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Linux Gazette... making Linux just a little more fun!
Copyright © 1996-97 Specialized Systems Consultants, Inc. linux@ssc.com
_________________________________________________________________
Welcome to Linux Gazette! (tm)
_________________________________________________________________
Published by:
Linux Journal
_________________________________________________________________
Sponsored by:
InfoMagic
S.u.S.E.
Red Hat
Our sponsors make financial contributions toward the costs of
publishing Linux Gazette. If you would like to become a sponsor of LG,
e-mail us at sponsor@ssc.com.
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
The Mailbag!
Write the Gazette at gazette@ssc.com
Contents:
* Help Wanted -- Article Ideas
* General Mail
_________________________________________________________________
Help Wanted -- Article Ideas
_________________________________________________________________
Date: Mon, 18 Aug 1997 00:25:47 -0400
From: Anthony Wilson anthony@pisces.globalserve.net
Subject: Difficulty running programmes
I am using Linux Slackware 3.0 with kernel version 2.0. I am running a
LAN and whenever I try to run a script or a program that I created on
the server, I get a command not found error, even though I have read
write permissions on the file in my own directory. If I transfer that
same file to another Linux box on this LAN, I can run it without any
problems.
Is there an easy fix to this problem?
Thank you.
Anthony Wilson
_________________________________________________________________
Date: Wed, 20 Aug 1997 06:00:38 +0200
From: Denny denny@ele.kth.se
Subject: Connecting to dynamic IP via ethernet
Hello. I want to connect my Linux box to our ethernet ring here at my
company. The problem is that they(we) use dynamic IP adresses, and I
don't know how to get an adress. I use win95 on one partition on my
pc, from where it works fine to connect. I know the IP adress to the
DCHP-server (that the one who distributes the IP-adresses, right?) but
how do I do to get assigned an IP-adress from Linux? I got so tired of
trying, that I finally just assigned an adress myself and hey,
somethings work. I can use telnet and ftp but X takes 15 minutes to
start, and emacs likewise. I can't wait that amount and also I'm sure
there are several thing that don't work. Please, if you know how to
do, explain carefully, I'm not all that good at linux and tcp/ip
hacking.
Denny
_________________________________________________________________
Date: Fri, 15 Aug 1997 09:47:03 -0500
From: Cory Sticha csticha@apci.net
Subject: Printing PostScript to a DeskJet 682C
I've got a question that I'd to have answered. I've got an HP DeskJet
682C printer that I'd like to use to print pages out from Netscape.
Unfortunately, the printer only recognizes text and PCL 3, while
Netscape only uses PostScript. Is there a filter that is capable of
converting PostScript to PCL 3. Also, to print text to this printer, I
have to pipe the file that I want to print to todos and then pipe that
to the printer. How can I automate this? Thank you very much in
advance for any help that you can give me.
Cory Sticha, SrA, USAF
_________________________________________________________________
Date: Mon, 04 Aug 1997 14:12:42 +1000
From: Marcus B marcus@cwi.net.au
Subject: Problem with adaptec 2940U
Answer: RedHat versions 2.x kernels only) but there are problems on
some hardware configurations.
_________________________________________________________________
Date: Wed, 6 Aug 97 20:55:49 BST
From: George russell george.russell@clara.net
Subject: Linux Help needed to connect to Internet
I am a new Linux user, and inexperienced in Unix environments. My aim
in using Linux is to connect to the internet without needing to use
Windows, in order to learn about Linux and update my linux setup
(Slackware Linux Toolkit March 1997, which I will install again soon).
I have had X Windows and Netscape Navigator 3.01 installed,and will do
so again after a hard disc upgrade. I am unable to connect to the
internet. Could anyone help me to do this? My modem is on COM2, and
works under windows as a generic modem. I know the number of my ISP,
that my IP address is server assigned. I have the IP addresses of the
primary and secondary DNS, and have my own username and password. Is
there anyhing else I need to know, and can anyone help me with this? I
would be very grateful for all assistance given.
_________________________________________________________________
Date: Wed, 06 Aug 1997 15:35:20 -0700
From: Luke luke@holdens.org
Subject:LILO Problems
I have this 2 gig scsi drive. I have Linux and Windows 95 on my
system. 95 is on the first gig and Linux is on the 2nd. Lilo gives me
problems with booting Linux from the second gig. And windows just will
not see it. Its a old scsi disk. So I cant use sector compadibility
mode. Right now. I use Lodlin (and some 95 proggy) to drop out of 95
and kick linux in. Eather this or I have to use a installation floppy
(I cant load lilo on a floppy because it gives me disks problems there
too) You know of any boot managers that I can gain access to that can
read the entire disk? I know the NT boot loader can do this. But there
is no point in loading NT for this task. Another problem I have is
this. I have a Windows NT box as a proxy server for my internet
connection. (I can't convert it to Linux, it's not my box) I can get
Windows 95 to send all ip requests threw the proxy using the ms proxy
client. (ex: quake over the net) But with Linux I can't seem to do
that. I have used Netscape a bit for this purpose. But I still can't
do anything else. Is there a way to get Linux to work over a proxy
itself? I could just dail into my ISP va PPP. But I already have a 10
megabit connection to them. What's the point of using a modem. Is
there a way I can get around this problem? Another question I have is
can I make a swap from an image or some other media. I don't want to
kill my Linux partition to gain this. But, I have a 16 meg swap
partition and 16 megs of ram. Trying to run progams like Wabi is of no
use. They don't seem to have enough memory. Is there a way to add more
swap space with out disturbing the exsisting partitions? Well thank
you for your time. Long live LINUX!!!
Luke Holden
_________________________________________________________________
Date: Sat, 09 Aug 1997 23:14:04 -0400
From: David Nghiem
Subject: Pointers
Hey all,
Do you guys know of any information regarding programming a game in
Linux on the X11 platform? I want to use it as a cross developer for
some DOS games. The main issue here is this: How do I display my
output?
Laterz,
Dave.
_________________________________________________________________
Date: Fri, 08 Aug 1997 20:03:21 -0400
From: Raymond E. Rogers rrogers@voyager.net
Subject: Apllixware -- Fax
I bought applixware some time ago and found that I was supposed to
roll my own Fax interface. Somebody at work suggested just setting up
a "printer" for fax. Logical to me. As I don't do Linux for a living
or a hobby; it would be nice if somebody could write and article on
how to do it. Or point me to instructions. I looked around and was
unable to find any.
There is supposed to be instructions in how to make netscape do
standard PGP/RSA digital signatures that can be verified on any PGP
system, not just inside of netscape. Simple instructions on this would
be nice.
If I get around to doing these things first, I will write an article
on how I did it.
Enjoy
Ray
(An article entitled "Faxing from the Web" will be included in the
upcoming November issue of Linux Journal. While the magazine won't
be out until next month, the listings that go with it (including
his front end) are available at
ftp://ftp.ssc.com/pub/lj/listings/issue43/2044.tgz. Since the
author was not using Applixware, I'm not sure how much his code
will help, but check it out, it may be just what you need.
--Editor)
_________________________________________________________________
General Mail
_________________________________________________________________
Date: Wed, 30 Jul 1997 12:22:41 -0700
From: Tom Schenck tschenck@concentric.net
Subject: Organize and overtake!
Well, I'm pretty sure there are people doing this, but not very fast
or efficiently. We need a stable, friendly, easy-to-install system
that comes equiped with applications that allow the user to begin
working right away, and configure without programming knowledge!
Yes, it's *nix. Yes, it's a programmers environment. Yes, it doesn't
HAVE to be terse, hard to configure, etc.
Hell, maybe I'll have to do it!
_________________________________________________________________
Date: Fri, 22 Aug 97 21:09:09 BST
From: Duncan Simpson feynmen.ecs.soton.ac.uk
Subject: M$ word
Those who need to read a word document might like to get the latest
version of wqord2x by anonymous ftp from amil.telstar.net in the
pub/duncan directory. Note the machine's main job is a mail
redirection service, which sends me the logs, amoung other things!!
Duncan
_________________________________________________________________
Date: Sun, 10 Aug 1997 13:56:23 -0600 (MDT)
From: Michael J. Hammel mjhammel@csn.net
Subject: MS quote
This comes via a Mac friend of mine. We should look closely at
aligning with the Mac users of the world. They hate MS almost as much
as we do. :-) From: EvangeList evangelist@apple.com This tidbit is
from: Dave Reiser, dbr@ptd.net In a page 1 article in the July 28,
1997 Computerworld there's an article ENTITLED "Microsoft Declares
War" about how MS has announced that it will not ship the Java class
libraries. I absolutely howled when I read this quote: "'We have no
intention of shipping another bloated operating system and forcing
that down the throats of our Windows customers'" [attributed to Paul
Maritz, Microsoft Group Vice President] Are they feeling guilty about
the fact that they've already rammed one bloated operating system down
their customers' throats? -- Michael J. Hammel
_________________________________________________________________
From mjhammel@csn.net Fri Aug 8 21:48:52 1997
Date: Fri, 08 Aug 1997 23:00:22 -0600
Subject: Descent 3D 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.
Actually I think many of the developers know the value of Linux, but
there is no marketing proof that a Linux port will make money. As many
others have said in the past, we need certifiable numbers to prove the
market exists and that its willing to spend money on commercial
products. I don't have any info on it, but I'd love to know if either
Id or Crack.com made any money on their Linux ports. And I'd like to
know if it was enough, in their eyes, to warrant future ports. I've a
gut feeling the Id guys may have done their port simply because they
liked the idea and did it for fun, but thats just an unsubstantiated
hunch.
I just got back from SIGGRAPH today and after having talked to many
engineers from lots of different companies I can say that nearly all
are *very* aware of Linux and most (that I talked to) are using it.
One engineer from Cosmos Software, the new division at SGI, said
they'd probably be happy to let someone do the port of the new Cosmo
Player 1.0 to Linux (although he wasn't sure how to go about getting
that done). Most of the companies at the conference who are Unix aware
are also Linux aware. They just need a little proof that the market
will return their investment within a reasonable time frame.
One of the things I decided to do while I was at SIGGRAPH was to write
an article outlining how to begin to get reasonable market figures for
Linux with respect to graphics tools and games (other vertical markets
are a bit out of my league). I'm sketching this out now and will
probably submit it to the Linux Journal in September or October. Much
of it resolves around the use of simple Multimedia applications.
Anyway, once we have the numbers to back us up, it will be a little
easier to convince game developers to include Linux ports of their
software.
-- Michael J. Hammel
_________________________________________________________________
Date: Fri, 08 Aug 1997 22:36:23 -0600
From: Michael J. Hammel mjhammel@csn.net
Subject: Firewire and DV
I just got back from SIGGRAPH. To my knowledge there are no plans for
Firewire support for Linux, but I have to admit I didn't specifically
go looking for it. I'm not even completely sure what it is (although
thought it was just another 3D chipset). I've been on a personal
crusade to get Linux noticed as a terrific platform for image
processing and graphic arts tools, and that includes (eventually)
Digital Video (DV) tools. However, although there are quite a large
number of tools for doing computer graphics (including plenty of
support for OpenGL, both commercially and in the freeware MesaGL
package), I've not seen any DV style tools. I'd say its a little early
for such tools on a commercial basis since more basic tools are not
commercially supported yet. But its certainly something I'll continue
to keep an eye on and do my best to encourage.
DV tools would work as well on Linux as any other high-end Unix
system, but tools like graphics tablets and scanners need better
support before we'll get into DV tools. We also need a decent GUI
toolkit. Motif is ok, but a bit bloated. Most of the other toolkits
don't have enough printed documentation available yet. While at
SIGGRAPH, Mark Kilgard told me that there is a new toolkit that sits
on top of GLUT that might be a good basis for a more advanced toolkit.
I haven't had time to look at it yet (I just got back today). Anyway,
I hope this helps a little. If you find any DV tools or have contacts
that could use a little polite prodding, feel free to drop me a line.
-- Michael J. Hammel
_________________________________________________________________
Date: Wed, 27 Aug 1997 09:04:22 -0700 (PDT)
From: Riley Eller RILEYE@datalight.com
It took Linus to make it happen
It took everyone to make it right
It takes HOWTOs to make it work
It takes the Gazette to make it FUN
Thank You Linux Gazette :-)
Riley Eller
Newbie Jihad Warrior
_________________________________________________________________
Published in Linux Gazette Issue 21, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Next
This page written and maintained by the Editor of Linux Gazette,
gazette@ssc.com
Copyright © 1997 Specialized Systems Consultants, Inc.
"Linux Gazette...making Linux just a little more fun! "
_________________________________________________________________
More 2¢ Tips!
Send Linux Tips and Tricks to gazette@ssc.com
_________________________________________________________________
Contents:
* Changing Video Modes
* Colormap Questions
* Netcat!
* Starting and Stopping Services
* A New Tool for Linux
* Of Logs and Other Things
* Calculator Tip
* Another Way to View Tarred Files
* Script Ease
* Syslog Thing
* Sorta E-mail-to-FAx...Well, to-Printer
* Setting Xterm Title to Current Process
* CVS
_________________________________________________________________
Changing Video Modes
Date: Fri, 08 Aug 1997 22:41:05 -0600
From: Michael J. Hammel mjhammel@csn.net
I don't know how AccelX and XiGraphics and MetroX handle these things.
AccelX is ( I think) a PC graphics company. You might mean Xaccel,
which is the actual program name for Xi Graphics X server. Its product
name is "AcceleratedX". Xi Graphics is the company name.
As for how Xaccel changes its video modes - try CTRL-ALT-+ (thats a
plus sign). I believe that cycles through the various modes. Check the
man pages or manual to be certain. I believe MetroX does similar, but
the keystroke is probably different.
--
_________________________________________________________________
Colormap Question
Date: Fri, 08 Aug 1997 23:47:31 -0600
From: Michael J. Hammel mjhammel@csn.net
The question was "can you force an X application to use its own
colormap in some way other than using a command line option". The
answer is: it depends (aint it always the case?).
An applications ability to use its own colormap is not a "builtin"
part of X. Colormaps are part of X, but the application still has to
add code to make use of colormaps. So if the application doesn't have
any code specifically for handling colormaps (for example, my
XPostitPlus doesn't have any such code) then neither the command line
or any other method will force it to use a private colormap. The
default for applications (like XPostitPlus) is to use the default
colormap, and thats why you often see applications with weird colors
that you can't get rid of till you exit some other application.
Now, if the application *does* have code to deal with colormaps, it
can also make the use of the private colormap a user configurable
option. X provides a mechanism for making an option either a command
line option (eg. -usePrivateColormap) or an X resource. X resources
can be specified in X resource files (like .Xdefaults) or on the
command line using the -xrm option. X is so configurable that the
number of ways for a user to supply configuration information can
often be quite confusing, both for the user and the developer. In any
case, its up to the programmer to make any of these methods available.
None is available by default simply becaue its "an X windows program".
The correct thing for an application to do is to allow the user to
configure the use of the private colormap in at least one way and to
provide a best-guess default for determining if a private colormap
would be the best thing to do or not if the user doesn't provide a
preference. Few applications do this, however. The GIMP does. So do XV
and Netscape. Even my own programs aren't very good at this, although
I intend to get much better in the very near future.
As for an X column, well, I'd love to see one. We just need to
convince some X hack to spend a little time writing articles instead
of code. Thats kinda hard to do. I'll probably be adding some X coding
tidbits to my Muse column, but only with respect to using Motif or
OpenGL in graphical and multimedia applications.
Hope this helps a little.
-- Michael
_________________________________________________________________
Netcat!
Date: 01 Aug 1997 15:46 EDT
From: Jean-Philippe Sugarbroad da1wizard@geocities.com
I was going through back issues of the Linux Gazette and I remembered
a program I use quite frequently... netcat. This program enables you
to open sockets and connect or listen with them - all from a shell
script! It's a great way to quickly fetch web pages or see if a server
is running... It even has UDP 'connection' mode and zero-io mode
(which closes the connection as soon as it succeeds...). The UDP mode
even uses a TCP connection to check round-trip time :) I love it!
Jean-Philippe Sugarbroad
_________________________________________________________________
Starting and Stopping Services
Date: Tue, 5 Aug 1997 18:55:19 -0600 (CST)
From: Terrence Martin twm139@its.to
I was just reading the August version of Linux Journal and I noticed
refrence to rebooting the system after making changes to the
/etc/syslog.conf file in order for those changes to take affect. This
is contrary to a feature that is the main reason I use Linux at home
and at work.
It is only generally necessary to reboot Linux to add/remove hardware
or when installing a new kernel. In the specific case of syslogd(8)
you can inform the server to reread it's initialization file by
sending it a SIGHUP signal.
eg.
kill -HUP `cat /var/run/syslogd.pid`
This will work with many of the servers available for Linux including
(most) httpd(8), named(8), and inetd(8).
Sometimes however it is preferable to actually restart these services.
In Slackware I believe most of your services are placed in a single
script and this makes it a little more difficult to pick and choose
which services to stop and start.
In RedHat it is a little more modular. In the directory
/etc/rc.d/init.d are the scripts that are run on bootup to start
various services.
These scripts allow you to start and stop various services just as if
you had shutdown and rebooted your machine. eg.
# /etc/rc.d/init.d/named.init stop
# /etc/rc.d/init.d/named.init start
This will start and stop the name service.
The scripts supplied with RedHat are not too complex compared to
similar scripts I have seen on other systems. They can usually be
adapted to new services that you may wish to have start on bootup,
without complicating the rc.local file and giving you much finer
control.
If you examine the soft links in /etc/rc.d/rc0.d through
/etc/rc.d/rc6.d you will notice that they link to the files in
/etc/rc.d/init.d. Each of these numbers on these directories refer to
a "runlevel".
As the system boots the /etc/inittab tells the init process which
directories to examine to determine which services to start up, most
systems not running xdm will end at runlevel 3, otherwise it is
runlevel 5.
All of the files(softlinks) in runlevel 3 beginning with 'S' are
executed in order of occurance in the directory, this is controlled by
giving each a number ie
S30syslog -> ../init.d/syslog comes before
S40cron -> ../init.d/cron.init.
Note: Links with the same number are executed in lexical order.
The sequence may be important depending what services depend on other
services.
I put most of the services I add in runlevel 3, as I usually boot into
multiuser mode. You then should add the approriate script link to
/etc/rc6.d as those are the files that are executed on shutdown. Note
the convention here is to begin all soft link names with 'K'. ie
K10named.init -> ../init.d/named.init
Again these scripts are executed on order with the highest number
being last to run.
The net effect of all these links is that with an 'S' preceding the
soft link the script is run with the argument "start" and with a 'K'
it is run with the argument "stop".
Over the last two weeks I have set up and configured a news server,
web server, name server, sshd server, updated the syslog.conf file
plus a hundred other little tweaks on our RedHat 4.x box and I have
not had to reboot once. In fact the system has not been rebooted since
we added a new CPU and SCSI card 31 days ago...I love Linux :)...
Regards
Terrence Martin
_________________________________________________________________
A New Tool for Linux
Date: Fri, 22 Aug 1997 08:29:59 -0500
From: Ian Beth13@mail.utexas.edu
The version posted in issue 20 assumes you have exec access to ALL
dirs under the one you 'TREE'
Here's a modified version which works even in cases of unreadable
folders:
-------------------------------- cut here --------------
#!/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
# Patch by : Ian Kjos, to support unsearchable dirs
# email: beth13@mail.utexas.edu
#
# 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"
if cd $dir ; then
deep=`expr $deep + 1`
search # with recursivity ;-)
numdirs=`expr $numdirs + 1`
fi
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"
-------------------------------- cut here --------------
The changes are to put the "cd $dir" as the predicate of an IF
statement, NOT IN A SUBSHELL, and the recursive part is the switched
clause. This prevents infinite recursion in the case of an unreadable
or unexecable dir.
