Linux Gazette... making Linux just a little more fun!
Copyright © 1996-97 Specialized Systems Consultants, Inc.
_________________________________________________________________
Welcome to Linux Gazette! (tm)
_________________________________________________________________
Published by:
Linux Journal
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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.
_________________________________________________________________
Table of Contents
October 1997 Issue #22
_________________________________________________________________
* The Front Page
* The MailBag
+ Help Wanted -- Article Ideas
+ General Mail
* More 2 Cent Tips
+ Netscape and Seyon questions
+ Keeping track of tips
+ Displaying File Tree
+ Making Changing X video modes easier
+ Tree Program
+ Finding what you want with find
+ Minicom kermit help
+ Postscript printing
+ Realaudio without X-windows
+ Connecting to dynamic IP via ethernet
+ Running commands from X w/out XTerm
+ Ascii problems with FTP
+ Red Hat Questions
* News Bytes
+ News in General
+ Software Announcements
* The Answer Guy, by James T. Dennis
+ Faxing and Dialing-Out on the Same Line
+ Linux and the 286
+ Accessing ext2fs from Windows 95
+ chattr +i
+ Linux sendmail problem
+ POP3 vs. /etc/passwd
+ Problem with make
+ Swap partition and Modems
+ Redhat 4.2/Motif
+ E-mail adjustment needed
+ REALBIOS?
+ X-Windows Libraries
+ PC Emulation
+ Visual Basic for Linux
+ Linux 4.2 software and Hardware compatablity problems
+ Moving /usr subdirectory to another drive..
+ C++ Integrated Programming Enviroment for X...
+ LYNX-DEV new to LYNX
* Graphics Muse, by Michael J. Hammel
* Linux Benchmarking: Part 1 -- Concepts, The first article in a
series, by Andrй D. Balsa
* New Release Reviews, by Larry Ayers
+ Word Processing vs. Text Processing?
+ A New GNU Version of Emacs
+ Notes-Mode for Emacs
* Using m4 To Write HTML, by Bob Hepple
* An Introduction to The Connecticut Free Unix Group, by Lou Rinaldi
* Review: The Unix-Hater's Handbook, by Andrew Kuchling
* The Back Page
+ About This Month's Authors
+ Not Linux
The Answer Guy
The Weekend Mechanic will be back next month
_________________________________________________________________
The Whole Damn Thing 1 (text)
The Whole Damn Thing 2 (HTML)
are files containing the entire issue: one in text format, one in
HTML. They are provided strictly as a way to save the contents as one
file for later printing in the format of your choice; there is no
guarantee of working links in the HTML version.
_________________________________________________________________
Got any great ideas for improvements! Send your comments, criticisms,
suggestions and ideas.
_________________________________________________________________
This page written and maintained by the Editor of Linux Gazette,
gazette@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, 25 Aug 1997 15:02:14 -0700
From: cooldude cooldude@digitalcave.com
Subject: how do
how do i setup a linux server from scratch?
my freind has the t1 connection and im gonna admin it with his
ermission need ta know A. S.A.P.
=)
thanks
_________________________________________________________________
Date: Mon, 1 Sep 97 18:59:51 UT
From: Richard Wang rzlw1@classic.msn.com
Hi,
I have just set up a system for RedHat Linux, but I am finding getting
real support for this system is very difficult. In fact, I cannot even
setup my webpage via SLIP from the manuals I have. Redhat seems to go
against it'scompetitor Caldera, and I am finding it hard to find the
right manuals and guides for this system.
Do you have an online help person, who I can log to ?
Looking forward to your reply,
Richard Wang
Cambridge
United Kingdom
_________________________________________________________________
Date: Wed, 17 Sep 1997 19:49:55 -0700
From: Garry Jackson gjackson@home.com
Subject: Linux Problem.
I'm a linux newbie and I'm having major problems. I have a monitor
that is kapible of 800X600 and I don't know anything else about it. I
Also have a Trio 32/64. I cannot get Xwindows to go so what should I
do.
Also I'm have a problem with my SB16 PNP and I can't get that to work
and I can't get a Supra 28.9 PnP and a SN-3200 witch is a NE-200 clone
if you could give me any tips on getting this stuff work It would be
thanked.
