you consider writing a letter to your
representative?
I would just like to add a counter point that I would prefer that my congress person not attempt to regulate any aspect of the net. I have the tools and skills to prevent spamming all by myself. Laws regulating behavior seems to set a dangerous precedent..
thanks for your time,
Rob
Date: Sat, 5 Jul 1997 21:25:48 -0600 (MDT)
From: Michael J. Hammel mjhammel@csn.net
Subject: User-Level Driver For HP ScanJet 5p?
To: lersch@thene.informatik.uni-bonn.de
You asked about HP Scanjet 5P support in Linux. Check XVScan at http://tummy.com. It supports this scanner and is a commercial product.
If you're looking for drivers for other scanners check out my review of scanners in my Graphics Muse column in the March 1997 Linux Gazette (that is in issue 15) at http://www.ssc.com/lg/.
Hope this helps.
Michael J. Hammel
Date: Sat, 5 Jul 1997 21:21:08 -0600 (MDT)
To: smalenfant@cablevision.qc.ca
Subject: Problems with XFree86
You wrote to the Linux Gazette:
I'm a new user to Linux and the problem still XFree86! So then I tried to know want can I do to Linux community. In Issue #16, you said that the problem is not video card and is Monitor balancing. So why Windows 95 can have all these preset on monitor and Linux don't have? Why we can't use the stuff in the Microsoft Lib to transfer it into the database of XF86Setup or something like that. Cause that's real that the dotclock and all this is very scrambled! Why not just resolution and Virtual Refresh, that's all we need to know, the program could do the rest! We don't have to know what horizontal frequency and dotclock it is!
Answer: Xi Graphics AcceleratedX 3.1. It does pretty much what you're asking for here. See http://www.xi.com.
Michael J. Hammel
Date: Sat, 5 Jul 1997 21:18:18 -0600 (MDT)
To: dmandel@transport.com
Subject: CD Burners, Scanners, Digital Cameras, etc.
You asked the following in the July Linux Gazette:
1.Will a Sony CDU926S burner work with xcdroast? Don't know about this one, but I may have to find out soon. I'd like to create a CD full of graphics tools, but I've never tried to do anything like this before. If I do find info I'll probably write it up in my Graphics Muse column in the Gazette.
2. What is a good, but cheap flatbed scanner to use? (Good means 24 bit color and >= 300dpi optical resolution.) What software (in Linux) supports the scanner?
Answer: Check my March 1997 Graphics Muse column. I did a review of the scanners currently supported (at that time). A good place to look (which is listed in that issue of the Muse) is the SANE Project.
3.I can't afford one, but... Are there any 35mm slide scanners on the market with Linux support?
Answer:I haven't seen any announced yet. I get info like this alot due to my work with Graphics Tools for Linux, but so far no one has pointed out any web pages or ftp sites for such drivers.
4.And as long as I'm asking dumb questions... Does Linux have support for any digital cameras yet?
Answer:Don't waste your money on these just yet, even if a driver exists (I haven't seen one of these either). Even the vendors have been saying this technology is too new and they haven't established the "rules of the game" for standards or formats. Many are using ordinary JPEG formats, but getting the data to your PC is variable and depends on the makers choice of protocols, connectors and so forth.
Hope this helps a little.
-- Michael J. Hammel
Date: Sat, 5 Jul 1997 21:09:06 -0600 (MDT)
To: rpragana@acm.org
Subject: Interfacing Genius Color Page-CS Scanner
You asked about using your Genius Scanner with Linux. I don't know if a driver is available although in a survey of scanners I did for the Graphics Muse Column (March 1997, Issue 15) of the Linux Gazette there was info on the Genius GS-B105G, Genius GS4500 and probably the GS4000 and GS4500A. Also, there is work being done on generic scanner support for the GIMP and other Linux applications via the SANE project.
I suggest you either look for the author of the Genius scanners to see if support for your particular scanner is forthcoming (assuming yours is from the same manufacturer as his). You should also check with the SANE Project to see if they have any ideas. Both should have pointers on how to write drivers and get info the specs for that scanner if they don't already have it.
One other place to look is http://tummy.com. This is the site for XVScan, a front end to xv that primarily supports HP scanners. They can also write the driver for a fee. XVScan is a commercial product.
-- Michael J. Hammel
Date: Sat, 5 Jul 1997 20:56:53 -0600 (MDT)
To: cricci@cpiprogetti.it
Subject: Matrox Mystique support
You wrote to the Linux Gazette:
Is there a chance to correctly configure a Matrox Mystique with 4MB RAM under X or I must throw away it ?
Answer: Xi Graphics AcceleratedX 3.1. I use it with my Matrox Mystique with 4MB RAM. There is a slightly annoying effect you'll see when moving windows (sort of like snow on a TV screen) but its minor and I hardly notice it anymore. They know about it and are working on a fix.
-- Michael J. Hammel
Date: Mon, 14 Jul 1997 13:51:38 -0400 (EDT)
From: Ade Bellini AdeBellini@aol.com
Subject: Re: *2+ Processing
Thank you for your interest and help, i am most pleased to have had so many
helpful replies, this just goes to show how many friendly and informed
readers the Linux gazette has (? blatant plug for the LG !).
I am sorry this reply is in the form of a "shotgun" approach, but i really
couldn't reply individually to so many, but to all of you that mailed me --
MANY THANKS.
I have "solved" 1/2 the problem - i rebuilt the kernel ( to install sound
blaster support) and some how (G-D knows how !) i can now run on *2 cpu but
only drawing the affects of 1 !. tur i ur tur as they say in Sweden ! (luck
in bad luck !!!).
Again thanks for the help and keep on hacking !:
Yours ade.
Ade Bellini
Date: Sat, 19 Jul 1997 12:24:41 -0700 (MST)
From: Joel Hardy deeng@nwcdh.inficad.com
Subject: Descent 3 for Linux?
Linux has always been the perfect platform for games, it's just very few developers (id and Crack.com are the only two worth mentioning that I know of) know that. Interplay and Parallax are developing the third game in their Descent series, and they're accepting ideas, so I think the Linux community should inform them of the benefits of supporting a Linux version. There have already been several (last estimate I heard was 90) people who have suggested that they support Linux, and they probably will if they're convinced enough people would buy it, so if you're interested in having the best DOS game ported to Linux, see http://www.interplay.com/descent/ideas and suggest Linux support.
-- Joel Hardy
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More 2¢ Tips!
Boot Information Display
Date: Wed, 2 Jul 1997 18:18:11 -0400
From: Jon Cox jcox@cx.tufts.edu
I saw an article in July's LG that talked about using watch as a better way to monitor ftp downloads -- there 's an even BETTER way: Check out ncftp. It works much like ftp, but shows a progress bar, estimates time to completion, and saves bookmarks of where you've been. I think ncftp is pretty standard on all distributions these days.
-Enjoy Jon
Consider Glimpse Instead of Grep
Date: Wed, 2 Jul 1997 18:18:11 -0400
From: Jon Cox jcox@cx.tufts.edu
While grep works as a tool for searching through a big directory tree
for a string, it's pretty slow for this kind of thing & a much better
tool exists --Glimpse. It even has an agrep-style stripped down
regexp capability for doing "fuzzy search", and is astonishingly fast.
Roughly speaking:
glimpse is to grep as
locate is to find
I believe the latest rpm version is glimpse-4.0-4.i386.rpm You can find it in any site that mirrors Red hat's contrib directory.
Enjoy!
-Jon
Copy
Date: Wed, 2 Jul 1997 18:18:11 -0400
From: Wim Jongman dblyuiam@xs4all.nl
I have hacked a helpful utility. Please have a look at it.
Regards,
Wim Jongman
I have been a satisfied diald user for quite some time. one of the things that were on my list of favorites was the possibility to activate the link from another location. I have written a small shell script that waits for activity on my telephone line.
If activity has been detected the script submits the ping utility which causes diald to set up a link to my ISP. If activity is detected from the inside (diald does the dialing) then the ping is also performed but there can be no harm in that.
My /etc/diald.conf looks like this:
mode cslip
connect /usr/local/bin/connect
device /dev/cua2
speed 115200
modem
lock
crtscts
local local.ip.ad.dres
remote ga.te.way.address
mtu 576
defaultroute
ip-up /usr/local/bin/getmail &
ip-down /usr/local/bin/waitmodem &
include /usr/lib/diald/standard.filter
The first time the link goes down, the program waitmodem is submitted. The script for /usr/local/bin/waitmodem is:
#!/bin/bash
# This script waits for data entering the modem. If data has arrived,
# then a host is pinged to allow diald to
# setup a connection (and you to telnet in.)
if test -f /var/locks/waitmodem
then
exit 0
else
touch /var/locks/waitmodem
sleep 5
read myvar < /dev/cua2
ping -c 10 host.com >
/dev/nul & > /dev/nul
rm /var/locks/waitmodem
exit 0
fi
If the diald decides to drop the link, the ip-down keyword activates the waitmodem script. This creates a lock in /var/lock(s) and sleeps for five seconds to allow the modem buffers to flush. Then the modem device is read and if activity occurs, the ping is submitted. Change the italic bits in the scripts. The lock is removed and diald dials out. This allows you to access your machine. I guess you have to have a static ip for it to be useful.
Regards,
Wim Jongman
A New Tool for Linux
Date: Wed, 2 Jul 1997 18:18:11 -0400
From: Jordi Sanfeliu mikaku@arrakis.es
hi !
This is my contribution to this beautiful gazette !! :))
tree is a simple tool that allows you to see the whole directory tree on your hard disk.
I think that is very cool, no?
The Mailbag!
#!/bin/sh
# @(#) tree 1.1 30/11/95 by Jordi Sanfeliu
# email: mikaku@arrakis.es
#
# Initial version: 1.0 30/11/95
# Next version : 1.1 24/02/97 Now, with symbolic links
#
# Tree is a tool for view the directory tree (obvious :-) )
#
search () {
for dir in `echo *`
do
if [ -d $dir ] ; then
zz=0
while [ $zz != $deep ]
do
echo -n "| "
zz=`expr $zz + 1`
done
if [ -L $dir ] ; then
echo "+---$dir" `ls -l $dir | sed 's/^.*'$dir' //'`
else
echo "+---$dir"
cd $dir
deep=`expr $deep + 1`
search # with recursivity ;-)
numdirs=`expr $numdirs + 1`
fi
fi
done
cd ..
if [ $deep ] ; then
swfi=1
fi
deep=`expr $deep - 1`
}
# - Main -
if [ $# = 0 ] ; then
cd `pwd`
else
cd $1
fi
echo "Initial directory = `pwd`"
swfi=0
deep=0
numdirs=0
zz=0
while [ $swfi != 1 ]
do
search
done
echo "Total directories = $numdirs"
Have fun !
Jordi
Hex Dump
Date: Wed, 18 Jun 1997 10:15:26 -0700
From: James Gilb p27451@am371.geg.mot.com
I liked your gawk solution to displaying hex data. Two things (which people have probably already pointed out to you).
-v: The -v option causes hexdump to display all input data. Without the -v option, any number of groups of output lines, which would be identical to the immediately preceding group of output lines (except for the input offsets), are replaced with a line comprised of a single asterisk.
00000000: 01df 0007 30c3 8680 0000 334e 0000 00ff ....0.....3N.... 00000010: 0048 1002 010b 0001 0000 1a90 0000 07e4 .H.............. 00000020: 0000 2724 0000 0758 0000 0200 0000 0000 ..'$...X........ 00000030: 0000 0760 0004 0002 0004 0004 0007 0005 ...`............ 00000040: 0003 0003 314c 0000 0000 0000 0000 0000 ....1L.......... 00000050: 0000 0000 0000 0000 0000 0000 2e70 6164 .............pad 00000060: 0000 0000 0000 0000 0000 0000 0000 0014 ................ 00000070: 0000 01ec 0000 0000 0000 0000 0000 0000 ................ 00000080: 0000 0008 2e74 6578 7400 0000 0000 0200 .....text....... 00000090: 0000 0200 0000 1a90 0000 0200 0000 2a98 ..............*.
(I don't suppose it is surprising that emacs does this, after all, emacs is not just and editor, it is its own operating system.)
Hard Disk Duplication
Date: Tue, 24 Jun 1997 11:54:48 +0200
From: Jerko Golubovic jerko.golubovic@public.srce.hr
A comment on article "HARD DISK DUPLICATION" written by mcablec@ucsd.edu in Linux Gazette #18 (June 97).
What I did at my place is following:
I SetUp root-NFS system to boot usable configuration over network. I just need a floppy with appropriate kernel command-line and system brings up.
When system brings up I mount as /root NFS volume where I store compressed images. In that way I have them readily available when I log-in.
With dmesg I find about geometry of the hard disk of the target system. Then, for taking a new image I do:
cat /dev/hda | gzip -9 > <somename>.gz
And for restore:
zcat <somename>.gz > /dev/hda
Of course, I don't have to use such system. It is enough to prepare one boot floppy containing just FTP client and network config. I made two shell scripts:
b: ---------------------- #!/bin/sh cat /dev/hda | gzip -9 r: ---------------------- #!/bin/sh gzip -d > /dev/hda Then, in FTP you do: put |./b <somename>.gz - to save image get <somename.gz> |./r - to restore image
ANY FTP server on ANY platform can be used for storage.
Not only that - you don't have to use FTP at all - you can use smbclient instead - and read directly from Win or Lanman shares - doing basically the same thing.
More on Grepping Files in a Directory Tree
Date:Tue, 1 Jul 1997 13:12:34
From: Gene Gotimer gotimer@cybercash.com
In Linux Gazette Issue 18, Earl Mitchell (earlm@Terayon.COM) suggested
grep foo `find . -name \*.c -print`
as a way to grep files in a directory tree. He warned about a command line character limit (potentially 1024 characters).
Another way to accomplish this, without the character limit, is to use the xargs command:
find . -name '*.c' -print | xargs grep foo
The xargs command accepts arguments on standard input, and tacks them on the end of the specified command (after any supplied parameters).
You can specify where in the command xargs will place the arguments (rather than just on the end) if you use the -i option and a pair of curly braces wherever you want the substitution:
ls srcdir | xargs -i cp srcdir/{} destdir/{}
xargs has a number of options worth looking at, including -p to confirm each command as it is executed. See the man page.
-- Gene Gotimer
More on Hard Disk Duplication
Date: Mon, 23 Jun 1997 08:45:48 +0200
From: Jean-Philippe CIVADE jpcivade@cge-ol.fr
I've written an utility under Windows 95 able to copy from disk to disk in a biney way. It's called Disk2file. It's findable on my web site under tools. The primary purpose of this utility was to make iso images from a hard disk (proprietary file system) to record them on a cdrom. I've used it yesterday do duplicate a red hat 4.1 installed disk with success. The advantage of this method is this is possible to product a serial of disk very quickly. This utility is written to tranfert up to 10Mb /s. The duplication time for a 540 Mb is about 10 mins.
The way to use it is:
It's referenced as a shareware in the docs but I conced the freeware mode to the Linux community for disk duplication only.
-- Best Regards Jean-Philippe CIVADE
A Script to Update McAfee Virus
Date: Fri, 20 Jun 1997 00:05:33 -0500 (CDT)
From: Ralph ralphs@kyrandia.com
Here is a script I hacked together (trust me after you see it I'm sure you'll understand why this is my first script hack I'm sure) to ftp McAfee virus definitions unzip then and run a test to make sure they are ok...now ya gotta have vscan for linux located at ftp://ftp.mcafee.com/pub/antivirus/unix/linux
the first one does the work of pulling it down unzipping and testing
#!/bin/sh
# =====================================================================
# Name: update-vscan
# Goal: Auto-update McAfee's Virus Scan for Linux
# Who: Ralph Sevy ralphs@kyrandia.com
# Date: June 19 1997
# ----------------------------------------------------------------------
# Run this file on the 15th of each month to insure that the file gets
# downloaded
# ======================================================================
datafile=dat-`date +%y%m`.zip
mcafeed=/usr/local/lib/mcafee
ftp -n ftp.mcafee.com << !
user anonymous root@home.com
binary
cd /pub/antivirus/datfiles/2.x
get $datafile
quit
!
if [ -f $mcafeed/*.dat ]; then
rm *.dat
fi
unzip $datafile *.DAT -d $mcafeed
for file in $(ls $mcafeed/*.DAT); do
lconvert $mcafeed/*.DAT
done
uvscan $mcafeed/*
exit
---------------------------------------------------------------------------
CUT HERE
lconvert is a 3 line script I stole looking in the gazette
CUT HERE
--------------------------------------------------------------------------
#!/bin/tcsh
# script named lconvert
foreach i (*)
mv $1 `echo $1 | tr '[A-Z]' '[a-z]'`
-------------------------------------------------------------------------
CUT HERE
The last thing you want to do is add an entry to crontab to update your files once a month....I prefer the 15th as it makes sure I get the file (dunno really how to check for errors yet, its my next project)
# crontab command line # update mcafee data files once a month on the 15th at 4am * 4 15 * * /usr/local/bin/update-vscan
Its not pretty I'm sure, but it works
Ralph http://www.kyrandia.com/~ralphs
Handling Log Files
Date: Thu, 3 Jul 1997 11:13:56 -0400
From: Neil Schemenauer nas170@mail.usask.ca
I have seen a few people wondering what to do with log files that keep growing. The easy solution is to trim them using:
cat </dev/null >some_filenameThe disadvantage to this method is that all your logged data is gone, not just the old stuff. Here is a shell script I use to prevent this problem.
#!/bin/sh # # usage: logroll [ -d <save directory> ] [ -s <size> ] <logfile> # where to save old log files SAVE_DIR=/var/log/roll # how large should we allow files to grow before rolling them SIZE=256k while : do case $1 in -d) SAVE_DIR=$2 shift; shift;; -s) SIZE=$2 shift;shift;; -h|-?) echo "usage: logroll [ -d <save directory> ] [ -s <size> ] <logfile>" exit;; *) break;; esac done if [ $# -ne 1 ] then echo "usage: logroll [ -d <save directory> ] [ -s <size> ] <logfile>" exit 1 fi if [ -z `find $1 -size +$SIZE -print` ] then exit 0 fi file=`basename $1` if [ -f $SAVE_DIR/$file.gz ] then /bin/mv $SAVE_DIR/$file.gz $SAVE_DIR/$file.old.gz fi /bin/mv $1 $SAVE_DIR/$file /bin/gzip -f $SAVE_DIR/$file # this last command assumes the PID of syslogd is stored like RedHat # if this is not the case, "killall -HUP syslogd" should work /bin/kill -HUP `cat /var/run/syslog.pid`Save this script as /root/bin/logroll and add the following to your /etc/crontab:
# roll log files 30 02 * * * root /root/bin/logroll /var/log/log.smb 31 02 * * * root /root/bin/logroll /var/log/log.nmb 32 02 * * * root /root/bin/logroll /var/log/maillog 33 02 * * * root /root/bin/logroll /var/log/messages 34 02 * * * root /root/bin/logroll /var/log/secure 35 02 * * * root /root/bin/logroll /var/log/spooler 36 02 * * * root /root/bin/logroll /var/log/cron 38 02 * * * root /root/bin/logroll /var/log/kernelNow forget about log files. The old log file is stored in /var/log/roll and gzipped to conserve space. You should have lots of old logging information if you have to track down a problem.