_________________________________________________________________
Of Logs and Other Things
Date: Sun, 10 Aug 1997 21:47:39 +0200
From: D. Emilio Grimaldo T. grimaldo@panama.iaehv.nl
Hi,
I recently saw on the August issue of Linux Gazzete and some previous
issues about the handling of system logs. Well, it doesn't have to be
complicated, in fact I have written a very useful script/package that
has been around for a couple of years, it is called Chklogs and is
used by major network providers, companies and small-time users of
Linux systems. In fact it is going to be featured in the Linux Journal
some time this year. IT fulfills all the log handling needs. For more
information see http://www.iaehv.nl/users/grimaldo/info/
Catch the link to Chklogs
Best Regards,
Emilio
_________________________________________________________________
Calculator Tip
Date: Sun, 27 Jul 1997 23:43:37 +0200 (MET DST) From: Hans Zoebelein
zocki@goldfish.cube.net
Hello Linux Gazetters,
Here comes a real cheap command line calculator. Since shell scripts
do only integer calculation, you are stuck if you want floating point
precision.
You also want to do sometimes stuff like 'how much is 1200*3/7' at the
commandline without firing up a full blown GUI calculator.
Just for that work you can use the calcme command line calculator,
which is hacked in perl. Dont forget that a shell thinks differently
about 10*3 than a calculator. So do it as 10\*3 or "10*3".
The icing of the cake is the optional formatting. If you supply
something like %.3f as second parameter, the output is nicely
formatted as floating point number and up/down rounded correctly after
3 decimals.
You also can do a calc 10/3 %20.6f which returns a string with 6
digits and 20-6=14 spaces like ______________3.3333. So formatting of
lists in shell scripts is real fun now.
Enjoy!
Hans
#!/usr/bin/perl
#
# The ultimate command line calculator :-^
# Usage calcme <string_to_calculate> [<output_format>]
#
# Input is a string like (10+3)/7 or "(10 + 3) / 7"
# Output is the calculated result of the string (sic!).
# Optional formatting can supplied as 2nd parameter.
if (@ARGV == 0 || @ARGV > 2)
{
die("Usage: $0 <\"formula_to_calculate\"> [<output_format>]\n");
}
$format = "";
$calcme = $ARGV[0];
(@ARGV == 2) && ($format = $ARGV[1]);
$output = eval($calcme);
if(@ARGV == 1)
{
print(STDOUT "$output\n");
}
else
{
printf(STDOUT "$format\n", $output);
}
exit(0);
-- Hans
_________________________________________________________________
Another Way to View Tarred Files
Date: Sat, 02 Aug 1997 02:18:07 +1000 (GST) From: Gerald J Arce
garce@starcommand.mang.net
In issue 19, I read a 2 cents tip regarding viewing a tarred file. I
use less instead..
ex:
tar tzf foo.tar.gz
less foo.tar.gz
Less typing (grin).
_________________________________________________________________
Script Ease
Date: Wed, 6 Aug 1997 01:54:19 +0200 (GMT+0200) From: Trucza Csaba
ctrucza@cemc.soroscj.ro
Hi all,
As a programmer-wannabe, I do a lot of typing. To ease at least the
beginning of each source file (which is mainly the same: include-s,
define-s, imports and stuff), I wrote a script to automatize this. For
the quality of the script please read the notice at the end of my
mail.
(file: se)
---------cut here---------------
#!/bin/sh
#
# source editor (se)
#
# usage: se <filename> <type>
#
# WARNINGS:
# 1. do not supply extension:
# se MyProg.java will make a MyProg.java.java!!!
#
# 2. manually create the
# SE_HOME_DIR,
# SE_HOME_DIR/temp,
# SE_HOME_DIR/templates
#
# man se:
#
# create two files for each type of the source you want to se.
# the script will copy the first file+filename+second file into a new
# file (you got it?:-)
#
# so: if you want java, create two files:
#
# templates/java.1:
#
# ---8<---
# public class
# --->8---
# (Do not put a newline at the end!)
#
# templates/java.2
#
# ---8<---
# {
# public static void main(String args[]){
# }
# }
# --->8---
#
# the script for se MyProg java (or jus se MyProg if the last time you
# used java as type) will create a new file called MyProg.java:
#
# public class MyProg
# {
# public static void main(String args[]){
# }
# }
#
# examine and modify at will
#
# author: Trucza Csaba ctrucza@cemc.soroscj.ro
#
# this script may be full of errors
#
SE_HOME_DIR=~/.source-editor
LAST_USED=$SE_HOME_DIR/last_used
if [ -f $LAST_USED ] ; then
SE_DEFAULT_TYPE=`cat $LAST_USED`
fi
case $# in
0)
echo "no parameter"
if [ -z $SE_DEFAULT_TYPE ] ; then
SE_DEFAULT_TYPE=java
fi
FILE_TYPE=$SE_DEFAULT_TYPE
FILENAME=~/.source-editor/temp/temp.$FILE_TYPE
;;
1)
echo "filename"
if [ -z $SE_DEFAULT_TYPE ] ; then
SE_DEFAULT_TYPE=java
fi
FILE_TYPE=$SE_DEFAULT_TYPE
FILENAME=$1.$FILE_TYPE
;;
2)
echo "name and type"
FILE_TYPE=$2
FILENAME=$1.$FILE_TYPE
;;
esac
echo "FILE_TYPE="$FILE_TYPE
echo "FILENAME="$FILENAME
if [ -f $FILENAME ]; then
echo file exists
else
build-template $FILE_TYPE $1
mv ~/.source-editor/templates/$FILE_TYPE.template $FILENAME
fi
echo $FILENAME
echo $FILE_TYPE > $LAST_USED
jstar -tab 4 $FILENAME
---------cut here---------------
The second script is a simple backup script, to back all the sources
up and edit the tracking file.
(file: backup)
---------cut here---------------
#!/bin/sh
#
# kind of backup with kind of version control
# usage: backup
#
# backs up the current directory (well not all of it, just your
# programs)
#
# 1. creates a dir named backup (or whatever)
# 2. in this directory will be a tracking file, a plain text file
# in which you can write some comments every backup
# 3. optionally in the file named filelist you can write the names of
# the files you want to back up
# 4. examine and modify at will
#
# author: Trucza Csaba ctrucza@cemc.soroscj.ro
#
# this script may be full of errors
#
#
# where to back up
#
if [ -z $BACKUPDIR ] ; then
BACKUPDIR=backup
fi
if [ ! -d $BACKUPDIR ] ; then
mkdir $BACKUPDIR
fi
#
# last version backed up
#
LAST_FILE=$BACKUPDIR/last
if [ -f $LAST_FILE ] ; then
VERSION=`cat <$LAST_FILE`
else
VERSION=0
fi
let VERSION=$VERSION+1
#
# prepare next backup directory
#
NEXT_DIR=$BACKUPDIR/ver.$VERSION
mkdir $NEXT_DIR
#
# get files to back up
#
LIST_FILE=$BACKUPDIR/filelist
if [ -f $LIST_FILE ] ; then
cp `cat $LIST_FILE` $NEXT_DIR
else
#
# if no filelist found, backup C and Java files
# modify as you wish
#
cp *.c $NEXT_DIR >/dev/null 2>&1
cp *.h $NEXT_DIR >/dev/null 2>&1
cp *.java $NEXT_DIR >/dev/null 2>&1
fi
#
# update last
#
echo $VERSION >$LAST_FILE
#
# edit trackfile
#
TRACK=$BACKUPDIR/track
echo >> $TRACK
echo >> $TRACK
echo "=====================================================================">>
$TRACK
date >> $TRACK
echo "Version: "$VERSION >>$TRACK
#
# here use your favorite editor :)
#
jstar $TRACK
---------cut here---------------
They should be self-explanatory. but, These scripts should not be used
for design or development of nuclear, chemical, biological, weapons or
missile technology, or any other places where humans can be hurt
_________________________________________________________________
Syslog Thing
Date: Thu, 07 Aug 1997 15:00:29 -0700
From: Kent Friis dk5f@ehs.dk
In issue 20, I saw a 2c tip regarding syslog, Including changing the
config file, and REBOOTING. Now wait a minute, I thought this was
Linux. How can one get uptime's of 300+ days, if you need to reboot
every time you change a config file.
The solution is simply to edit the config file, and kill -HUP (pid of
syslogd).
You should NEVER need to reboot, except to install a new kernel.
Kent Friis.
_________________________________________________________________
Sorta E-mail-to-Fax...Well to-Printer
Date: Fri, 8 Aug 1997 20:04:30 +0500 (PKT)
From: Tee Emm tm@super.net.pk
Hello,
I can bet that many of you readers will try out this tip atleast for
once. Here we go:
I work at an ISP here in Pakistan with 4 more shift engineers. We have
offices in three different locations and, although email and talk are
used very frequently, we sometime require ABSOLUTELY IMMEDIATE
responce from the other office. Emails remain unchecked and talk
request are sometimes ignored because the other party might be busy
doing something else on a talk-disabled terminal. Well, you cannot
ignore a Panasonic Dotmatrix printer printing out messages in your
control center!
One of my so-to-say boss talked of having a utility which will poll a
POP3 mailbox every few seconds and printing out any mail that might be
in the box. He, being a visual basic guru, started writing a windows
based application that would do the required. I, being a die hard
Linux creature, started thinking how I can do the same on my dear
Linux box. Well, it took me a day to ponder on this issue and when I
clicked, it was just a breeze! Sixteen key strokes and I was ready
with my system. I yelled 'Windoz Suxs, Linux Rules'!
I edited the /etc/aliases file and keyed in the following line:
urgent: "| lpr"
saved, the file and did a 'newaliases' and bingo! Any mail sent to
urgent@super.net.pk was immediately printed on the screaming dot
matrix printer. My boss was duly stunned!
(Note: You must have your 'lpr' command working before you can go
ahead with this tip.)
Tariq Mustafa,
_________________________________________________________________
Setting Xterm Title to Current Process
Date: Tue, 12 Aug 1997 01:09:02 -0500 (CDT)
From: Rob Mayoff mayoff@dqd.com
I saw this tip the Gazette: 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 #)
If you use ksh instead of bash, you can get the same effect without
changing the source:
typeset -A Keytable
trap -- 'eval "${Keytable[${.sh.edchar}]}"' KEYBD
[[ "$TERM" == xterm ]] && \
Keytable[$'\r']=$'[[ -n ${.sh.edtext} ]] && print -n "\E]2;${.sh.edtext}\a"'
You can download ksh (the POSIX-compliant Korn shell) for free from
http://www.research.att.com/orgs/ssr/book/reuse
_________________________________________________________________
CVS
Date: Thu, 14 Aug 1997 11:08:27 -0400
From: Paul Rensing paulr@dragonsys.com
Mario Storti wrote:
Using shar + RCS to Backup Set of Source Files
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 think a good way to handle this is by "upgrading" to CVS. CVS is a
version control system built on top of RCS and was designed
specifically to handle version control of large trees of files (the
company who wrote it was a Sun VAR and handled the > 1000 files which
they regularly received from Sun).
Once you have the project set up, you could simply do "cvs commit"
from the top directory of a project, and CVS will check in all the
changes to all the controlled files in the tree. If you are using this
for "backup", you would only need to keep a copy of the CVS
"repository".
Paul Rensing
_________________________________________________________________
Published in Linux Gazette Issue 21, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
This page maintained by the Editor of Linux Gazette, gazette@ssc.com
Copyright © 1997 Specialized Systems Consultants, Inc.
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
News Bytes
Contents:
* News in General
* Software Announcements
_________________________________________________________________
News in General
_________________________________________________________________
Linux® Trademark Resolution
Ownership of Linux® Trademark Resolved
Monterey, California, August 20, 1997 - A long standing dispute over
ownership of the Linux® operating system trademark has been resolved.
As a result of litigation brought by a group of five Linux companies
and individuals against William R. Della Croce, Jr. of Boston,
Massachusetts, Della Croce has assigned ownership for the registered
mark to Linux Torvalds, the original author of Linux, as part of the a
settlement agreement.
The plaintiffs in the suit were Linus Torvalds; specialized Systems
Systems Consultants, Inc. (the Linux Journal of Seattle; Yggdrasil
computing, Inc. in San Jose; Linux International, Amherst, NH; and
Work Group Solutions of Aurora, CO. Non-plaintiffs Red Hat Software,
Inc., Metrolink Inc., and Digital Equipment Corporation supported the
litigation and contributed to the cost of the litigation.
The five plaintiffs brought suit against Della Croce in the U.S.
Trademark Trial and Appeals Board, in November 1996. Della Croce had
obtained registration of the Linux mark in September 1995, which
created a storm of protests by the Linux community, who felt the mark
belonged to Torvalds or the Linux community and not to any individual.
In an attempt to correct the situation, the plaintiffs retained the
internationally known intellectual property law firm of Davis &
Schroeder of Monterey, California, who handled the case on a greatly
reduced fee bases, as a service to the Linux community.
The five plaintiffs, through their attorneys, announced that (1) the
matter has been settled by the assignment of the mark to Linus
Torvalds, on behalf of all Petitioners and Linux users, and the
dismissal with prejudice of the pending PTO Cancellation Proceeding;
and (2) that Respondent was reimbursed for his trademark filing fees
and costs by Petitioners. The other terms of the Settlement Agreement
are confidential.
All inquiries should be referred to Petitioners' law firm, Davis &
Schroeder at 408-649-1122 or by email at ggd@iplawyers.com. A copy of
the original Cancellation Petition filed in the TTAB, can be found at
http://www.iplawyers/text/linux.htm.
_________________________________________________________________
Linux Journal 1996 Back Issue CD-ROM
Linux Journal announced the release and ship date of their 1996
back-issue CD-ROM. It will be available September 17, 1997. LJ's first
back-issue CD-ROM will consist of twelve issuews of Linux Journal
published during 1996. Features covered in 1996 include; systems
administration, World Wide Web, back-ups, Linux distribution
comparisons, software development, shell programming, getting new
users started, graphics and several other topics.
An HTML interface will allow you to access the CD-ROM infromation
using any World Wide Web browser. For those that don't have a World
Wide Web browser, gzilla, has been included on the CD-ROM.
Linux Journal's 1996 back issues CD-ROM is $19.95 plus shipping and
handling and can be ordered directly from Linux Journal.
For more information take a look at http://www.linuxjournal.com/.
_________________________________________________________________
Vi Mugs
You might be interested in the vi reference mugs found at
http://www2.cic.net/~gpoulos/vimug_main.html. Check them out!
_________________________________________________________________
New Mailing List
Check out a new mailing list for Linux users to help each other with
problems.. To subscribe send email to majordomo@ourweb.net with the
following in the body: subscribe linuxlst
_________________________________________________________________
Linux Aptitude Test
There is a project which is trying to establish a quantitative measure
to assist in determining a person's knowledge and general usefulness
in Linux setup, configuration, and maintenance. The project is aiming
to create a test that can be used to assess an employee's strenths and
general understanding of Linux.
Take a look at http://www.icv.net/LAT
_________________________________________________________________
Software Announcements
_________________________________________________________________
The Hawkeye Project
"Hawkeye" is the name of a new Linux Web server program, which has
recently been released to the public. IT is an Internet/Intranet
server suite, implementing Internet protocols for information
interchange. A short list of the most important functions of Hawkeye:
* HTTP 1.0 Server, HTTP 1.1 coming soon
* POP3 / SMTP Server (E-Mail)
* NNTP Server (Newsgroups)
* FTP Server (File area)
Hawkeye is running under the LINUX operating system and requires the
Linux SQL database MySQL http://www.tcs.se. Hardware requirements are
much like what you would need to build a normal Linux system. For
optimal performance, we recommend a Pentium machine withat least 16
Megabytes of RAM. Hawkeye itself uses very little Harddisk space, so
the size depends mainly on your site. Check it out on the Hawkeye Web
Home Site
_________________________________________________________________
LinkScan 3.1 Released
Electronic Software Publishing Corporation introduced a number of new
features in LinkScan version 3.1. There is added ability to check
hyperlinks that are embedded within Adobe Acrobat PDF files and
enhanced TapMap features such as...
Free evaluation copies of LinkScan 3.0 may be downloaded from the
company's website at: http://www.elsop.com/linkscan
_________________________________________________________________
Published in Linux Gazette Issue 21, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
This page written and maintained by the Editor of Linux Gazette,
gazette@ssc.com
Copyright © 1997 Specialized Systems Consultants, Inc.
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
The Answer Guy
By James T. Dennis, jimd@starshine.org
Starshine Technical Services, http://www.starshine.org/
_________________________________________________________________
Contents:
* Linux Control Panel
* Linux Command Line Arguments
* More Random Crashes
* More on Disk Defrag
* X-Windows is Crashing
* Lunx and Frames
* More on ftpd
* DNS Problem
* Sendmail
* Linux PPP Server
* Linux/Unix Emulator
* LILO Concerns
* Crypt
* Apache 1.2.1
* PPP and Internet MCI
* Enabling Automounter on a Linux Notebook
* XLocks Monitor
* Pop3d That Doesn't Use /etc/passwd
* Configuration of Two Ethernet Cards
* Attaching a Colsole to a PC
_________________________________________________________________
Linux Control Panel
To: ggonzale@ix.netcom.com
I have recently installed RedHat Linux ver 4.2 on my pc . My problem
is that I cannot get the control-panel to work when I run startx or
XDM . The panel comes up but I am unable to activiate any buttons in
control-panel . I don't know what I did wrong or what to check !
Please help...
Are you running it as root? Are there any interesting error messages
in /var/log/messages? Are there any interesteing error messages back
on the text console from which you ran "startx" (you can switch out of
XFree86 with {Ctrl}+{Alt}+{Fx} -- where {Fx} is the function key that
corresponds to any of you other virtual consoles). Are you sure you
installed the Python and related libraries (last I heard all of the
Red Hat GUI control panel stuff is written in Python).
As I've said several times -- I'm not a Red Hat specialist (although
that is what I'm running here at the moment) and I barely use X (since
I vastly prefer old fashion text mode).
Have they ever gotten a support line running that can answer questions
that are specific to their code? (Hey! I wouldn't even object to a
paid support line -- if it was good).
Thank you for responding to my question I will look into the areas you
suggested . However I have one other question that is how would I
activate my modem from a Linux command line? I thought I needed the
xwindow to do that in the first place.
One of the virtues of Unix is that you don't need X Windows to do
anything except run X applications -- there are other ways to access
graphics (SVGALib, MGR) use your mouse (GPM) do cut and paste
(GPM/select, 'screen'), provide task/session switching (virtual
consoles, and 'screen'), do screen management ('splitvt', emacs) etc.
In answer to your question regarding modems: There are a number of
programs that are included with the typical Linux distribution that
may use your modem:
pppd is the PPP daemon -- it usually uses the 'chat' command to talk
to the modem.
minicom is a vaguely Telix like ncurses terminal emulation package
(Telix is a popular shareware MS-DOS program). It provides a
fullscreen, color interface.
'cu' is a "call utility" usually associated with UUCP. It uses the
UUCP configuration files for information about your modem -- if you
have those configured. It's a very limited communications package --
that's only virtue is that it is small.
UUCP is a suite of programs -- of which the uucico program actually
talks to the modem. You almost certainly are not planning on using
this. However UUCP was (and still is) used as a mail, file, and
netnews transport protocol for years before TCP/IP existed. I still
use it for my mail.
C-Kermit is a communications package from Columbia University. You can
fetch it freely -- but it can't be included with Linux (or other)
CD-ROM collections of software due to it's licensing model. If you
decide you like it you should buy a copy of the C-Kermit book by Frank
da Cruz (the program's principal architect and head of the project
since it's foundation).
C-Kermit is also a scripting language and can be used as a telnet or
rlogin client, and Kermit is a file transfer protocol which can be
used by C-Kermit over any communications channel that it can
establish. I wrote an article for SysAdmin Magazine on the subject
just a couple of months ago.
There are other program that access your modem if you want to use
them, There's a SLIP package which usually controls the modem via
'dip' -- there's a variety of different "getty" implementations which
"Get a tty" (terminal) so that you can log in from a terminal, or
another system running a terminal package.