Garry Jackson
_________________________________________________________________
Date: Wed, 3 Sep 1997 19:28:20 -0400
From: Prow Prowlyr@mindspring.com
Subject: Just some really basic help please.
I want to learn about unix but really dont know where to start. Can I
get a free version somewhere to get me started? Do you know of a good
Unix for dummies site that might help? Would greatly appreciate any
reply via e-mail. Thanx in advance.
_________________________________________________________________
Date: Tue, 09 Sep 1997 00:49:50 +0200
From: Michael Stumpf ms@astat.de
Subject: Linux Kernel
I'm searching information about the status of the current kernel
(release and/or developer). Do you have a web-address from an
up-to-date site ? I used to look at "http://www.linuxhq.com" for this,
but it seems that it is forever down.
tia
Michael
_________________________________________________________________
Date: Sat, 27 Sep 1997 11:02:04 -0400
From: Dave Runnels drunnels@panix.com
Subject: 3com509b problems
I recently added a 3com509b Ethernet card to my Win95/Linux machine. I
run the machine in PnP mode and the RedHat 4.2 install process won't
recognize the card. RedHat's solution was to disable PnP for the
machine. While this might be fine for Linux, I am forced to use Win95
for a number of things and turning off PnP (which works great for me
on Win95) will be a real pain in the ass.
Is there a way I might have my cake and eat it too? I do know which
IRQ the card is being assigned to.
Thanks, Dave
_________________________________________________________________
Date: Mon, 22 Sep 1997 10:06:04 +0200
From: Erwin Penders ependers@cobweb.nl
Subject: email only
Hi,
My name is Erwin Penders an i'm working for a local ISP in the
Netherlands. I don't know if i send this mail to the right place, but
i have a question about a Linux problem. I want to know how to set up
an email-only account (so you can call the ISP, make a connection and
send/receive email) without the possiblity for WWW, Telnet etc. The
main problem is that i don't know how to set up the connection (the
normal accounts get a /etc/ppp/ppplogin).... . .
Can anybody help me with this problem !?
Thanks,
Erwin Penders
(CobWeb)
_________________________________________________________________
Date: Sat, 20 Sep 1997 22:00:38 +0200
From: Richard Torkar richard.torkar@goteborg.mail.telia.com
Subject: Software for IDE cd-r?
First of all Thanks for a great e-zine!
And then to my question... (You didn't really think that I wrote to
you just to be friendly did you? ;-)
Is there any software written for IDE cd-r for example Mitsumi
CR2600TE?
I found two programs; Xcdroast and CDRecord for Linux, but
unfortunately they don't support IDE cd-r :-(
I haven't found anything regarding this problem and I've used darned
near all search tools on the net... Any answer would be appreciated.
If the answer is no, can I solve this problem somehow?
Regards,
Richard Torkar from the lovely land of ice beers .. ;-)
_________________________________________________________________
Date: Thu, 18 Sep 1997 16:03:04 -0400 (EDT)
From: Eric Maude sabre2@mindspring.com
Subject: Redhat Linux 4.3 Installation Help
I am trying to install Redhat Linux 4.3 on a Windows 95 (not OSR 2)
machine. I do want to set this machine up as dual boot but that's not
really my problem. I have been totally unable to set up Linux because
I am unable to set up the Non-MS DOS partition that Linux requires. I
am pretty new to Linux. I would appreciate anyone that could give me
detailed step by step instructions on how I go about setting up Redhat
Linux. I would call Redhat directly but I am at work during their
operating hours and not near the machine I need help with this!
Please, somebody help me out!!
Thanks!!
_________________________________________________________________
General Mail
_________________________________________________________________
Date: Fri, 29 Aug 1997 11:02:39 -0300
From: Mario Storti mstorti@minerva.unl.edu.ar
Subject: acknowledge to GNU software
(Sorry if this is off-topic)
From now on I will put a mention to the GNU (and free in general)
software I make use in the "acknowledgment" section of my (scientific)
papers. I suggest to do the same to all those who are working on
scientific applications. Since Linux is getting stronger every day in
the scientific community, this could represent an important support,
specially when requesting funding. Even better would be to make a
database with all these "acknowledgments" in a Web site or something
similar. Do anyone know of something like this that is already
working? Any comments?