Neil
Exciting New Hint on xterm Titles
Date: Fri, 27 Jun 1997 15:43:44 +1000 (EST)
From: Damian Haslam damian@srsuna.shlrc.mq.edu.au
Hi, after searching (to no avail) for a way to display the currently executing process in the xterm on the xterm's title bar, I resorted to changing the source of bash2.0 to do what I wanted. from line 117 of eval.c in the source, add the lines marked with # (but don't include the #)
117: if (read_command () == 0)
118: {
#119: if (strcmp(get_string_value("TERM"),"xterm") == 0) {
#120: printf("^[]0;%s^G",make_command_string(global_command));
#121: fflush(stdout);
#122: }
#123:
124: if (interactive_shell == 0 && read_but_dont_execute)
.....
you can then set PROMPT_COMMAND to reset the xterm title to the pwd, or
whatever takes your fancy.
cheers - damian
C Source with Line Numbers
Date: Sun, 29 Jun 1997 10:09:52 -0400 (EDT)
From: Tim Newsome drz@froody.bloke.com
Another way of getting a file numbered:
grep -n $ <filename>
-ntells grep to number its output, and $ means end-of-line. Since every line in the file has an end (except possibly the last one) it'll stick a number in front of every line.
Tim
Another Reply to "What Packages Do I Need?"
Date: Wed, 02 Jul 1997 20:17:26 +0900
From: Matt Gushee matt@it.osha.sut.ac.jp
About getting rid of X components, Michael Hammel wrote that "...you still need to hang onto the X applications (/usr/X11R6/bin/*)." We-e-ll, I think that statement needs to be qualified. Although I'm in no sense an X-pert, I've poked around and found quite a few non-essential components: multiple versions of xclocks (wristwatches are more accurate and give your eyes a quick break). Xedit (just use a text-mode editor in an xterm). Fonts? I could be wrong, but I don't see any reason to have both 75 and 100dpi fonts; and some distributions include Chinese & Japanese fonts, which are BIG, and which not everyone needs. Anyway, poking around for bits and pieces you can delete may not be the best use of your time, but the point is that X seems to be packaged with a very broad brush. By the way, I run Red Hat, but I just installed the new (non-rpm) XFree86 3.3 distribution--and I notice that Red Hat packages many of the non-essential client programs in a separate contrib package, while the Xfree86 group puts them all in the main bin/ package.
Here's another, maybe better idea for freeing up disk space: do you have a.out shared libraries? If you run only recent software, you may not need them. I got rid of my a.out libs several months ago, and have installed dozens of programs since then, and only one needed a.out (and that one turned out not to have the features I needed anyway). Of course, I have the RedHat CD handy so I can reinstall them in a moment if I ever really need them.
That's my .02 .
--Matt Gushee
Grepping Files in a Tree with -exec
Date: Wed, 2 Jul 1997 09:46:33 -0400 (EDT)
From: Clayton L. Hynfield hynfiecl@mnemo.mcs.muohio.edu
Don't forget about find's -exec option:
find . -type f -exec grep foo {} \;
Clayton L. Hynfield
How Do You Un-Virtual a Virtual Screen?
Date: Mon, 07 Jul 97 15:08:39 +1000
From: Stuart Lamble lamble@yoyo.cc.monash.edu.au
With regards to changing the size of the X screen, I assume you're using XFree86. XFree will make your virtual screen size the larger of: *the specified virtual screen size *the _largest_ resolution you _might_ use with your video card (specified in 'Section "Screen"').
Open your XF86Config file in any text editor (ae, vi, emacs, jed, joe, ...) _as root_. (You need to be able to write it back out again.) Search for "Screen" (this is, IIRC, case insensitive, so for example, under vi, you'd type:
/[Ss][Cc][Rr][Ee][Ee][Nn]yeah, yeah, I know there's some switch somewhere that makes the search case insensitive (or if there isn't, there _should_ be :), but I can't remember it offhand; I don't have much use for such a thing.)
You'll see something like:
Section "Screen"
Driver "accel"
Device "S3 Trio64V+ (generic)"
Monitor "My Monitor"
Subsection "Display"
Depth 8
Modes "1024x768" "800x600" "640x480"
ViewPort 0 0
Virtual 1024 768
EndSubsection
Subsection "Display"
Depth 16
Modes "800x600" "640x480"
ViewPort 0 0
Virtual 800 600
EndSubsection
Subsection "Display"
Depth 24
Modes "640x480"
ViewPort 0 0
Virtual 640 480
EndSubsection
EndSection
(this is taken from a machine I use on occasion at work.)
The first thing to check is the lines starting with Virtual. If you want the virtual resolution to be the same as the screen size, it's easy to do - just get rid of the Virtual line, and it'll be set to the highest resolution listed in the relevant Modes line. (In this case, for 24bpp, it would be 640x480; at 16bpp, 800x600; at 8bpp, 1024x768.) Just be aware that if you've got a 1600x1200 mode at the relevant depth listed, the virtual screen size will stay at 1600x1200. You'd need to get rid of the higher resolution modes in this case.
I would strongly recommend you make a backup of your XF86Config file before you mess around with it, though. It's working at the moment; you want to keep it that way :-)
All of this is, of course, completely incorrect for MetroX, or any other commercial X server for Linux.
Cheers.
File Size Again...
Date: Sun, 6 Jul 1997 13:13:29 -0400 (EDT)
From: Tim Newsome drz@froody.bloke.com
Since nobody has mentioned it yet: procps (at least version 1.01) comes with a very useful utility named watch. You can give it a command line which it will execute every 2 seconds. So, to keep track of file size, all you really need is: watch ls -l filename Or if you're curious as to who's logged on: watch w You can change the interval with the -n flag, so to pop up a different fortune every 20 seconds, run: watch -n 20 fortune Tim
syslog Thing
Date: Fri, 04 Jul 1997 14:50:08 -0400
From: Ian Quick ian@dot.superaje.com
I don't know if this is very popular but my friend once told me a way to put your syslog messages on a virtual console. First make sure that you have the dev for what console you want. (I run RedHat 4.0 and they have them up tty12). Then edit your syslog.conf file and add *.* <put a few tabs for format> /dev/tty12. Reboot and TA DA! just hit alt-F12 and there are you messages logged to a console.
-Ian Quick
Ascii Problems with FTP
Date: Mon, 7 Jul 1997 15:59:39 -0600 (CST)
From: Terrence Martin twm139@missing.link.ca
This is a common problem that occurs with many of our Windows users when they upload html and perl cgi stuff to our web server.
The real fix for this has been available for years in ftp clients themselves. Every ftp client should have support for both 'Binary or type I' and 'Ascii or type 2' uploads/downloads. By selecting or toggling this option to Ascii mode (say in ws_ftp) the dos format text files are automagically translated to unix style without the ^M. Note you definitely do not want to transfer binary type files like apps or programs as this translation will corrupt them.
Regards
Terrence Martin
Running Squake from Inside X
Date: Fri, 11 Jul 1997 00:27:49 -0400
From: Joey Hess joey@kite.ml.org
I use X 99% of the time, and I was getting tired of the routine of CTRL-ALT-F1; log in; run squake; exit; switch back to X that I had to go through every time I wanted to run squake. So I decided to add an entry for squake to my fvwm menus. To make that work, I had to write a script, I hope someone else finds this useful, I call it runvc:
#!/bin/sh # Run something on a VC, from X, and switch back to X when done. # GPL Joey Hess, Thu, 10 Jul 1997 23:27:08 -0400 exec open -s -- sh -c "$* ; chvt `getvc`"Now, I can just type runvc squake (or pick my fvwm menu entry that does the same) and instantly be playing squake, and as soon as I quit squake, I'm dumped back into X. Of course, it works equally well for any other program you need to run at the console.
Runvc is a one-liner, but it took me some time to get it working right, so here's an explanation of what's going on. First, the open -s command is used to switch to another virtual console (VC) and run a program. By default, it's going to switch to the next unused VC, which is probably VC 8 or 9. The -s has to be there to make open actually change to that console.
Next, the text after the -- is the command that open runs. I want open to run 2 commands, so I have to make a small shell script, and this is the sh -c "..." part. Inside the quotes, I place $*, which actually handles running squake or whatever program you told runvc to run.
Finally, we've run the command and nothing remains but to switch back to X. This is the hard part. If you're not in X, you can use something like open -w -s -- squake and open will run squake on a new VC, wait for it to exit, and then automatically switch back to the VC you ran it from. But if you try this from inside X, it just doesn't work. So I had to come up with another method to switch back to X. I found that the chvt command was able to switch back from the console to X, so I used it.
Chvt requires that you pass it the number of the VC to switch to. I could just hard code in the number of the VC that X runs on on my system, and do chvt 7, but this isn't portable, and I'd have to update the script if this ever changed. So I wrote a program named 'getvc' that prints out the current VC. Getvc is actually run first, before any of the rest of the runvc command line, because it's enclosed in backticks. So getvc prints out the number of the VC that X is running on and that value is stored, then the rest of the runvc command line gets run, and eventually that value is passed to chvt, which finally switches you back into X.
Well, that's all there is to runvc. Here's where you can get the programs used by it:
/* getvc.c
* Prints the number of the current VC to stdout. Most of this code
* was ripped from the open program, and this code is GPL'd
*
* Joey Hess, Fri Apr 4 14:58:50 EST 1997
*/
#include <sys/vt.h>
#include <fcntl.h>
main () {
int fd = 0;
struct vt_stat vt;
if ((fd = open("/dev/console",O_WRONLY,0)) < 0) {
perror("Failed to open /dev/console\n");
return(2);
}
if (ioctl(fd, VT_GETSTATE, &vt) < 0) {
perror("can't get VTstate\n");
close(fd);
return(4);
}
printf("%d\n",vt.v_active);
}
/* End of getvc.c */
I hope this tip isn't too long!
-- see shy jo
Copying a Tree of Files
Date: Fri, 18 Jul 1997 00:33:48 +0200 (SAT)
From: ixion@ilink.nis.za
Hi!
First of all, I want to congratulate you with your fine magazine. Although I've been around for quite some time and known about the existance of LG, I've never had the time (or should I say I have been to ignorant) to read it. Well, I finally sat down and started reading all the issues and I must say I'm impressed. Therefore I decided I would show my gratitude by showing you some of my 2c Tips. Enjoy...
# Quick way to copy a tree of files from one place to another
----< cptree <----
#!/bin/sh
if [ $# = 2 ]
then
(cd $1; tar cf - .) | (mkdir $2; cd $2; tar xvfp -)
else
echo "USAGE: "`basename $0`" <source_directory> <dest_directory>"
exit 1
fi
----< cptree <----
# Quick way to move a tree of files from one place to another
----< mvtree <----
#!/bin/sh
if [ $# = 2 ]
then
(cd $1; tar cf - .) | (mkdir $2; cd $2; tar xvfp -)
rm -rf $1
else
echo "USAGE: "`basename $0`" <source_directory> <dest_directory>"
exit 1
fi
----< mvtree <----
# Rename numeric files (1.*, 2.*, 3.*, etc.) to it's correct numeric
# equivalents (01.*, 02.*, 03.*, etc.). Useful to prevent incorrect wild
# card matching
----< fixnum <----
#!/bin/sh
if [ $# = 0 ]
then
FILELIST=`ls {1,2,3,4,5,6,7,8,9}.mp3` 2> /dev/null
MPFILE="empty"
chmod -x *
for MPFILE in $FILELIST
do
if [ -e $MPFILE ]; then mv $MPFILE "`echo "0$MPFILE"`"; fi
done
fi
----< fixnum <----
# This one strips the given file name from it's extension (i.e. "file.txt"
# would become "file"
----< cutbase <----
#!/bin/sh
if [ $# = 1 ]
then
dotpos=`expr index $1 "."`
if [ $dotpos -gt 0 ]
then
dotpos=`expr $dotpos - 1`
stripfile=`expr substr $1 1 $dotpos`
else
stripfile=$1
fi
echo $stripfile
else
echo " USAGE: `basename $0` <filename>"
exit 1
fi
----< cutbase <----
# If you're desperately looking for a file containing something and you
# don't have a clue where to start looking, this one might be for you.
# It greps through all the files in the given directory tree for the given
# keyword and list all the files. For example: grepall /usr/doc PAP secrets
----< grepall <----
#!/bin/sh
if [ $# = 0 ]
then
DIR="."
else
DIR=$1
shift
find $DIR -type f -exec grep -lie "$@" {} \; | less
fi
----< grepall <----
# You might have seen some of the xterm titlebar tips posted in LG. Here
# is my variation of the theme. I like my xterm to keep it's title that
# I've either specified on the command-line or the name of the program
# and after I've run programs like Midnight Commander, that's changes the
# titlebar, I want it restored to it's old value. Here is my way of doing
# it. Just put the code in /etc/profile or ~/.profile or whatever startup
# file you use...
----< Titlebar 2c tip <----
if [ $TERM = "xterm" -o $TERM = "xterm-color" -o $TERM = "rxvt" ]
then
function TitlebarString()
{
local FOUND=0
local PIDTXT=`ps | grep $PPID`
for WORDS in $PIDTXT
do
if [ $FOUND = 1 ]; then break; fi
if [ $WORDS = "-T" ]; then export FOUND=1; fi
done
if [ $FOUND = 0 ]
then
WORDS=`(for TMP in $PIDTXT;do echo -n $TMP" ";done) | cut -f5 -d" "`
if [ "`echo $WORDS | grep -i xterm`" != "" ]; then WORDS="xterm"; fi
fi
echo -n $WORDS
unset WORDS
}
if [ $COLORTERM -a $COLORTERM = "rxvt-xpm" ]
then
alias mc='mc -c;echo -ne "\033[m\033]0;`TitlebarString`\007"'
else
alias mc='mc -c;echo -ne "\033]0;`TitlebarString`\007"'
fi
fi
----< Titlebar 2c tip <----
# This is an add-on for du. It shows the total disk usage in bytes,
# kilobytes, megabytes and gigabytes (I thought terabytes wouldn't be
# necessary (: )
----< space <----
#!/bin/sh
BYTES=`du -bs | cut -f1` 2> /dev/null
if [ $BYTES -lt 0 ]
then
KBYTES=`du -ks | cut -f1` 2> /dev/null
else
KBYTES=`expr $BYTES / 1024`
fi
MBYTES=`expr $KBYTES / 1024`
GBYTES=`expr $MBYTES / 1024`
echo ""
if [ $BYTES -gt 0 ]; then echo " $BYTES bytes"; fi
if [ $KBYTES -gt 0 ]; then echo " $KBYTES KB"; fi
if [ $MBYTES -gt 0 ]; then echo " $MBYTES MB"; fi
if [ $GBYTES -gt 0 ]; then echo " $GBYTES GB"; fi
echo ""
----< space <----
# A scripty to unzip all zipfiles specified or all those in the current
# directory and remove the orginal ones (Remember that GNU zip/unzip
# doesn't support wildcards)
----< unzipall <----
#!/bin/sh
if [ $# = 0 ]
then
ZIPLIST=`ls *.zip` 2> /dev/null
else
ZIPLIST="$@"
fi
ZIPFILE="garbage"
for ZIPFILE in $ZIPLIST
do
unzip -L $ZIPFILE
done
rm -f $ZIPLIST 2> /dev/null
----< unzipall <----
# Zip all the files in the current directory seperately and wipe the
# original files. Zip's them in a dos style (i.e. hungry.txt would
# be zipped to hungry.zip and not hungry.txt.zip)
----< zipall <----
#!/bin/sh
function stripadd ()
{
local dotpos=`expr index $1 "."`
if [ $dotpos -gt 0 ]
then
dotpos=`expr $dotpos - 1`
local stripfile=`expr substr $1 1 $dotpos`
else
local stripfile=$1
fi
echo $stripfile".zip"
}
function ziplist ()
{
zipfile="garbage"
for zipfile in "$@"
do
zip -9 `stripadd $zipfile` $zipfile
rm $zipfile
done
}
if [ $# -gt 0 ]
then
ziplist "$@"
else
ziplist `ls`
fi
----< zipall <----
Okay, now for some Window manager tips. Since '95 microsoft has launched a '95 keyboard campaign and in the process a lot of people (including me) have ended up with keyboards containing those silly, useless buttons. Luckily I've put them to good use. To give them the same functions in your window manager as in doze 95, just follow the instructions:
Edit ~/.Xmodmap and add the following lines: keycode 115 = F30 keycode 116 = F31 keycode 117 = F32
Now, edit your window manager configuration file and bind those keys. Here is the proper keybindings for fvwm95 and afterstep respectively
# Fvwm95 (edit ~/.fvwm2rc95) Key F30 A A CirculateDown Key F31 A A CirculateUp Key F32 A A PopUp "Utilities" # Afterstep (edit ~/.steprc) Key F30 A A CirculateDown Key F31 A A CirculateUp Key F32 A A PopUp "HotList"
Just remember that PopUp "Utilities" and PopUp "HotList" should be replaced by your actual popup menus. If you don't known what I'm talking about, just browse through your configuration file and read the comments - It'll become clear very soon.
I guess that's all for now. I've got some other (more useful) scripts and tips, but they are either system specific or just to large to include here and if I don't stop now, you'll need a seperate issue just for my tips.
Cheers
ixion
Using shar + RCS to Backup Set of Source Files
Date: Wed, 23 Jul 1997 09:28:24 -0300
From: Mario Storti mstorti@minerva.unl.edu.ar
Hi, RCS (see rcs(1)) is a very useful tool that allows to store versions of a file by storing only the differences between successive versions. In this way I can make a large amounts of backups of my source files but with a negligible amount of storage. I use it all the time, even for TeX files!! However, when you are working with a set of source files (*.c, shell or Perl scripts, I work mainly with Fortran .f and Octave *.m files) what I want is to make backups of the whole set of files in such a way that you can recover the state of the whole package at a given time. I know that there is a script called rcsfreeze around, but I know that it has problems, for instance if you rename, delete or create new files, it is not guaranteed to recover the same state of the whole set.
I found a solution that seems to be simpler and is working for me: I make a `shar' of the files and then a version control of the shar file. (see shar(1)). Shar is a file that packs a set of text files in a single text file. It has been used since a long time to send set of files by e-mail.
It would be easy to write a script for this, but I prefer to include the shell code in a Makefile. The commands to be issued each time you want to make a backup are:
$ co -l source.shar
$ shar *.m Makefile >source.shar
$ ci -m"save package" source.shar
Here *.m and Makefile is the set of files that I want to backup periodically.
(I want to point out that RCS version control is far beyond the simple fact of making backups: It serves to manage files to be worked by different people, etc... Here I'm using a very small subset of the utilities of RCS.)
Hope this could be of use for someone else. It would be nice also to hear of other solutions,
Mario
Learning Experience
Date: Wed, 23 Jul 1997 15:53:31 -0500
From: Debie Scholz debie@sirinet.net
If you have a ps2 style mouse and the /dev/psaux gets deleted you must do a MAKEDEV busmice but it doesnt make a psaux it makes a psmouse so you must make a symbolic link to psaux.;
Debie Scholz
Sirius Systems Group, Inc.