I use mgetty which not only allows incoming dial-up data connections
but adds support for FAX and even voice/DTMF with some modems. That
package also includes "sendfax" -- a program for outgoing faxes. efax
is another package for support FAXes under Linux.
Judging from your earlier question regarding the Red Hat Control Panel
I suspect that you're just interested in configuring your system for
PPP access to your Internet service provider (ISP). There is a script
floating around (on http://sunsite.unc.edu somewhere) called
'pppsetup'. I think this will allow you to setup your PPP
configuration from a text console (I used plain old 'vi' and made my
own configuration files -- so I've never used this -- though I've seen
it recommended many times).
There are several HOW-TO's on configuring PPP (and SLIP) which can be
found at http://sunsite.unc.edu/LDP/HOWTO Look for the ones that refer
to "PPP" and "ISP."
Hope all of that helps.
-- Jim
_________________________________________________________________
Linux Command Line Arguments
From: Ronald B. Simon ronald.b.simon@boeing.com
Where can I find a list of the linux boot command line arguments?
e-mail addresses:
Look in the following HOW-TO document: BootPrompt HOWTO
http://sunsite.unc.edu/LDP/HOWTO/BootPrompt-HOWTO.html
-- Jim
_________________________________________________________________
More Random Crashes
Date: Fri, 01 Aug 1997 14:40:06 -0700
From: sloth sloth7@hotmail.com
Hi, I wrote to you a while ago with a problem regarding random crashes
while installing Linux... I recently tried again, with exactly the
same hardware but a different hard disk and the whole thing worked
fine. unfortunately, the hdd i used was only and 80mb conner :). The
hard disk i want to use is a 2.1 gb Quantum Fireball. When I try on
this hard disk the computer locks up at a different place each time
during the installation ( but only when it is decompressing the
files). I have an IDE Hard disk controller.
h/w list:
* Intel Pentium 150 CPU
* Intel Triton VX m/b
* S3 Virge 3d graphics card
* 16mb EDO RAM
* 2.1gb Quantum Fireball
* onboard (ide) hdd controller
* 24x IDE CDROM
any help would be much appreciated.
cheers, sloth...
This new information about your situation suggests two possibilities:
1) Your HD is bad -- possibly it has some bad sectors that the drive
electronics haven't mapped out, or possibly it's something more
subtle.
2) Your controller (IDE) is incompatible with your HD and/or the
combination of your HD and CD drive.
Some notes:
Any IDE drive that's over 540Mb requires an EIDE (enhanced IDE)
controller/BIOS. There have been cases where specific IDE devices
weren't compatible with one another -- where a particular combination
of devices couldn't share the same IDE channel.
So, try getting a new EIDE controller and disabling the interface on
the motherboard (or configuring the new on as a "secondary" IDE
channel. Try running the two devices on the new EIDE controller if you
can get it installed as the primary (but don't blindly trust the
motherboard documentation -- I've heard that some of the "disable me"
settings on some boards just don't work). Then try running the CD-ROM
drive and the hard disk on separate channels (controllers).
If you can get a copy of Spinrite or the Norton Utilities for DOS then
you might install a small DOS partition and run that on your Fireball.
It might be able to map out any bad sectors.
If you get a new controller (which will be less expensive then buying
either of the software packages I just mentioned) I'd try a a
QuickPath Portfolio or a GSI brand multi-funtion card with 4 high
speed (16550 UART) serial ports. The QuickPath is an ISA card (rather
than taking up one of your PCI slots for a set of relatively slow
interfaces) and is what I'm using in a couple of my machines here. It
combines floppy, four serial, two parallel, two IDE channels and a
game port (for 13 devices in all).
Hope that helps. Unfortunately the diversity and cheapness of PC
hardware results in a diversity of inexplicable incompatibilities and
a common "cheapness" in quality that's imposed by the competition. So,
as much as I hate to recommend "black magic" experiments in new
hardware -- it's frequently the most effective approach.
-- Jim
_________________________________________________________________
More on Disk Defrag
Date: Mon, 4 Aug 1997 20:27:11 +0200
From: Markus Enzenberger Markus.Enzenberger@physik.uni-muenchen.de
...them in any Linux books that I have consulted. Is disk
degragmentation not needed in maintaining a Linux file system?
No, disk fragmentaion is a particular problem of the DOS FAT file
system and its descendants. You can see the fragmentation status of
one your partitions by running the e2fsck file system check program as
root on an unmounted partition. It is run every boot time too. It will
report the amount of non-contiguous files.
- Markus
_________________________________________________________________
X-Windows is Crashing
Date: Sun, 13 Jul 1997 19:34:12 -0700
From: Gerramie Dinselgerr@weaveworld.unix.net
Hello. I am searching all over for an answer or a pointer to this
problem:
I upgraded my memory from 18 megs to 48. Now, X-Windows crashes on me
when I load FVWM2.. Odd, because XDM loads fine and will sit there,
waiting, without crashing for as long as you want. Also, console mode
works wonderfully...
Can you offer any help? Gerramie Dinsel
The first guess might be that the new memory is bad -- and that you
normal (console) usage -- and the overhead of xdm just doesn't "land"
on the bad chips.
One way to test this would be to do something from console mode that
will use *a lot* of memory. make's -j switch (to parallelize as many
gcc processes as memory allows) is a good way to test for this sort of
thing. Just make a new kernel (no need to even to an install of it --
just the make is fine).
If that runs O.K. than we have linked the problem X -- possibly to any
graphical use of the card beyond xdm's. So we try to run X with no
window manager and a minimal configuration file (no setting of special
root images like xli, xloadimage, or xsetroot, no -16bpp or any of
that).
It could be that your video card uses a region of address space (a
video frame buffer). Look carefully in the configuration settings, or
call the manufacturer's tech support. That's the most likely problem.
If you have access to another, simpler video card -- try swapping it
in and seeing if that helps. If it does than you need to reconfigure
that video card or use one that's better behaved.
If that doesn't help then it's just anyone's guess what's happening.
Try rearranging the adapters in your card cage -- it may be that the
video card is emanating some noise or crosstalk that's affecting your
RAM. Re-arranging adapters used to be a time honored sport among PC
technicians. I think it's more rare in the PCI era -- but you don't
even mention what sort of bus your using -- and I have no information
about your hardware. Besides -- it can't hurt.
If it still doesn't work try switching to 32Mb. This might be some
weird chipset bug on your amount of RAM. More systems work with 16 or
32Mb of RAM than with 24 or 48Mb.
There are a plethora of parameters you can pass to the kernel for
excluding specific memory address ranges from its use. They might help
-- but I'd hate to have to experiment with them.
-- Jim
_________________________________________________________________
Lynx and Frames
Date: Tue, 05 Aug 1997 02:48:26 -0700
From: Scott omegam@COMMUNIQUE.NET
Hey Jim, Caught this quote in your article:
(Warning for Lynx users -- both of these sites use frames and neither
bothers to put real content in the "noframes" section -- Yech!)
Current versions of lynx support frames and tables in a fairly nice
and elegant fashion. They even handle cookies.
Check out http://lynx.browser.org
Just thought you should know. Sure, I use Netscape for some of my
browsing and I hope to begin using Mnemonic soon. But for really fast,
heavy-content oriented browsing, lynx on the console or in a
color-xterm does the trick.
Scott
Oh, I know that Lynx 2.7.1 can handle frames, by simply showing you a
list of the available frames as a set of hot points at the top of the
rendered page. I use Lynx for almost all of my web browsing.
The problem is that the HTML editors used by many sites don't put
meaningful names on the frames so you get a list of: frame01.html,
frame02.html, etc. instead of something like: navigation.html,
main.html, toolbar.html etc.
It's as irritating as those sites that use large tableaus of image
icons with no Alt="" attributes or imagemaps that with no sane
information in the .map file. (The current Lynx can also handle most
types of image maps.
-- Jim
_________________________________________________________________
More on ftpd
Date: Tue, 05 Aug 1997 01:59:18 -0700
From: Benjamin Peikes benp@npsa.com
Jim,
I am currently trying to set up some user accounts on our webserver so
that other people working on their sites can ftp their files up and
down easily. I am using wu.ftpd and have set up the line
guestgroup ftponly
in /etc/ftpaccess. I have also added the group into /etc/group and
added the users name to the group. The problems is that everything
seems to work correctly except that ls and dir return nothing during
an ftp session.
1. ftpd chroot's to the correct directory.
2. ftpd changes to the correct home directory.
3. you can upload and download files without any problems if you know
the name of the files you want.
4. I have made the directories world rwx just to make sure it wasn't
a permissions problem.
I'm so close that it's driving me nuts. The main problem arises when
people need to transfer entire directories. Most of them are using GUI
driven ftp clients and the lack of directory listings kill those
clients. I know there must be a simple solution. Any help would be
great.
Ben
You're probably having problems with the shared libraries or devices
that are typically required by the ls command. Some version of ls
require that you have a /dev/null and/or a /dev/tcp in order to work
properly. Most versions of ls require some shared libraries and all of
them require the existence of some of /etc/passwd and /etc/group files
(even with completely fictional data in them) in order to resolve UID
numbers into symbolic ownership information to display in long
listings.
For real information about setting up wu-ftpd on any platform look at
the following resources: http://www.landfield.com/wu-ftpd/
http://www.cetis.hvu.nl/~koos/we-ftpd-faq.html (Or, send mail with
subject of "send faq" no quotes, body ignored).
... and information about the guestgroups feature in particular can be
found at: http://www.landfield.com/wu-rtpd/guest-howto.html
... or ftp://ftp/fni/com/pub/wu-ftpd/guest-howto
A document describing virtual ftp servers:
http://www.westnet.com/providers/multi-wu-ftpd.txt
Ftpaccess on virtual ftp servers
ftp://ftp.meme.com/pub/software/wu-ftpd-2.4.2/README.ALT.FTPACCESS
Hope that covers it.
-- Jim
_________________________________________________________________
DNS Problem
Date: Mon, 04 Aug 1997 18:31:36 -0700
From: Dr Ceezaer ceezaer@cyberspace.org
(Ping doesn't work -- but /etc/resolv.conf and /etc/hosts.conf are
correct and nslookup works).
It used to work before I upgraded my library files (/lib and /usr/lib)
so I don't think there is an error in /et/resolv.cfg
Well... I've solved the problem. First I re-installed Linux on a small
120 MB harddisk. By comparing all relevant directories I found that I
had a file called libc.so.5 (no symlink) in /usr/X11R6/lib plus the
normal one in /lib. By removing the file /usr/X11R6/lib/libc.so.5 it
all works again :)
Ahh the mysteries of the shared libraries. I've always wondered how
the dynamic loading code searches for these .so (shared object) files.
However I've never wondered enough to leave stray copies of them
laying around.
Well... I would need such a HOWTO, I didn't even got chroot to run...
The only real trick is to do a 'cd' before trying to execute the
command -- otherwise your process is very confused becuase it can't
access its current working directory (cwd).
The other problem is that your target program must be contained in the
chroot tree with any shared libraries and usually it will need a set
of /etc/ files including the termcap and maybe a set of
/usr/lib/terminfo files.
-- Jim
_________________________________________________________________
Sendmail
Date:Sun, 10 aug 1997 14:4457 -0700
From: Stephen P. Smith ssmith1@vilma.bcasd.az.honeywell.com
When I send mail (using the mail program) to someone my reply to
address is wrong. What sendmail is sending is
account@computername.isp.com What I want is popaccount@isp.com What do
I need to change to fix this
Stephen Smith
You use the "masquerade" feature in your local sendmail configuration.
I recommend that you use the m4 macro package to reate a new sendmail
configuration.
First copy the old configuration. I like to use RCS -- the revision
control system to track changes to my configuration files. Here's how
you'd do that:
(As root)
# cd /etc
# mkdir RCS
(unless you already have one)
# ci sendmail.cf
(checks the cf file into the RCS directory)
# co -l sendmail.cf
(checks it back out, locked for editing)
Now you want to create a sendmail "mc" file. This is a file that uses
sendmail specific macros -- which is then processed by the m4 program
to generate the full sendmail.cf. A typical sendmail.cf is over a 1000
lines long -- a typical "mc" file is less than 20.
Under my Red Hat installation the sample "mc" files are located in
/usr/lib/sendmail-cf/cf/. You can put yours there, or you might use
/usr/local/lib/sendmail (and perhaps add a symlink under the other
path). This helps maintain the separation between your local changes
and the distribution's files "as shipped."
I name my "mc" files after my hostnames -- so mine is "antares.mc." It
looks like this:
divert(-1)
include(`../m4/cf.m4')
VERSIONID(`@(#)antares.uucp.mc .9 (JTD) 8/11/95')
OSTYPE(`linux')
FEATURE(nodns)
FEATURE(nocanonify)
FEATURE(mailertable)
FEATURE(local_procmail)
FEATURE(allmasquerade)
FEATURE(always_add_domain)
FEATURE(masquerade_envelope)
MAILER(local)
MAILER(smtp)
MAILER(uucp)
MASQUERADE_AS(starshine.org)
SITECONFIG(uucp.antares, starshine.org, U)
define(`UUCP_RELAY', a2i)
define(`UUCPNAME', starshine)
define(`UUCPNODES', a2i)
define(`RELAY_HOST', a2i)
define(`RELAY_MAILER',uucp)
define(`SMART_HOST', uucp-dom:mailer)
define(`PSEUDONYMS', starshine|antares|antares.starshine.org|starshine.org)
undefine(`BITNET_RELAY')
I've seen some of these that end each line with a 'dnl' -- which is a
macro to "do newline" -- I don't bother with that.
You'll want to ignore all the UUCP references and my SITECONFIG line
(mine is also a UUCP reference -- so yours will be different --
preserve whatever is in the samples that mathc your current
configuration).
What your interested in here is the various "masquerade" lines. Now
you'd just 'cd' to the directory where you've created this "mc" file
and issue a command like:
m4 < $MYFILE > /etc/sendmail.cf
(where you replace $MYFILE with whatever you named your "mc" file, of
course).
It's also possible to to simply add a line like:
DMisp.com
... directly to your /etc/sendmail.cf. DM "defines masquerading" to be
for "isp.com" (from your earlier example). This is easier, on the one
hand -- but learning the m4 configuration method will serve you well
if you ever have to do upgrades to your sendmail -- and it's a
valuable skill if you ever have to administer Unix systems as (or as
part of) your work.
There are a variety of HOWTO's on configuring your mail to work well
with your ISP. I don't have my PPP connection up at the moment -- but
you should search the SSC web site (http://www.ssc.com) for the the
HOWTO archive and look for the strings "ISP" and "mail."
-- Jim
_________________________________________________________________
Linux PPP Server
Date: Sun, 10 Aug 1997 05:34:45 -0700
From: sengir@ozemail.com.au
I have a Linux PPP server but I can not get my Windows95 client to do
the "automatic" login. Sure, I can get it all to work if I check
"bring up terminal window after connecting".
All I have is the login: prompt, followed by the Password: prompt then
right into PPP.
What gives ?
TIA
-Rob
Here's a URL that talks about getting Linux mgetty to work with
Microsoft's infamous "AutoPPP":
ISP Resources - mgetty info(AutoPPP)
For more general information about mgetty look at: Mgetty + Sendfax
Documentation Centre
-- Jim
_________________________________________________________________
Linux/Unix Emulator
Date: Sun, 10 Aug 1997 05:30:18 -0700
From: Jun Liu stefan@public.sta.net.cn
Hi, Dear James,
First I'd like express my gratitude for your great work on the Linux
Gazette. But for the Linux/Unix Emulator, I think you're somehow
wrong. Actually there do exist at least one such product as far as I
know. When I was staying in Japan, I've learned there're quite some
people there use a software called BOW (namely BSD on Windows ), which
is a BSD emulator for Windows. Check out
http://www.ascii.co.jp/superascii/bow if you do know Japanese. In
short, this is a BSD kernel emulator for 4.4BSD-Lite based BSD Unix
program. It's said most BSD binaries (x86 certainly,character mode
applications only, no X, no debuggers like gdb) can be run unmodified.
Actually, there has been quite a bit of work on supporting Unix under
NT. Cygnus Support (http://www.cygnus.com) has made quite a bit of
progress with their GNU-Win32 Project
A couple of other sources worth noting are: OpenNT 2.0 Server Data
Sheet UNIX to NT Resource Center
There was also a paper presented at the Anaheim USENIX conference this
year:
* Title: Porting UNIX to Windows NT
* Author: David G. Korn
* Pages: 43-57
* Publisher: USENIX
* Proceedings: 1997 Annual Technical Conference
* Date: January 6-10, 1997
* Location: Anaheim, CA
* Institution: AT&T Labs-Research
The advantages are, you have the rich development environment from
Unix, and the nice( ? ) UI from Windows as well as lots of Windows
applications around all at the same time. It's said BOW Version 1.5
which is Windows95 compatible, is already published last year in May
as a book and available in Japanese bookstores, priced at 9,800 yen
with one floppy disk and one CD-ROM.
Hope this can be helpful.
Best regards.
Stefan
Again, in the article to which you refer I was asking what the
original person was asking for. Many Unix packages have been ported to
NT, Windows '95, and DOS (emacs, perl, awk, most of the simple
commands like grep, cp, find, and a couple of shells: Korn, bash) --
and it would certainly be possible to host some binaries under (ELF,
iBCS).
At what point to NT become Unix?
-- Jim
_________________________________________________________________
LILO Concerns
Date: Sun, 10 Aug 1997 03:50:35 -0700
From: Tibs tjf1@acpub.duke.edu
I have been looking all over for an answer to my linux
question...nobody seems able to help so I thought I'd ask you (liked
the LG web stuff very much). I am about to take the plunge and install
linux but I am concerned about how LILO will work on my system. I have
two IDE drives on my system. The first is 1 gig and I have DOS, Win95,
etc. on it and that's what I boot to. The second is divided into two
1.5 gig partitions, and 1 500 meg partition. I planned on putting
linux on that last 500 meg partition.
First: you'll want to learn how to use paragraphs. Break your question
down into short steps so we can read it (particularly when we're doing
the reading at 3:30 in the morning after hacking all day)
.... The problem is that in order for my computer to recognize the
full 3.5 gig capacity of the second hard drive, the hard drive
installation floppy (it's a Maxtor) installed something called
EZ-BIOS. So booting to DOS or Win95 now works and my BIOS recognizes
all 3.5 gigs of the space. When I boot to a floppy I have to use the
EZ-BIOS "boot to a:" option otherwise I can only access the first
partition on the second drive. So when I install linux and add LILO,
will LILO start doing stuff after the EZ-BIOS stuff loads? If so then
it is not a problem but if LILO starts before EZ-BIOS does it's thing,
then I don't think I'll be able to access my 500 meg partition. And
since that's wherelinux would be, that would be a bit of a problem.
You're using an alternative master boot program which will be
incompatible with any other boot software.
You should use LOADLIN and forget all about LILO.
I've written about LOADLIN several times in this column -- so please
look back through some of the pack issues for details.
So I guess my question would be: 1. do you know anything about this
EZ-BIOS stuff and it's compatibility with linux (the Maxtor people
aren't helping with linux questions)
The EZ-BIOS and the old Ontrack Disk Manager and similar drivers were
originally created to allow DOS to see larger partitions (which they
did by hooking into the BIOS Int 13H disk access routines before DOS
was loaded -- by replacing the MBR). They have always been a bad idea.
Now that DOS supports partitions larger than 32Mb these programs have
a different purpose -- to allow older systems to see IDE drives that
are larger than 512Mb. The BIOS interface only supports a maximum of
1024 cylinders of up to 64 sectors each. A typical drive is less than
16 heads. This "geometry" gives a maximum of about 528Mb. It's
possible to "lie" to some BIOS' and double the number of heads -- or
even go up do 255 "virtual heads" -- the drive electronics will simply
translate for you.
Essentially this is how SCSI and EIDE drives give you access to larger
disks (up to about 9Gb).