Mario
_________________________________________________________________
Date: Sun, 07 Sep 1997 23:58:16 -0500
From: mike shimanski mshiman@xnet.com
Subject: Fun
I just discovered Linux in July and am totally pleased. After years of
Dos, Win 3.1, OS/2 and Win95, ( I won't discuss my experience with
Apple), I think I found an operating system I can believe in.I cannot
make this thing crash!
The Linux Gazette has been a rich source of information and makes
being a newbe a great deal easier.I want to thank you for the time and
effort you put into this publication. It has made my induction into
the Linux world a lot easier.
Did I mention I am having way too much fun exploring this operating
system? Am I wierd or what?
Again, thanks for a great resource.
Mike Shimanski
_________________________________________________________________
Date: Sat, 06 Sep 1997 18:01:52 -0700
From: George Smith gbs@swdc.stratus.com
Subject: Issue 21
THANKS! Thanks! Thank You!
Issue 21 was great! I loved it! I most appreciate the ability to
download it to local disk and read it without my network connection
being live and with the speed of a local disk. Please keep offering
this feature - I wish everyone did. BTW, I am a subscriber to the
Linux Journel from issue 1 and enjoy it immensely also.
Thanks again.
_________________________________________________________________
Date: Wed, 03 Sep 1997 19:34:29 -0500
From: Mark C. Zolton trustno1@kansas.net
Subject: Thank you Linux Gazzette
Hello There,
I just wanted to thank you for producing such a wonderful publication.
As a relative newbie to Linux, I have found your magazine of immense
use in answering the plethora of questions I have. Keep up the good
work. Maybe oneday I'll be experienced enough to write for you.
Mark
_________________________________________________________________
Date: Mon, 1 Sep 1997 00:09:53 -0500 (CDT)
From: Arnold Hennig amjh@qns.com
Subject: Response to req. for help - defrag
I saw the request for information about the (lack of) need for
defragging in issue 20, and have just been studying the disk layout a
bit anyway.
Hope the following is helpful:
In reference to the question titled "Disk defrag?" in issue 20 of the
Linux Gazette:
I had the same question in the back of my mind once I finally Linux up
and running after some years of running a DOS based computer. After I
was asked the same question by someone else, I poked around a bit and
did find a defrag utility buried someplace on sunsite. The
documentation pretty much indicated that with the ext2 file system it
is rarely necessary to use the utility (he wrote it prior to the
general use of ext2fs). He gave a bit of an explanation and I found
some additional information the other day following links that (I
believe) originated in the Gazette.
Basically, DOS does not keep a map of the disk usage in memory, and
each new write simply starts from the next available free cluster
(block), writes till it gets to the end of the free space and then
jumps to the next free space and continues. After it reaches the end
of the disk or at the next reboot, the "next free cluster" becomes the
"first free cluster", which is probably where something was deleted,
and may or may be an appropriate amount of free space for the next
write. There is no planning ahead for either using appropriate sized
available spaces or for clustering related files together. The result
is that the use of space on the disk gets fragmented and disorganized
rather quickly, and the defrag utilities are a necessary remedy.
In fairness to DOS, it was originally written for a computer with
precious little memory, and this method of allocating write locations
didn't strain the resources much.
The mounting requirement under unices allows the kernel to keep a map
of the disk usage and allocate disk space more intelligently. The Ext2
filesystem allocates writes in "groups" spread across the area of the
disk, and allocates files in the same group as the directory to which
they belong. This way the disk optimization is done as the files are
written to disk, and a separate utility is not needed to accomplish
it.
Your other probable source of problems is unanticipated shutdowns
(power went out, Dosemu froze the console and you don't have a way to
dial in through the modem to kill it - it kills clean, btw ;-), or
your one year old niece discovered the reset button). This will tend
to cause lost cluster type problems with the files you had open at the
time, but the startup scripts almost universally run fsck, which will
fix these problems. You WILL notice the difference in the startup time
when you have had an improper shutdown.
So, yes, you may sleep with peace of mind in this respect.