LG #19, Grepping Files Comments
Date: Wed, 30 Jul 1997 08:35:46 +0200 (MET DST)
From: Werner Fleck Werner.Fleck@prompt.de
Hi!
I have read all the 2c tips on grepping files in a directory tree but I think
all missed the ultimate tool for this: a perl script named ``mg''. With this
you can:
Although it is written in perl it is very fast - I used it now for many years and it works wonderful for me.
FTP search results
Hardware by Opticom ASA, ITEA and IDI. Network by UNINETT. This server is located in Trondheim, Norway
"Exact search" for "mg-2.16"
1 -r--r--r-- 38.8K 1996 Oct 2 ftp.nuie.nagoya-u.ac.jp /languages/perl/sra-scripts/mg-2.16 2 -rw-r--r-- 38.8K 1995 Nov 16 ftp.et-inf.fho-emden.de /pub/.mnt2/perl/sra-scripts/mg-2.16 3 -rw-r--r-- 38.8K 1996 Oct 3 ftp.hipecs.hokudai.ac.jp /pub/LANG/perl/utashiro/mg-2.16 4 -rw-r--r-- 38.8K 1997 Mar 4 ftp.st.ryukoku.ac.jp /pub/lang/perl/mg-2.16 5 -r--r--r-- 38.8K 1996 Oct 2 ftp.elelab.nsc.co.jp /pub/lang/perl/scripts.sra/mg-2.16 6 -r--r--r-- 38.8K 1996 Oct 3 ftp.sra.co.jp /pub/lang/perl/scripts/utashiro-scripts/mg-2.16 7 -r--r--r-- 38.8K 1996 Oct 3 ftp.sra.co.jp /pub/lang/perl/sra-scripts/mg-2.16 8 -rw-r--r-- 38.8K 1995 Nov 16 ftp.fujitsu.co.jp /pub/misc/perl/sra-scripts/mg-2.16 9 -r--r--r-- 38.8K 1996 Oct 2 ftp.eos.hokudai.ac.jp /pub/tools/sra-scripts/mg-2.16 9 reported hits 0.018 seconds prospero 0.018 seconds HTTP 0 partial writes. DONE
FTP search, Copyright © 1994-1997 Tor Egge
Greetings, Werner
|
Contents: |
SAL--Scientific Applications on Linux
If you are looking for a great collection of software information relating to science and engineering be sure to take a look at SAL -- the Scientific applications on Linux page. The page contains broad converage of different advancements adn points of interest in the Linux community. There are currently 1250 software entries at the SAL page! Luckily if you are looking for something specific, you may choose to search the Linux Applications. There are also sections which will help you find what you need. There are sections from Mathematics to Office Software and Numerical Analysis to Computer Graphics. Not only can you roam around the page looking at all of the applications, but you have a chance to make contributions of your own to the page. Don't miss the new and improved SAL at http://SAL.KachinaTech.COM. You'll be happy you visited.
Readers' Choice Awards
Vote in Linux Journal's 1997 Readers' Choice Awards!
Linux Journal, the Premier Linux Magazine, is conducting its annual poll of Linux users. Vote for your favorites in twenty different categories including: Most desired upgrade, favorite shell and most indispensible Linux book.
The voting will take place on the Linux Journal web site from July 11th through August 26th. To place your vote simply go to http://www.ssc.com/lj/readchoice.html and follow the directions there. Please do not submit more than one form because all duplicate entries will be deleted.
Results will be published in the December issue of Linux Journal (on newsstands early November).
Subscriptions to Linux Journal are available by calling our toll free number (in the US/Canada) 888 66 LINUX or over our web page at http://www.ssc.com/lj/.
Check Out This Site!
Take a look at http://www.m-tech.ab.ca/linux-biz. This page contains a list of commercial sites that use Linux for business. Check out all of the Linux users at work!
Evolution Scheduler
Check out Evolution Scheduler. The Evolution Scheduler is based on Genetic Algorithms and Evolutionary Programming. This scheduler can live with original Linux priority scheduler. This means you don't have to reboot to change the scheduling policy. You may switch between them at any time just by a simple command, say,
esep -cp 3.
A manager program esep(Evolution Scheduling and Evolving Processes), with which you can do scheduling administration job is provided.
If you are interested, see http://sunsite.unc.edu/pub/Linux/kernel looking for "esep-1.2.tgz" and "esep-1.2.lsm" or visit Jinlong Lin's homepage at http://www.iit.edu/~linjinl/esep.html
Alien
Apache-SSL
GNU Midnight Commander
The GNU Midnight Commander is a Unix file manager and shell, useful to novice and guru alikes. Version 4.0 has many enhancements. See http://mc.blackdown.org/mc4 for the list of seventy download sites
GNU Midnight Commander is also included on most CD-ROMs containing GNU software and we expect the publishers of these CD-ROMs to include MC version 4.0 when they publish a next version of their CD-ROM.
See also the GNU Midnight Commander website at http://mc.blackdown.org/mc/
Watchdog
Watchdog is a daemon that checks if your system is still working. If programs in user space are not longer executed it will reboot the system.
A few new features in 3.0 include:
Watchdog is available from: tsx-11.mit.edu /pub/linux/sources/sbin sunsite.unc.edu /pub/linux/system/daemons ftp.debian.org /pub/debian/development/source/misc
As of the end of July, O'Reilly and Associates have the domain http://www.oreilly.com. The company figured it would be easier to remember than their previous domain. Check out their site!
The Answer Guy
Security Issues
From: Marcus Hufvudsson talos@algonet.se
Greetings Linux guru!
I recently read the Linux Journal May edition and some people had some serious security problems. I got some of them to, and in your answer to one you recommended the "Tripwire" program for more security. I hope you don't mind me mailing you (got the address from the article). Anyway you recommend ftp.cs.perdue.edu for downloading. But when I tried to connect it didn't respond. Do you know any mirrors or any other ftp that contains Linux security tools?
- talos (root today, gone tomorrow)
There was a typo in that article. It WAS supposed to be ftp.cs.purdue.edu -- but is now supposed to be at ftp://coast.cs.purdue.edu/pub/COAST (they've been moved).
Here's the full URL to Tripwire: ftp://coast.cs.purdue.edu/pub/COAST/Tripwire
You should definitely browse around and read some of the other papers -- and try some of the other tools out there at the COAST (computer operations and security tools?) archive.
Sadly it seems to be neglected -- the whole "tools_new" tree is dated "October, 1995" and is empty.
All of the good stuff there is under: ftp://coast.cs.purdue.edu/pub/tools/unix (including symlinks that lead back to the Tripwire package).
Apparently they don't do anything with the FTP site because the real work as gone into their web pages at: http://www.cs.purdue.edu/coast/archive/Archive_Indexing.html
Another more recent effort which will be of more direct interest to Linux admins is: http://skynet.ul.ie/!flynng/security/The Irish Computer Security Archives ... with the following being of particular interest: http://skynet.ul.ie/~flynng/security/bugs/linux/ ... and: http://skynet.ul.ie/~flynng/security/tools
Another good site (recently moved) is at: http://www.aoy.com/Linux/SecurityThe Linux Security WWW ... where I particularly like: http://www.aoy.com/Linux/Security/OtherSecurityLinks.html
One of these days I'm going to annotate the 600 or so links in my main lynx_bookmarks file and post it to my own web pages. But -- not this morning (3 am).
I spend so much time doing TAG (The Answer Guy) and other mailing list and newsgroup stuff that I never get to my own web pages. However the patch that I created to allow Tripwire to compile cleanly under Linux is on my ftp site and a link can be found somewhere under http://www.starshine.org/linux/ (I really have to organize those pages one of these days).
-- Jim
All Those Little % Thingies
To: Jonathan Albrecht albrecht@algorithmics.com
When setting your prompt or dates or app-defaults you sometimes need those little %N, or %d, or %m substitution thingies. What are they and where can I get a list of what they mean?
They are "replaceable parameters" and are used by a variety
of shells and applications.
They differ for each shell or application. For example I use bash -- and my prompt is:
PS1=[\u@\h \W]\$
Which looks like:
[jimd@antares jimd]$
When I'm in my home directory and logged in as jimd and would look like:
[root@main local]#
If I was 'root' on the host "main" and in the /usr/local directory.
zsh, and tcsh also have similar "meta sequences" for their shell prompts. Just read the man pages for your shell and search for "prompt."
X app-default and other xrdb (X Windows resource database) entries are pretty mysterious to me. But I imagine that the info about these sequences is mostly in their man pages somewhere. I'm sure it's all in the sources.
The %d syntax is most often seen in the C programming language's printf() and scanf() functions. There are various "format specifiers" that dictate how a particular argument will be formatted. This includes information about whether a value will be displayed as a decimal number, a string, a hexadecimal value -- and how wide the field will be, whether it will be left or right justified -- etc. The \c syntax is also used in C for inserting "non-printing" characters -- like newlines, tabs, and for specifying ASCII characters by octal or hexadecimal value.
Since programmers are used to this syntax in their code they often use a similar syntax when they write scripting languages (shells) and when they design the configuration file syntax for their applications.
I'm sorry there's no "single source" or reference of all of these. However there isn't. You'll just have to hunt through the docs and man pages for easy of the apps and utilities that you're interested in.
Follow-up To NT and Linux Article
From: Cyrille Chepelov chepelov@rip.ens-cachan.fr
So far I've had the good sense to stay away from striping under NT and Linux. I've heard that the ccd code for FreeBSD is pretty stable, though.
Well, my linux partition is used <5% of the overall time, but sometime I need it to figure things -- once the "small" problem with disks ID was solved, there are no cohabitation problems between NT and Linux.
This sounds like a typically ignorant design decision.
It seems to say to the world:
"Standards are for weaklings -- we don't need to follow them -- even when we created them!"
Sure, even if they did it unilaterally, it was up to them to at
least loudly publicize what they did.
I disagree. "Unilateral" is completely anathema to
"Industry Standards." It is totally arrogant to speak
for an industry.
(We won't cover the issue of government regulatory bodies making determinations in a "unilateral" way -- since those aren't "industry standards" they are "government regulations").
Publicizing that you are violating industry standards doesn't improve interoperability. What other reason is there to create and publish a "standard" (even an ad hoc one).
If they think there's a real need to put proprietary information in the very first sector of the disk (the spot reserved for the MBR -- then perhaps they should announce that these disks won't have PC partitions at all. It then becomes a "all NT or nothing" decision for each disk.
I don't think there is such a need -- and I think their approach displays either a gross lack of consideration, creativity and foresight -- OR -- a deliberate act of hostility to those unruly customers who would dare use any "other" operating systems on "their" NT boxes (or maybe a little of each -- some from the programmers and some of the QA teams).
Microsoft can cop out with a line like: "We don't intend that NT Servers should be installed systems with other operating systems -- it is intended for dedicated systems."
It would irritate me. But I'm not one of their "important" customers anyway. Since most platforms outside of the PC market have an OS that's supplied by the vendor -- there isn't an expectation that those system will allow multiple operating systems to co-exist on the system (much less on the same drive).
However, in the PC market there is that expectation -- and has been for over fifteen years. IBM and Microsoft created that expectation (to co-exist with CP/M-86 and the UCSD p-system if my memory and reading of the history is correct).
Naturally the obvious place to put this sort of information would be in the logical boot record (what Unix/Linux refers to as a "Superblock"). This would only cost NT's code a few extra disk seeks at boot time -- seeks that it has to do anyway.
The reason (IMHO) why they put it in the MBR is that even an unpartitioned disk gets its ID. The ID is here for the disk, not the partition -- so it makes less sense to put it in the S-block (even if that sounds safer, cohabitation-wise. Those IDs are what they are -- disk IDs, not partition IDs.)
Classically an OS should ignore an unpartitioned disk. Why should the disk have an ID if it has no partition? If the purpose is to provide unique identification of filesystems so that the striping and mounting mechanisms won't fail as new drives are added to the system -- then you need a partition ID -- and you don't care about disk ID's at all. Additionally you want enough information stored in that ID to minimize the chance of inadvertent duplication and collision (for cases when we move a drive from one system to another).
Finally your mounting/mapping utilities should be robust enough to allow you to mount any of these stripe segments and get what you can off of them.
This sounds robust. NOT! Just what I want -- double the failure points for every volume.
Regardless of the OS, whenever you stripe, you double the possibility of not being able to mount. Not mounting at all (or mounting read-only) when something goes wrong can not be a blamable decision ! (and in the case of striped sets, mounting r-o makes little sense, since all structures are dispatched on both disks)
I can certainly "blame" a company for any deficiency
that I perceive in their software. I select software to
meet *my* requirements. Therefore I am the ultimate judge
of what is a "deficiency."
My requirements for striping say that the loss of one segment or element in a striped set should not entail the loss of the data on the remaining segments. If no currently available striping system meets that requirement I'll avoid the use of the technology.
This means that a striping system should distribute "superblocks" and inode and directory entries in such a way as to keep them localized to the same segment as the data to which they apply (or duplicated on all segments).
(I realize that duplicating directory information on all segments may be costly -- and I understand that data files may cross multiple segments. Those are implementation details for the author(s) of the file system).
Out of curiosity: How many different striping systems have you used? The phrase "Regardless of the OS" seems awfully broad.
I will plead complete inexperience with them. My take on the term is that it refers to any technique of making multiple drives appear as a single file system (or volume) that doesn't involve redundancy (RAID) or duplication (mirroring/duplexing).
Is there a standard that specifies more implementation details? (i.e. does my set of requirement some how NOT qualify as a "striping" system).
Well, now that Microsoft has "spoken" we're probably all stuck with this [expletive omitted] forever. Please consider mailing a copy of your message and your patches to the LILO and fdisk maintainers.
The problem is : where are they (I tried to send it once, a few month ago, to an address which was given me as W. Almesberger's, but to no avail).
In my fdisk man page I see the following (under Authors):
A.V. Le Blanc. v1.0r: SCSI and extfs support added by Rik Faith. v1.1r: Bug fixes and enhancements by Rik Faith, with special thanks to Michael Bischoff. v1.3: Latest enhancements and bug fixes by A. V. Le Blanc, including the addition of the -s option. v2.0: Disks larger than 2GB are now fully supported, thanks to Remy Card's llseek support.
So it would seem that Rik Faith, Mr. Le Blanc, Michael Bischoff would be good choices.
The address I see for Werner Almesberger is: almesber@bernina.ethz.ch (from the lilo (8) man page).
If that gets no response than I'd post notes to comp.os.linux.development to see who is maintaining the code.
--Jim
ActiveX for Linux/Unix
From: Anders Karlsson andersk@lysator.liu.se
Hi, I read an article in the Linux Gazette where the author hadn't found any evidence for the rumors about ActiveX for Unix. By mistake I found a press release from M$ about this.
I believe what I said was that I had heard the same rumor
-- but that the search engine at www.microsoft.com couldn't
find any reference to Linux at all.
I don't know who (if any) is interested in this, but you can find it on:
http://www.microsoft.com/corpinfo/press/1997/mar97/unixpr.htm
Yes. I see. This basically says that the job was
farmed out to Software AG (http://www.sagus.com)
which has a release schedule at:
DCOM Availability Schedule http://www.sagus.com/Prod-i~1/Net-comp/dcom/dcom-avail.htm
Let's hope that this isn't the beginning of a new M$-invasion,
against a new platform or market, our Linux.
Luckily there's not much MS can do about Linux. They can't
"buy it out." -- They can pull various stupid stunts
(like tossing new values into partition tables, trashing
ext2 filesystems, even exerting pressure on hardware
manufacturers to develop and maintain proprietary adapters
that require Microsoft written drivers). These will just
make them less interoperable. IBM tried stunts like this
in the early days of the PC cloning.
However I think the cat is out of the bag. All we as a community have to do is clearly continue our own work. When you buy a new computer -- as for Linux pre-installed (even if you plan on re-installing it yourself). If you don't plan to use Windows '95 or NT on it -- demand that it not be included in the price of your system and -- failing that -- VOTE WITH YOUR FEET!
Recently I saw an ad on CNN for Gateway. The ad went on about all the options that were available and encouraged me to call for a custom configured system. Since I'm actually looking at getting a small system for my mother (no joke!) I called and asked if they could pre-install Linux.
Now I will hand it to the sales dude -- he didn't laugh and he didn't stutter. He either knew what I was talking about or covered up for it.
Naturally the answer was: "No. We can't do that."
There are places that can. Two that come to mind are:
(Warning for Lynx users -- both of these sites use frames and neither bothers to put real content in the "noframes" section -- Yech!)
There are several others -- just pick up any copy of Linux Journal to find them.
Granted this is a small niche now. However, it's so much more than any of us back in alt.os.linux (before the comp.os.linux.* hierarchy was established) thought was possible just four years ago.
Even two years ago the thought of buying a system and putting Linux on it -- to send to my MOTHER (literally, NO computer experience) would have been totally absurd. Now it's just a little bit of a challenge.
What's exciting to me is the prospect that Linux may make it mostly irrelevant what hardware platform you choose. Linux for the Alpha, for SPARC, and mkLinux for PowerMacs gives us back choices -- at prices we can dream of.
It's easy to forget about the hardware half of the "Wintel" cartel. However, the hardware platform has had severe design flaws from the beginning. Hopefully we'll see some real innovation in these new hardware platforms. [The introduction of the IBM PC back in '81 caused the "great CP/M shakeout." It also caused me to take a 5 year hiatus from the whole industry -- out of disgust with the poor design of the platform. Even as a high school student I saw these flaws]
-- Jim
Mounting Disks Under RedHat 4.0
From: Bruce W. Bigby bbigby@frontiernet.net
Jim Dennis wrote:
The really important question here is why you aren't asking the support team at RedHat (or at least posting to their "bugs@" address). This 'control-panel' is certainly specific to Red Hat's package.
Well, I've tried communicating with RedHat and had problems. I
registered and everything and tried to get support via e-mail.
Something went wrong, although I followed their instructions, for
reporting problems, exactly. At the time, I was at work when I read
your web page and decided to give you a try. Thanks for all of the
information!
I hope it helped. I too have been unsatisfied with Red
Hat's level of support. Not that I expect alot of
complex personal attention for a package that only costs
$50 -- but I was calling representing the US Postal Service's
Data Processing Center -- and I was willing to put up about
$50/hr for the support call(s).
Alas they just didn't have the infrastructure in place.
Yggdrasil has a 900 line for support -- and Adam Richter has
been doing Commercial Linux longer than just about anyone
else (SLS might have been there earlier -- but I haven't
heard anything about Soft Landing Systems in years).
Yggdrasil also publishes _The_Linux_Bible_ and has a video cassette tutorial on Linux. Unfortunately I haven't installed a copy of their distribution, Plug and Play Linux, for a couple of years. Slackware and later Red Hat seem to have won the popularity contest in recent years -- and
Unfortunately I've never used Yggdrasil's tech support services. So I can't give a personal recommendation. They do have two pricing plans ($2.95/min. US or $100 (US) for one "guaranteed" issue resolved) and they do mention that the support is available to Linux users regardless of what distribution you're using.