Your other alternative is to get an EIDE controller and get rid of the
non-standard software (sofware which isn't supported under OS that I
know of, Linux, any Unix, FreeBSD, NT, OS/2 or anything other than
DOS).
2. is there some workaround that would still let me use linux if
EZ-BIOS would be a problem (like using a boot floppy everytime I
wanted to use linux, or something like that)
You can probably just use LOADLIN. However you might have to cook up
some weird boot time parameters (you can store them in the bathc file
that invokes LOADLIN) to tell the kernel what the drive geometry
really is -- so it doesn't step on anything.
Here are the two HOWTO documents you want to read:
Large Disk mini-HOWTO
Loadlin+Win95 mini-HOWTO
-- Jim
_________________________________________________________________
Crypt
Date: Fri, 08 Aug 1997 20:47:11 -0700
From: David Saccon, dasac@speed.it
Hi; I'm a Linux enthusiast bla bla bla, compliments for the good work,
etc etc.
Well, charmed I'm sure!
I don't know if an e-mail to this address is the right way to ask you
a question.
It isn't really -- but most of the readers of Linux Gazette's "The
Answer Guy" column haven't see the "tag@" address that I currently
prefer.
Please feel free to get rid of this mail if it bugs you. Anyway, my
question is: where can I find an implementation of the fine tool
"crypt" for Linux ? You know, "crypt <myfile >myfile.x password", and
back to the clear text the same way.
I'm not sure that the traditional Unix 'crypt' command is all that
"fine." I'd suggest that you obtain a copy of PGP from one of the
international sites that carry it.
(Please don't obtain it from any of my "free" fellow U.S. citizens --
since it would be illegal for them to exercise this particular form of
free speech at this time. I'd like to apologize for the ludicrous
attitude my government takes with regards to cryptographic software --
feel free to refer to the "Electronic Freedom Frontier"
(http://www.eff.org) for more information about that).
I haunted the internet for days but couldn't find it. I also tried
something like this:
include "stdio.h"
include "unistd.h"
void main(int argc, char ** argv )
{
puts(crypt(argv[1], argv[2]))
}
but it doesn't work the same way.
Help!
Thank you
Davide Saccon
There is a library function named "crypt" which is technically a
"hash" rather than a cryptographic function -- it's used to compute
the hash of a password for comparison to that which is stored in the
second field each entry in the /etc/passwd file.
I've heard that the program named 'crypt' varies from one Unix
implementation to another. I think its currently not included in many
Linux distributions to the export (U.S. ITAR and related) restrictions
to which I alluded earlier. Since many of the companies that produce
these distributions are U.S. they would have to ensure that their
products were for "domestic use" only if they were to include this on
their CD's and in their FTP sites.
Here are a few sites I picked off of Yahoo! International PGP FAQ
Guida Pratica a PGP Guida Pratica a PGP PGP User's Guide (in Italian
-- 250K) The Crypto Chamber -- Italian Cryptographer's WorkBench.
There are other strong cryptographic products available
internationally for other purposes. I think the new Linux "TCFS"
(transparent cryptographic filesystem) is being done in Italy. TCFS is
apparently similar to Matt Blaze's research on CFS -- it allows a
Linux admin to create filesystems that are encrypted in such a away
that users can have confidence that no other user access their files.
Given its design is should be difficult even for the root user to
compromise the cryptographic integrity of any local user -- and it
should be impractical for remote systems.
Here's some more links for that: Transparent Cryptographic File System
Project Page TCFS TCFA FAQ v1.7.7
Come to think of it STEL (a secure telnet) was also done in Italy.
Seems that a lot of work on cryptography is coming out of your
country. Obviously your government hasn't been interferring in this
work. If you'd like to look at the sources for STEL I'd FTP over to
ftp://idea.sec.dsi.unimi.it/cert-it/
Another set of useful cryptographic resources are in Eric A. Young's
free implementation of Netscape's SSL (secure sockets layer)
specification and a set of related applications (like ssltelnet and
sslftp): SSLeay: SSLeay and SSLapps FAQ SSLeay: SSLeayand SSLapps FAQ
(This set of pages is an excellent resource for anyone that wants to
learn anything about SSL).
Eric's work was instrumental in the development of the Stronghold web
server by C2 Software Inc. (http://www.c2.net) (I recently published
an interview with C2's founder, Sameer Parekh, in Linux Journal, if
your interested).
And, of course, no discussion of Internet cryptography tools would be
complete without a mention of Tatu Ylongen's SSH ssh (Secure Shell)
ssh FAQ
-- Jim
_________________________________________________________________
Apache 1.2.1
Date: Mon, 11 Aug 1997 13:53:14 -0700
From: Alf Stockton stockton@acenet.co.za
I am playing with Apache 1.2.1 and have it running well except that it
won't run cgi scripts. If I give the full path in the command line of
the browser the CGIs run fine but the server cannot/does not run these
CGIs when I expect it to. Where can I turn for help? The Apache team
don't appear too interested. I suspect that one of my config files is
wrong but don't know enough to tell which.
I wouldn't necessarily say that the Apache team isn't "interested."
However, they far more interested in providing the software than in
answering questions about it.
It sounds like you don't have your "ScriptAlias" set up correctly --
or you're trying to access a CGI script that isn't stored in one of
the proper "ScriptAlias" directories.
Here are links to the relevant documentation pages at the Apache site
(http://www.apache.org):
Apache: Configuration: ScriptAlias
http://www.apache.org/docs/mod/mod_alias.html#scriptalias
Apache: FAQ: How do I enable CGI execution in directories other than
the ScriptAlias?
http://www.apache.org/docs/misc/FAQ.html#CGIoutsideScriptAlias
Another possibility is that you have built it with no CGI support.
Apache has many compile-time configuration options -- include a large
list of "modules" that can ben enabled or disabled. However I'm sure
that it would take some work to build Apache with no CGI support -- so
I think this possibility is remote.
-- Jim
_________________________________________________________________
Red Hat Questions
From: Brent Johnson brent@saturn.msstate.edu
So are you the answer guy and can you answer a very important question
for me?
I appear to have been dubbed "The Answer Guy" (it wasn't a
self-appointment -- but I did volunteer for it).
I can certainly answer any question. Answering it correctly and
usefully are not as sure a bet -- but I'll try.
I first heard about RedHat's Linux distribution about a year ago and
there was no way Slackware could compete to the easy installation
procedure, RPMS, and other great features included in RedHat.
But, ever since I moved to RedHat Ive had a terrible gcc compiler
problem. This has happened to me on two different machines... on the
first Id assumed it was some memory problem (as in hardware), but now
Im on a totally different machine that has (or shouldnt have) any
memory problem.
Everytime I try and compile anything (Apache 1.2.1 for example)... it
gets to about the 3rd or 4th .c file, and it bombs out with the
following error:
gcc -c -Iregex -O2 -DLINUX=2 util_date.c
gcc -c -Iregex -O2 -DLINUX=2 util_snprintf.c
gcc: Internal compiler error: program cc1 got fatal signal 11
make: *** [util_snprintf.o] Error 1
It happens at different times on different .c files when compiling
different things. Any help would be greatly appreciated... a Unix
system with a defective compiler or defective hardware is almost
useless!
- Brent
I notice that you haven't told me *which version* of Red Hat you're
working with. However I've used 3.03, 4.0, 4.1, and 4.2 -- and I think
I remember playing with an earlier one before 3.03 and I never saw
this behavior from gcc.
I did get it from my original copy of minicom anytime I was running in
an extended video mode and trying to use the dialer (and not when
issuing the same dialing function as a direct ATDT command from the
terminal window). In this case I suspect there was a bug in the
ncurses calls being made by minicom. In any event I switched to
CKermit and forgot all about it.
In your case the signal 11 (SEGV) is probably not caused by
curses/ncurses calls.
Do you have a swap partition or file? If so, have you tried disabling
it (possibly creating a new one temporarily)? If you have a defect on
the disk you could get a SEGV from some piece of data/code that gets
swapped out, read back in (with errors) and subsequently used by the
running process.
If you don't have a swap partition or file you might just be running
out of RAM completely. gcc does use up quite a bit of memory -- so I'd
suggest at least 32Mb virtual memory (RAM + swap) available when
running it (you could certainly ask the FSF for more specific
recommendations -- this is just my unsubstantiated and untested
suggestion).
When you installed, did you let Red Hat's install routine perform
thorough block checking while it was making filesystems? If not, try
re-installing and enabling that (in case you hit some bad spots on
your disk and you have corrupted gcc binaries).
This is extremely unlikely to be related to your distribution, but you
could try installing Slackware to see if its gcc works on this system
-- or you could try booting up in single user mode and just run a few
test "make's" from a simple shell line (no emacs M-x shell mode, no X
Windows, no "integrated dev. environment" nothing else running).
If you still get SEGV's then, you want to find some other sort of
memory intensive program to run as a test -- to see what else will
die. It may be worth extracting the RAM and taking it to a good
hardware tester -- and/or removing any ethernet cards or unecessary
adapters for other tests.
These sorts of things can be very frustrating to track down regardless
of OS. If you have a copy of DOS and an old copy of Norton Utilities
(version 8 or later) you could boot that up and run NDIAGS.EXE. There
are several other diagnostics packages that were available before it
-- but NU is still my personal favorite untill the Linux crowd does up
a suite of them. Unfortunately the results of any software diagnostics
package aren't definitive -- they can detect trouble -- but they can't
"prove" that there isn't any hardware problem.
I suppose, for some systems, particularly some 386's and 386SX's, you
might also try twiddling the CMOS "wait states" settings. Those used
to make a difference -- particularly with earlier generations of
"3-chip" SIMM's. Apparently in the early attempts to use SIMM's with
three chips (two four bit chips and a parity bit chip) there were some
slight timing differences between the "signal settling"
characteristics -- so the parity bit wouldn't "settle" before the
system was trying to read the memory. This resulted in parity errors
if the systems were set for "zero wait states" -- and was generally
solved by changing the CMOS settings.
(I've never heard of a Pentium system or any system using 72-pin
SIMM's having these problems -- but that doesn't mean it's not worth
looking in your "advanced" CMOS and trying some experiments therein).
I hope some of this helps.
-- Jim
_________________________________________________________________
PPP and Internet MCI
From: Demosthenes radams@capaccess.org
Subject: Re: PPP and InternetMCI
Hey there, I've been reading through your column from August in the
Linux Gazette, and ran across the gentleman's question regarding GTE's
internet services.
I'm trying to switch over to MCI from a local ISP, and I'm having some
of the oddest connection problems. I use PAP currently with my local
ISP, and MCI is supposed to use PAP/CHAP (one, the other, or both :P).
I beleive i have everything setup properly, as I don't get any
rejections from PAP/CHAP, but after a few seconds of modem activity
with the server, MCI just hangs up. I did misspell something before,
and got a PAP rejection, and I've got full debugging logs regarding
the connection, but I can't make much sense of them. I know the server
isn't asking for MS-CHAP (chap 80, vs chap 05). It looks like it dies
during the configuration. I'm not sure.
Do you have any information regarding connecting to InternetMCI via
Linux? MCI tech support is clueless, and I can't even get someone that
knows how their own software works on the phone.
Any help would be highly appreciated, and I'd be more than glad to
share my debugging logs if you think they will help.
Thanks again!
Russell Adams
My first impulse is to say "vote with your feet." Fire off a polite,
assertive, note to their VP of Customer Service and go find a
Linux/Unix friendly ISP with quality tech support (and maybe spend a
little more in the process).
My provider isn't the cheapest -- and isn't even the friendliest --
but they understand Unix and they provide quality service (refusing to
structure their rates to "compete" with an unreasonable "quality of
service" -- i.e. I get few busy signals).
That bit of non-technical advice aside I'd ask: What are your MTU and
related parameters?
You could send the logging output -- but it would probably be as
incomprehensible to me as it is to you. I've never set up a PAP/CHAP
system (yet). However I'll look at them and suggest some experiments.
-- Jim
_________________________________________________________________
Enabling Automounter on a Linux Notebook
From: Dennis Dai gqdai@intergate.bc.ca
Hi, Jim
I think I need to ask you for help. My problem is:
Originally I have a 1.6G HD. Last month I bought a new one (3.2G) in
order to accommodate linux and NT. I placed the swap partition in the
very last part of the new harddisk (it seems that this is a bad idea,
isn't it?) which is hdc8 and initialized it without problem. After a
while, I made a new NTFS partition for NT which resides in front of
the swap partition (I installed NT system on one of my original HD's
partition which is hda7), then I moved some of my data on the new NTFS
partition. But after I booted up to linux, I realized that the swap
partition didn't initialized properly, so I issue a command like this:
mkswap /dev/hdc8
And this was how I screwed up things. Actually the new NTFS partition
became hdc8, and the original swap partition became hdc9. Now I can't
access the new NTFS partition from NT!
Immediately after I issued that command, I realized that I made a big
mistake so I issued a "free" command and it showed that the swap
partition (which is my NTFS partition) was not used.
So I think I still have hope to retrieve the data on my NTFS
partition. I know they are still there, just I can't get them out.
I posted this to linux newsgroups, and received some kind response
that suggested me to use linux fdisk to change the partition type to
NT one. But I did check that, it is still NTFS (actually HPFS under
linux fdisk). Others suggested me to zero out the first 512 byte of
that partition as part of the recovery, but since I am not quite
familiar with that I didn't dare to do that.
So I hope you can get me out of the hole. Thanks in advance.
Well, I haven't done regular data recovery for a few years (since I
left Symantec' Peter Norton Tech Support Department). It's not
something that I can do via e-mail (or for free) -- and I don't know
diddly about the internals of NTFS (or HPFS or ext2fs for that
matter).
You best bet, of course, is to have recent backups from which you can
recover. I don't know why they were suggesting that you blast the boot
record (the first 512 bytes of a partition is the "logical boot
record" or "superblock" while the first 512 bytes of a drive is the
"master boot record" or MBR). Perhaps they believe that NT will be
able to recover from this. If I was to do anything with the LBR I'd go
to a different machine, create a new NTFS partition that was
indentical in size and configuration to the one you think you've
damaged, and use a disk editor (or a Linux dd command) to cut and
paste that from the other machine onto the allegedly damaged
partition.
Before doing much of that I'd suggest do a dump to tape of the entire
raw device (using 'dd'). This may allow you to return to the current
state of brokenness after you've made unsuccessful attempts at repair.
I don't recommend these procedures (disk surgery) unless the data on
that drive is very important to you (and otherwise unreproducable) or
you really like playing with hex editors.
If it's of considerable financial value to you -- I'd suggested making
a dump tape, extracting the drive from the system and sending it to a
data recovery specialist.
-- Jim
_________________________________________________________________
X Locks Monitor
From: Gord Urquhart urquhart@Newbridge.COM
I have found when playing with my Xconfig I could get my monitor
(MAG15) to go into power saving state (with a resulting black monitor)
when I changed the pre and post sections of the horizontal scan line
timings (I can't remember the proper names of these), to certain
values.
gord u.
... and? ...
You can also cause a monitor to permanently damage itself if you play
with those long (wrong) enough. This is well known and noted in the
XFree86 configuration file.
So, what's the point of this message? Or is it just a stray
observation?
-- Jim
_________________________________________________________________
Pop3d That Doesn't Use /etc/passwd
From: Benjamin Peikes benp@npsa.com
Do you know if there is a pop3d that does not use /etc/passwd? I want
to set up mail only accounts for some people but in.pop3d that I have
uses /etc/passwd. I want to set up accounts that sendmail knows how to
deliver for but I don't want to put these people in /etc/passwd
because then I have to worry about all the other services on the
machine. Have you heard of some daemon that will do this, or a set of
packages that will do this type of seperate user management? Thanks.
Ben
Ultimately this issue of restricting specific classes of users to
specific services on a system is goes way beyond the particular
services you pick. PAM (the pluggable authentication modules) is
supposed to solve this problem eventually. That is already included
with recent versions of the RedHat distributions (and with recent
Solaris releases). However it is still evolving -- so few of us have
any idea how to "do it right." (A fact which leads to an
understandable lack of confidence in recommending it).
So, getting back to the original question:
What POP daemon supports a user/password database that's distinct from
the one used by other Unix services (/etc/passwd)?
I've heard the rumor that this can be done in qpopper but I'd like to
confirm that. So I go to Yahoo! and issue the "+qpopper +account"
search and get:
There is: http://www.hdshg.com/fixes/mail_patch/
... which is supposed to be a patch to qpopper to allow this. However
I couldn't connect to and I couldn't find any mirror of it even after
several hours of trying.
I traversed a number of links searching on strings like "+pop3 +passwd
+passwd +separate" and various permuations. This was the only firm
reference I found.
Another approach would be to create a custom chroot environment. This
isn't as hard as it sounds. The hard part is making your binary
statically linked or including the necessary libraries. The other
thing you'll have to consider is whether you want the POP-only
accounts to use their own "virtual mail host" (requires an IP alias or
an additional interface) or whether you your smtpd to run in the same
chroot "jail" -- then requiring any local account holders to also use
POP (perhaps using the fetchmail client to the "localhost" target).
Here are some of the links that have more information on mail and POP
in general.
Harker's sendmail References Page
Mr. Harker gives seminars and classes in sendmail
Free Servers from Eudora: Servers
Qualcomm, publishers of Eudora, also are the source of qpopper.
POP/IMAP FAQ
Passwdd/Passwd -- An authentication Daemon/Client
This isn't mail related specfically -- but relates to alternative
authentication model -- a passwd daemon running on a privileged TCP
port via inetd. It shows examples for supporting Eudora/APOP and using
alternate passwd files. /pub/smtpd directory -- Similar to TIS FWTK
smapd
Running a simpler, perhaps unprivileged smtpd to toss incoming mail
into the queue is considered to be a good idea -- for isolating
sendmail (which is large, powerful, complex, and has a long history of
compromises). http://www.qmail.org The qmail Page
An alternative to running sendmail at all. I won't get into this
debate -- I'm just including it in this list because I'll receive lots
of unnecessary mail if I don't. MH Message Handler Home Page
The Rand MH is a particular mail user agent -- actually a set of
programs for working with mail from a shell command line. There are
several packages that provide full screen interfaces to this --
including an emacs mode/package, mh-e, which is what I use. Scripts
and Patches for ISP's 4th UNIX SECURITY SYMPOSIUM -- Sendmail w/o
Superuser How to Get There From Here -- Scaling e-mail to the
enterprise Linux: Server-Linux FAQ
I hope all of this helps.
-- Jim
_________________________________________________________________
Configuration of Two Ethernet Cards
From: Carlos Gonzalez Andrade cglez@cfe.gob.mx
Date: Mon, 11 Aug 1997 23:40:16 -0700
Hi Jim.
I have a question about some problems i have while I was seting up 2
ether cards.
first . the device eth1 is not recognized when I add the line append =
ether=0,0,eth1 into the lilo.conf.
You should consider putting the I/O base address, the IRQ, and any DMA
or memory address information into this append clause in place of
those zero's.
You can test these by entering them at the LILO prompt (interactively,
during boot) before editing the /etc/lilo.conf file.
second . What files are necesary to set up to configure two IP address
for my machine and get runing my gateway?
I will apreciate your answer
This depends on which distribution you're using and how closely you
want to stick to their configuration conventions. Minimally all you
need is a script file (typically located under /etc/rc.d/ and invoked
by the rc.local) with calls to the 'ifconfig,' and a 'route add'
command or two. Under Red Hat's SysV init system you'd leave your rc.d
files alone and edit some file under your
/etc/sysconfig/network-scripts/ directory (ifcfg-eth0, and ifcfg-eth1
if I recall correctly -- it should be obvious by browsing through
those files).
-- Jim
_________________________________________________________________
Attaching a Console to a PC
To: Benjamin Peikes benp@npsa.com
Date: Mon, 11 Aug 1997 23:14:37 -0700
Jim,
I'm not sure if you are the right person to ask but I figured you
would be a good place to start. I have a handful of PC's that I need
to be able to watch as they boot. What I would like to do is connect a
dumb terminal(old laptop) to a rs-232 switch box and then be able to
switch to any of the machines as I boot them. I was wondering if you
knew any way to do this. Thanks.