Arnold M.J. Hennig
_________________________________________________________________
Date: Wed, 3 Sep 1997 16:19:17 -0600 (MDT)
From: Mark Midgley midgley@pht.com
Subject: Commercial Distribution
Mo'Linux, a monthly Linux distribution produced by Pacific HiTech,
Inc. includes current Linux Gazette issues. They are copied in whole,
according to the copyright notice.
Mark
_________________________________________________________________
Date: Thu, 11 Sep 1997 12:26:53 -0400
From: Brian Connors connorbd@bc.edu
Subject: Linux and Mac worlds vs Microsoft?
Michael Hammel made an interesting comment in the September letters
column about aligning with Mac users against Microsoft. The
situation's not nearly as rosy as all that, what with Steve Jobs'
latest activity in the Mac world. As a Mac diehard, I'm facing the
prospect of a good platform being wiped out by its own creator,
whether it's really his attention or not. IMHO the Linux world should
be pushing for things like cheap RISC hardware (which IBM and Motorola
have but aren't pushing) and support from companies like Adobe. I know
that in my case, if the MacOS is robbed of a future, I won't be
turning to Windows for anything but games...
_________________________________________________________________
Date: Thu, 11 Sep 1997 22:59:19 +0900
From: mark stuart mark@www.hotmail.com
Subject: article ideas
why not an issue on linux on sparc and alpha(especially for scientific
applications) and also how about an issue on SMP with linux?
_________________________________________________________________
Date: Sat, 27 Sep 1997 01:57:09 -0700 (PDT)
From: Ian Justman ianj@chocobo.org
Except for the SNA server, all I've got to say about Linux with all
the necessary software is: "Eat your heart out, BackOffice!"
--Ian.
_________________________________________________________________
Date: Wed, 24 Sep 1997 21:49:28 -0700
From: Matt Easton measton@lausd.k12.ca.us
Subject: Thanks
Thank you for Linux Gazette. I learn a lot there; and also feel more
optimistic about things not Linux after visiting.
_________________________________________________________________
Date: Fri, 26 Sep 1997 13:24:29 -0500
From: "Samuel Gonzalez, Jr." buzz@pdq.net
Subject: Excellent Job
Excellent job !!!
Sam
_________________________________________________________________
Published in Linux Gazette Issue 22, October 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 2ў Tips!
Send Linux Tips and Tricks to gazette@ssc.com
_________________________________________________________________
Contents:
* Netscape and Seyon questions
* Keeping track of tips
* Displaying File Tree
* Making Changing X video modes easier
* Tree Program
* Finding what you want with find
* Minicom kermit help
* Postscript printing
* Realaudio without X-windows
* Connecting to dynamic IP via ethernet
* Running commands from X w/out XTerm
* Ascii problems with FTP
* Red Hat Questions
_________________________________________________________________
Netscape and Seyon questions
Date: Mon, 8 Sep 1997 11:23:51 -0600 (MDT)
From: "Michael J. Hammel" mjhammel@long.emass.com
Lynn Danielson asked:
I downloaded Netscape Communicator just a few weeks ago from the
Netscape site. I'm not sure older versions of Netscape are still
available. I'm probably wrong, but I was under the impression that
only the most current beta versions were freely available.
Answer:
A quick search through Alta-Vista for Netscape mirrors showed a couple
of different listing for mirror sites. I perused a few and found most
either didn't have anything or had non-English versions, etc. One site
I did find with all the appropriate pieces is:
ftp://ftp.adelaide.edu.au/pub/WWW/Netscape/pub/
Its a long way to go to get it (Australia), but thats all I could
find. If you want to go directly to the latest (4.03b8) Communicator
directory, try:
ftp://ftp.adelaide.edu.au/pub/WWW/Netscape/pub/communicator/4.03/4.03b
8/english/unix/
I did notice once while trying to download from Netscape that older
versions were available, although I didn't try to download them. I
noticed this while looking for the latest download of Communicator
through their web sites. Can't remember how I found that, though.
The 3.x version is available commercially from Caldera. I expect that
the 4.x versions will be as well, though I don't know if Caldera keeps
the beta versions on their anonymous ftp sites.