Usually I've managed to bang my head on problems hard enough and long enough that they crack before I do. So I haven't needed to call yet. One would hope that -- with my "reputation" as "The Answer Guy" -- I'd be able to stump them. However Adam Richter has been at this a lot longer than I have -- and was selling Linux distributions before I'd even heard of Linux -- when I was barely starting to play with a used copy of Coherent. So, maybe the next time I have a headache I'll give them a call. I think I'm still entitled to one freebie for that subscription to Plug & Play from a couple of years ago.
Meanwhile, if anyone else has used this service -- or has been using any other dial-in voice support service for Linux -- please let me know. I'll try to collate the opinions and post them in an upcoming issue of LG.
For details look at: http://www.yggdrasil.com/Support/tspolicy.html
[Note: I don't have any affiliation with Yggdrasil or any other Linux vendor -- though several of them are located within a few miles of my home and I do bump into principals for a couple of them at local users groups and "geek" parties]
Another company that offers Linux (and general Unix) support and consulting is Craftworks I've worked with a couple of their consultants before (when I was a full time sys admin and they were providing some on site expertise to handle some overflow). They don't mention their prices up front (which forces me to suspect that they are at least as expensive as I am). I'm also not sure if they are available for short term (1 and 2 hour) "quickshots."
I suppose I should also mention that I'm the proprietor of Starshine Technical Services. My niche is providing support and training for Linux and Unix system's administrators. I also offer off site support contracts (voice, and dial-up or via the Internet using ssh or STEL). Normally I don't "push" my services in my contributions to Linux Gazette -- I just do this to keep me on my toes.
-- Jim
PPP Problems
From: Chris Bradford reynard@gte.net
I have tried and failed to get a fully working ppp link up with GTE Internet Services. When I start pppd manually after dialing in using MiniCom, it'll start the link, and ifconfig shows that it's up and running. However, when I try to ping any site other than the peer, I get a 'Network Unreachable' error on every single packet that ping tries to send out. I'm using Slackware 3.2 w/ pppd v2.2f on a 486SX w/ 8MB of RAM and a 14.4K bps modem on /dev/cua3.
What's your advice to me?
What does your routing table look like?
(Use the command netstat -nr to see that).
Your ppp options file (usually /etc/ppp/options) should have a default route directive in it. That will set the ppp0 link as your default route.
That's usually what "network unreachable" means.
You'll also need to have a proper value in your /etc/resolv.conf. This is the file that your "resolver libraries" use to figure out what DNS server they should ask to translate host/domain names into IP addresses. Basically all applications that do any networking under Unix are linked with the resolver libraries.
-- Jim
Z Protocol
From: Gregor Gerstmann gerstman@tfh-berlin.de
Hi Mr. Jim Dennis,
Thanks for your e-mail remarks in reply to my remarks regarding file
transfer with the z protocol in Linux Gazette issue17, April 1997. In
the meantime I received an e-mail that may be interesting to you too:
Hello!
I noticed your article in the Linux Gazette about the sz command, and really don't think you need to split up your downloads into smaller chunks.
The sz command uses the ZMODEM protocol, which is built to handle transmission errors. If sz reports a CRC error or a bad packet, it does not mean that the file produced by the download will be tainted. sz automatically retransmits bad packets.
If you have an old serial UART chip ( 8250 ), then you might be getting intermittent serial errors. If the link is unreliable, then sz may spend most of its time tied up in retransmission loops.
In this case, you should use a ZMODEM window to force the sending end to expect an `OK' acknowledgement every few packets.
sz -w1024 Will specify a window of 1024 bytes.
I'm familiar with some of the tweaking that can be done -- and the fact that it is a "sliding window" protocol. However I still maintain that Kermit is more reliable and gets better overall throughput over an unreliable connection.
Also ZModem is designed for use on 8-bit serial lines. Kermit can be used easily over TCP connections and on 7-bit serial connections. You could definitely use the C-Kermit package from Columbia University however. The Kermit implementations from other sources are usually reliable enough -- but slower than molasses compared to the "real" thing.
Video Cards
From: Pedro Miguel Reis reis@aaubi.ubi.pt
Hi Jim. I have a simple question to you :) ! How can i put my video card to work under Linux ? Its an Intel Pro-share. I would like to save a jpg pic every 1 or two secs.
Thx for your time.
The Intel ProShare is a video conferencing system. These
are normally not called "video cards" in the context of
PC's because the phrase "video cards" is taken to refer to
one of the cards that drives your video display for normal
applications and OS operations (i.e. a VGA card).
There are several framegrabbers that are supported under Linux. However it doesn't appear that the Intel ProShare is supported under any for of Unix. Of course that's just based on a few searches of their web site -- so it's not from a very reliable source on the subject. (I swear, the bigger the company the worse the support information on their web site. You'd think they'd like to trim some of the costs of tech support that their always griping about).
Naturally you should contact their support department to verify this (or be pleasantly surprised by its refutation).
Here's a couple of links I found that are related to video capture using CU-SeeMe (a competing technology to Intel's ProShare):
Basically CU-SeeMe uses "off the shelf" video cams -- like the Connectix QCam (which goes for about $100 in most places). It also uses any of several sound boards.
Unfortunately the simple answer to your question may bd desktop camera.
-- Jim
Linux and Zip Drives
From: midian@home.ifx.net
Can you tell me if it is possible to set up a Linux system on a Zip disk and where I could find info on doing this? I found a file that
It should be possible. I don't know where you'd
find the info, though. I'd start by looking at the
Linux HOWTO's collection. There is a HOWTO on Zip
Drives with Linux (even the parallel port version
is supported).
I'd look at putting DOSLinux on an MS-DOS formatted (FAT) Zip disk. DOSLinux is a very small distribution (about 20Mb installed) which is designed to be installed on a DOS filesystem. It uses LOADLIN.EXE (which I've described in other "Answer Guy" articles) which basically loads a Linux kernel from a DOS prompt -- and kicks DOS out from under itself.
You can find that collection of HOWTO's at: http://sunsite.unc.edu/LDP/HOWTO/ (and various mirrors).
You can also find a copy of DOSLinux at 'sunsite' and most mirrors.
I use DOSLinux on my laptop (an OmniBook 600CT) and my only complaint has been that it wasn't configured to support the power management features of my laptop.
Frankly I'm not even sure if Linux' APM support will work with the Omnibook at all. I've heard that the PCMCIA adapter is basically too weird for them (which is a real bummer to me).
You have to watch out if you get a copy of DOSLinux. The maintainer, Kent Robotti, has been making frequent sometimes daily changes to it (or was a couple of months ago).
describes this process IF you have a pre-existing Linux system to install from. I am running a Win95 system with absolutely no hard drive space available. Thanks for any info.
Are you sure you can't even squeeze twenty or thirty meg? With that you can get DOSLinux installed on your normal hard drive -- which is likely to offer much more satisfactory performance. The ZIP drive is likely to be a bit too slow at loading programs, share libraries and DREADFUL if you do any swapping.
Of course if you boot Linux from a Zip disk (or using the "live filesystem" offered by some CD's) you can mount your DOS (Windows '95) partition(s) and create a swap file there.
Although most people use swap partitions -- Linux will allow you to create swap *files* (see the 'mkswap' and 'swapon(8)' man pages for details).
Note: since you don't have a copy already installed I realize that you don't have the man pages handy -- however you can read those man pages by looking at: http://www.linuxresources.com/man.html
The 'swapon(8)' refers to the man page that's in section 8 (system administration tools) of the system. That's necessary because there's also a man page in section 2 (system calls) which the man command will normally display in precedence to the one you want. So you use a command of the form 'man 8 swapon' to tell the manual system which one you mean. This is unnecessary with most commands since most of the ones you'd be looking for -- most of the time -- would be the "user commands" in section one. Also most of the administrative commands, like mkswap, don't have functions with a conflicting name. This is just one of those quirks of Unix that old hands never think of while it gets novices climbing the walls.
When you use the online man pages at ssc.com (the publisher of the Linux Journal and the Linux Gazette) the form is a little confusing. Just check the "radio button" for "( ) Search for a command" and put "8 swapon" (a digit eight, a space, and the word "swapon") in the text field (blank). Ignore the "Section Index" and the section selector list below that.
Lastly, I'd like to make a comment about running Linux with "absolutely no disk space"
DON'T!
With hard disks as cheap as they are now it doesn't make any sense to try to learn an advanced operating system like Linux without plenty of disk space. Buy a whole hard disk and add it to your system. If you already have two IDE drives -- see if your controller will support four. Most EIDE controllers have two IDE channels -- which allow two IDE drives each on them. If you have a SCSI controller than it seems *very* unlikely that you'd have the whole chain full.
(My old 386 has an old Adaptec 1542C controller on it -- with three hard disks, a magneto optical, a DAT autochanger tape drive, a CD drive and a CD writer. That's full! But, while other people have been buying 486's, then DX2's, then Pentiums, and upgrading their copies of Windows and Office -- I've been filling out my SCSI chain -- so that's a five year accumulation of toys!)
If you really can't afford $200 on a new hard drive -- ask around. You might find a friend with a couple of "small" (200 Mb) drives around that they can't use. I have a couple myself (spare parts drawer).
If you try to run Linux with no disk space you probably won't be satisfied. You can install a base system (no X Windows, no emacs, no kernel sources, no dev. tools, no TeX) in a very limited disk space. That's fine if you know exactly what the system is going to be used for. It's perfect for routers, gateways, and terminal servers -- and I see people putting together a variety of custom "distributions" for these sorts of dedicated tasks. I've even heard that some X Terminals (diskless workstations) use Linux with etherboot patches. In ;login (the magazine for members of USENIX/SAGE -- professional associations of Unix users and Sys Admin's) someone described their use of Linux as a method for distributing software updates to their Win '95 boxes across their networks. Apparently they could squeeze just enough onto a Linux boot floppy to do the trick.
However, I'm guessing that your intent is to learn a new OS. For that you want a more complete installation -- so you can play with things.
-- Jim
Red Hat CD Problem
From: Vivek Mukherji vivekmu@del2.vsnl.net.in
I bought a book on linux titled "Using Linux,Third Edition by Que Inc." It had Redhat CDROM with it, but when i tried to install it, it did not recognize the REDHAT CD though it previously made the boot disk and supp disk from the CD. It gave the following error after asking me for source of media i.e. from which drive or local CDROM or FTP or NFS I am going to install it.The error message was: "That CDROM device does not seem to contain Redhat CD in it "
There seems to be no damage on the CD i.e. no physical damage.I think there must be some other way to install it after all i have paid US$ 60 Dollars for that book. please reply me soon.
yours truly
Vivek Mukherji
When you select "CD-ROM" as your installation medium --
what interface are you having the setup program attempt
to use?
When you use the CD to create your boot and supplemental diskettes you are presumably using DOS -- which has its own drivers to access the CD.
There are many sorts of CD-ROM drives:
CD-ROM and tape drive support came a few years after the IDE interface became popular for hard drives. ATAPI is an ad hoc standard between those interfaces and these other types of drives. It is an "applications programming interface" to which the drivers must be written. Typically all support for ATAPI CD-ROM and tape drives must be done in software.
EIDE is a set of enhancements to the IDE spec. The most notable enhancement is the ability to support drives larger than 528Mb (which was the old BIOS limit of 1024 cylinders by 63 sectors by 16 heads). This is usually done via extended ROM's on the controller, or enhanced BIOS ROM's on the motherboard -- or possibly via software drivers (which are OS specific, naturally).
In addition to those to types of CD-ROM drive there are a variety of proprietary interfaces such as the Mitsumi (very popular for a while -- as it was the cheapest for a while), Sony, Wearnes/Aztech, and others.
Linux supports a very wide variety of these interfaces. However -- it's vital to know what you have. You also might need to know "where" it is. That is to say you might need to know I/O port addresses, IRQ's, DMA settings or parameters. You might also need to pass these parameters along to the kernel as it boots.
Another issue is the version of your distribution. Most books are printed in large batches -- so they have a long "shelf life." Most Linux distributions change a couple of times a year. Red Hat, in particular, seems to be putting out a new version every 2 or 3 months. Most of these include significant improvements.
So your money is probably much better spent on the distribution itself rather than trying to get a "bargain" in a book and CD combination. Specifically I recommend buying any book solely on it's merits. I don't approve of CD's full of software included with a book unless the software has been stable for some time.
CD's with sample code, HTML and searchable text copies of the books contents, clip art or fonts related to the book, even large bookmark files of related web sites, custom software by the authors -- those are all excellent ideas; otherwise it's shovelware that adds a buck to the production costs (fifty cents for the CD and another fifty cents for the little glue-on vinyl holder and the additional handling) -- and twenty bucks to the price.
So, another thing to try is a copy of the latest Red Hat (4.2) or Debian or whatever. In any event you really need to know the precise hardware and settings for your machine.
-- Jim
Cookies
From: Michael Sokolow mxs46@po.cwru.edu
Dear Ladies and Gentlemen,
Given the previous discussion about cookies, could someone explain to me
(or point out a topic in help, URL, etc.) just what ARE cookies?
Search the Netscape web site.
Here's an independent answer courtesy of "The Answer Guy" (Linux Gazette's nickname for me):
In programming terminology -- specifically in discussions of networking protocols (such as HTTP and X Windows) a "cookie" is an arbitrary data token issued by a server to a client for purposes of maintaining state or providing identification.
Specifically "Netscape HTTP Cookies" are an extension to the HTTP protocol (implemented by Netscape and proposed to the IETF and the W3 Consortium for incorporation into the related standards specifications).
HTTP is a "stateless" and protocol. When your browser initiates a connection and requests a document, binary or header the server has no way of distinguishing your request from any other request from your host (it doesn't know if you're coming from a single-user workstation, or a multi-user Unix (or VMS, MVS, MPE, or whatever) host -- or the IP address that it sees as the source for this request is some sort of proxy host or gateway (such as those run by CompuServe and AOL).
Netscape cookies are an attempt to add and maintain state between your browser and one or more servers. Basically on your initial connection to a "cookie generating" site your browser is asked for a relevant cookie -- since this is your initial connection there isn't one -- so the server prefers one to your browser (which will accept it unless it's not capable of them, or some option has been enabled to prevent it or prompt you or something like that). From then on all other parts of that site (and possibly other hosts in that domain) can request your cookie and the site's administrators can sort of track your access and progress through the site.
The main advantage to the site is for gathering marketing statistics. They can track which versions of a web page lead to increased traffic to linked pages and they can get some idea how many new and repeat visits they're getting. (Like most marketing efforts at statistics there are major flaws with the model -- but the results are valid enough for marketdroids).
There are several disadvantages -- including significant privacy concerns. There are several tools available to limit the retention and use of cookies by your browser (even if you're using Netscape Navigator). PGP Inc (the cryptography company) has a link on their site to one called "cookie cutter" (or something like that).
About the only advantage to some users is that some sites *might* use cookies to help you skip parts of the site that you've already seen or *might* allow you to avoid filling in forms that you've already filled out.
Personally I think cookies are a poorly chosen way to do this -- client-side certificates (a feature of SSL v. 3.x) is a much cleaner method (it allows the user to get an maintain cryptographically strong "certificates" which can be presented to specific servers on demand -- this exchange of certificates involves cryptographic authentication in both directions -- so your browser knows it isn't authenticating to some bogus imposter of a server -- and the server knows that your certificate isn't forged.
SSL client certificates allow you to establish accounts at a web site and securely interact with that site. Cookies can't do that. In addition many people have a vague notion that "cookies" where "snuck in" under them -- so they have a well-deserved "bad press."
-- Jim
New Hard Disc
From: A Stephen Morse morse@sysc.eng.yale.edu
Dear Mr Dennis:
I currently own an IBM 560 with a one gig hard disc which
has both a win95 partition and a 200m Linux partition
running version 2.0. We plan to upgrade today to a 2gig
Is this one of their "ThinkPad" laptops?
hard disk which accepts its data from the old disc through
the PCMICA ports using a special piece of hardware. I believe the
drive is called Extreme Drive. We also have available versions 4.1 and 4.2
of Linux on floppies (by the way 2.0 = 4.0 above). So far we've not been
able to get any advice on how to proceed.
"...using a special piece of hardware."
I love that term "special." Sometimes you have to
say it with the right inflection
Any suggestions. We are not super strong with Linux etc.
I think the question is:
How do I backup my current drive and restore it to the new drive?
(with the implication that you'd like to use this "special" device and just "copy" everything across).
There are several ways of backing up and restoring a Linux system. If you have an Ethernet connection to a system with lots of disk space -- or to a system with a tape drive you can do interesting things of the form:
dump -0f - | rsh $othersystem "dd of=$path_or_device ..."
If you can borrow or purchase a PCMCIA SCSI controller that Linux supports on this system you can hook up an external hard drive or tape unit and use that.
Those are the most straightforward methods for getting *everything* across.
Another approach is to identify just your data (maybe you keep it all under your /home/ and /usr/local/ directory trees -- or maybe you *should*). Now you get your new disk, install it, get some upgrade of your favorite Linux distribution (I hear the new Debian 1.3 is pretty good), install and configure that and -- finally -- just restore the selected portions of your data that you want.
If you're concerned about the potential loss of data or down time from any of these methods you might also consider renting a system (desktop or laptop) for a week to use while you're straightening things out on your main system. This is advice to consider any time you're doing a major hardware upgrade to an "important" system.
Interesting question!
Do any of the computer rental services offer Linux systems?
(PCR, Bit-by-Bit -- who else is in that business?)
-- Jim
Random Crashes
From: sloth lsoth7@hotmail.com
hi. whenever i try to install linux (so far i have tried redhat, Slackware and Debian) the install program crashes at random times. I have tried removing all unnecessary hardware, ie sound cards etc, but it doesn't seem to make a difference. I have a Intel p150mhz, triton VX main board, s3virge graphics card, 16mb ram and a 2.0gb quantum harddisk. Any help would be MUCH appreciated! cheers, sloth...
Have you had your memory thoroughly tested?
I would take out your memory (presumably they're SIMM's) and bring them into to a good repair shop for testing. I DON'T recommend software diagnostics for this (like AMIDIAGS, Norton's NDIAGS, "System Sleuth" etc).
Do you run any other 32-bit software on this system? (Win '95 and Windows 3.x don't count)
Can you install and run NT, Netware, or FreeBSD?
I've seen motherboards that just wouldn't handle any true 32-bit OS for sustained use (presumably buggy chipsets) -- that's why Novell and Microsoft have these "compatibility" lists of motherboards.
Have you tried taking out the fancy video card and putting in a simple VGA (no frills -- Paradise chipset)?
Most of the Linux install scripts and programs (different for each distribution) just use text mode. Therefore it's very unlikely that the video card *type* is a problem. However if your particular card has a defect it could be something that only affects your system under Linux or some other OS'. It's a long shot, and some EE (electronics engineer) might tell me it's impossible -- but I'd try it anyway.
(I keep a couple of spare old VGA cards and even an old Hercules -- monochrome graphics -- card around for just these sorts of testing).
What sort of hard disk controller are you using? (IDE? SCSI?)
Some IDE controllers have buggy chipsets (some of them are even supported by compile time options in the Linux kernel). However, IDE controllers are cheap -- so keeping an extra around for testing is a very small investment.
SCSI host adapters are somewhat touchier and more expensive. Some of them are nominally supported by Linux (and other OS') but aren't worth keeping in your system. For example the Adaptec 1542B was a piece of junk. At the same time I use Adaptec 1542C and 1542CF and the various 2940's without hesitation.