Ben Peikes
It is possible to use a serial terminal as a console for Linux --
given some patches. With some PC hardware you'll have to leave the
video card in their -- though you don't need a monitor attached.
Unfortunately I don't remember where I saw these patches. I'd so a
search on "+Linux +serial +console" (using the Yahoo! convention of
preceding "required" terms with "plus" signs).
-- Jim
_________________________________________________________________
Copyright © 1997, James T. Dennis
Published in Issue 21 of the Linux Gazette September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
CLUELESS at the Prompt: A new column for new users
by Mike List, troll@net-link.net
_________________________________________________________________
[INLINE]
Welcome to installment 7 of Clueless at the Prompt: a new column for new
users.
_________________________________________________________________
Well it's starting to happen.My learning curve is starting to settle
down, and if you have been following this column, yours is too,
although depending on what you want from Linux, you may have many more
questions. At this point you probably are feeling more comfortable
using the online resources like the comp.os.linux.??? newsgroups and
some of the Linux pages that are hanging out there for you to glean
info from.
Some of my regular stops are:
* Linux Users Support Team
* Linuxnow.com
* Walnut Creek ftp archive
* Sunsite ftp archive
If you use a browser the first time you visit the ftp sites you can
get a good feel for the directory breakdown, but if you want to
download large files ie. distributions, you should use the command
line ftp, in my experience, it's faster.
Speaking of the command line ftp program, here are a few tips that can
make things go more quickly. You may already be familiar with some or
all, but if not, just type ...
ftp [ftp.cdrom.com] or whichever site you wish to visit. you will
get a prompt to give a username, most commonly anonymous, followed by
one for a password usually your e-mail address.
If you have used a browser to check out these sites previously, you
can cd to the desired directory.If not, cd pub usually is a good
start.
ls will show you whatis contained in that directory.If you are in a
VC rather than an xterm, you can use theSHIFT+PageUp keys to scroll
back, sinceyou will get a screenful or more of filenames that will
just shoot by.This may or may not work in an xterm.
If you want to download the files to a directory other than your
current directory, lcd [directoryname] will direct the downloads to
that location.
hash will give you a display of# marks, one for each block rerieved,
usually 1024 bytes.You can use this to check the progress of your
download.
bell will send an audible signal when your file is finished
downloading.
get [filename] will start your download,mget will retrieve
everything in the current directory if you have an empty directory of
the same name in your destination directory(the one you "cd'ed" to).
You will be prompted for each file as the previous one finishes
loading.
when you finish downloading, type bye. That will close the
connection.
_________________________________________________________________
Config, dot and .rc files
There are many ways that your linux programs can be altered to your
liking, or just to make it work the way it should. Last time I gave an
example of how to customize FVWM, but it hardly scratched the surface
of all the things that can be done to make your linux environment
truly yours.
If you type: ls -a, you'll see several files that start with ".".
These are typically configurable files that among other things, create
aliases for shell commands, set environment variables, geometry of X
applications, and other similar functions.
Some of these "dotfiles"have eluded my attempts to alter them in the
ways I'd like, but others have been extremely compliant. Some of the
no-gos (for me) include .bashrc and .bash.profile. I'm sure someone
will e-mail me and tell me why my aliases don't work, even though I
edited the file exactly as shown in the"Bible". Others like the
aforementioned .fvwmrc have had extemely gratifying results.Maybe my
colleagues at "The Answer Guy" and "The Weekend Mechanic" can shed
alittle more light on the subject. In the meantime, backup your dot
files before altering them, by cp'ing them to, say .foo.old to keep
serious problems at bay, should your editing fail to yield the desired
results.
Some of the "dot files" you might want to take a look at for possible
tailoring (depending on what you have installed)include your
.bash.profile, your .bashrc, or .rc files for any shell you might use,
.xinitrc, your window manager's .rc file, browser .rc and .bookmark
files.
If you have root privilege. there are many more you have access to but
be careful - some files have their own ways of being altered for
instance crontabs -e is the way to edit your crontab which has the
capability of taking care of routine maintenance at off hours upatedb
to create a database for the find and locate commands. Usually run in
the wee hours of the morning, this could be configured to run at
bootup or every 12 hours or at the end of a workday. This would assure
that all of the current day's work would be easily located the next
day.
The /etc/ppp/ip-upand ip-down files can cause certain functions when a
ppp connection is established. If you don't have one already, you can
probably write one that will be noticed by the current software. The
same goes for the .bashrc and .bash_profile, with the above caveat in
mind.
For the most part, the lines you need to enter or alter will be
essentially the same as you would use at the command line, and
sometimes it will be as easy as removing the # from the beginning of
the line.
_________________________________________________________________
Don't use a .bat!
One 'dot file that you can't edit to your liking, but could be useful
just the same is .bash_history. If you cat .bash_history |
sort>[filename] then less filenameyou will get an idea of what
commands are used most often. You can then use this information to
create shell scripts or aliases in your .bashrc or .bash.profile or
other shell.rc files and save a few keystrokes.
_________________________________________________________________
Keep those e-mails coming in, but just so you know, I don't run linux
on a new pentium with all the bells and whistles and I don't know much
about stuff I haven't used, so I might not be able to help you much
with tape drives, CDroms, SCSI peripherals and the like. I'll do my
best to point you in the right direction,but I use a 486/66 box with
IDE drives and a floppy(3.5"), a vga monitor, a cirruslogic 5428
videocard, internal modem, and an 8bit soundblaster card.I mention
this, not to beg for new hardware (although...), but to give you some
kind of idea what kind of hardware questions I might be of help with.
_________________________________________________________________
I invite questions, suggestions, reasonable criticism and just plain
e-mail:
troll@net-link.net
See you next month!
_________________________________________________________________
Copyright © 1997, Mike List
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
A Non-Technical Look Inside the EXT2 File System
By Randy Appleton, randy@euclid.nmu.edu
_________________________________________________________________
Introduction
Everyone wants a fast computer. However, not everyone realizes that
one of the most important factors of computer performance is the speed
of the file system. Regardless of how fast your CPU is, if the file
system is slow then the whole computer will also seem slow. Many
people with very fast Pentium Pro's but slow disk drives and slower
networked file systems rediscover this fact daily.
Luckily, Linux has a very fast file system called the Extended File
System Version 2 (EXT2). The EXT2 file system was created by Remy Card
(card@masi.ibp.fr). This article will show you how the EXT2 file
system is organized on disk and how it gets it's speed.
Disk Layout
Goals
There are several objectives when deciding how to lay data out upon a
disk.
First and foremost, the data structure should be recoverable. This
means that if there is some error while writing data to the disk (like
a silly user pulling the power cord) the entire file system is not
lost. Although loosing the data currently being written is often
acceptable, loosing all the data on the disk is not.
Secondly, the data structure must allow for an efficent implementation
of all needed operations. The hardest operation to implement is
normally the hard link. When using a hard link, there are more than
one directory entry (more than one file name) that points to the same
file data. Accessing the data by any of the valid file names should
produce the same data.
Another hard operation involves deleting an open file. If some
application has a file open for access, and a user deletes the file,
the application should still be able to access the file's data. The
data can be cleared off the disk only when the last application closes
the file. This behavior is quite unlike DOS/Windows, where deleting a
file means that applications who have already begun to access the file
loose all further access. Applications that use this UNIX behavior
concerning deleted files are more common than one might think, and
changing it would break many applications.
Thirdly, a disk layout should minimize seek times by clustering data
on disk. A drive needs more time to read two pieces of data that are
widely seperated on the disk than the same sized pieces near each
other. A good disk layout can minimize disk seek time (and maximize
performance) by clustering related data close together. For example,
parts of the same file should be close together on disk, and also near
the directory containing the file's name.
Finally, the disk layout should conserve disk space. Consurving disk
space was more important in the past, when hard drives were small and
expensive. These days, consurving disk space is not so important.
However, one should not waste disk space unnecessarily.
Partitions
Partitions are the first level of disk layout. Each disk must have one
or more partitions. The operating system pretends each partition is a
seperate logical disk, even though they may share the same phyical
disk. The most common use of partitioning is allow more than one file
system to exist on the same physical disk, each in its own partition.
Each partition has its own device file in the /dev directory (e.g.
/dev/hda1, /dev/hda2, etc.). Every EXT2 file system occupies one
partition, and fills the whole partition.
Groups
The EXT2 file system is divided into groups, which are just sections
of a partition. The division into groups is done when the file system
is formatted, and cannot change without reformatting. Each group
contains related data, and is the unit of clustering in the EXT2 file
system. Each group contains a superblock, a group descriptor, a block
bitmap, an inode bitmap, an inode table, and finally data blocks, all
in that order.
Superblock
Some information about a file system belongs to the file system as a
whole, and not to any particular file or group. This information
includes the total number of blocks within the file system, the time
it was last checked for errors, and so on. Such information is stored
in the superblock.
The first superblock is the most important one, since that is the one
read when the file system is mounted. The information in the
superblock is so important that the file system cannot even be mounted
without it. If there were to be a disk error while updating the
superblock, the entire file system would be ruined. Therefore, a copy
of the superblock is kept in each group. If the first superblock
becomes corrupted, the redundent copies can be used to fix the error
by using the command e2fsck.
Group Descriptors and Bitmaps
The next block of each group is the group descriptor. The group
descriptor stores information on each group. Within each group
descriptor is a pointer to the table of inodes (more on inodes in a
moment) and allocation bitmaps for inodes and data blocks.
An allocation bitmap is simply a list of bits describing which blocks
or inodes are in use. For example, data block number 123 is in use if
bit number 123 in the data bitmap is set. Using the data and inode
bitmaps, the file system can determine which blocks and inodes are in
current use and which are available for future use.
Inodes and Such
Each file on disk is associated with exactly one inode. The inode
stores important information about the file including the create and
modify times, the permissions on the file, and the owner of the file.
Also stored is the type of file (regular file, directory, device file
like /dev/ttyS1, etc) and where the file is stored on disk.
The data in the file is not stored in the inode itself. Instead, the
inode points to the location of the data on disk. There are fifteen
pointers to data blocks within each inode. However, this does not mean
that a file can only be fifteen blocks long. Instead, a file can be
millions of blocks long, thanks to the indirect way that data pointers
point to data.
The first thirteen pointers point directly to blocks containing file
data. If the file is thirteen or fewer blocks long, then the file's
data is pointed to directly by pointers within each inode, and can be
accessed quickly. The fourteenth pointer is called the indirect
pointer, and points to a block of pointers, each one of which points
to data on the disk. The fifteenth pointer is called the doubly
indirect pointer, and points at a block containing many pointers to
blocks each of which points at data on the disk. Perhaps the picture
below will make things clear.
[INLINE]
Figure showing the pointers between an inode and it's associated data.
This scheme allows direct access to all the data of small files (files
less than fourteen blocks long) and still allows for very large files
with only a few extra accesses. As the table below shows, almost all
files are actually quite small. Therefore, almost all files can be
accessed quickly with this scheme.
File Size (bytes) 0-768 769-1.5K 1.5K - 3K 3K - 6K 6K-12K 12K and up
Occurence (%) 38.3 19.8 14.2 9.4 7.1 10.1
Cumulative (%) 38.3 58.1 72.3 81.7 89.8 99.9
Table showing occurence of various file sizes.
Inodes are stored in the inode table, which is at a location pointed
to by the group descriptor within each group. The location and size of
the inode table is set at format time, and cannot be changed without
reformatting. This means that the maximum number of files in the file
system is also fixed at format time. However, each time you format the
file system you can set the maximum number of inodes with the -i
option to mke2fs.
Directorie>
No one would like a file system where files were accessed by inode
number. Instead, people want to give textual names to files.
Directories associate these textual names with the inode numbers used
internally by the file system. Most people don't realize that
directories are just files where the data is in a special directory
format. In fact, on some older UNIXs you could run editors on the
directories, just to see what they looked like internally (imagine
running vi /tmp).
Each directory is a list of directory entries. Each directory entry
associates one file name with one inode number, and consists of the
inode number, the length of the file name, and the actual text of the
file name.
The root directory is always stored in inode number two, so that the
file system code can find it at mount time. Subdirectories are
implemented by storing the name of the subdirectory in the name field,
and the inode number of the subdirectory in the inode field. Hard
links are implemented by storing the same inode number with more than
one file name. Accessing the file by either name results in the same
inode number, and therefore the same data.
The special directories "." and ".." are implemented by storing the
names "." and ".." in the directory, and the inode number of the
current and parent directories in the inode field. The only special
treatment these two entries recieve is that they are automatically
created when any new directory is made, and they cannot be deleted.
The File System in Action
The easiest way to understand the EXT2 file system is to watch it in
action.
Accessing a file
To explain the EXT2 file system in action, we will need two things: a
variable that holds directories named DIR, and a path name to look up.
Some path names have many components (e.g. /usr/X11/bin/Xrefresh) and
others do not (e.g. /vmlinuz).
Assume that some process wants to open a file. Each process will have
associated with it a current working directory. All file names that do
not start with "/" are resolved relative to this current working
directory and DIR starts at the current working directory. File names
that start with "/" are resolved relative to the root directory (see
chroot for the one exception), and DIR starts at the root directory.
Each directory name in the path to be resolved is looked up in DIR as
it's turn comes. This lookup yields the inode number of the
subdirectory we're interested in.
Next the inode of the subdirectory is accessed . The permissions are
checked, and if you have access permissions, then this new directory
becomes DIR. Each subdirectory in the path is treated the same way,
until only the last component of the path remains.
When the last component of the pathname is reached, the variable
DIR contains the directory that actually holds the file name we've
been looking for. Looking in DIR tells us the inode number of the
file. Accessing this final inode tells where the data for the file is
stored. After checking permissions, you can access the data.
How many disk accesses were needed to access the data you wanted? A
reasonable maximum is two per subdirectory (one to look up the name,
the other to find the inode) and then two more for the actual file
name itself. This effort is only done at file open time. After a file
has been opened, subsequent accesses can use the inode's data without
looking it up again. Further, caching eliminates many of the accesses
needed to look up a file (more later).
Put the starting directory in DIR.
Put the pathname in PATH.
While (PATH has one than one component)
Take one component off PATH.
Find that component in DIR yielding the INODE.
If (permissions on INODE are not OK)
Return ERROR
Set DIR = INODE
End-While
Take the last component off PATH yielding FILENAME.
Find FILENAME in DIR yielding INODE.
If (permission on INODE are not OK)
Return ERROR
Store INODE with the process for quick later lookup.
Return SUCCESS.
Pseudo-code for opening a file.
Allocating New Data
When a new file or directory is created, the EXT2 file system must
decide where to store the data. If the disk is mostly empty, then data
can be stored almost anywhere. However, performance is maximized if
the data is clustered with other related data to minimize seek times.
The EXT2 file system attempts to allocate each new directory in the
group containing it's parent directory, on the theory that accesses to
parent and children directories are likely to be closely related. The
EXT2 file system also attempts to place files in the same group as
their directory entries, because directory accesses often lead to file
accesses. However, if the group is full, then the new file or new
directory is placed in some other non-full group>
The data blocks needed to store directories and files can found by
looking in the data allocation bitmap. Any needed space in the inode
table can be found by looking in the inode allocation bitmap.
Caching
Like most file systems, the EXT2 system relies very heavily on
caching. A cache is a part of RAM dedicated to holding file system
data. The cache holds directory information, inode information, and
actual file contents. Whenever an application (like a text editor or a
compiler) tries to look up a file name or requests file data, the EXT2
system first checks the cache. If the answer can be found in the
cache, then the request can be answered very quickly indeed without
using the disk.
The cache is filled with data from old requests. Therefore, if you
request data that you have never requested before, the data will not
be in the cache, and must be retrieved from disk. Luckily, most of the
time most people ask for data they have used before. These repeat
requests are answered quickly from the cache, saving the disk drive
much effort while providing the user quick access.
Of course, each computer has a limited amount of RAM available. Most
of that RAM is used for other things like running applications,
leaving perhaps 10% to 30% of total RAM available for the cache. When
the cache becomes full, the oldest unused data (least recently used
data) is thrown out. Only recently used data remains in the cache.
Since larger caches can hold more data, they also can satisfy a larger
number of requests. The figure below shows a typical curve of the
total cache size versus the percent of all requests that can be
satisfied from the cache. As you can see, using more RAM for caching
increase the number of requests answered from the cache, and therefore
increase the apparent speed of the file system.
[INLINE]
Figure #1: A typical curve of total cache
size vs. the number of requests satisfied from the cache.
Conclusion
It has been said that one should make things as simple as possible,
but no simpler. The EXT2 file system is rather more complex than most
people realize, but this complexity results in both the full set of
UNIX operations working correctly, and good performance. The code is
robust and well tested, and serves the Linux community well. We all
owe a debt of thanks to M. Card.
Sources for More Information
The data for the figures in this paper can all be found in my
dissertation Improving File System Performance with Predictive
Caching. See the URL http://euclid.nmu.edu/~randy .
An excellent paper with more technical detail can be found at
http://step.polymtl.ca/~ldd/ext2fs/ext2fs_toc.html .
Some performance data can be found at
http://www.silkroad.com/linux-bm.html .
_________________________________________________________________
Copyright © 1997, Randy Appleton
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Fvwm Configuration in Different Environments using cpp
By Gerd Bavendiek, bav@rw.sni.de
_________________________________________________________________
Do you use Linux at home ? In the office ? On a laptop ? Do you use fvwm 2.xx
or fvwm95 as your windowmanager ?
If yes, you should read on.
Perhaps you have read my article about Using a Laptop in Different
Environments. There I described an easy way to setup a Linux laptop to
boot into different network configurations. I mentioned that setting
up a shell variable called PROFILE is useful not only for configuring
the network but also the windowmanager.
Why should you do that ?
Your windowmanager needs to be configured quite different when you are
using it on a laptop with 600x420 pixel or on a 17"-monitor with
1024x768 pixel. This is a rather basic difference - there may be
others. Think of using your system in a network environment. There it
will be handy to have a taskbar labeled appropiate to rlogin-sessions.
After fiddling some time with patching different fvwm configuration
files on different machines I found this to be a pain. A typical
.fvwm95rc is about 900 lines. Keeping several of them in sync is not
the thing I like.
Generating ~/.fvwm95rc using cpp
My solution is simple: Use cpp, the C-preprocessor ! fvwm 2.xx as well
as fvwm95 are configured by a central file. fvwm95 is derived from
fvwm, so the basic idea applies to both. Let me show you the details
using fvwm95. I keep my fvwm95 configuration in the file
~/.fvwm95rc-cpp.
You can use the system default setup in
/etc/X11/fvwm95/system.fvwm2rc95 as starting point. Look at this code
fragment from my .xinitrc (For me, .xsession is linked to .xinitrc):
...
# I need the value of PROFILE for generating .fvwm95rc
# netenv contains an assignment like e.g. PROFILE=32
if [ -r /tmp/netenv ]; then
. /tmp/netenv
fi
# Now the actual .fvwm95rc is generated depending on the value of PROFILE
cpp -lang-c++ -D PROFILE=$PROFILE ~/.fvwm95rc-cpp ~/.fvwm95rc
exec fvwm95 # exec saves the extra memory for a no longer useful shell ...
...
The shell variable PROFILE contains the information about the current
environment. The file /tmp/netenv is set up by init when going to run
level 2. I described this in the article mentioned above. Obviously
you need cpp, which comes either as an extra package or as part of
gcc. Yes, I know that there is a module FvwmCpp (which calls cpp) -
but I never managed to get it work.
One advantage of the old-fashioned style of configuration files is
that you can put comments in. You really should do this ! All that
hidden dot files in your home directory make up your personal
environment (these files will never be touched by a system update).
Having comments will make it easier to maintain this environment.
system.fvwm95rc comes in shell style comment syntax (so does fvwm).