BTW, the Page Composer is pretty slick, although it has no interface
for doing Javascript. It has a few bugs, but its the best WYSIWYG
interface for HTML composition on Linux that I've seen. Its better
than Applix's HTML Editor, although that one does allow exporting to
non-HTML stuff. Collabra Discussions sucks. The old news reader was
better at most things. I'd still like to be able to mark a newsgroup
read up to a certain point instead of the all-or-nothing bit.
For anyone who is interested - 4.x now supports CSS (Cascading Style
Sheets) and layers. Both of these are *very* cool. They are the future
of Web design and, IMHO, a very good way to create Multimedia
applications for distribution on CDs. One of C|Net's web pages (I
think) has some info on these items, including a demo of layers (moves
an image all over the screen *over* the underlying text - way cool).
The only C|Net URL I ever remember is www.news.com, but you can get to
the rest of their sites from there.
-- Michael J. Hammel
_________________________________________________________________
Keeping track of tips
Date: Tue, 26 Aug 1997 16:29:13 +0200
From: Ivo Saviane saviane@astrpd.pd.astro.it
Dear LG,
it always happens to me that I spend a lot of time finding out how to
do a certain thing under Linux/Unix, and then I forget it. The next
time I need that information I will start all the `find . ...', `grep
xxx *' process again and waste the same amount of time!
To me, the best way to avoid that is to send a mail to myself telling
how to do that particular operation. But mail folders get messy and,
moreover, are not useful to other users who might need that same
information.
Finally I found something that contributes solving this problem. I set
up a dummy user who reads his mail and puts it in www readable form.
Now it is easy for me to send a mail to news@machine as soon as I
learn something, and be sure that I will be able to find that
information again just clicking on the appropriate link. It would also
be easy to set up a grep script and link it to the same page.
The only warning is to put a meaningful `subject: ' to the mail, since
this string will be written besides the link.
I am presently not aware of something similar. At least, not that
simple. It you know, let me know too!
If you want to see how this works, visit
http://obelix.pd.astro.it/~news
A quick description of the basic operations needed is given below.
----------------------------------------------------------------------
----
The following lines briefly describe how to set up the light news
server.
1. Create a new user named `news'
2. Login as news and create the directories ~/public_html and
~/public_html/folders (I assume that your http server is configured so
that `http://machine/~user' will point to `public_html' in the user's
$HOME).
3. Put the wmanager.sh script in the $HOME/bin directory. The script
follows the main body of this message as attachment [1]. The script
does work under bash.
The relevant variables are grouped at the beginning of the script.
These should be changed according to the machine/user setup
4. The script uses splitmail.c in order to break the mail file in
sub-folders The binary file should be put in the $HOME/bin dir. See
attachment [2].
5. Finally, add a line in the `news' user crontab, like the following
00 * * * * /news_bin_dir/wmanager.sh
where `news_bin_dir' stands for $HOME/bin. In this case the mail will
be checked once every hour.