RAM is the most likely culprit. The motherboard chipset is another possibility. A defective video card or a buggy HD controller are next in line.
It's possible that you're system has some sort of bizarre "top memory" which requires an address range exclusion or that you need to "reserve" some I/O ports so Linux won't use them or probe into them for hardware. You could spend a career trying different "stripped down" kernels on boot floppies and learning all the idiosyncrasies of your hardware. However -- it's probably more profitable in the long run to replace any hardware that's causing trouble.
The advantage of PC hardware is that it's cheap and widely available. It's curse is that it's often *cheap* and the specs are *widely* interpreted. Now that Linux is becoming available on some other hardware platforms -- and especially now that we're seeing "clones" of SPARC, Alpha, and PowerPC systems for rates that some of us can afford -- we might see some advantages from stepping away from the hardware half of the WIntel cartel.
-- Jim
gcc and Slackware Question
From: Steven Smith ischis@evergreen.com
GNU's gcc is part of the slackware package that I have loaded on my system. I can and have compiled and linked C code.
I can compile the standard C++ code below (if I haven't miss entered the code but for some reason the C++ libraries will not link correctly (ie. i get and error):
#includ <iostream.h>
I think you mean
#include ...
main()
{
cout << "hello world\n";
}
Poor form. Unix programs should be
int main ( int argc, char * argv[] )
... or at least:
void main () ...
----------------
gcc -c program_name.C <- no errors
gcc program_name.C <- errors
Do you know what might be missing?
Your error messages.
Here's a way to capture sessions when you're trying to write messages to the Linux User's Support Team , to me or to the Linux Programmer's Mailing List ,or any of the appropriate news groups:
Get to a shell prompt. Issue the command: script ~/problem.log Run your test (demonstration of the problem). Back at the shell prompt, type Ctrl-D or issue the exit command. Edit the ~/problem.log file (take all the weird escape sequences out).
An easier way is to use emacs' "shell-mode" -- just start emacs and use the M-x shell-mode command. This creates a shell buffer (a sub task in emacs) which allows you to run tty style programs (no full screen "curses" stuff). The output from these shell commands will appear in this buffer and you can use normal emacs cursor, scrolling, cut, and paste operations to work with that output. For example I pasted your program into a new buffer, saved it, "fixed" a couple of minor things, switched to my shell mode buffer (I usually keep one handy) and ran the following sequence:
[jimd@antares lgaz]$ ls
hello.C
[jimd@antares lgaz]$ cat hello.C
#include <iostream.h>
int main( int argc, char * argv[] ) {
cout << "hello world\n";
return(0);
}
[jimd@antares lgaz]$ make hello
g++ hello.C -o hello
[jimd@antares lgaz]$ ./hello
hello world
[jimd@antares lgaz]$
... which I then simply pasted into this buffer.
Note that I use the make command here. A nice feature of 'make' (at least the GNU make) is that it can make some guess about what you mean even if you don't supply it with a Makefile. So my command make hello forces make to look for a .c, .C or .cpp file to compile and link. If it sees a .o file it will try to link it with cc -- but for a C++ file you need to link it with g++.
A nice side effect of using make this way is that I don't have to specify the -o (output name) and I don't end up with a file named a.out. It "makes" a program named hello.
So the source of your problem is probably that you are compiling your program with gcc in a way that confuses it -- and tries to link it as a C program rather than a C++ program. If you call gcc under the link 'g++' (just another name for it) you'll see the whole think work. The compiler pays attention to how you called it (the value of its argv[0]) and makes assumptions based on that.
Of course I can't verify that the errors I got were the same as the ones that you see -- since you didn't capture them into your message. In any event using make hello works -- using g++ hello.C works -- using gcc hello.C doesn't link properly and complains about unreferenced stuff and using gcc or g++ with the -c gives me an object file (hello.o) which is, for our purposes, useless.
A better venue to ask questions about compiling under Linux might be the Linux programmers list (as I mentioned earlier) or in any of several comp.lang.c and comp.lang.c++ newsgroups (since there is nothing Linux specific about this).
If you consider it a bug that gcc recognizes the capital C for C++ when generating .o files and doesn't automagically link with the appropriate libraries in the next pass -- take it up with the participants of the gnu.gcc.* or the gnu.g++.* newsgroups. (There's probably a very good reason for this behaviour -- though I confess that I don't see it).
-- Jim
LILO
To: Toby Riley toby@handc.btinternet
James,
I have been reading your page with great interest but I can't find
anything about removing LILO and restoring My MBR. Unfortunately I have
to de-install Linux for a while. I have tried running lilo -u and lilo
-U and when the PC reboots I just get LI and the system hangs.
Personally I've never heard of a -u switch to lilo.
Normally you have to replace your lilo MBR with some other valid MBR. Most people who are disabling Linux on a system are restoring access to an existing set of DOS partitions -- so using the DOS MBR is in order.
To do that -- boot from a DOS floppy -- and run FDISK /MBR This should exit silently (no error and no report of success). The /MBR switch was added, undocumented, to version 5.0 of MS-DOS. It won't work with previous versions.
I can boot Linux off a floppy and the re-run LILO which adds my boot
options and restore my system to a usable state. But I can't get rid of
it and restore the Win95 boot up.
Under the hood Win '95 is MS-DOS 7.0 -- just run FDISK /MBR.
We eagerly await your return to the land of Linux.
-- Jim
Printing Problems
From: RHS Linux User 6ng1@qlink.queensu.ca
hello answer guy!
Problem: Printing text / postscript documents.
Printing graphics (using xv) works fine, after having my printcap file set up for me, using apsfilter. I own a kyocera f-3010 and this printer can emulate an HP LaserJet Ser II. However, printing documents is a completely different story. Trying to print from, say, Netscape or LyX gets a printout of two or three "step ladder" lines, the output usually being something like "/invalid font in findfont . cannot find font Roman ... etc". Looks like it is not finding the appropriate ghostscript fonts. Is there any way to ensure that ghostscript can recognize my fonts (using xfontsel shows all my installed fonts)? Would you know how to rectify this problem?
Like X Windows, printing is a great mystery to me.
I managed to get mine working -- including TeX with
dvips (on my DeskJet 500C) -- but I still don't know
quite how.
xv works and Netscape and LyX don't. Can you print a .dvi file using dvips? Can you print a Postscript file using lpr? How about mpage? Does that work?
The stairstep effect is common when raw Unix text is going to a printer that's expecting MS-DOS CRLF's (carriage return, linefeed pairs). That makes it sound as though the other applications are bypassing the filter in your /etc/printcap file (or that xv is somehow invoking the write filter before passing the directly to the printer).
Thanks a million for your help, this is something that has been
bothering me for a while now.
Yeah. I let printing bother me for about a year before
I finally forced it to print something other than raw
(MS-DOS style) text.
You have gone through the Printing-HOWTO's haven't you?
-- Jim
Linux Disk Support
From: Andrew Ng lulu@asiaonline.net
Dear Sir,
I have a question to ask: Does Linux support disks with density
2048bytes/sector?
Linux currently doesn't support normal disk with large
block sizes. (CD-ROM's have large block sizes -- but this
is a special case in the code).
It is likely that support for larger block sizes will eventually be added to the kernel -- but I don't think it will be in before 2.2 (not that I actually have an inside track on if or when anything is going to happen in kernel development land -- that's just my guess).
I have bought a Fujitsu MO drive which support up to 640MB MO disks with
density 2048bytes/sector. The Slackware Linux system does not support
access to disks with this density. Windows 95 and NT support this density
and work very well. Is there any version of Linux which support
2048bytes/sector? If not, is there any project working on that?
Someone from Fujitsu's support team called me back on this
(as I'd copied an earlier message to their webmaster).
The report was that the smaller 540Mb MO media are supported with no problem -- but that the high density media with the large block sizes weren't supported. If I recall correctly he said that this doesn't work for any of the other versions of Unix that Fujitsu knows of (with their drive).
-- Jim
Renaming Problems
From: Sean McCleary sean@cdsnet.net
Anyhow, here's my problem:
I recently renamed my system in my /etc/HOSTNAME file. Ever since I
made that change, my system's telnet daemon has stopped allowing incoming
connects from ANYWHERE. I was told this has to do with my recent
system-renaming, but the man who I was talking to about it never told me
WHY or how to fix it.
I've checked my /etc/hosts.allow and /etc/hosts.deny.
These two files control the behavior of tcpd (the TCP Wrappers program by Wietse Venema).
You might also want to look at your /etc/hosts file. This file is used by most system resolver libraries in preference to DNS.
The resolver libraries are the code that allows client programs on your system to translate domain/host names into IP addresses. There are several schemes for doing this -- which can be set in different priorities for each host.
The oldest method for performing this resolution was a simple lookup in the local /etc/hosts file (there was also an /etc/networks file back then -- you don't see them very often now). This is still common for small networks (less than about 25 systems).
The most widely used method is DNS (also know as BIND -- Berkeley Internet Naming Daemon -- a.k.a. 'named'). Actually DNS is the protocol and BIND is the commonly available server software.
Another fairly widespread naming service is NIS and its causing NIS+. These were both created by Sun Microsystems and published as open specifications. This system was originally known as "Yellow Pages" -- and many of the commands for managing the service still have the prefix "yp" (i.e. 'ypcat'). However a company (British Telecom if I recall correctly) objected to the trademark infringement and Sun was forced to change the designation.
NIS and NIS+ are designed to distribute more than host and network name resolutions -- they are primarily used to manage accounts across whole domains (networks) of hosts. This is especially important among systems that are using NFS since that usually requires that you maintain synchronized UID across the enterprise. (The normal NFS behavior is to grant file access based on the effective UID of the user on the client system -- this can be overwritten in a cumbersome fashion -- but most sites simply synchronize the UID's -- usually via NIS or by using rdist and distributing whole /etc/passwd files).
Under Linux there is a file named /etc/host.conf (note: SINGULAR "host"). This sets the priorities of the resolver libraries -- which is typically something like:
order files bind nisplus nis multi on(look in the /etc/hosts and /etc/networks first -- then try DNS -- then NIS+ and finally NIS -- try multiple resolutions).
Why is this happening, Answer Man?
I don't know. Did you look at a tail /var/log/messages
for clues? Are you sure that this is a problem with
your host's name? Did you change to shadow passwords
around the same time?
One way to get more clues about any failure you get from any service in the inetd.conf file is to replace the service's entry temporarily with a command like:
## telnet stream tcp nowait root /usr/sbin/tcpd in.telnetd telnet stream tcp nowait root /usr/sbin/tcpd /usr/sbin/strace \ -o /root/tmp/telnet.strace /usr/sbin/in.telnetdHere I've commented out the old telnetd line and put in one that keeps a system call trace file. Looking at this file can give some clues about what the program was trying to do up until it disconnected you.
I'll grant that you need to know something about programming to make any use of this file. However you probably don't need to know as much as you'd think. That start to make a little sense after you run a few dozen of them -- particularly if you have a "working" and a "broken" configuration to run your tests with.
-- Jim
X Locks Monitor
From: Jon Jacob xaviermoon@earthlink.net
I am trying to configure X. I have a Config file set to the SVGA generic using the XF86Config.eg file that comes with the Slackware96 distribution.
I have a Sony Multiscan15sf with a ATI mach64 PCI video care with 1 meg of VRAM. When I run startx, the monitor locks so that it turns to black but it still is getting a signal from the PC because the PowerSaving light stays green.
I tried fiddling with the Config file with no change. I ran the startx to redirect to an out file to see the error message, but I just get the same file I got when I ran x -probeonly.
I could not find a drive for an ATI Mach64 PCI card that matches mine. Do I need one? If so, where would I get it? Can I use some generic driver?
Also, Ramdoc was shown by the probe to be "unknown" so I left it commented out in the Config file. Could this be the problem?
I am very frustrate after hours and hours of attempts. Please help!
I keep trying to tell people: I barely use X. X Windows
configuration is still a mysterious "black art" to me that
requires that I have the system in front of me to do my
hand waving in person.
I think you should search the X Windows HOWTO file for the strings "ATI" an "Mach." I'm pretty sure you need a special server for the Mach 64's and I wouldn't be at all surprised if it was one of those deviants that doesn't work with a generic SVGA driver.
The first time I ever got X running I resorted to IRC (Internet Relay Chat) -- where I joined the #Linux channel and hung out for awhile. After watching the usual banter for about 20 minutes and adding a few (hopefully intelligent) comments to the discussions at hand I timidly asked for some help. Some kind soul (I don't remember the nickname) asked for some info -- show me how to do a /dcc (direction communications connection?) to send the file to him -- edited my XConfig file and sent it back.
One of the beauties of Linux is that I was able to test a couple of revisions of this file while maintaining my connection. Naturally, I glanced over the file before using it. If you decide to take this approach I recommend that you avoid any binaries or source code that you don't understand that someone offers to xfer to you. You will be running this as 'root' on your system.
A config file with which you are moderately familiar is a bit safer -- though you could always end up with some weird trojan in that, too.
This is not to suggest that IRC has a higher percentage of crackers and "black hats" than anywhere else on the net -- just trying to emphasize that you have no way of identifying who you were working with -- and all it takes is one.
Another approach you might try is to call ATI and let them know what you want. As more of us use Linux and demand support for it the various hardware companies will have their choices -- meet market demands or lose marketshare.
If you decide to take this to the news groups be sure to go for comp.os.linux.x -- rather than one of the more general newsgroups. It is a little frustrating that so many X questions end up in the various other Linux news groups -- X Windows for Linux is no different than X Windows for any other x86 Unix. However I've never seen an XFree86 newsgroup so...
-- Jim
Using JDK 1.1 for Solarix x86 on Linux
From: Romeo Chua rchau@st.nepean.uws.edu.au
Hi! I would like to know if I can use the JDK 1.1.2 for Solaris x86 on Linux. Does the iBCS2 module support Solaris x86 applications?
Last I heard a native JDK was already available for Linux
(although that might be 1.1.1).
I have no idea whether SunSoft has maintained any compliance to iBCS in the Java stuff for Solaris.
-- Jim
Colormap Question
From: Kevin T. Nemec knemec@mines.edu
Dear Answer Guy,
I was wondering if it is possible to force a program to use its own
colormap externally. That is, can you force a program without a built in
option to use its own colormap to do so in some other way. I don't mind
the "flashing" in some applications as long as I can see all the colors.
Kevin Nemec
I've heard that xnest can be used to run one X session inside
of another. I don't know if this would help. I've used
XFree86's support for multiple virtual consoles to run two
X Windows sessions concurrently (using {Ctrl}+{Alt}+{Fx} to
switch between them, of course). These can be run with different
settings (such as 8bpp on one session and 16pbb on the other.
Other than that I have no idea. I keep trying to tell people I'm a *Linux* guy -- NOT an XFree86 guy. I run X Windows to do the occasional XPaint or XFig drawing, to run Netscape on sites that are just too ugly to tolerate in Lynx, and (recently) to play with xdvi and ghostview (to preview my TeX and PostScript pages).
So, anyone out there that would like an XFree86 Answers Column in Linux Gazette (or anywhere else preferably under LDP GPL) has my utmost support. (Although our esteemed editor, Marjorie Richardson will certainly make the decisions).
-- Jim
More on LILO
From: Paul L Daniels jdaniels@stocks.co.za
With respect to a question that was in "The Answers Guy" re LILO only presenting "LI" on the screen then _hanging_.
I found that problem too... the problem (at least for me) was that I was including a DOS partition in the LILO.conf file. After removing the partition manually, running liloconfig and reinstalling from current lilo image, everything worked.
If you were including a DOS partition in your lilo.conf
file with some syntactic errors (making it look like a
Linux partition perhaps) or if your previous edit of the
file had not be followed by run /sbin/lilo (the "compiler"
for the /etc/lilo.conf file) -- I would expect you to have
problems.
However it is quite common to include one or several DOS partitions in a lilo.conf file. That is the major purpose of the LILO package -- to provide multiple boot capabilities.
If this is all babble and drivel, then ignore it, I wasn't sure who to
post to.
I suspect that there was something else involved in the
"stanza" (clause, group of lines) that you removed from
your conf file. Since you've solved the problem it
sounds like little would be gained from attempts to
recreate it -- or to guess at what that had been.
-- Jim
95 GUI
From: Sean sdonovan@hq.si.net
Sorry if I am one of hundreds w/ this kinda question./....but try to answer if you have time..
So I had linux loaded up and working fine was even able to make my dos/95 partition work ok too. So then I actually loaded the 95 gui {it had just been a sys c: to get a bootable dos/95 since I didn't have the 95 files for the gui at the time}
So now all I can get is 95...I tried the primitive fdisk thing thats part of the do you want to install linux again deal w/ the two disks also tried making different partitions active w/ fdisk as well...but no workie workie. I can boot w/ the two disks that are part of the linux install use the rescue option and then mount the hd linux partition to a directory of my choice and if I try to run lilo from their {since its not in /sbin/lilo on the floppies} it moans about lilo.conf not around and /boot/boot.b not present and such sooo I try to recreate that structure on the root {ramdisk:?} or floppy or whatever I am running everything from...run out of diskspace trying to copy hda files from now mounted hd to /dev of ram/floppy. So I'm stuck...Any ideas? I have read all relevant faq's/scanned every apparently related how-to's etc... to no avail...maybe its like you said on your page; maybe I'm not really running a "boot" floppy... help if ya can, My lilo.conf was reliably letting me into command line dos/95 and linux/xwindows etc.. system is an IBM thinkpad 760el if that's relevant.
The short story is that you don't know how to run
/sbin/lilo.conf from a boot floppy (rescue situation).
There are two methods. One is to use the chroot command:
Basically after you boot you mount your root file system (and your usr if you have that separate) -- something like so:
mount /dev/sda5 /mnt/ mount /dev/sdb1 /mnt/usr
(Here I'm using the example of an extended partition on the first SCSI drive for my normal root partition and the first partition on my second SCSI drive as my usual usr partition -- change those as necessary).
You can (naturally) create a different directory other than /mnt/ or under /mnt and mount your filesystem under that.
Now you cd to that:
cd /mnt/And run the chroot command -- which takes two parameters: where to make the new root of your session's filesystem and what program to run in that "jail"
chroot /mnt/ /mnt/bin/bash
Here we're running the copy of bash that's under our chroot environment. Thus this session, and all processes started by it now see /mnt as /.
This was the original use of the chroot call -- to allow one to work with a subset of your filesystem *as though* it were the whole thing (handy for developers and doing certain types of testing and debugging -- without risking changes to the whole system).
Now should be able to vi /etc/lilo.conf and run /sbin/lilo to "compile" that into a proper boot block and set of mappings. (note the "/etc/" and "/sbin/" will be really /mnt/etc and /mnt/sbin -- to the system and to any other processes -- but they will *look like* /etc/ and /sbin/ to you).
The other approach is to create a proper (though temporary) lilo.conf (any path to it is fine) and edit in the paths that apply to your boot context. Then you run /sbin/lilo with the -C file to point it at a non-default lilo.conf (which can be named anything you like at that point.