You can't feed this into cpp. I didn't like traditional c-style
comments in a configuration file, so I switched all these comment
lines
# this is a useful comment
into c++-style comments
// this is a useful comment
(hail emacs !). Calling cpp with
-lang-c++
tells cpp to preprocess c++-code. A hint for those, who are not
familiar with cpp: cpp strips off the comment lines of the input file.
You probably will get output with a lot of blank lines.
Examples how to use cpp-syntax
Now let us have a look inside my .fvwm95rc-cpp. Of course, everything
herein is strongly a matter of personal taste.
I don't like to stress my eyes. So I hate small letters, I barely can
read them in the evening of a long day ... So my desktop has 4x2
pages. Each page is assigned to one application (or a few). I use
<Alt><F1> to <F8> to switch quickly between pages. Using the fabulous
fvwm95 mini icons my screen holds the FvwmTaskBar and on the right
hand side a column holding some icons. This way I can maximize the
application window.
The screenshot should make it clear.
Defining geometry
One important application is xemacs for me. So I define a mini button
in the FvwmButtons section like this:
*MiniButtons - mini-edit.xpm Exec "Xemacs" /usr/bin/xemacs \
-geometry EMACS_GEO &
EMACS_GEO is to be substituted by cpp. I put all the #define in the
beginning of my .fvwm95rc-cpp. Basically it reads like this
#if PROFILE == 30 || PROFILE == 31 || PROFILE == 32
#define EMACS_GEO 80x25+0+480
#else
#define EMACS_GEO 96x31+0+767
#endif
Whenever I'm on my laptop, PROFILE equals 30, 31 oder 32 (at home, in
the office, on customers site). The LCD-Display has 600x420 pixel. My
other systems have 17" monitors and there I use 1024x768. The +0+480
or +0+767 pops up the xemacs window on the leftmost page on the bottom
row of my 4x2 desktop. But this is true only when being on the very
first page while clicking the icon. I'm shure, this could be improved.
With defining
Key F5 A M GotoPage 0 1
I can conveniently switch to my xemacs window using without leaving
the keyboard.
Launching applications
Being at home or in the office, I have usually some rlogin sessions to
some well known machines. Being on a customers site I frequently have
to work with high availability configurations mostly consisting of two
machines. I call them always abba and bebe. See how this can be set up
(shortened for clarity):
DestroyFunc "InitFunction"
#if PROFILE == 30
AddToFunc "InitFunction" \
"I" Exec xsetroot -solid turquoise4 -cursor_name top_left_arrow &
+ "I" Exec xconsole -font 6x10 -geometry XCONSOLE_GEO -sb -file /dev/xconsole &
+ "I" Exec rxvt -geometry 94x28+0+0 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID1 -n TERMWIN_ID1 -cr Yellow3 &
+ "I" Exec rxvt -geometry TERMWIN_GEO2 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID2 -n TERMWIN_ID2 -cr Red3 &
+ "I" Exec rxvt -geometry TERMWIN_GEO3 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID3 -n TERMWIN_ID3 -cr Magenta3 &
+ "I" Module FvwmButtons MiniButtons
+ "I" Module FvwmTaskBar
+ "I" Module FvwmAuto 700
+ "I" Module FvwmPager 0 0
#elif PROFILE == 10
...
#else
AddToFunc "InitFunction" \
...
...
+ "I" Exec rxvt -geometry 94x28+0+0 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID1 -n home -cr Yellow3 &
+ "I" Exec rxvt -geometry TERMWIN_GEO2 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID2 -n TERMWIN_ID2 -cr Red3 &
+ "I" Exec rxvt -geometry TERMWIN_GEO3 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID3 -n TERMWIN_ID3 -cr Magenta3 &
+ "I" Exec rxvt -geometry TERMWIN_GEO4 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID4 -n TERMWIN_ID4 -cr Green3 &
+ "I" Exec rxvt -geometry TERMWIN_GEO5 -fn DEF_FONT -ls -sb -vb \
-title TERMWIN_ID5 -n TERMWIN_ID5 -cr Blue3 &
...
...
#endif
The terminal geometry und identifiers are defined as follows:
#if PROFILE == 10
#define TERMWIN_ID1 bav@nana
#define TERMWIN_ID2 nana
#define TERMWIN_ID3 lulu
#elif PROFILE == 20
...
#elif PROFILE == 30
...#define TERMWIN_ID1 bav@lulu
#elif PROFILE == 31
...
#elif PROFILE == 32
#define TERMWIN_ID1 bav@lulu
#define TERMWIN_ID2 lulu
#define TERMWIN_ID3 abba
#define TERMWIN_ID4 bebe
#define TERMWIN_ID5 abba
#endif
Conclusion
Screen geometry and network environment differ from one machine to
another. Everyone, who wants to have one configuration file for his
fvwm 2.xx or fvwm95 to reflect these differences, should consider to
use cpp as shown.
Perhaps you know, that xrdb(1) also can make use of cpp. So you can
preprocess your ~/.Xdefaults achieving the discussed advantages.
I hope you will find these ideas somehow useful !
Kind regards
Gerd
_________________________________________________________________
Gerd Bavendiek
_________________________________________________________________
Copyright © 1997, Gerd Bavendiek
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
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_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Impressions reading Peter H. Salus `A Quarter Century of UNIX'
By Leif Erlingsson <leif@lege.com>
_________________________________________________________________
I have been involved with Unix and the Internet since '88, and with
Linux since '95, but it isn't until reading Peter H. Salus' `A Quarter
Century of UNIX' during this summer vacation that I see where Linux
fits in into the last 25 years of operating systems development.
Unix came about as a revolt against cumbersome propriety operating
systems shipped by the various hardware-vendors. In contrast, Unix was
developed by a handful of people. An example of a "huge" software
project in the development of Unix is `awk'--developed by three
people.
UNICS (original name) was developed at Bell Telephone Laboratories in
the Summer 1969 - Fall 1970. Ken Thompson was the initiator and Dennis
Ritchie and Rudd Canaday were active contributors.
The intent was to create a pleasant computing environment for
themselves. The hope was that others would like it also. The basic
notion at the Labs (in Dennis Ritchie's words as quoted from the
book),
was and is to hire people who generate their own good ideas and
carry them out....
The Bell Telephone Laboratories staff (BTL) were supposed to discover
or invent new things. There was always management encouragement.
It turned out Unix was easy to use and understand when compared to the
competition. It was extremely compact. It wasn't until much later that
anything and everything the user wanted was supplied (like vi, emacs,
X, ksh, csh,... :-)).
The single most important factor behind Unix' popularity was that in
the beginning the source code was practically free. Thus it was used
in education and as a base for derivate systems. The universities
loved it. Later, when AT&T realized that they had in Unix something of
great value and tried to capitalize on that, universities were
forbidden to use the source code in education. This motivated Andy
Tanenbaum to write MINIX, from whence Linus Torvalds got his
inspiration to write a kernel for his Intel 386, the kernel that later
became Linux.
Bell Telephone Laboratories (50/50 owned by AT&T and Western Electric
Company) was, by the so called "consent decree" of Jan 24, 1956
(entered into because of the Sherman Antitrust Act and a complaint
filed by the Department of Justice in Jan 14, 1949), required to
reveal what patents it held and supply information about them to
competitors. Also, the terms of the decree required BTL to license to
anyone at nominal fees. So we have this "consent decree" to thank for
the phenomenal spread of Unix!
BTL had the following support policy:
no advertising
no support
no bug fixes
payment in advance
This forced the users to band together, which resulted in better and
more responsive support than any vendor could have managed. Also, an
"us" (users) against "them" (vendors) mentality formed, reinforced by
actions taken by AT&T to stifle "the Unix problem".
This is very important: Unix begat Internet!
For a long time no one in business took Unix seriously. For AT&T it
was just a legal problem. It was run on VAX'es, but it took the
Digital Equipment Corporation about a decade to learn how to support a
Unix system as opposed to a Virtual Machine system because of the NIH
syndrome. (NIH = Not Invented Here.)
Does it sound like Linux or does it [sound like Linux] ? :-)
On 20 Nov 1974, the U.S. government filed a new antitrust action
against AT&T, Western Electric, and Bell Telephone Labs. The
settlement reached in 1984 dissolved Western Electric, formed the
"Baby Bells" and reorganized AT&T Bell Laboratories into Bell
Telephone Labs.
AT&T was now permitted to enter the hardware and software computer
business. AT&T sharply raised Unix license fees ...
One reaction was Richard M. Stallman's Free Software Foundation with
it's GNU (Gnu is Not Unix) project, that has given the world a wealth
of free versions of Unix systems programs. Another is Keith Bostic's
CSRG project to create a license free version of Unix. Today, all free
Unix clones except Linux use the CSRG code, and all free Unix clones
use the GNU code, Linux included.
This is very important: Internet begat GNU and CSRG, and therefore the
free Unixes, Linux included. And Unix begat Internet, so therefore,
Unix begat Linux. Also, as we all know, Linux is continually developed
on the Internet by a looseknit band of programmers from around the
world, each doing their little piece -- truly users banded together!
So where do Microsoft and others fit into this picture? DOS/Windows is
just one of many systems sprung out of the fountain of Truth -- though
there is much debate as to how much truth has rubbed off on them. :-)
There is a huge cultural barrier between the Unix camp and the other
guys. It took DEC a decade before the DEC Unix Engineering Group was
formed, and when it was, it was located in a separate location from
the rest of the company.
Salus tells the story in the book:
there was a lot of animosity towards Unix up and down the company at
DEC. Armando Stettner relates how Dave Cutler, one of DEC's
engineering elite, at one point got two Unix engineers, Armando
Stettner himself and Bill Shannon, to drive down to his office 20
minutes away to help him with, Armando thinks it was, some SRI package
on top of VMS. They got there and Cutler was in his office. Armando
and Bill sat down at a terminal, and it just didn't do what they
expected it to do. Cutler asked them how it was, and Armando replied
that it didn't work. To this Cutler said "Well, thank you very much"
and they were dismissed. Cutler then called their Senior Group Manager
and chewed him out and said Armando and Bill were sorry excuses for
engineers and he never wanted to see them in Spitbrook (his office)
again. Armando believes that Cutler's disdain has been reflected in
his work ever since. Armando says:
Cutler was doing yet another OS based on a new architecture
called Prism, not Unix, during Digital's internal RISC
wars. Initially, Cutler's OS wasn't portable, but was
culturally compatible with VMS. There is a lot of stuff
in NT that I think can be traced to Prism. [Cutler went
to work for Microsoft around 1983.]
To round this off I'd like to itemize a few general factors for the
success of Unix:
Simplicity
Small projects
No restrictions put on creativity
Freedom
Free source
Fun
Collect a lot of great ideas that are around plus some
original ideas and put them together in a very
interesting, powerful way.
Users supporting themselves
Internet
Portability
Universality
Stability -- i.e., the antithesis of the continuous
change needed to keep the DOS/Windows personal computer
market alive. System programs don't need to change. Well
designed OS's don't need fundamental changes. No need to
do Windows 95 this year, Windows 97 the next and then NT.
Just stick with what works!
"Us against them" -- thanks AT&T, DEC and Microsoft!
There must be a fundamental difference of thinking between the free
software camp and the other guys:
The first mind-set is to share in order to gain. The other mind-set is
hoarding out of fear that something is going to be taken away. Out of
the latter mind-set springs the correct business-types managing their
various copy-protected products, while from the sharing win-win
culture, where each person's efforts becomes a multiplier toward a
common goal, springs an open and nonconformistic, somewhat anarchistic
type of person. The two often do not like or understand each other.
(This article is copyright Leif Erlingsson. As long as this copyright
notice is preserved, and any cuts clearly marked as such, the author
hereby gives his consent to any and everybody to use this text.)
(The book `A Quarter Century of UNIX' is Copyright © 1994 by
Addison-Wesley Publishing Company, Inc.)
_________________________________________________________________
Copyright © 1997, Leif Erlingsson
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
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_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Installing Linux on an IBM ThinkPad 365XD Notebook
By Sam Trenholme, set@reality.samiam.org
_________________________________________________________________
My latest roadstop in the quest for the perfect affordable portable
computer stops with the IBM ThinkPad 365XD notebook. Hawked from
Egghead for only $1000, and with successful reports of sticking X on
this thing form the 'net, I proceeded to install Linux on this beast.
The install was one of the more difficult Linux installs I have had,
with a number of problems:
First problem:
*Booting directly in to the RedHat install from the CD-ROM, the
install could not see the CD-ROM.
The CD-ROM in a ThinkPad 365xd is a standard IDE CD-ROM. For unknown
reasons this CD-ROM was invisible when I booted into the install
directly from the CD-ROM. Making a RedHat install boot disk and
booting from that resolved the concern. The CD-ROM was visible, and I
was able to install normally.
Second problem 2:
* RedHat crashed in the middle of the install.
RedHat seems to do that sometimes, for very mysterious reasons. On the
first install, RedHat crashed. I had to go back to square one and
completely reinstalled. The second install of RedHat 4.2 went without
incident, resulting in a functional RedHat system.
Third problem:
* After installing LILO, the ThinkPad refuses to boot from the hard
disk.
After mutch futzing, I discovered that the BIOS refused to boot from
the hard disk if it saw more than one primary partition. I configured
fdisk thusly:
I made one primary partition the Linux partition, then made the swap
partition the extended partition. I did this as follows:
* I deleted all pre-existing partitions
* I added the main partition, making sure enough space was set aside
for swap. I used 'n' to create the new partition, and 'p' to
indicate that it was a primary partition.
* I then added an extended partition, having the extended partition
take up the rest of the hard disk--my swap space.
* I then added a logical partition, which was the swap space.
* I marked the primary partition as a Linux Native partition, and
the extended partition as an extended partition.
* I made the primary Linux partition bootable with the 'a' option.
* Finally, I wrote the partition table to disk.
My fdisk session went like this:
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-789): 1
Last cylinder or +size or +sizeM or +sizeK ([1]-789): 741
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4): 2
First cylinder (742-789): 742
Last cylinder or +size or +sizeM or +sizeK ([742]-789): 789
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (742-789): 742
Last cylinder or +size or +sizeM or +sizeK ([742]-789): 789
Command (m for help): t
Partition number (1-5): 1
Hex code (type L to list codes): 83
Command (m for help): t
Partition number (1-5): 5
Hex code (type L to list codes): 82
Changed system type of partition 5 to 82 (Linux swap)
Command (m for help): a
Partition number (1-5): 1
Command (m for help): p
Disk /dev/hda: 32 heads, 63 sectors, 789 cylinders
Units = cylinders of 2016 * 512 bytes
Device Boot Begin Start End Blocks Id System
/dev/hda1 * 1 1 741 746896+ 83 Linux native
/dev/hda2 742 742 789 48384 5 Extended
/dev/hda5 742 742 789 48352+ 82 Linux swap
Command (m for help): w
[It wrote the information to the hard disk, then exited.]
When I installed LILO, I placed LILO on the boot sector of the first
(bootable) partition (/dev/hda1) instead of the master boot record
(/dev/hda).
Fourth Problem:
* After installing X, as per the XF86 configurations on the Linux
ThinkPad survey, I was unable to start X. X would just cause the
screen to become blank.
X has to be "Kicked in", so to speak, by hand. After X starts, hit
Fn+F7 (the Fn and the F7 keys at te same time) to get the X display to
function.
Fifth Problem:
* After starting X, one can not exit X and return to a normal text
display.
One can not leave X after entering it on the ThinkPad. The best
workaround this problem is to edit /etc/inittab to make the default
runlevel 5. This enables a mode where you can log in and log out
without leaving X, using a program known as xdm.
In order to make the default runlevel 5, look for a line like this in
/etc/inittab:
id:3:initdefault:
Change the line to look like this:
id:5:initdefault:
Note the number 5 instead of 3.
You may also wish to disable most of the virtual terminals in runlevel
5, since you won't be using them [1]. There are a series of lines that
look like this in /etc/inittab:
1:12345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6
Change the lines to look like this:
1:12345:respawn:/sbin/mingetty tty1
2:234:respawn:/sbin/mingetty tty2
3:234:respawn:/sbin/mingetty tty3
4:234:respawn:/sbin/mingetty tty4
5:234:respawn:/sbin/mingetty tty5
6:234:respawn:/sbin/mingetty tty6
Note that most of the above lines no longer have a '5' in them. For
various reasons, it's a good idea to have an emergency virtual
terminal. Linux does (or, at least, used to do) funny things without
at least one virtual terminal.
Sixth problem:
* I was unable to have the kernel see a parallel port zip drive
The I/O base of the parallel port is at 0x3bc instead of 0x378. To
have Linux see a parallel zip drive on the ThinkPad 365xd:
insmod ppa.o ppa_base=0x3bc
instead of simply:
insmod ppa.o
Note that the I/O base of the parallel port was determined with the
MSD program on a MS-DOS boot disk.
Seventh problem:
* After entering 'suspend mode' on the ThinkPad (Fn+F4), the system
would crash when I tired to exit from suspend mode.
The kernel needs to be recompiled with APM support on the ThinkPad
365xd. To do this, make sure the kernel source is installed on your
system.
You can install the kernel source from the RedHat CD, as in the
following example Linux session:
[root@localhost /]# mount /mnt/cdrom
[root@localhost /]# cd /mnt/cdrom/RedHat/RPMS/
[root@localhost RPMS]# rpm --install kernel-source-2.0.30-2.i386.rpm
If you do not have a RedHat CD, do the procedure most appropriate for
your RedHat system to install the above RPM package.
I then went to the directory /usr/src/linux, ran 'make menuconfig' and
went to 'Character Devices --->', then enabled 'Advanced Power
Management BIOS support' without enabling any of the other features
('Ignore USER SUSPEND', etc.).
I then made a kernel image with 'make zImage' (and waited a while,
hitting the space bar every 5-10 minutes so the machine would not
crash), and copied the kernel image (located in the directory
'/usr/src/linux-2.0.30/arch/i386/boot' as the file 'zImage') over to
/boot.
I then edited my /etc/lilo.conf so that the boot line which looked
like this: image=/boot/vmlinuz looked like this: image=/boot/zImage
and re-ran Lilo thusly: /sbin/lilo
** Be very careful with changing Lilo. Doing things incrrectly can
make it difficult to re-enter Linux**
Once I did all this, I had a functional Linux system on my ThinkPad
365xd, which I am currently using to type this in (on the streets of
Santa Cruz, no less)
Speaking of being on the streets, I find the DTSN display almost
unreadable in direct sunlight, and only somewhat readable in the shade
on a sunny day (fortunatly, the Pacific coast fog is strong tonight).
I hear that TFT displays are a lot better in this regard. [1] The
virtual terminals is something you can use to multitask in text mode
with Linux. To change virtual terminals, simply hit alt and a function
key between F1 and F6.
_________________________________________________________________
Copyright © 1997, Sam Trenholme
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
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_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Adventures with PPP
By Larry Ayers, layers@marktwain.net
_________________________________________________________________
Introduction
When I first began using Linux a couple of years ago, one of my goals
was to be able to go on-line. At that time I was constantly rebooting
into OS/2 so I could use the internet and this OS schizophrenia was
becoming tiresome.
Eventually, after many chatscript iterations and minicom sessions I
had a dependable PPP setup. I thought my PPP troubles were over; as
time passed my command of the various pppd and chat options began to
fade.
This past month my local internet service provider sold its machines
and signed up with a large provider in Atlanta. When the accounts were
switched over suddenly I could no longer log in and life became a bit
too interesting...
Log-In Fashions Change
A couple of years ago an ISP was happy just to have a set of working
log-in scripts which could be distributed to its Windows and Mac
customers. At that time most computer users were either hobbyists or
professionals, and could be counted on to know what to do with the
script. As the internet surged in popularity more and more customers
appeared without much knowledge of basic computer usage, and the
help-desks and support personnel began to be swamped with requests for
set-up help. Naturally, the tendency was to move towards simpler
log-in set-ups, if possible without any script at all. As customer
interest in text-mode shell accounts waned, a log-in could be
accomplished with little more than the username and password. This (I
was informed in an e-mail from my provider) was our new log-in
sequence: just the username and password.