---------------------------------- attachment [1]
#!/bin/sh
# wmanager.sh
# Updates the www news page reading the user's mails
# (c) 1997 Ivo Saviane
# requires splitmail (attachment [2])
## --- environment setup
BIN=/home/obelnews/bin # contains all the executables
MDIR=/usr/spool/mail # mail files directory
USR=news # user's login name
MFOLDER=$MDIR/$USR # user's mail file
MYFNAME=`date +%y~%m~%d~%H:%M:%S.fld` # filename for mail storage under www
FLD=folders # final dir root name
PUB=public_html # httpd declared public directory
PUBDIR=$HOME/$PUB/$FLD
MYFOLDER=$PUBDIR/$MYFNAME
INDEX=$HOME/$PUB/index.html
## --- determines the mailfile size
MSIZE=`ls -l $MFOLDER | awk '{print $5}'`
## --- if new mail arrived goes on; otherwise does nothing
if [ $MSIZE != "0" ]; then
## --- writes the header of index.html in the pub dir
echo "<html><head><title> News! </title></head>" > $INDEX
echo "<h2> Internal news archive </h2> <p><p>" >> $INDEX
echo "Last update: <i>`date`</i> <hr>" >> $INDEX
## --- breaks the mail file in single folders; splitmail.c must be compiled
$BIN/splitmail $MFOLDER > $MFOLDER
## --- each folder is copied in the folder dir, under the pub dir,
## and given an unique name
for f in $MFOLDER.*; do\
NR=`echo $f | cut -d. -f2`;\
MYFNAME=`date +%y~%m~%d~%H:%M:%S.$NR.fld`;\
MYFOLDER=$PUBDIR/$MYFNAME;\
mv $f $MYFOLDER;\
done
## --- prepares the mailfile for future messages
rm $MFOLDER
touch $MFOLDER
## --- Now creates the body of the www index page, searching the folders
## dir
for f in `ls $PUBDIR/* | grep -v index`; do\
htname=`echo $f | cut -d/ -f5,6`;\
rfname=`echo $f | cut -d/ -f6 | sed 's/.fld//g'`;\
echo \<a href\=\"$htname\"\> $rfname\<\/a\> >> $INDEX;\
echo \<strong\> >> $INDEX;\
grep "Subject:" $f | head -1 >> $INDEX;\
echo \</strong\> >> $INDEX;\
echo \<br\> >> $INDEX;\
done
echo "<hr>End of archive" >> $INDEX
echo "</html>" >> $INDEX
fi
---- attachment [2]
/******************************************************************************
Reads stdin. Assuming that this has a mailfile format, it breaks the input
in single messages. A filestem must be given as argument, and single
messages will be written as filestem.1 filestem.2 etc.
(c) 1997 I.Saviane
******************************************************************************/
#define NMAX 256
/*****************************************************************************/
#include <stdio.h>
/*****************************************************************************/
/*****************************************************************************/
/************************** MAIN **************************************/
int main(int argc, char *argv[]) {
FILE *fp;
char mline[NMAX], mname[NMAX];
int nmail=0, open;
if(argc < 2) {
fprintf(stderr, "splitmail: no input filestem");
return -1;
}
fp = fopen("/tmp/xx", "w");
while(fgets(mline, NMAX, stdin) != NULL) {
open = IsFrom(mline);
if(open==1) {
fclose(fp);
nmail++;
sprintf(mname, "%s.%d", argv[1], nmail);
fp = fopen(mname, "w");
open = 0;
}
fprintf(fp, "%s", mline);
}
fclose(fp);
system("rm /tmp/xx");
return 1;
}
/*****************************************************************************/
int IsFrom(char *s) {
if(s[0]=='F' && s[1]=='r' && s[2]=='o' && s[3]=='m' && s[4]==' ') {
return 1;
} else {
return 0;
}
}
_________________________________________________________________
Displaying File Tree
Date: Tue, 26 Aug 1997 16:40:43 -0400 (EDT)
From: Scott K. Ellis storm@gate.net
A nice tool for displaying a graphic tree of files or directories in
your filesystem can be found at your local sunsite mirror under
/pub/Linux/utils/file/tree-1.2.tgz. It is also included as the package
tree included in the Debian distribution.
_________________________________________________________________
Making Changing X video modes easier
Date: Thu, 28 Aug 1997 20:29:59 +0100
From: Jo Whitby pandore@globalnet.co.uk
Hi
In issue 20 of the Linux gazette there was a letter from Greg Roelofs
on changing video modes in X - this was something I had tried and had
found changing colour depths awkward, and didn't know how to start
multiple versions of X.
I also found the syntax of the commands difficult to remember, so
here's what I did.
First I created 2 files in /usr/local/bin called x8 and x16 for the
colour depths that I use, and placed the command in them -
for x8
#!/bin/sh
startx -- :$* -bpp 8 &
and for x16
#!/bin/sh
startx -- :$* -bpp 16 &
then I made them executable -
chmod -c 755 /usr/local/bin/x8
chmod -c 755 /usr/local/bin/x16
now I simply issue the command x8 or x16 for the first instance of X
and x8 1 or x16 1 for the next and so on, this I find much easer to
remember:-) An addition I would like to make would be to check which X
servers are running and to increment the numbers automatically, but as
I have only been running Linux for around 6 months my script writing
is extremely limited, I must invest in a book on the subject.