The trick here is to edit the paths in properly. Here's the lilo.conf for my system (antares.starshine.org):
boot=/dev/hda map=/boot/map install=/boot/boot.b prompt timeout=50 other=/dev/hda1 label=dos table=/dev/hda image=/vmlinuz label=linux root=/dev/sda5 read-only
Here's how I have to edit it to run lilo -C when I'm booted from floppy and have mounted my root and usr as I described above (on /mnt and /mnt/usr respectively):
boot=/dev/hda map=/mnt/boot/map # current (emerg) path to map install=/mnt/boot/boot.b # current (emerg) path to /boot prompt timeout=50 other=/dev/hda1 label=dos table=/dev/hda image=/mnt/vmlinuz # path to my kernel label=linux root=/dev/sda5 read-only
Note that I've added comments to the end of each line that I changed. (I think I got them all write -- I don't feel like rebooting to test this for you). The specifics aren't as important as the idea:
The lilo program (/sbin/lilo) "compiles" a boot block from information in a configuration file -- which defaults to /etc/lilo.conf.
References to directories and file in the .conf file must be relative to the situation *when the /sbin/lilo is run*. References to devices and partitions typically don't change in this situation.
I hope that helps. It is admittedly one of the most confusing aspect of Linux to Unix newbies and professionals alike. In some ways I prefer FreeBSD's boot loader (the interactive and visual debug modes are neat -- you can disable various drivers and view/tweak various kernel settings during the boot). In other ways I prefer LOADLIN (which can load Linux or FreeBSD kernels from a DOS command prompt or from a DOS CONFIG.SYS file). In yet other ways I like the OpenBoot (forth interpreter and system debugger) used by SPARC's.
I would like to see PC's move to the OpenBoot standard -- it's SUPPOSED to be part of the PCI spec. Basically this works by replace the processor specific machine code instructions in device ROM's (for video cards and other adapters) with FCode (byte compiled forth). The system (mother) board then only has to implement a forth interpreter (between 8 and 32K of footprint -- much smaller than existing BIOS chips).
The advantage is that it allows your adapters to be used on systems regardless of the processor. Forth is a very efficient language -- as close to machine language as an interpreter can get -- and closer than many assemblers (some of which generate stray code).
Too bad there are no PC manufacturers who understand this YET!
Letter of Thanks
From: Sean sdonovan@hq.si.net
Thank you from the bottom of my heart for your informative and very useful email. It took about 50 seconds using the chroot command {see I learned something new today :-) } I am back up...worked like a charm... I'll try not to bother you in the future but if I ever need to blow the horn at time of utmost need... It's pretty cool when stuff works, what is frustrating as heck is when you can't find the answers, I really did try reading the faq's/how to's and so on... You are right about the email coherency, need to work on that, guess I figured to a hack like yourself it would make sense {all the stuff that I had tried} and I wasn't sure you would actually write back.}
I'm doing this from minicom so everything workie workie :-)
When you have time; why did another friend {not in your league
apparently} suggest:
linux root=/dev/hda2 ro
thanks again,
From: John Messina John.Messina@astramerck.com
My dad just gave me his old 386 machine. It's not much, but I wanted
to start experimenting with it and to try to use it as a firewall.
I upgraded it to 8MB of RAM and dropped in an ISA Ethernet card -
just the bare minimum. I'm attempting to install RedHat 4.1 onto this
machine. My main machine is already up and running with COL Standard
and since the 386 has no CD-ROM, I attempted to do an NFS install.
he NFS part of the install works perfectly (nameserver, exports,
etc. on my main machine is configured correctly and autoprobe can find
the 386's ethernet card). The problem occurs when the install starts
to look for the 386's SCSI card. The 386 has a Seagate ST01/02 SCSI
card with one hard drive attached. The ST01/02 is supported by the
install, but autoprobe cannot find the card and I've tried all of the
combinations for the parameters that are listed - checked the RedHat,
CND, and COL manuals. No IRQ/Base address combination that I've tried
works. I've looked at the board itself, but can't tell how it's set up.
I guess my question comes down to the following:
Is there a way during the install to find out what the IRQ/Base
address for this board is? Or, since the machine will successfully
boot to DOS/Win3.1, is there a way to determine these settings from
the DOS/Windows environment?
Another program that might list the information you're looking
for is Quarterdeck's "Manifest" which used to be included
with QEMM since about version 7 or 6 and with DESQview/386
(one of my all-time favorite DOS programs -- with features I
still miss in Linux!).
The system I'm typing this on is an old home built 386.
It is the main server for the house (the clients are Pentia
and 486's -- mostly laptops). So you don't have to "apologize"
about the age of your equipment. One of the real virtues of
Linux is that it breathes new life into old 386's that have been
abandoned by the major software vendors.
One approach to consider it to find a good SCSI card. I
realize that you'll spend more on that than you did on the
computer -- but it may be worth it nonetheless. Over the
years I've upgraded this system (antares) from 4Mb of RAM
to 32Mb and added:
Adaptec 1452C controller,
one internal 2Gb SCSI,
and a 538Mb internal,
a 300Mb magneto optical drive,
a 4mm DAT autochanger,
an 8x CDROM,
a Ricoh CD burner/recorder,
and an external 2Gb drive
(that fills out the SCSI chain --
with additional drives including a Zip
on the shelf)
upgraded the old 200Mb IDE hard drive to a pair of
400 Mb IDE's,
upgraded the I/O and IDE controller to one with
four serial ports (one modem, one mouse, two terminals --
one in the living room the other in the office),
and a 2Mb STB Nitro video card.
My point is that you can take some of the money you save
and invest in additional hardware. You just want to ensure
that the peripherals and expansions will be useful in your
future systems. (At this point memory is changing enough
that you don't want to invest much in RAM for your 386 --
you probably won't be able to use it in any future systems) --
bumping it up to 16Mb is probably a good idea -- more only if
it's offered to you for REAL cheap.
Other than than I'd do an Alta-Vista search (at Yahoo!)
for Seagate ST01/02 (ST01, ST02, ST0). My one experience
with the ST01 is that it was a very low quality SCSI card
and not suitable for serious use. I'd also search the
"forsale" newsgroups and ads for a used BusLogic (you might
find one for $10 to $25 bucks -- don't pay more than $50
for a used one -- low end new cards can be had for $60).
--
Jim
From: Vaughn (Manta Ray) Jardine vaughn@fm1.wow.net
I Use a multiconfig to boot either to Dos, Win95, or Linux (Redhat 4.1).
I use loadlin from the autoexec.bat to load the linux kernel, however I
recently accidently deleted the dir with loadlin and the vmlinuz.
Do I have to get the loadlin that came with redhat 4.1? What am I doing
wrong. It boots fine off the boot disk.
Vaughn
This file would be a "hidden + system" file in C:\REALBIOS.INT
The idea of this file is to allow LOADLIN to "unhook" all
of the software that's redirected BIOS interrupts (trap vectors
-- sort of like a table of pointers hardware event signal handlers)
to their own code. To do this you must have a map of where
each interrupt was pointed before any software hooked into it
(thus the boot disk). This boot disk doesn't boot any OS --
it just runs a very short block of code to capture the table
and save it to floppy -- and displays some instructions.
You may have to re-run REALBIOS.EXE (generate a new BIOS
map) any time you change your hardware. This is particularly
true when changing video cards or adding removing or changing
a SCSI adapter.
Obviously the version of LOADLIN that's used by Red Hat's
"turbo Linux" and by the CD based installed program of other
Linux distributions doesn't require this -- though I don't know
quite how they get around it.
So, try installing the rest of the LOADLIN package and running
REALBIOS.EXE. Then make sure you are booting into "safe"
DOS mode under Win '95. I'd also consider putting a block
(like a lilo.conf stanza) in your CONFIG.SYS which invokes
LOADLIN.EXE via your SHELL= directive. That block should have
any DEVICE= or INSTALL= directives except those that are needed
to see the device where your LOADLIN.EXE and kernel image file
are located. This should ensure that you aren't loading
conflicting drivers. There are details about this in the
LOADLIN documentation.
--
Jim
From: Ken Ken@KenAndTed.com
Hi... I'm having some trouble, and maybe you could help??
I recently went from kernel 2.0.27 to 2.0.3. Of course, =) I used Red Hat's
RPM system (I have PowerTools 4.1) and upgraded. After the config,
compile (zImage), and modules stuff, I changed LiLo's config, to have
old be my backed up kernel of 2.0.27, and linux be the new one. Then,
I did a zlilo, and everything ran smoothly.
I've tried recompiling and remaking lilo many times. (oh yeah... I didn't
forget dep or clean either) Nothing works. I'm using the extended 2
fs, and it's built right in the kernel...
If you do a 'diff' between /usr/src/linux/.config and
/usr/src/linux-2.0.27/.config what you you see?
Are you sure you need features from the 2.0.30 release?
You may want to stick with 2.0.29 until a 2.0.31 or 32
goes out. I know of at least one problem that's forced
my to revert for one of my customers*.
It has always been the case with Linux and with other
systems that you should avoid upgrading unless you know
exactly what problem you're trying to solve and have some
understanding of the risks your are taking. That's why it's
so important to make backups prior to upgrades and new software
installations. I will note that my experience with Linux
and FreeBSD has been vastly less traumatic in these regards than
the years of DOS and Windows experience I gained before I
taught myself Unix.
* (using the -r "redirect" switch of the ipfwadm command to
redirect activity on one socket to another works through
2.0.29 and dies in 2.0.30 -- and gets fixed again in a "pre31"
that one of my associates provided to me).
I suspect there's some difference between your kernel
configurations that's at fault here. Run diff on them
(the files are named .config in the toplevel source
directory). or pull up the 'make menuconfig' for each
and place them "side-by-side" (using X or on different
VC's).
Hint: You can edit /usr/src/linux/scripts/Menuconfig
and set the single_menu_mode=TRUE (read the comments in
the file) before you do your make menuconfig -- and you'll
save a lot of keystrokes.
Maybe you need one of those IDE chipset boxes checked.
In issue 18, I described how to avoid certain security risks when
removing files from your /tmp directory.
I have received some letters as feedback, and I'll summarize the
issues here.
Some people said they didn't need the extra security. Well, they're
free not to use my script.
Michael Veksler <mveksler@VNET.IBM.COM> told me he
was worried about the use of the access time to determine the file's
age. His main concern was that files could be ``accidently'' touched
by
As I said in my first article, it's a personal taste. I frequently
unpack archives in my /tmp hierarchy. And I want to be
certain the files will stay there until I don't need them anymore.
To me, 3 days after last looking at the file seems a reasonable
delay for that.
But recently, I started using afio for transporting files
that won't fit on one floppy. And afio Remembers the access
time during archiving, and also sets this date while unpacking. This
could limit the lifespan of my files if I don't look at them
immediately. (As a sidenote, zip also sets the access time.)
Obviously, there is one other possibility I neglected: using ctime
(inode change time). It is not possible to set this to an arbitrary
value, and it doesn't change as easily as the access time.
Perl has a rather large memory footprint, and is not available on
every site. Therefore, Francois Wautier <
suggested:
rm-static and find-static are statically compiled
versions of rm and find, respectively. The
-p flag ensures the resulting binary is owned by
root, closing one security risk. (A user might have created
her own /tmp/rm-static with the intend of changing the binary.)
This gives rise to a new set of race conditions, although they
aren't as easy to exploit as the
In general, I would advise against executing arbitrary files with
root permissions, especially if they are residing in a
publicly writeable directory (like /tmp). (It is also related
to the reason why `.' should never be in root's path.
This leads me to a real security risk:
(This one I found myself.)
I recently upgraded to perl 5.004. After the upgrade, I noticed my
cleantmp script started emitting warnings about not finding
the pwd program.
I looked into the perl module code, and it uses pwd to
determine the current directory.
The script itself doesn't have problems with the missing binary, as
I'm using absolute paths everywhere. But it opens a huge
security hole: An executable called pwd in the right place in
the /tmp tree can give a user a process executing with
root permissions.
In this case, the chroot decreases security,
instead of increasing it.
For this reason, I have decided to remove the chroot from
the script entirely. That way, I can be sure only trusted binaries are
executed.
In the first version of my script, I demonstrated how to exclude
some files from being deleted. I obviously forgot one thing: a user
could create files or directories with the same names, and they would
never be deleted.
The solution is easy: test the owner of the file, and if it isn't
root, just delete the file.
Here is a link to the new script.
Comments are welcome.
It started out pretty simple. I was on a my client's webserver,
simply paging through routine entries, when I came on the following
entries (IP addresses have been changed to protect the guilty):
Uh-oh. For a couple of minutes, someone was definitely rattling my
client's locks, looking for a way in. As a system administrator, what
do you do now?? How do you find out if the intruder managed to
actually get in? Did he *do* anything to your system? How do you
make sure he doesn't get back in?
In this article, I'll make a few suggestions about a few basic steps
that can be taken and some of the specialized tools that can help keep
your system secure.
The first thing you want to check for is the possibility that the
intruder is still logged on. A quick way to check this is 'w' or
'who' commands--look for someone logged from a remote machine. The
thing to remember about these commands is that they work by reading a
file ('utmp', typically found in /var/adm) that keeps track of who is
logged in. If the intruder has broken into the root account, then he
can change that file to make it look like he's not there.
Two good ways of finding such phantom users are to use the ps and
netstat programs. Since these query kernel data structures rather
than files, they are harder to spoof. Using ps, look for shells and
programs that aren't associated with a legitimate user. Netstat is a
lesser-used utility used to display the network status. If it is not
in the normal system directories, look in /sbin or /usr/sbin. By
default netstat displays active Internet connections. Again, look for
connections to suspicious sites.
In the worst case, the intruder is lurking around in your system. If
the intruder has managed to break into the root account, he will be
able to remove all your files with a quick rm -rf /. Fortunately,
such toe-to-toe combat with intruders is rare.
The best solution to an intruder on your system is to immediately
disconnect the Ethernet cable. Without giving him any warning, this
puts a stop to whatever he is doing and isolates your computer,
preventing further damage. Furthermore, it will appear to him that
the network has failed-- which is in fact what has happened.
Unfortunately, you (or no one you can contact) may not have physical
access to the machine when this happens. The second best thing to do
about an intruder involves a judgment call. You can A) let him alone
and hope he doesn't destroy the system and assess the damage later, B)
talk to him using 'talk' or C) kick him off and hope he can't get back
in.
If you decide to kick him off, you of course need to be root. Simply
rebooting the system isn't a good idea, since the system will come
back up and the intruder will probably be able to re-enter and will
know that someone is onto him. The usual way of kicking someone off
is to run a kill -9 command on their telnetd or rshd processes.
These processes act as glue connecting the network to the intruder's
shell. An equally valid method is to kill their shells. Either way,
the intruder will see the message "Connection closed by foreign host"
and will know that something is up.
The right way to do this is to remember that kill -9 will accept
multiple process ids, and you want to blindside him. After you've
used 'ps' to find *all* of his process ids, include the process id of
the 'inetd' process. Inetd is sometimes referred to as the "Internet
super-server"-- all it does is watch for incoming network connections
and makes sure they are connected to the right handler. By killing
inetd, you prevent new connections from being accepted, be they
telnet, ftp, finger or whatever. Of course, if he's root, he can do
this to you.
The real danger posed by an intruder is that once in, he can make it
easy for himself to get back in, though you may close the hole he
originally came through. The way this has to be done is by modifying
the filesystem in some manner (with Linux, he could easily compile you
a new kernel, but the kernel is ultimately stored in the filesystem).
The freeware program tripwire is used to detect modified system
files. The idea is that tripwire records the size, date and a
quantity called a "one way hash function". The idea is to take the
data of the file and compute a fairly large random number. If the
file changes, a different hash value results. The "one way" part
means that it is "difficult" to make a small change to file and still
come up with the same hash value. Of course, if the database of hash
values is stored on the hard disk and the cracker finds it, he can
just update the database... which is why you want to keep the database
on a floppy.
The find program is extremely useful for finding suspicious looking
files that the intruder has left laying around. Use find to look for
recently-modified files in the /lib, /usr and /etc hierarchies,
keeping in mind that it is possible to change the timestamps.
An easy situation occurs when you have installed a system via CDROM.
Since the CDROM cannot be modified, you can compare what is on the CD
with what is on the hard disk. Something like:
Another thing to check for is:
Note that the -perm option is specific to GNU find-- other systems may
have different syntax. What you're looking for are suspicious files.
A great way to learn Unix is to simply go through the system files and
figure out what each one does.
Perhaps the best way to sleep easier at night is to simply reinstall
the operating system and all of the utilities after a breakin. This
operation is much easier under Linux than most other Unixes and goes a
long way toward giving you peace of mind about any time-bombs left
behind. Besides, you were meaning to upgrade anyway, weren't you?
By default, most Linux systems come with tcp wrappers automatically
installed. This program intercepts the initial service requests from
remote machines and logs them in the system logs. The wrappers can be
configured to reject or allow access from listed sites.
In the attempted bankweb breakin, the wrappers let me know that there
had been an attempt in the first place. From the listings, you can
see that by default several services were enable during the
installation that really shouldn't be running. The ps service let
the intruder see processes running on our machine-- and gain account
names. netstat let him see the machine's active network connections.
The first step was to disable those two "services" by commenting out
their lines in /etc/inetd.conf and resetting inetd.
Step number two was to track the cracker back to his network provider.
Fingering and telnetting to the IP number produced a refused
connection, implying that the machine in question was probably not a
Unix machine. Telnetting to port 137, the windows name service port
was accepted, implying that the machine was a windows box. It was
quite possible that the machine I was looking at was not the
intruder's machine-- if the intruder was dialed in via ppp, then the
IP number could have simply been reassigned to the machine that I was
probing.
A lookup using whois with the first three parts of the IP number
produced the provider's name but not an email address to send a
complaint to. Using the traceroute program gave some intermediate
addresses that I used to find the intruder's provider. The
next-to-last address in the route to the intruder refused connections,
but trying to telnet into the second-to-last produced a shocking
result-- the address turned out to be a completely unprotected router.
Not only were current network statistics displayed and updated, but
"Configure" was a prominent menu item...
I logged in to a workstation cluster at school late one Saturday night
to check the progress of one of my jobs. I was quite surprised to
find 'root' logged in running a couple of shells and a chess demo from
the local X-windows console. I chose to leave the intruder alone
since I was unable to do much-- the recent installation of NIS had
been botched and left me unable to change the cluster's root password.
I called the police after he shut down the system, since we've had a
few computer thefts. I did have to do some fancy explaining to the
dispatcher on why I thought a theft was taking place from several
miles away. It turned out that the intruder was an idiot who didn't
know the difference between shutting the system down and logging out.
He had acquired the password by watching one of the faculty miss the
"enter" key while logging in as root-- the password was echoed right
after "root". Coincidentally, I had acquired the cluster's root
password in the same way, only I found it by seeing the log entry
login failed for rootrs314m. The moral is change the password
if someone sees it, or if it has accidentally gone into the system
logs.
One day, on a machine I used as well as administered, I received a
very strange letter that had been originally addressed to root-- I had
forwarded root's mail to myself. The letter appeared to be (and in
fact was) a command that was supposed to mail our password file to an
address at an ivy-league university on the east coast. Old versions
of the 'sendmail' program had a mode that allowed commands to be sent
in letters to facilitate debugging. When the program was distributed,
this "feature" was not disabled. Fortunately, the vendor for the
workstation (not a Linux box) had closed that hole.