This sounded simple enough; all I had to do was delete the expect-send
sequence selection: PPP from the chat-script and all would be well.
Or so I thought: using this script led to a scrolling list of errors
on the console I set up to display all daemon and error messages. It
looked like the router I was attempting to connect to was first trying
PAP authentication, failing, then trying CHAP authentification,
failing that as well; the sequence would repeat until the router would
hang up in disgust.
Other variations of the chat-script I tried would result in a "serial
line not 8-bit clean" message. I talked with the technician who had
set up the local router and he claimed that neither PAP nor CHAP were
in use; Win95 log-ins were working fine, so I was on my own.
The next step was to try logging in with Minicom, just to see what the
actual log-in screen looked like. I connected and found the expected
Username: and Password: prompts. I logged in and a command prompt
appeared, with no sign of the typical PPP garbage characters. What
now? I typed help and a list of available commands scrolled by. I was
logged in to the Cisco router, evidently, and before long I found that
I could telnet anywhere I liked. I could run a systat command and see
which other users were logged in. The command show hosts provided a
list of hosts which I could connect to, and soon I was logged in at
the main WWW server in Atlanta! I'd never been logged in at an
UltraSparc server running Unix SysVR4 before, and it was great fun
exploring the directory structure and running real VI for the first
time. I could run pine (and I ended up with yet another e-mail
address) and read news with the nn newsreader.
This was all quite diverting, but didn't address the PPP problem. So
soon I was back at the router's prompt. I tried typing ppp and the
indicative garbage characters appeared. This looked encouraging, so I
added this exchange to my chatscript and tried again. The pppd daemon
was satisfied this time, and I had what looked like a real PPP
session. Unfortunately, it turned out to be limited to the router and
I could do nothing with the connection. Another dead-end!
Back to OS/2
At first I couldn't even log in with OS/2 when I revived an old
installation and tried to dial in. Deleting the entire log-in sequence
in the dialer got me online again, but even with debugging turned on I
still couldn't determine just when the username and password strings
were being sent to the server.
On-line once again, I was off to the newsgroups hoping to find advice.
Eventually I came across a posting in comp.os.linux.networking which
contained a couple of intriguing statements. The first intimated that
Win95 by default makes use of PAP authentification, but the user isn't
necessarily informed of the fact. Possibly the Netscape dialer which
my ISP distributes was using PAP as well, I thought. The second
statement recommended using the pppd option +ua /etc/ppp/pap-secrets.
I had seen this option while reading the pppd /etc/ppp/options file,
but the manual listed this option as being obsolete, so I'd never
tried it.
The posting's author recommended an unusual format for the pap-secrets
file, unlike the format recommended in the documentation I'd been
reading and unlike the sample included in my PPP installation: just a
simple two-line file, the first line containing the username and the
second displaying the password. No server or client names, just the
two words.
Success
I was surprised and elated when this configuration worked the first
time. I had the chat-script simply dial the number and wait for the
CONNECT string. The server asked for PAP authentification and I was
online without even dealing with the username and password prompts,
which I suppose are only for the maintainers of the router.
I'm writing this piece because I suspect that many other servers will
probably be adopting similar streamlined login procedures, and the
approach I've outlined here may prove useful in at least some of these
cases. One thing to remember is that directing the pppd debugging
messages to an unused virtual console is very helpful, most easily
accomplished by inserting the line:
*.* /dev/tty8
in your /etc/syslog.conf file.
_________________________________________________________________
Copyright © 1997, Larry Ayers
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
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_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
SVGATextMode
By Larry Ayers, layers@marktwain.net
Fit More Text On Your Console Screen
Introduction
This summer a new version of SVGATextMode was released, and thinking
that many Linux users might be unfamiliar with the package, I put
together this review as an introduction to a versatile and useful
console utility.
Typically, Linux distributions use LILO as the boot loader, which
refers to the file /etc/lilo.conf for instructions. One of the lines
in the file is vga = , with either the number of a console video mode
following the "=", or the word ask. If "ask" is specified, the Linux
boot process is interrupted and you are asked which (EGA) video mode
you prefer. An option (thankfully!) is also provided allowing the user
to peruse a menu of available console video modes, which varies
depending on the video chipset. With my generic S3 Virge card, these
modes are offered:
* 80x25
* 80x50
* 80x43
* 80x28
* 80x30
* 80x34
* 80x60
* 132x25
* 132x43
It's nice to have a choice of video modes (which determine the screen
font size) but these boot-time options just scratch the surface of
what the newer video cards and monitors offer. SVGATextMode is a
utility which borrows some of the techniques which the X-Window system
uses to exploit the resources of your video system and applies them to
the console screen.
How It Works
SVGATextMode actually reprograms the registers of your video card,
allowing many more modes than the preprogrammed modes available at
boot-up. It borrows some of the techniques used by XFree86 in order to
make available more console video modes. The modes provided by your
video-card BIOS are EGA modes, and they run at a low refresh-rate and
dot-clock compared to those used by X-windows.
The program can be either started at boot-time from one of the
init-files, or at any time from the console prompt. When it starts a
configuration file (/etc/TextConfig) is parsed. The defaults are very
conservative. The file needs to be read and edited before any real
advantage can be obtained from the program. This is due to the vast
differences in capability between various video cards and monitors. As
in X configuration, the correct values for your monitor's horizontal
and vertical refresh rates need to be entered in the TextConfig file.
If you've successfully configured X you shouldn't have any problems
with SVGATextMode.
Configuration and Use
SVGATextMode is what I consider to be a "mature" package, in that it
has been under development long enough to have received contributions
and bugfixes from a worldwide community of users. Many video cards are
supported, though I don't think quite as many as XFree86 supports.
In the default /etc/TextConfig file many of the lines are
high-resolution modes contributed by users. Once you have entered your
video chipset and monitor timings into the file, the command
SVGATextMode -n [mode] will let you know if your hardware can support
the mode without actually starting the program. Once you've found some
promising modes just eliminate the "-n" from the command and with any
luck you'll have the new text mode visible on your console screen.
Possibly the screen will be corrupted. Running the SVGAlib utility
savetextmode before trying a new mode, then if corruption appears
restoretextmode afterwards ought to allow recovery of your previous
default text mode. It will take some experimentation, but the package
is very well documented and is worth the trouble.
There are some included modes with 160-character wide screens, which
can be very useful while running an editor which allows two
80-character pages to be displayed side-by-side. Emacs can do this,
and there is a LISP package available called follow-mode which allows
both pages to scroll relative to each other.
SVGATextMode doesn't just allow more characters to be displayed on the
screen. Even relatively low-resolution modes will look crisper and be
easier to read due to the higher refresh rates typically used. The
most dramatic advantages, naturally, are evident with newer, more
powerful video-cards and large monitors, but even with my
middle-of-the-road equipment the utility is well worth using.
Caveats
If you use Dosemu from the console there can be problems. I have to
reset the text-mode to my old default 80x43 mode before starting
Dosemu or I get unrecoverable corruption requiring a reboot. I haven't
had any problems switching from a console session to X and back, but,
just as with X-windows, performance varies depending upon the
video-card and monitor involved. Read the documentation; it's very
complete and a great help while getting started.
Availability
The source package (version 1.6) can be retrieved from the Sunsite
archive site or one of its mirrors, in this directory. A binary
package for Redhat systems is available here, and a Debian binary can
be downloaded from here.
_________________________________________________________________
Copyright © 1997, Larry Ayers
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Yet Another Window Manager
By Larry Ayers, layers@marktwain.net
_________________________________________________________________
Introduction
Marco Macek, a Slovenian computer-science student, has been developing
a quite powerful and configurable editor called FTE for the past
couple of years. FTE is a multi-platform folding editor, available for
Linux, OS/2, DOS, and Windows; I wrote a short review of an earlier
beta in issue 7 of LG. Lately Marco has turned his hand to developing
a new window-manager. Unlike some Linux projects, which are released
to the FTP sites in the early stages of development, the Ice
window-manager seems to have been under development as a non-public
project throughout the early beta versions. It just showed up one day
in the Sunsite incoming directory in a remarkably complete and usable
form.
Differences and Features
Lately window-managers seem to be proliferating, with offshoots and
variants of fvwm predominating. Icewm is in large part inspired by the
OS/2 Workplace Shell interface. Though OS/2 has been never gained the
market acceptance its adherents have hoped for, the Workplace Shell is
a remarkably advanced object-oriented GUI, and Macek has attempted to
adapt some of its "look-and-feel" to the Linux environment. Another
influence is the common Windows 95 interface, which does have some
useful features worth emulating.
Win95's bottom-of-the-screen icon bar , with its cascading menus and
dynamic window indicators, has been nicely reproduced in Icewm. The
equivalent of the "Start" menu (which functions much like Win95's) has
a "Linux" label with a penguin icon.
icewm bottom-bar
The general appearance of the windows (borders, titlebars, et al) is
very reminiscent of OS/2. Various types of "X" kill buttons are
available, but the general appearance of the window-borders seems to
be hard-coded; that is, not configurable. Here's a screenshot of a
typical window:
Icewm window
_________________________________________________________________
I liked the cascading mouse button menus, with a different menu shown
for each mouse button. The Enlightenment window-manager has a similar
feature. These menus are hierarchical and behave like their OS/2
equivalents.
ice menu
_________________________________________________________________
This window-manager really doesn't have such compellingly new features
that many long-time Fvwm2 or AfterStep users would want to adopt it,
but for new Linux users more familiar with Win95 or OS/2, the
similarities might serve to ease the transition. It compiled easily on
my 2.0.30 system, and it seemed to be stable and dependable.
The source archive is available from the icewm home-page, as well as
the sunsite FTP site. Icewm's home page also has Redhat RPM's of the
source.
_________________________________________________________________
Copyright © 1997, Larry Ayers
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Remote Compilation Using SSH and Make
By John R. Daily, jdaily@bbn.com
_________________________________________________________________
Problem
Occasionally I use my Linux machine at home to write code that I
intend to compile on a remote machine.
While maintaining open ftp and telnet connections to the remote
machine to handle the transfer and compilation steps is a manageable
solution, I decided to explore ssh and make to develop a more
automated method.
The benefits of my solution:
* No need to remember which files have been modified.
* Ability to use Emacs' compilation capabilities to move to errors
in the source.
* As mentioned above, no need to use ftp and telnet, and hence no
benefit to keep an open dialup connection when not compiling.
* Automate, automate, automate. Laziness is a virtue.
Overview of Solution
My first step was to set up ssh and related tools in order to allow
secure copying of files to my remote system. While setting up a
.rhosts file is a (barely) acceptable solution, my IP address and name
is different each time I dial in, and it would be rather awkward to
change the remote system's .rhosts file each time I dialed in.
ssh allows me to use a much more secure form of authentication to copy
files and execute remote commands.
Once I had ssh behaving properly, I used Emacs' info facility to
explore implicit rules in makefiles, and wrote a simple makefile to
handle the file transfers and remote compilation.
As an example of the intended effect, assume my remote machine is
called "remote" (and my local machine "local"), and I've just modified
a source file called daemon.c. I would like to execute the following
commands in an automated fashion (note that scp is a secure copy
command packaged with ssh, and that the -C option specifies
compression, useful for dialup connections):
scp -C daemon.c jdaily@remote:~/source-directory
ssh -C remote "cd source-directory && make"
Implementation
First, I needed sshd running on the remote system to handle my secure
connections. Fortunately, sshd was already running on the remote
system in question, but according to the man pages, it can be run as
any user, and is restricted to handling connections for that user
(which should be quite sufficient for our needs).
Then, I needed to install the ssh toolset on my local machine. Again,
ideally these would be installed in a public binary directory such as
/usr/local/bin, but any user can install them in his/her home
directory.
I also wanted a key which would allow me to authenticate myself
between systems, and which would eliminate the need to type my
password each time I tried to run one of the ssh commands. For this, I
just ran ssh-keygen, and made sure to not give a pass phrase, so that
none would be needed to use my private key to establish the
connection.
[jdaily@local ~]$ ssh-keygen
Initializing random number generator...
Generating p: ............++ (distance 186)
Generating q: ......................................++ (distance 498)
Computing the keys...
Testing the keys...
Key generation complete.
Enter file in which to save the key (/home/jdaily/.ssh/identity): <CR>
Enter passphrase: <CR>
Enter the same passphrase again: <CR>
Your identification has been saved in /home/jdaily/.ssh/identity.
Your public key is:
1024 35 718535638573954[...] jdaily@local
Your public key has been saved in /home/jdaily/.ssh/identity.pub
Once I had a public key, I used scp to copy it to the remote machine.
[jdaily@local ~]$ scp -C ~/.ssh/identity.pub jdaily@remote:~/.ssh/key
jdaily's password: <entered my remote password>
Then I logged into the remote host and copied the key file into
~/.ssh/authorized_hosts. If that file already existed, I would have
appended the key file.
Following all this, I could run ssh and scp without needing either a
password or a pass phrase to connect to remote.
Now I needed a makefile to automate my system. Ideally, the files on
the remote machine would be checked to see if they were older than the
files on my local machine, and if so, they would be copied over. To
simplify matters, I decided to keep a record of the "last transferred
date" for each file by touching a corresponding file each time I
copied a source file over.
As an example, when I transferred a newer copy of daemon.c over, I
touched daemon.ct in the same directory. Any transfer of a .h file
would be marked by the creation of a file with a .ht suffix.
After poking around the info file for make, I came up with the
following makefile.
TRANSFER=scp
REXEC=ssh
SSHFLAGS=-C # Compress data
REMOTE=jdaily@remote:~/source-directory
FILES=debug.ht messages.ht client.ct daemon.ct queue.ct queue.ht
%.ht : %.h
$(TRANSFER) $(SSHFLAGS) $< $(REMOTE)
touch $@
%.ct : %.c
$(TRANSFER) $(SSHFLAGS) $< $(REMOTE)
touch $@
all-done: $(FILES)
$(REXEC) $(SSHFLAGS) remote "cd source-directory && make"
touch all-done
This had one limitation in particular; I was unable to specify
command-line arguments for make on the remote machine without writing
them directly into the makefile on my local system. While this was
fine for the current application, I decided to generalize it by
creating a run-make shell script, which would handle the remote
execution of make after calling make on the local system.
Here is my run-make shell script:
#!/bin/sh
make
echo ssh -C remote \"cd source-directory \&\& make $*\"
ssh -C remote "cd source-directory && make $*"
I then removed the line from my makefile which remotely ran make.
Here's the output from a successful compilation sequence.
cd ~/source-directory/
./run-make
scp -C debug.h jdaily@remote:~/source-directory
touch debug.ht
scp -C messages.h jdaily@remote:~/source-directory
touch messages.ht
scp -C client.c jdaily@remote:~/source-directory
touch client.ct
scp -C daemon.c jdaily@remote:~/source-directory
touch daemon.ct
scp -C queue.c jdaily@remote:~/source-directory
touch queue.ct
scp -C queue.h jdaily@remote:~/source-directory
touch queue.ht
touch all-done
ssh -C remote "cd source-directory && make "
gcc -Wall -Wstrict-prototypes -Wmissing-prototypes -g -c queue.c
gcc -Wall -Wstrict-prototypes -Wmissing-prototypes -g -DPORT=3000 -o daemon dae
mon.c queue.o -lsocket -lthread
gcc -Wall -Wstrict-prototypes -Wmissing-prototypes -g -DPORT=3000 -o client cli
ent.c -lsocket
Compilation finished at Sat Aug 9 01:22:19
Tools
ssh is a secure replacement for such tools as rsh, rlogin, and rcp. It
can be found at http://www.ssh.fi.
make is a standard Unix utility. GNU's make comes with most, if not
all, Linux distributions.
_________________________________________________________________
Copyright © 1997, John R. Daily
Published in Issue 21 of the Linux Gazette, September 1997
Spare Cycles Needed for Promoting Linux
By Bill Duncan, bduncan@teamlinux.org
_________________________________________________________________
Ever wish you could do more to promote Linux and yet you never seem to
have enough time? Now for a few pennies worth of electricity per day
you can put your Linux machine to work promoting Linux!
There are a number of distributed computing projects in progress or
being organized, and Linux Advocacy teams are one method available to
us which can help raise the visibility of Linux. What I'd like to
describe in this article is one such effort called the RSA Data
Security Secret-Key Challenge.
This article will describe what the project is; why we are doing this
and how it might benefit Linux and how to get started. There is also a
section on who is involved; other links for further information and
when to get involved at the end.
_________________________________________________________________
What?
_________________________________________________________________
The Secret-Key Challenge is a contest sponsored by RSA Data Security
which is being used primarily to further research into the strength of
encryption standards. The DES challenge was won back in June. RSA is
offering a $10,000US prize to the winning team which breaks the
RC5-32/12/7 challenge which uses a 56 bit key. The challenge has been
running since January 28th, 1997.
The status of the various challenges can be seen here. The method
being used for cracking the code by the various groups is a brute
force check of the entire 2^56 keyspace.
To give you an idea of the magnitude of the problem, consider that a
single fast Pentium Pro based system would take in excess of 4000
years to run through the entire keyspace. A 200 Mhz Pentium would take
about 9000 years.
_________________________________________________________________
Why?
_________________________________________________________________
Promoting Linux
Promoting Linux is the main reason we are participating in this
effort. We would like to raise public awareness of Linux, and this
seems like one of many good avenues for doing it. It is a relatively
easy and fun way to get a large number of Linux users involved in a
publicity effort.
Linux is in one of those "chicken-and-egg" situations at the moment.
We need to make more software companies aware that Linux is a market
force to be recconned with. With more software, it will be easier to
convince more users, which will convince more companies etc. A
snowball effect is what we need to break off the plateau we're on.
There are many operating system advocacy groups participating in the
effort. One of the strongest ones at the moment is Apple. It seems
like they've been putting all their available systems into the effort
and are currently ranked number one in the Bovine effort. This is the
one to beat! The other Linux advocacy group linux@linuxnet.org is in
second place on Bovine, but they do not seem to have a presence in the
Cyberian effort. The group we are involved with, rc5@teamlinux.org is
moving up from behind very quickly on Bovine, and are consistantly in
the Top 20 teams on Cyberian for the key rates.
Naturally we hope that you'll consider the team which we are involved
with, but both Linux teams have similar goals and reasons for being,
and either team would be a good choice.
Helping to Change Encryption Restrictions
To prove that 56-bit encryption is insufficient. It is high time for
the U.S. government to rethink the current encryption export policies
and standards.
Stronger encryption is readily available and the belief that
"bad-guys" might restrict themselves to using encryption that could be
tapped by the government does not make sense.
Having Fun!
It is fun to watch your system work on the project, see the results
and get into mild competitions with other teams. Your system is
probably idle most of the time and it is satisfying to know that all
of the "idle-cycles" can now be put to productive use!
Most groups and teams have some methods available for looking at the
statistics. Check into these sites on a regular basis, and see how
well your team is doing! The competitive aspect can spur growth as it
motivates people to get other people involved. This is good!
_________________________________________________________________
How?
_________________________________________________________________
There are three overall efforts working on the RSA RC5 Challenge that
we know of. Each one has different client programs to run and
different procedures to follow. They also each have their own pros and
cons. Each overall effort is also divided up into "teams". We believe
that only the first two groups have active Linux Advocacy groups, but
we may be mistaken. (The third group had a team called Linux!, but did
not have a web address or a way to contact them which we could see.)
* The Bovine RC5 Cracking Effort Headquarters
* The Cyberian RC5-56 Project CommCentre
* Infinite Monkeys RC5 Coordinated Attack
You will need to pick a team. Either of the Linux teams will make a
good choice and both teams have instructions for setting up which you
can read on their respective Websites. See the section below for more
of a description on both teams.
The team we are involved with, Team Linux, has members involved with
both Bovine and Cyberian, so we will describe both here.