Linux is a fantastic OS, now I've tried it I could not go back to
Windoze and hate having to turn my Linux box into a wooden doze box
just to run the couple of progs that I can't live without (Quicken 4
and a lottery checking prog), so if anyone knows of a good alternative
to these please let me know, the sooner doze is gone for good the
better - then Linux can have the other 511Mb of space doze95 is
hogging!
ps. Linux Gazette is just brilliant, I've been reading all the back
issues, nearly caught up now - only been on the net for 3 months. I
hope to be able to contribute something a little more useful to the
Gazette in the future, when my knowledge is a little better:-)
keep up the good work.
_________________________________________________________________
Tree Program
Date: Mon, 01 Sep 1997 03:28:57 -0500
From: Ian Beth13@mail.utexas.edu
Try this instead of the tree shell-script mentioned earlier:
--------- Cut here --------
#include <stdlib.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/types.h>
#include <dirent.h>
// This is cool for ext2.
#define MAXLEN 256
#define maxdepth 4096
struct dnode {
dnode *sister;
char name[MAXLEN];
};
const char *look;
const char *l_ascii="|+`-";
const char l_ibm[5]={179,195,192,196,0};
int total;
char map[maxdepth];
void generate_header(int level) {
int i;
for (i=0;i<level;i++) printf(" %c ",(map[i]?look[0]:32));
printf (" %c%c ",(map[level]?look[1]:look[2]),look[3]);
}
dnode* reverselist(dnode *last) {
dnode *first,*current;
first=NULL;
current=last;
// Put it back in order:
// Pre: last==current, first==NULL, current points to backwards linked
list
while (current != NULL) {
last=current->sister;
current->sister=first;
first=current;
current=last;
}
return first;
}
void buildtree(int level) {
dnode *first,*current,*last;
first=current=last=NULL;
char *cwd;
struct stat st;
if (level>=maxdepth) return;
// This is LINUX SPECIFIC: (ie it may not work on other platforms)
cwd=getcwd(NULL,maxdepth);
if (cwd==NULL) return;
// Get (backwards) Dirlist:
DIR *dir;
dirent *de;
dir=opendir(cwd);
if (dir==NULL) return;
while ((de=readdir(dir))) {
// use de->d_name for the filename
if (lstat(de->d_name,&st) != 0) continue; // ie if not success go on.
if (!S_ISDIR(st.st_mode)) continue; // if not dir go on.
if (!(strcmp(".",de->d_name) && strcmp("..",de->d_name))) continue; //
skip ./
..
current=new dnode;
current->sister=last;
strcpy(current->name,de->d_name);
last=current;
}
closedir(dir);
first=reverselist(last);
// go through each printing names and subtrees
while (first != NULL) {
map[level]=(first->sister != NULL);
generate_header(level);
puts(first->name);
total++;
// consider recursion here....
if (chdir (first->name) == 0) {
buildtree(level+1);
if (chdir (cwd) != 0) return;
}
current=first->sister;
delete first;
first=current;
}
free (cwd);
}
void tree() {
char *cwd;
cwd=getcwd(NULL,maxdepth);
if (cwd==NULL) return;
printf("Tree of %s:\n\n",cwd);
free (cwd);
total=0;
buildtree(0);
printf("\nTotal directories = %d\n",total);
}
void usage() {
printf("usage: tree {-[agiv]} {dirname}\n\n");
printf("Tree version 1.0 - Copyright 1997 by Brooke Kjos
<beth13@mail.utexas.ed
u>\n");
printf("This program is covered by the Gnu General Public License
version 2.0\n
");
printf("or later (copyleft). Distribution and use permitted as long
as\n");
printf("source code accompanies all executables and no additional\n");
printf("restrictions are applied\n");
printf("\n\n Options:\n\t-a use ascii for drawings\n");
printf("\t-[ig] use IBM(tm) graphics characters\n");
printf("\t-v Show version number and exit successfully\n");
};
void main (int argc,char ** argv) {
look=l_ascii;
int i=1;
if (argc>1) {
if (argv[1][0]=='-') {
switch ((argv[1])[1]) {
case 'i':
case 'I':
case 'g':
case 'G':
look = l_ibm;
break;
case 'a':
case 'A':
look = l_ascii;
break;
case 'v':
case 'V':
usage();
exit(0);
default:
printf ("Unknown option: %s\n\n",argv[1]);
usage();
exit(1);
} // switch
i=2;
} // if2
} // if1
if (argc > i) {
char *cwd;
cwd=getcwd(NULL,maxdepth);
if (cwd==NULL) {
printf("Failed to getcwd:\n");
perror("getcwd");
exit(1);
}
for (;i>argc;i++) {
if (chdir(argv[i]) == 0) {
tree();
if (chdir(cwd) != 0) {
printf("Failed to chdir to cwd\n");
exit(1);
}
}
else printf("Failed to chdir to %s\n\n",argv[i]);
} // for
free (cwd);
} else tree();
}
------- Cut Here --------
Call this tree.cc and run gcc -O2 tree.cc -o /usr/local/bin/tree.