The next step was to contact the source of the attacks. I have found
that the proper attitude is to be polite, and inform the
administrators that you are having a problem with one of their users,
then show them everything you have... and hope that the person you've
contacted isn't the one who is launching the attacks. The address
turned out to be on a completely insecure mail server, ending the
hunt, but we at least made the right people aware of the problem.
That machine suffered several additional attacks over the next couple
of months. The reason was that one of my users, who happened to be
Russian, had a bunch of less-than-reputable "friends" back home who
wanted impress him by breaking into his machine. At a group meeting, I
mentioned these attacks, and half-suggested we all kick in twenty
dollars, send the total to Moscow, and have a few legs broken. The
other Russian, in our group, a very mild-mannered man, said
"Break their legs?? Break their heads!". Watch out for those Russians...
I received an email notifying me that the machine in War Story #3 was
being used as a base for attacking other machines. I forwarded root's
mail to myself by putting my email in a file named .forward in root's
home directory. If you administer a workstation, you want to do
something like this, because the root account is typically rarely used
and you want to know about this sort of thing the moment it happens.
As it turned out, the people complaining had waited too long for us to
figure out who had been on the machine when the attacks took place.
The logs on that machine were rotated every two weeks. Since the
prime suspect had graduated, we chose to close his account along with
all the other accounts that had never been deleted. Examining the
suspect's files, we did find tools for breaking in to a variety of
systems as well as a utmp editor for hiding his tracks. The root
password was changed at the same time.
So, in conclusion, if you find out that *your* machine is under
attack, stay calm, do it quick, do it first and keep your backups
handy.
Check out Bill Cheswick's classic "Evening with Berferd" paper.
ftp://cert.org/pub/papers/Bill_Cheswick_berferd.ps
Andy Vaught
andy@maxwell.la.asu.edu
In this months column I'll also be covering:
Anyway, the one with perhaps the greatest relevance to GIMP users is
the sRGB standard, which specifies how images should look when displayed
on the Internet. If you're interested at all in gamma correction and monitor
color spaces, take a look at:
If you're not familiar with the color management literature, some of
it will be hard going, but it might be worthwhile anyway.
For people who are not intimately familiar with CIE color spaces and
all that stuff, the bottom line of sRGB is that the default gamma value
for Gimp should be 1.0 (as indeed it is in 0.99.10). For people that have
calibrated monitors (most likely a tiny fraction of Gimp users), it would
be appropriate to use some form of color management technology (I think
some of the new X's have color management defined, but I'm not sure how
good it is) and do a transformation from the image color space to the screen
color space. However, in the absence of that, gamma correction is generally
not appropriate.
In the long term, it might be a good idea to add color management to
the Gimp, but for now I think it's fine without. Color management tends
not to work well unless it's very carefully applied - generally, something
that only happens in high end environments. The interface was developed with Font3D
v1.6. Font3D generates geometry (model) files for 3D text
in a variety of output formats (POV, RIB, etc.) from True Type font files.
I designed xfont3d to
be used as a tool mainly for POV-Ray. The built-in POV-Ray pre viewer
allows you to render a sample of the font generated by Font3D. However,
xfont3d supports all the output options of Font3D - you just won't be able
to preview it directly from xfont3d.
You can view an image of the interface and get the source
code from
http://cspar.uah.edu/~mallozzir
I wrote the thing in about three days, so by that time
I was sick of it, and hence it has not really undergone much testing
Please send any bug reports or comments to mallozzir@cspar.uah.edu.
Dr. Robert S. Mallozzi
About 400 plotting and parameter setting routines of DISLIN
can be called from GCL for displaying data as curves, bar graphs, pie charts,
3D-colour plots, surfaces, contours and maps. Several output formats are
supported such as X11, PostScript, CGM, HPGL, TIFF and Prescribe.
Some quickplots are also added to GCL that can display
data with one command. Similar to programming languages such as Fortran
and C, high-level language elements can be used within GCL. These are variables,
operators, array operations, loops, if and switch statements, user-defined
subroutines and functions, and file I/O routines.
GCL is free available for the operating systems MS-DOS,
Windows 95, VMS, Linux, AIX, Digital UNIX, HP-UX and SunOS.
FTP sites:
ftp://ftp.gwdg.de/pub/grafik/dislin
Home Page:
ImageMagick (TM), version 3.8.8, is a package for display and interactive
manipulation of images for the X Window System. ImageMagick performs,
also as command line programs, among others these functions:
Freedom VR applet:
Paul and Olivia's VR Garden (produced with Freedom VR):
An introduction to VR photography:
Jawed Karim
There is now a campaign attempting to convince Connectix
to make the specifications for their VIDEC compression algorithm available
publicly. Without the spec, it is not possible for any third-party
projects (such as SANE) to support 16 bit color mode. If you want
to join or learn more about the campaign, please visit:
Axis uses OpenGL on
SGI and Win 95/NT, and Mesa
on the remaining platforms. The 3dfx accelerated version utilizes
the Mesa Voodoo
libraries. The Linux version currently has the best coloring/shading;
the different OpenGL implementations have quirks that we haven't sorted
out yet.
The rendering engine uses a simple stack machine interpreter,
and processes a language that has similarities to Lisp, Forth, and Adobe's
PostScript. The interpreter is multi-threaded, so objects in the 3D environment
can have private namespaces. We are working on a programming manual
for the language.
It is also network-ready; you can talk directly to the
rendering engine with a TCP/IP connection. The distribution includes
source code for an example TclTk program which utilizes the network connection
(this is the tool we used to position models within the 3D environment).
We will be releasing more complex modelers shortly.
The rendering engine and language interpreter will be the
base for our multi-user shared environment application, which we plan to
release near the end of July. Environments, and information about
positions of other users, will be downloaded via TCP/IP; if you choose
to customize your avatar, code for that can be uploaded.
Enjoy, and let me know if you have questions.
Patrick H. Madden
The latest information is available at:
Full announcement in plain text is available. If you're interested in getting a copy of this CD, please check out
the IRTC Web site for more information.
All proceeds from the CD go to the maintenence and expansion of the Web
server. EPSCAN is available from:
The rpm version will probably be moved, if it hasn't already, to
The sunsite version will probably be moved to
Adam P. Jenkins
Requirements:
Its 37M and downloading across a 36.6 modem is painful at best.
I'd love to try it, but I don't have the cash on hand for ordering it and
having it shipped (I don't mind paying for it, but next months trip to
SIGGRAPH plus some vacation time sort of sucked me dry for the time being).
If you've used it let me know your thoughts. I'll be happy to pass
any review on to my readers, with full credit to you of course! ...there is a very nifty morphing tool, called xmrm,
available at http://www.cg.tuwien.ac.at/research/ca/mrm/index.html.
I played with this a little and it has one of the most professional
looking interfaces I've seen in awhile. Its relatively easy to use,
at least if you follow the one example morph it provides.
...there is a Web site devoted to explaining how to make MPEG movies?
Take a look at http://www.arc.umn.edu/
GVL/Software/mpeg.html to find out more.
A: Well, I don't know of any tools that can take a set
of TGA files and directly turn them into an animation on Linux systems.
I'm not that familiar with animations yet, but here is what I do know.
First, you have two types of animations you can create (with freely
available tools) from a set of raster images: MPEG or an animated
GIF. The latter requires the images to be in GIF format (GIF89a,
actually). There are two tools for taking the GIF files and turning
them into an animation: WhilrGIF
and MultiGIF.
Both are command line tools and both are fairly easy to use. I like
MultiGIF a little more simply because it can create smaller animation using
sprites (small images that can overlay the previous image). Understanding
how to do this is a little tricky, but not that tough. WhirlGIF simply
concatenates the set of GIFs together into an animated sequence.
Playing an animated GIF can only be done by Web browsers, although I only
know for certain that both Netscape and MSIE support this format.
To my knowledge (someone correct me if I'm wrong) there are no "animated
GIF players" for Linux.
MPEG is an animation format that I've just started to experiment with.
There is only one command line tool that I'm aware of for creating the
animations - mpeg_encode
- but there are quite a few tools for viewing them (xanim,
MpegTV, mpeg_play,
etc). Creating the animation is done by setting up a text file with
the configuration information needed by mpeg_encode. It then reads
the configuration file, determines what sort of processing is to be done
and takes the input files and creates the MPEG output file. The configuration
can be fairly sophisticated, but I found the default template worked fairly
well with only a few minor modifications. One of those modifications
was to tell mpeg_encode what other tool to use to convert the input files,
which were in TIFF format (rendered from BMRT), into a format that mpeg_encode
could handle. Fortunately, mpeg_encode handles two fairly common
formats: JPEG and PPM/PNM (it actually supports a couple of others,
but these two will be readily recognizable to most users). I used
the NetPBM tool tifftopnm. The TIFF files are converted
on the fly by mpeg_encode as long as you tell it what converter to use.
So now that you know what formats you need to put the animation in you
might wonder how to get the TGA files into the formats you need.
Thats a common question when dealing with both 2D and 3D images, in both
animated and static formats. The answer: get either the NetPBM
tools. ImageMagick, or ImageAlchemy (the latter being a more sophisticated
commercial product). Any of these are valuable tools for your arsenal
of image processing since they all perform the often needed task of converting
from one format to another. NetPBM is what I currently use, although
I don't believe it has a tool for converting JPEG images to other formats
(there is an add-on package for NetPBM that handles this, but I don't think
the NetPBM package itself has JPEG conversion tools - I could be wrong,
its been awhile since I downloaded the package).
So, to summarize how to get your TGA files into an animation:
Reagen Ward wrote:
Originally I had objected to it due to bandwidth issues. I've
learned since then that this may not be as big a limitation as I once thought
since VRML provides a language which can be passed between client and server
and doesn't (to my knowledge - which admittedly is still somewhat limited)
require the actual images to be passed. PHIGS could probably be done
this way too, but PHIGS needs a "PHIGS for Dummies" layer slapped on top
to make it a little more user friendly.
However, the real limitation right now is processing power. Even
if you pass only descriptions of the objects to render, the end system
still has to be fast enough to render them from the point of view
of the user. This is very CPU intensive. The
average user doesn't have this kind of processing power (have you seen
the new WebTV boxes? They are even slower and
Now its not unlikely to see VRML in some environs: kiosks in stores
or malls (real ones, not Internet Malls) come to mind or any kind of public
facility that provides information to users to be browsed at their own
pace. These places will have limited point-of-view (like point-of-sale)
locations on a local network so bandwidth is not a problem, nor is server
capacity (its known pretty much ahead of time how much activity they're
likely to have). The point-of-view boxes can be as powerful as the
mall can afford. VRML provides a reasonable return-on-investment
for these situations.
But the big money, and money (income, that is) is what drives acceptance,
only comes when you can move the technology into the home. Thats
what WebTV's are all about - computers for the common man at toaster prices.
VRML requires too much processing for the average home, so its not likely
to be a big technology for at least 2-5 years. It depends on if Intel/Sun/HP/etc
can find a way to make money producing VRML-toasters.
Hows that?
Some of the Mailing Lists and Newsgroups I keep an eye on and where
I get alot of the information in this column:
The Gimp User and Gimp
Developer Mailing Lists.
No Muse next month (September). I'll be at SIGGRAPH and otherwise
busy throughout August and just won't have time for it. But I'll
be back in October, probably with lots of goodies from SIGGRAPH (or at
least I hope I am!).
Let me know what you'd like to hear
about!
Sean
ST01/02 SCSI Card
There are a variety of "diagnostics" utilities for DOS
-- MSD (Microsoft) comes with some recent versions of DOS
and Windows, NDIAGS comes with recent versions of the
Norton Utilities, American Megratrends used to sell the
AMIDIAGS, and there used to be some others called
Checkit! and System Sleuth. There are also a large
number of DOS shareware and freeware programs which perform
different subsets of the job.
Booting Linux
Ooops! I hate it when that happens!
I made a boot disk on installation so I use that to get to Linux. I
copied the vmlinuz from the /boot dir and put it on my Dos partition.
Now I don't have the original loadlin so I took one from a redhat 4.2
site on the net. It still won't boot. It starts and halfway through
bootup it stops.
I'd want to find out why the LOADLIN is failing.
The old version of LOADLIN that I'm used to did require
that you create a map of the "real BIOS vectors" -- which
is done by allowing REALBIOS.EXE to create a boot disk,
booting off of that, and then re-running REALBIOS.EXE.
Kernel Panics on root fs
I presume you mean that you installed the 2.0.30 sources
and that you did a make zlilo (after your make config;
make dep; and make clean)
But now, one the new kernel, after it finds my CD-ROM drive, it won't
mount my root fs. It gives me a kernel panic, and says unable to mount
root fs, then gives me the address 3:41. What's going on??
Did you do a 'make modules' and 'make modules_install'?
Here's my lilo config file...
...[ellided]...
That looks fine.
My hard drive that boots is hda, and my Linux drive is hdb. I took out
read-only a while ago, to try to solve the problem. It made no difference.
It'd be great if you could help me out a little. Thanks, Ken...
Copyright © 1997, James T. Dennis
Published in Issue 20 of the Linux Gazette August 1997
"Linux Gazette...making Linux just a little more fun!"
Cleaning up you /tmp -- Revisited
By Guy Geens,
ggeens@iname.com
mtime vs. atime
find ... | xargs grep ...
constructions. Personally, I don't have this problem, as I tend to
restrict the domain of my find sweeps.
Avoiding perl
cp -p /bin/rm-static /usr/bin/find-static /tmp
chroot /tmp /find-static ... -exec /rm-static {} \;
rm /tmp/rm-static /tmp/find-static
find ... | xargs rm
security hole described in my first article.
Perl's internals
Omitting certain files and directories
cleantmp, version 2
Guy Geens
Copyright © 1997, Guy Geens
Published in Issue 20 of the Linux Gazette, August 1997
"Linux Gazette...making Linux just a little more fun!"
Dealing with System Crackers--Basic Combat Techniques
By Andy Vaught,
andy@maxwell.la.asu.edu
May 2 23:25:09 bankweb ps[12613]: connect from 128.128.128.128
May 2 23:25:09 bankweb netstat[12614]: connect from 128.128.128.128
May 2 23:25:10 bankweb wu.ftpd[12616]: connect from 128.128.128.128
May 2 23:25:10 bankweb in.telnetd[12617]: connect from 128.128.128.128
May 2 23:25:15 bankweb in.fingerd[12619]: connect from 128.128.128.128
May 2 23:25:16 bankweb in.pop3d[12620]: connect from 128.128.128.128
May 2 23:25:17 bankweb in.nntpd[12622]: connect from 128.128.128.128
May 2 23:25:17 bankweb nntpd[12622]: 128.128.128.128 connect
May 2 23:25:17 bankweb nntpd[12622]: 128.128.128.128 refused connection
May 2 23:26:55 bankweb wu.ftpd[12624]: connect from 128.128.128.128
May 2 23:28:03 bankweb ftpd[12624]: FTP session closed
May 2 23:28:19 bankweb in.telnetd[12632]: connect from 128.128.128.128
May 2 23:28:44 bankweb login: 2 LOGIN FAILURES FROM 128.128.128.128, guest
May 2 23:29:12 bankweb ps[12634]: connect from 128.128.128.128
May 2 23:31:20 bankweb ps[12637]: connect from 128.128.128.128
May 2 23:32:25 bankweb netstat[12638]: connect from 128.128.128.128
May 2 23:34:21 bankweb in.fingerd[12641]: connect from 128.128.128.128
May 2 23:35:54 bankweb in.rlogind[12644]: connect from 128.128.128.128
May 2 23:35:54 bankweb in.rshd[12645]: connect from 128.128.128.128
May 2 23:35:54 bankweb rshd[12645]: Connection from 128.128.128.128 on illegal port
May 2 23:36:56 bankweb in.telnetd[12647]: connect from 128.128.128.128
May 2 23:37:11 bankweb login: 2 LOGIN FAILURES FROM 128.128.128.128, root
If he's on your system
Assessing the damage
find /bin -exec cmp {} /CDROM/dist/{}
will compare files on the disk to what is on the CDROM.
find / -perm +6000 -print
which will find all the setuid and setgid files on the disk. A setuid
file is one which runs with the permissions of the file's owner or
group, not the person running the file. This is how the passwd
program lets a user change the password file... but only their own
entry. The intruder may have left something behind which lets him
become root at will.
War Story #1
War Story #2
War Story #3
War Story #4
Further reading:
Copyright © 1997, Andy Vaught
Published in Issue 20 of the Linux Gazette, August 1997
"Linux Gazette...making Linux just a little more fun!"
muse:
elcome
to the Graphics Muse! Why a "muse"? Well, except for the sisters aspect,
the above definitions are pretty much the way I'd describe my own interest
in computer graphics: it keeps me deep in thought and it is a daily source
of inspiration.
his column
is dedicated to the use, creation, distribution, and discussion of computer
graphics tools for Linux systems.
The format of this months column has changed just a tad.
I rebuilt my template for the column using Netscape's Page Composer, part
of the Communicator 4.01 Preview Release 6. There are lots of little
things I don't like about Communicator but the Page Composer is quite nice.
Its the first WYSIWYG HTML editor I've used on Linux that I've really liked.
I intend to do many of my pages using it from now on. To be fair
to Communicator, it is a preview release (once known as Beta, but I guess
that has bad connotations now). I've always been pleased with Netscape's
products. If I could just get them to publicly support Linux I'd
be happier. Anyway, once the little annoying aspects are cleared
up the 4.x release should be quite a boost to Netscape's product line. 
During the month of July I was finishing up a major X
application for my employer (EMASS, Inc, a division of Raytheon/E-Systems/TI/and
who knows what else). One of the last things I had to do was port
the application to a slew of Unix platforms. Well, the ports were
pretty easy - it was just a matter of getting the build environment set
up right - but I had lots of free time to burn while some compiles were
running. Fortunately I was able to log in from home to do these,
so I started to look at a few graphics applications that I've been meaning
to get to for some time. The first is Image Alchemy, a commercial
product from Handmade Software that provides extensive image conversion
capabilities. I'd long ago promised Hap Nesbitt of Handmade Software
that I would do the review. My apologies to him and Handmade for
taking so long to get around to it.
The next package is ImageMagick. I've seen the posts
for this package on comp.os.linux.announce many times and have heard lots
of good things about the package. I decided it was time to take a
closer look.
Finally, I decided to take a look at a tool thats been
around for awhile but that hasn't really been discussed much in the forums
that I frequent: Geomview. A quick glance at the pre-built
binary really caught my eye. This is a tool with a lot of potential.
Oh, and the image on the right, Graphics for the Masses, was created
as a demonstration of what can be done with the GIMP. It was enough
to convinve the Linux Journal that I could do the cover for their November
Graphics issue using this handy Photoshop clone. The final cover
art doesn't look anything like this one, however. It was just a way
of showing off what is possible. If anyone else needs a cover done,
feel free to drop me a line!
Disclaimer: Before I get too far into this
I should note that any of the news items I post in this section are just
that - news. Either I happened to run across them via some mailing list
I was on, via some Usenet news group, or via email from someone. I'm not
necessarily endorsing these products (some of which may be commercial),
I'm just letting you know I'd heard about them in the past month.