We will also assume that you are using a Linux machine, although we
(Team Linux) don't restrict you to using Linux. Our feeling on the
matter is that the other machines on our team are "Linux
Sympathasizers" or "Linux Wannabee" machines! ;-)
All groups work on the basis of keyservers handing out work for the
distributed systems, or client systems (that's you and me) to work on.
There is very little network traffic to do this. Basically the
keyservers hand out a range of keys to work on. Your system then
checks each key by brute force and contacts the keyserver again when
it needs more work to do. The programs work at very low priority
(nice-level) so that you shouldn't notice any change in interactive
sessions, effectively only using "idle cycles". The client system also
tells the server which range it has checked so that the numbers can
show up in your team's statistics. (This is the fun part.)
The following will not be an exhaustive description of either system
but will give you a few pointers on setting up. For more information,
see your team's Web pages. Hopefully, this get you started and show
you how easy it is.
_________________________________________________________________
Bovine Clients
The Bovine effort has a lot going for it. They are well organized;
have fast client programs for a number of platforms; have checked a
larger portion of the key space and will be giving away a larger
portion of the winnings (should they win). They have stated that they
will give $8000US of the winnings to Project Gutenberg which is a very
worthwhile cause. They are keeping $1000US and will give $1000US to
the winning team.
Both Linux teams will be giving all the prize money away. The
linux@linuxnet.org group will be donating the money to Linux
International, while the Team Linux group is leaving it to members to
vote on, and may well end up doing the same. Team Linux is also in
discussions with several other companies about additional sponsorship
for a worthy Linux cause. We will have an announcement about this
soon.
Both linux@linuxnet.org and the team we are involved with, Team Linux
(with an email of crusader@mo.net) are represented in this group. You
may pick either team if you choose to use the Bovine system.
The first thing to do is to get a copy of the client program and
unpack the archive into an empty directory. At the time of this
writing, the latest version was v2 build 4 and the Linux archive
contains:
-rwxrwxr-x bovine/rc5 292892 Aug 7 05:06 1997 rc5v2b4/rc5v2
-rw-rw-r-- bovine/rc5 2085 Aug 6 22:11 1997 rc5v2b4/README.TXT
You'll notice that the files are containted in a subdirectory relative
to where you unpack them. So if you unpack in your home directory you
will create a subdirectory called rc5v2b4 containing the files. (I
also create a symlink [symbolic link] here, to make typing easier.
Pick a name which is easier to type such as bovine. You can then use
this as an alias.)
ln -s rc5v2b4 bovine
The Bovine system uses one program which both does the key checking
and also maintains a cache of keys, contacting a keyserver when it
needs more work, and checking in the finished blocks.
Configuring the Bovine client involves running the client program with
the -config option. You will then be presented with a menu, which
should be similar to the one reproduced here:
CLIENT CONFIG MENU
------------------
1) Email to report as [default:rc5@distributed.net] ==> rc5@distributed.net
2) Blocks to Buffer [default:5] ==> 5
3) Blocks to complete in run [default:0] ==> 0
4) Hours to complete in a run [default:0] ==> 0
5) Keys per timeslice - for Macs etc [default:65536] ==> 65536
6) Level of niceness to run at [default:0] ==> 0
7) File to log to [default:] ==>
8) Network communication mode [default:1] ==> 1
14) Optimize performance for CPU type [default:-1] ==> -1
0) Quit and Save
The important one to change is "1". This email address you add here
determines which team your blocks will be counted for. This is case
sensitive, and does not tolerate typos, so be careful when typing this
in and double check.
Press the "1" key, followed by the "Enter" key and you will be
presented with the following prompt:
Email to report as (64 characters max) [rc5@distributed.net] -->
If you decide to count your blocks for linux@linuxnet.org then enter
it here.
If you decide to work with Team Linux then you need to enter
crusader@mo.net. (The reason we don't use rc5@teamlinux.org on Bovine
is that we received our teamlinux.org domain after actually starting
the effort. The Bovine group was unwilling to move our stats to the
new email address so we had to keep the old one to maintain our block
counts. The crusader@mo.net email address actually belongs to Eric P.
Anderson, who started Team Linux.)
Fine Tuning
If you are only connected to the net part time, you should consider
buffering a larger number of blocks. Assuming that you connect once
per day, you'll need to get at least a day's worth and maybe a bit
more, for good measure. (The limit is 200 on the latest clients I
think.) If you are connected to the 'Net full time, then you can leave
this at the default setting.
I also suggest that you define a log file, perhaps
/var/tmp/bovine.log might be a good choice. This is all you really
need to define unless you have specific needs, such as getting around
a firewall. (These subjects are beyond the scope of this article, and
you should consult the Bovine Client Documentation for more help if
you run into difficulties. They also maintain several mailing lists
where you might find additional help.)
At this point, save the setup by pressing the "0" key, and you should
be ready to test it out. The configuration file which is saved is
called rc5v2.ini, and is placed in the current directory.
Test it out! Type the name of the program and watch it go! (We usually
leave it running with a spare xterm or on one of the text consoles.
One nice thing about the Bovine client is that it gives you feedback
on how far through each block it is.)
_________________________________________________________________
Cyberian Clients
Personally, we find the Cyberian Effort more satisfying, although it
is not without its problems. They have been going through some
difficulties on their server in the last week while one of the key
developers was away in China. (This should be cleared up by the time
you read this.) They also only have one server whereas Bovine have
many, so Cyberian are currently more prone to having problems. Lastly,
they have not been working as long as Bovine, so have not checked as
much of the keyspace.
On the positive side, Cyberian have far better stats which make them
much more fun to be involved with. Currently, the Bovine stats are
only updated once per day and do not give you access to your
individual numbers. The Cyberian stats are updated every 10 minutes or
so and gives you a list of all of the team members as well as your
overall team statistics.
This is a great boon for people getting involved as they can see
themselves up on the board within minutes! Cyberian also has many more
categories of numbers and graphs to delight the people involved.
Lastly, the Bovine effort is offering $1000US to the winning team,
while the Cyberian effort is offering $5000US. This would mean more
money for a worthwhile Linux effort, should one of the Linux teams
win. Note that the Bovine group is giving the bulk of the money to a
worthwhile cause, it's just not a Linux cause.)
At the time of this writing, we believe that the only Linux advocacy
group here is Team Linux. The email address they are using here is:
rc5@teamlinux.org.
First, you need to download their client program. Pick the appropriate
one for your architecture. We assume that most of us will be using the
"Client v3.04 for Linux [X86]" although others are available.
This tar archive will unpack in your current directory so you should
make a directory for it: $HOME/cyberian, for example, then change to
that directory.
Unpacking with tar tvzf Linux-x86.bin304.tgz will give you the
following files:
-rwxrwxr-x tic0/tic0 20315 Jul 25 15:08 1997 rc5client
-rwxrwxr-x tic0/tic0 18093 Jul 25 15:08 1997 sa_simple
The Cyberian system uses these two programs: one (rc5client) which
checks the keys and the other (sa_simple) which maintains the cache
and contacts the server when necessary. Both programs will list the
available options if you run the program with "-\?". (The backslash
may be necessary to escape the question mark on some shells.)
You will need to contact the server to load the initial cache of
blocks at this point. For now, run
sa_simple -1
If everything works OK, you should see a message saying that the
server has been contacted and that your cache has been loaded. If the
program has difficulty contacting the server, you will see repeated
messages to that effect. If this condition lasts more than ten minutes
or so, then there may be a problem. See the Cyberian or Team Linux
Websites for more details. It may be a networking issue, or it may be
that their server is still having some problems.
The Cyberian system does not use configuration files, nor does it
create logfiles; so all options must be supplied on the command line.
(We like to use logfiles to maintain a record of what was done and to
see what it is doing occasionally.) You can automate this by creating
a shell script such as the following:
#!/bin/sh
#
# Run the Cyberian client programs:
# (This version is for part-time connections, full-time connections don't
# use the -1 option on sa_simple, or the -q option on rc5client)
#
MY_EMAIL=yourname@yourdomain # Change This!!!
TEAM="rc5@teamlinux.org"
LOW_WATER_MARK=500
HIGH_WATER_MARK=1000
export TEAM HIGH_WATER_MARK LOW_WATER_MARK MY_EMAIL
sa_simple -1 -l $LOW_WATER_MARK -h $HIGH_WATER_MARK > /var/tmp/sa_simple.log
2>&1 &
rc5client -t $TEAM -e $MY_EMAIL -N -q -n19 > /var/tmp/rc5client.log
2>&1 &
With a shell script such as this you can find out what is happening at
any time by doing a
"tail -f /var/tmp/rc5client.log" or
"tail -f /var/tmp/sa_simple.log".
(In fact, we just leave a few xterms running with a tiny font, so we
can keep an eye on them while doing other things.)
Assuming that everything is running OK, you can start seeing your own
email address in your team's statistics in a very short period of
time. After a few hours of processing, make a connection to the net
again (if you are dialing in part time), and run sa_simple -1 by
itself. After the server has acknowledged your blocks, you should be
able to do a search and see your email address show up here in about
15 minutes!
Another nice feature which we like about Cyberian is the ability to
see what is left in the cache. This is very useful for users with
part-time connections. The following is a script we use to summarize
what is in the cache. You can use this as is, or even modify it to
give you estimates of the number of hours left. If you have trouble
cutting and pasting from here, you can find it on the Team Linux site.
#!/bin/sh
#
# @(#) cache.sh - summarize rc5 cache information dump
# Author: Bill Duncan, bduncan@teamlinux.org
#
# Note: make sure rc5client is in your PATH. I assume current directory.
PATH=$PATH:
rc5client -d |
awk '
BEGIN {
F = "%-6s %4d %s\n"
}
FNR == 1 { next }
NF > 0 {
time = $2
$1 = $2 = ""
s = sprintf("%6s~%s", time, $0)
a[ s ]++
}
END {
for (i in a) {
split(i, b, "~")
printf F, b[1], a[i], b[2]
total += a[i]
if (i ~ /COMPLETED/)
done += a[i]
else
notdone += a[i]
}
# sort these lines to the end
printf "~\n"
printf F, "~", done, " DONE"
printf F, "~", notdone, " NOT DONE"
printf F, "~", total, " TOTAL IN CACHE"
}' |
sort | sed 's/^~/ /'
This script will give you a display such as the following:
122:59 27 COMPLETED REPORTING
125:47 101 COMPLETED REPORTING
137:15 93 COMPLETED
137:15 125 COMPLETED REPORTING
150:26 1 RESERVED
150:26 4
5 NOT DONE
346 DONE
351 TOTAL IN CACHE
This display tells us that we need to connect to the server soon as we
only have 5 blocks to go before running out! The numbers down the left
column are the number of hours and minutes left before that block
expires. The middle column is the number of blocks with that specific
expiry. The rest of the line is a status, with "RESERVED" being the
block currently being worked on and no status means that the group has
not been started yet.
_________________________________________________________________
Stats, Numbers and Graphs
_________________________________________________________________
As we have mentioned elsewhere, the Cyberian group pay more attention
to the statistics and graphs, which we tend to think are more fun for
people.
Both groups tend to pay alot of attention to the blocks already
completed. This is like saying that someone has bought 10,000 losing
lottery tickets vs. someone else who has only bought 10. The prize is
not given to the group with the most losing tickets! Both teams have
an equal chance of buying the next winning lottery ticket!!
More important is the current rate at which the tickets are being
bought, or in our case, the rate at which key blocks are being
checked.
If you compare teams on that basis, it gives a more realistic relative
probability on which team will find the secret key and win the prize
money.
Having said all that, watching the numbers and the graphs, and
comparing your team's numbers with other teams is all part of the fun.
The Bovine stats recently had an overhaul but is still only updated
once per day. For example: only team statistics are shown, without
mentioning individual efforts.
The Cyberian stats and their search facility are a joy to use. They
provide almost instant feedback for anyone getting involved as you can
usually find your entries within minutes of contacting the server. You
can also see how your contribution has helped the overall team effort.
_________________________________________________________________
Who?
_________________________________________________________________
So Where do I Sign Up?
Why two teams? Why don't we just join up with the other team, and
combine our numbers? We've been asked this probably the most since
Eric Anderson started Team Linux.
The reason is that we feel that "friendly" rivalry will benefit both
teams and help get people excited about getting involved. The benefit
to Linux will hopefully be greater participation and better
visibility.
Both teams have the same main goals in mind with promoting Linux the
highest on the list. However, we both have different ways of going
about this.
The linux@linuxnet.org team has plenty going for it. It's been around
a lot longer and has accumulated a much larger total number of blocks
checked. They have openly stated that they will donate the entire
$1000 to Linux International if they win. They seem to have two sets
of Web pages and you can access the second set here.
The Team Linux group have stated that they will donate all of any
prize money or other revenue directly to a Linux group of the members'
choosing. Any administrative costs will be paid for out of our own
pocket. Since Team Linux is also involved in the Cyberian effort, the
prize money may very well be $5000US for Team Linux, or $1000US if the
key is found through the Bovine effort.
Team Linux is also in discussion with several companies about up-ing
the anti, possibly by having them match the prize money available, or
perhaps some other method which does not rely on chance nearly as
much. We should have an announcement on this soon.
We would like to encourage you to get involved in either team and
compete in the spirit of Linux, for the benefit of Linux. As long as
the competition remains friendly, it will be healthy and help out.
_________________________________________________________________
The Future of Distributed Computing
_________________________________________________________________
Getting tens of thousands of computers working on a common problem is
an awesome technical accomplishment. It is made all the more
interesting by the fact that the computers are spread out world-wide,
some of them available full-time, some not, with different hardware
and operating systems. Having them all owned by different people and
organizations, each with their own agenda and motivations adds yet
another dimension to the task.
Some papers and sites on the topic of distributed systems and related
subjects which we've found:
* Condor is a project at University of Wisconsin-Madison which has
been going on for about 10 years. They have published a number of
interesting papers on what they call High Throughput Computing
(HTC). They are the movers and shakers for the third group working
on the RSA Challenge called Infinite Monkeys.
* Yahoo have a whole section devoted to distributed computing. There
is a good collection of material here, with many universities
being represented.
* The GREAT Internet Mersenne Prime Search is another way to use
those spare cycles.
* In Search Of The Optimal 20 & 21 Mark Golomb Rulers
* SETI@home is an effort to use spare cycles in the Search for
Extra-Terrestrial Intelligence (SETI). It looks like this might
ramp up to be a very big thing by next Spring. They are looking to
put hundreds of thousands of machines to work. Let's make sure
they do a Linux client program!
* As we all know, lots of cool research has come from the folks at
Xerox PARC (Palo Alto Research Center), including probably the
first windowing environment. It's not surprising to find that they
have a number of papers on the subject. There is one which looks
particularly interesting in a section called allocating time on
idle computers: C. A. Waldspurger et al., Spawn: A Distributed
Computational Economy, 1992. Unfortunately, it has been taken
off-line. I seem to recall something like this published some
years ago, possibly in Byte, although no reference could be found.
While researching the Xerox PARC site, we came across a section
called the Dynamics of Computation Area. You have to see this, if
for no other reason, to see the graphic depicting many small
distributed efforts overtaking one large effort!!
_________________________________________________________________
When?
_________________________________________________________________
Do it now!!
It's easy. You'll have plenty of help. And once you are set up, you
can let your system do the rest!
_________________________________________________________________
Copyright © 1997, Bill Duncan
Published in Issue 21 of the Linux Gazette, September 1997
_________________________________________________________________
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_________________________________________________________________
_________________________________________________________________
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_________________________________________________________________
Linux Gazette Back Page
Copyright © 1997 Specialized Systems Consultants, Inc.
For information regarding copying and distribution of this material see the
Copying License.
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
_________________________________________________________________
Contents:
* About This Month's Authors
* Not Linux
_________________________________________________________________
About This Month's Authors
_________________________________________________________________
Randy Appleton
Randy Appleton is a new professor in the Math and Computer Science
department of Northern Michigan University. He typically teaches the
higher lever C.S. classes, especially the operating systems classes.
He has two dogs, two cats and speaks a small amount of German. He
likes to SCUBA dive and has his very own pilots license.
Larry Ayers
Larry Ayers lives on a small farm in northern Missouri, where he is
currently engaged in building a timber-frame house for his family. He
operates a portable band-saw mill, does general woodworking, plays the
fiddle and searches for rare prairie plants, as well as growing
shiitake mushrooms. He is also struggling with configuring a Usenet
news server for his local ISP.
Gerd Bavendiek
Gerd has worked as a software engineer with various flavors of Unix
since 1988. In 1994 he realized that using Linux could make his
every-day work more convenient. Since that time he has used Linux and
various GNU-software. He lives in Essen, Germany. In his spare time he
builds model-steam engines using real hardware: lathe, milling-machine
and a lot of hand tools.
John Daily
John Daily works for BBN (or is that GTE?) as a systems
administrator/software engineer. He spends far too much time in front
of computers, but when he's not, he prefers to be outside riding his
new bicycle, or otherwise exploring New England.
Jim Dennis
Jim Dennis is the proprietor of Starshine Technical Services. His
professional experience includes work in the technical support,
quality assurance, and information services (MIS) departments of
software companies like Quarterdeck, Symantec/ Peter Norton Group, and
McAfee Associates -- as well as positions (field service rep) with
smaller VAR's. He's been using Linux since version 0.99p10 and is an
active participant on an ever-changing list of mailing lists and
newsgroups. He's just started collaborating on the 2nd Edition for a
book on Unix systems administration. Jim is an avid science fiction
fan -- and was married at the World Science Fiction Convention in
Anaheim.
Bill Duncan
Bill has worked with Unix systems since the early Version 7 days on
PDP-11's. He worked with Xenix hroughout most of the eighties and has
also worked with many other flavors of Unix over the years, but his
operating system of choice is now Linux. When not working or fiddling
with his four Linux systems at home (which is rare), he might have
some time left over for his other hobbies: his dog (Daisy),
photography and Amateur Radio. He can be reached at
bduncan@BeachNet.org.
John Fisk
John Fisk is most noteworthy as the former editor of the Linux
Gazette. After three years as a General Surgery resident and Research
Fellow at the Vanderbilt University Medical Center, John decided to
":hang up the stethoscope":, and pursue a career in Medical
Information Management. He's currently a full time student at the
Middle Tennessee State University and hopes to complete a graduate
degree in Computer Science before entering a Medical Informatics
Fellowship. In his dwindling free time he and his wife Faith enjoy
hiking and camping in Tennessee's beautiful Great Smoky Mountains. He
has been an avid Linux fan, since his first Slackware 2.0.0
installation a year and a half ago.
Sam Trenholme
Sam Trenholme has been using Linux since June 19, 1995. He sees Linux
as a very powerful tool for communicating and maintaining connections
with people. His goal is to eventually obtain a Master's degree in
Computer Science.
_________________________________________________________________
Not Linux
_________________________________________________________________
Thanks to all our authors, not just the ones above, but also those who
wrote giving us their tips and tricks and making suggestions. Thanks
also to our new mirror sites.
My assistant, Amy Kukuk, did all the work again this month. She's so
good to me. Thank you, Amy.
Our beautiful new logo was designed by our very own Graphics Muse,
Michael J. Hammel. (He used The Gimp.) Thanks, Michael.
Well, this is the last issue that Amy and I will be working on. We are
turning over the editorship to Viki Navrotilova. Here's a bit about
Viki:
Viktorie Navratilova has been using Linux for the past 4 years, and
has been active in both the Israeli and Chicago Linux Users' Groups.
She started using Linux because of its network capabilities, and then
stayed for the compilers.
I know Viki will have as much fun as we have and do a wonderful job.
Show your support and send her lots of articles.
LG will remain under the guardianship of Linux Journal and neither the
web address or e-mail address will change. Articles from LG will
continue to appear in LJ.
Have fun! Bye-Bye!
_________________________________________________________________
Marjorie L. Richardson
Editor, Linux Gazette gazette@ssc.com
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back
_________________________________________________________________
Linux Gazette Issue 21, September 1997, http://www.ssc.com/lg/
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gazette@ssc.com
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