I ran across this in the GIMP
Developers mailing list. Unfortunately, I forgot to save the
attribution. My apologies to the original poster of the message.
I've been reading some of the W3 specs recently, and I've come
across some good stuff. I'm impressed - until recently it seemed like the
W3 either wouldn't or couldn't get their act together, but now they seem
to be putting out genuinely useful specifications.
xfont3d
This program is a graphical interface to Font3D
(http://www-personal.ksu.edu/
~squid/font3d.html), and requires the XForms library (http://bragg.phys.uwm.edu/xforms).
University of Alabama in Huntsville
GCL
GCL (Graphics Command
Language) is an interpreting language that is based on the data plotting
library DISLIN. Version 2.2 of GCL is now released.
ftp://linhmi.mpae.gwdg.de/pub/dislin
ImageMagick 3.8.8
The newest version of the binary distribution of ImageMagick,
version 3.8.8, has been uploaded to Sunsite.. You can also get it
from its primary site at ftp.wizards.dupont.com
/pub/ImageMagick/linux.
The major changes in ImageMagick 3.8.8 are:
Retrieve, list, or print files from a remote network site
ImageMagick supports also the Drag-and-Drop protocol form the OffiX package
and many of the more popular image formats including JPEG, MPEG, PNG, TIFF,
Photo CD, etc.
Freedom VR - Java Virtual Reality Applet
Freedom VR is a photographic
VR applet that was developed with Linux but also works on other flavors
of Unix, the Macintosh and even Windows. It beats Quicktime VR in
compression performance -- because Freedom VR uses Internet standards such
as .gif and .jpeg, Freedom VR content can be produced on any platform.
The developers are interested in working with other programmers to develop
software for converting other VR formats such as VRML and Quicktime VR
to Freedom VR. We've also written up a tutorial for taking VR photographs.
http://www.msc.cornell.edu/
~houle/vr/freedom/
http://www.msc.cornell.edu/
~houle/vr/garden/
http://www.msc.cornell.edu/
~houle/vr/howto/
Jaw3DLib
Jaw3DLib, a 3d programming
library has been released for several platforms: linux, ms-dos, and sunos.
I'd like a few alpha testers to take a look at this. An example app is
included that can be easily modified. Go to: http://umn.edu/~jawed/jaw3d/
jawed@tc.umn.edu
http://umn.edu/~jawed
For those of you owning or otherwise interested in Connectix
QuickCams:
IKM Interactive announces the release of axis 1.0alpha, a 3D rendering
engine for Linux/SGI/Sun/Win95/WinNT.
A 3Dfx accelerated version is also available for Win95 (and
possibly Linux soon). A Power Mac version is currently in development.
You can download the current version from http://www.ikm.com
This is an alpha release, mostly of interest to 3D hackers.
phm@webvision.com
pickle@cs.ucla.edu
or
phm@ikm.com when we get our mail server
sorted out.....
WSCG '98 International Conference and Exhibition
Call for Papers and Participation
Deadline for papers September 30,1998
The Sixth International Conference in Central
Europe on Computer Graphics and Visualization 98 in cooperation with IFIP
working group 5.10 on Computer Graphics and Virtual Worlds will be held
in February 9 - 13, 1998 in Plzen at the University of West Bohemia close
to PRAGUE, the capital of Czech Republic
Conference Chairs
POV Texture Library
This texture library has been updated and the URL has changed. This
site is done by a non-Unix user, but the textures are platform inspecific.If
you're looking for some interesting textures for your POV-Ray scenes take
a look at
http://www.informatik.tu-cottbus.de/
~rs/povray/texlib/
IRTC CD-ROM Due out soon!
Chris Cason, who manages the server which supports the IRTC
and POV-Ray Web sites. is
getting ready to publish the IRTC CD-ROM. This CD contains the collection
of images submitted to the IRTC over that last year, the IRTC's first year
of existance (in its reincarnation that is).
EPSON Scanner Driver
EPSCAN is a scanner driver for EPSON
ES-1200C/GT-9000 scanners. It includes a driver and a nice X frontend.
It allows previewing, and selecting a region of an image to be scanned,
as well as changing scanner settings. It only supports scanners attached
to a SCSI port, not to the parallel port. The driver should
support any of the ES-{300-800}C / GT-{1000-6500}.
ftp://sunsite.unc.edu/pub/
Linux/Incoming/epscan-0.1.tar.gz
and an rpm version to
ftp://ftp.redhat.com/pub/
Incoming/epscan-0.1-1.src.rpm
ftp://ftp.redhat.com/pub/
Incoming/epscan-0.1-1.i386.rpm
ftp://ftp.redhat.com/pub/
contrib/epscan-0.1-1.src.rpm
ftp://ftp.redhat.com/pub/
contrib/epscan-0.1-1.i386.rpm
ftp://sunsite.unc.edu/pub/ Linux/apps/graphics/scanners/epscan-0.1.tar.gz
ajenkins@cs.umass.edu
You can get the Qt library from http://www.troll.no.
EPSCAN may work with older versions of Linux, XFree, and g++; this is just
what it was developed with.
Has anyone tried out ELECTRO-GIG's product, 3DGO? The Graphics
Muse wants to know!
Iv2Pov/IV2Ray
Cow House Productions is pleased to
announce the release of Iv2POV. Iv2POV
is a translator / converter for Inventor 2.0 / VRML 1.0 files to POVRAY,
the popular raytracing program. Both source code and an Irix 5.3 executable
are available (free!) at
While you are at www.cowhouse.com
- feel free to take a look around, download some samples, and otherwise
exerciseyour browser.
Did You Know?
...the growth of 3D modellers continues at a frightening pace. Another
modeller was recently announced: GL-SPACE.
You can find information on this new modeller at http://tularosa.eece.unm.edu/staff/greywolf/glspace/.
It requires Tcl7.5/Tk4.1 and Mesa 1.2.8 or OpenGL. The interface
is quite cool - one of the best I've seen yet. The cameras location
is represented by - a camera! Really. Take a look at it.
Q and A
Q: I am quite new to POVRAY and would like to know
where I can get an application which plays a series of *.tga files as an
animation. I have created all the TGA files using POV. What
can I use to play these files in sequence?
Merv Young.
AUSTRALIA.
There is another format called FLI which has an encoder. My understanding
is that this format is slowly dying as MPEG gains popularity.
Is VRML ready for PrimeTime?
Some time back I had a reader send me email asking my thoughts on VRML.
Below is the response I sent. After rereading it I have to say I
still agree with it, although I reserve the right to change my mind after
my trip to SIGGRAPH next month.
I come from the world of PHIGS for visualization, and thus can't
stand VRML as a supposed data format. I'd love to hear your opinions
on why it's not ready for personal use.
dumber than the average 2 year old PC). This processing could
be moved off CPU into some adapter card (maybe a VRML-ready display card),
but such technology isn't available yet so its cost would still be (for
some time) out of the reach of the average home.
Image Alchemy
One of the most common tasks graphic artists will face is
converting stock images from CDs and other resources from their original
format to one that can be used by their particular software or medium (such
as for use on the Web). There are actually a plethora of tools for
doing this conversion. xv
will convert between a limited set of formats, but does handle most
of the most common formats. The NetPBM tools handle a huge number
of formats using a very large set of command-line programs. And ImageMagick
has both command line and X-based interfaces for converting images.
Each of these has advantages and users will want to play with each to find
one that suits their needs.
Another solution for image conversion and manipulation
comes from Handmade Software in
their Image Alchemy package.
This is a commercial package that features support for over 60 different
image file formats using a command line interface. A graphical interface
is available for Sun systems using OpenLook and there may now be a Motif
version as well, however these do not appear to be available for Linux
yet.
Getting the software requires that you simply download
the Linux binary package from the download
page of Handmade's Web site. There is a demo package available
for free, but the retail version requires a username and password that
can be obtained from their sales department.
The package I have, which I got from Hap Nesbitt at Handmade
Software, contains two binaries: alchemy and alchfont. The
former is the graphics conversion package. The latter is a font manager,
although I'm not really clear on how to use it. The documentation,
330+ pages in a PDF file, didn't contain any references to it. Since
I wasn't expecting this tool I didn't spend any time looking for info on
it at the Handmade Software Web site.
The manual
is available for download from their Web site. Its quite large
(something you'd expect from commercial software and something that is
seriously lacking in many freeware packages) but it covers all the versions
of the software, including 2 chapters (out of 8) and 1 appendix (out of
11) on the DOS/Windows Graphical interface. Along with the manual
you can get runtime help by using the -help command line option.
The runtime help is broken into several categories, each with its own command
line option.
The basic usage takes the following form:
Unlike NetPBM the images don't have to be converted to
an interim format before the final image is produced. NetPBM
used the interim format to do its image manipulation, such as scaling or
quantizing the colors in the image. Image Alchemy can do this in
one step using various options.
Speaking of options, the Image Alchemy manual breaks the
available options into 4 categories:
General options include items such as usage, statistics
and memory features. Conversion options specify the output file types
and any related options. For example, -g is the option
for converting to the GIF format. This option has an additional numeric
argument, 0 or 1, to specify which version of the GIF format to use - GIF87A
or GIF89A respectively.
Color and Palette options cover such things as alpha channels,
true color options, dithering and gamma correction. Scaling options
allow the resizing of the input image and along with the Filters provide
for convolution, flipping, positioning and aspect modifications.
All of the options are covered in detail by the manual and summaries are
available through the builtin help option (-help).
When evaluating image conversion utilties the artist will
want to compare the quality and sizes of the images. On my 24-bit
display the quality of the sample JPEG image provided with Image Alchemy
(a photo of the Golden Gate Bridge) didn't change perceptibly when converted
to GIF, Targa (TGA) or TIFF formats. The same image was converted
using xv and NetPBM to these same formats and also showed almost not visible
differences. The following table shows the file sizes for each:
GIF
TGA
TIFF
alchemy
192360
924059
769700
xv
142784
921618
772046
NetPBM
146100
921618
-
ImageMagick
Based on this a user might assume xv or NetPBM might be
better suited for their needs. In many cases this is true, especially
if you are only doing a personal web page or perhaps creating simple greeting
cards. For professional work alchemy provides a wider range of tools
and supported formats than xv and NetPBM, and does so with a single command
line program. Both xv and alchemy provide significant documentation
(you can get xv's by registering your copy and paying a little extra for
the manual). NetPBM provides man pages but these can be difficult
to print and its not always easy to determine which tool fits which format.
Only Image Alchemy offers commercial support and with continued development
at published intervals. For commercial operations this can be of
key importance.
The moral here is to spend a little time examining your
image conversion needs before investing time in any one particular tool.
Image processing is provided by all of these, but aside from scaling and
perhaps color palette operations you may find the GIMP a better tool for
interactive editing of images. If you need the convenience of command
line oriented operation for batch processing, along with commercial support,
then Image Alchemy may be the tool for you.
The following links are just starting points for finding more information
about computer graphics and multimedia in general for Linux systems. If
you have some application specific information for me, I'll add them to
my other pages or you can contact the maintainer of some other web site.
I'll consider adding other general references here, but application or
site specific information needs to go into one of the following general
references and not listed here.
Linux Graphics
mini-Howto
Unix Graphics Utilities
Linux Multimedia Page
The IRTC-L discussion list
comp.graphics.rendering.raytracing
comp.graphics.rendering.renderman
comp.graphics.api.opengl
comp.os.linux.announce
Future Directions
Next month:
Copyright © 1997, Michael J. Hammel
Published in Issue 20 of the Linux Gazette, August 1997
More...
ImageMagick Overview
After months of procrastination, I finally got around to taking
a closer look at the ImageMagick set of tools from John Cristy and E.I.
DuPont De Nemours and Company Incorporated. I've had a number of
readers write and ask me about the program, what I thought of it and how
does it work, etc. Its time to address some of those issues.
ImageMagick is a graphics manipulation tool along the
lines of XV or the GIMP that runs on a variety of Unix systems, including
Linux, along with MS and Macintosh platforms. The package is available
in source or binary distributions from http://www.wizards.dupont.com/cristy/ImageMagick.html.
I downloaded the binary package which was a gzipped tar file of the
installation package using relative paths. Since the package attempts
to place the binaries and some other files under the /usr/X11R6 directory
tree, and I only install system files there (everything else goes under
/usr/local), I had to unpack the file in a local directory tree, change
the name of the X11R6 directory to local, recreate the tar file and then
unpack it as root from the root (/) directory. Other than this, the
installation of the binary package was painless.
The distribution comes with a set of 9 tools that allow
both interactive and command line editing of images: 
All of the tools come with well written man pages and honor the -? command
line option to get usage summaries.
The first of these, display,
is an interactive program that uses X Windows. The interface is consists
of a single, columnar set of buttons, each of which opens a menu, and a
viewing window. Figure 1 shows the default image window and
the menu box.
The image window will dither images to fit on the display based on
the hardware support you are using.
The menu buttons are simple to use - just click on one
to see the options available for that menu. The top level menu options
are:
Under File the options include such things as a Print function (using Postscript,
so you'll want to make sure you have Ghostscript installed first), New,
Open, Next, Former, and Visual Directory, among others. The Visual
Directory appears much like the Open option in that both provide a File
Selection box from which to choose an image. I'm not certain if I
was using it correctly, however, since I got the feeling the visual directory
is supposed to be similar to XV's visual schnauzer.
The Effects and F/X menus are similar in that both provide
access to features that manipulate the image, much like XV's algorithms
or the GIMP's plug-ins. I found the Shade function interesting in
that it turned the 2D planet into a slightly 3D image by adding shadows
in the appropriate places. Most of the functions are similar to the
features found in the stock GIMP distribution but there are a few more
than what XV provides in its algorithms menu.
The number of features of the display program is attractive,
but as an image editing tool for artists it is a step or two behind the
ease of use of the GIMP. Some of the effects features are a little
nicer than what is currently available for the GIMP, however. And
the annotate feature, which allows you to insert text into an image, does
provide a reasonable font previewer. Still, the GIMP is a more sophisticated
end-user interface. During my brief testing of display I had multiple lock
ups on my Linux 1.2.13 box, but that may be due to older libc. I
also noticed that display appeared to run a bit slow in refreshing the
image window. Redraws of the windowing toolkit (looks a bit like Tk or
Motif, but I'm not certain what it is really) were really slow. Again,
this may be due to my slightly older Linux system.
Beyond the graphical interface, the other 8 programs in
the distribution are command line oriented. From what I can gather
this is what makes ImageMagick a valuable addition to the Linux graphics
artists toolchest. Each of the commands serves a general purpose but handles
that purpose with an extensive array of options. As a group these
tools can be used to automate the handling of images for display on web
pages quite nicely. I think that many of the features builtin into
the display program are covered by these command line interfaces, but I
also found a few features that I think display may not handle.
Import is used to
do screen captures of windows or rectangular regions of your monitors display.
You can specify an window ID or name or you can use import interactively
by using the mouse to specify the window or region to capture. Options
include allowing capture of the window manager frame, dithering and cropping
the image before saving. The output file format depends on the filename
extension used for the saved file or by prefixing the filename with the
file type followed by a colon, such as ps:output_image.
By default import will save the file as an Encapsulated Postscript file.
Animate will take
a series of images in just about any format and display them as an animation.
As with most animation software the quality of the animation will depend
on the number and type of images, the speed of the computer and the memory
available to process the images. Since I didn't have a series of
images to experiment with I wasn't able to really look into this particular
tool.
Montage allows you
to create a single image built from a series of other images. Input
images are scaled to fit a specified tile size, a square of 120x120 by
default, and then places the images side by side in a series of rows. By
default 5 tiles are used in a row and 4 rows are produced. If more
than 20 images are supplied then additional output montages are produced.
You can specify a larger number of tiles to use for a single montage, and
thus the number of input images to use, with the -tile
option. Montage offers a large set of options. The page size
can be set so that the postscript output will fit on various paper sizes.
You can set the gamma level for the output files, crop and dither the input
images, provide an ornamental frame around the output image, and where
to place an image inside a tile if it doesn't fill the entire tile region
(this is known as where the image will gravitate within the tile).
Input files can be identified with labels using various fonts. 3D
shadows can be added to input images as well as a textured backdrop in
the tile areas and borders not covered by input images.
Convert and Identify
are complimentary programs. Identify can be used to determine,
based on the files magic number, the image format of a particular file.
Along with the file type information such as the size of the file, whether
or not it is colormapped, and the number of colors in the image are also
printed. Convert takes an image in one format and converts it to
another file using a different, specified format. The format type
can be specified just as with import, with a prefix or suffix denoting
the format of the input and output types. Convert can also read Unix
compressed (.Z suffixed) image files, but does not write the converted
image as a compressed file. Multipage or multipart images are converted
with output files using the filename with a scene number for a suffix.
This is a modifiable option, however. You can embed a printf() style
formatting string in the output file name to sequentially number the images
and still include the format type as a suffix.
Mogrify manipulates
images the way the Effects and F/X menu options in display do. This
tool takes an input file and processes it based on the options specified
and in the order they are specified. Since options are processed
in the order they are presented on the command line, it is possible to
set a series of options to be globally applied to a series of images, then
change one or more of these options for individual images - all from a
single command line. Mogrify permits scripting and batch processing
of images. XV can do this to some extent, but I've never used it
that way and the number of processing functions is greater in mogrify.
The GIMP has a scripting interface, but batch processing has to go through
Net-FU (a network based interface). NetPBM provides only command
line interfaces, but you have to script a series of programs together to
get the same effect you get from mogrify. Image Alchemy, a commercial
product for image processing from Handmade Software, appears to be the
only real match for the way mogrify functions for batch processing.
Finally, the ImageMagick tool set includes an extra feature
- xtp - which allows for network transfer of files simiilar to the way
ftp works. According to the ImageMagick web site, xtp doesn't require
any interactive commands so file transfers can more easily be batch processed.
Beyond the base tools, John Christy and E.I. Dupont De
Nemours and Company also provide a plug-in package called the ImageMagick
Plug-In. This appears to be (although I'm not quite clear about it)
the shared image libraries for a number of popular image file formats.
It is basically equivalent to what libgr provides except that the ImageMagick
libraries include support for MPEG files. There are also a number
of programs in the Plug-In packages, including a TIFF thumbnail generator
and the cjpeg and djpeg tools for compressing and decompressing images
to and from the JPEG format. Most of the tools in the Plug-in package
are related to TIFF handling.
As you can see the ImageMagick tools cover a lot of ground.
I didn't get to comparing the quality of the images from ImageMagick versus
XV or NetPBM so this review is really just an introduction to the toolset.
But the tools are obviously high quality, feature rich, and well documented.
The developers announce frequent updates and additions which is better
than what you generally hear of XV or NetPBM. If you've used XV,
the GIMP or NetPBM and find these might not quite fill all your needs you
owe it to yourself to take a look at ImageMagick. No graphics fanatics
arsenal of tools is ever complete and no tool can handle every need.
Its important to keep aware of the tools that are available. ImageMagick
is a tool that deserves serious consideration for your collection of graphics
tools for Linux.
© 1997 by Michael
J. Hammel