_________________________________________________________________
Managing an Entire Project
Date: Tue, 26 Aug 1997 16:44:06 -0400 (EDT)
From: Scott K. Ellis storm@gate.net
While RCS is useful for managing one or a small set of files, CVS is a
wrapper around RCS that allows you to easily keep track of revisions
across an entire project.
_________________________________________________________________
Finding what you want with find
Date: Tue, 2 Sep 1997 21:53:41 -0500 (CDT)
From: David Nelson dnelson@psa.pencom.com
While the find . -type f -exec grep "string" {} \; works, it does not
tell you what file it found the string in. Try using find . -type f
-exec grep "string" /dev/null {} \; instead.
David /\/elson
_________________________________________________________________
Minicom kermit help
Date: Wed, 10 Sep 1997 12:21:55 -0400 (EDT)
From: "Donald R. Harter Jr." ah230@traverse.lib.mi.us
With minicom, ckermit was hanging up the phone line after I exited it
to return to minicom. I was able to determine a quick fix for this. In
file ckutio.c comment out (/* */) line 2119 which has tthang() in it.
tthang hangs up the line. I don't know why ckermit thought that it
should hang up the line.
Donald Harter Jr.
_________________________________________________________________
Postscript printing
Date: Sun, 7 Sep 1997 15:12:17 +0200 (MET DST)
From: Roland Smith mit06@ibm.net
Regarding your question in the Linux Gazette, there is a program that
can interpret postscript for different printers. It's called
Ghostscript.
The smartest thing to do is to encapsulate it in a shell-script and
then call this script from printcap.
----- Ghostscript shell script -------
#!/bin/sh
#
# pslj This shell script is called as an input filter for the
# HP LaserJet 5L printer as a PostScript printer
#
# Version: /usr/local/bin/pslj 1.0
#
# Author: R.F. Smith <rsmit06@ibm.net>
# Run GhostScript, which runs quietly at a resolution
# of 600 dpi, outputs for the laserjet 4, in safe mode, without pausing
# at page breaks, writing and reading from standard input/output
/usr/bin/gs -q -r600 -sDEVICE=ljet4 -dSAFER -dNOPAUSE -sOutputFile=- -
------- Ghostscript shell script ------
You should only have to change the resolution -r and device -sDEVICE
options to something more suitable to your printer. See gs -? for a
list of supported devices. I'd suggest you try the cdeskjet or
djet500c devices. Do a chmod 755 <scriptname>, and copy it to
/usr/local/bin as root.
Next you should add a Postscript printer to your /etc/printcap file.
Edit this file as root.
-------- printcap excerpt -----------
ps|HP LaserJet 5L as PostScript:\
:lp=/dev/lp1:\
:sd=/var/spool/lp1:\
:mx#0:\
:if=/usr/local/bin/pslj:sh
-------- printcap excerpt ------------
This is the definition of a printer called ps. It passes everything it
should print through the pslj filter, which converts the postscript to
something my Laserjet 5 can use.
To print Postscript, use lpr -Pps filename.
change this to reflect your script name.
Hope this helps!
Roland
_________________________________________________________________
Realaudio without X-windows
Date: Sun, 7 Sep 1997 00:45:58 -0700 (PDT)
From: Toby Reed toby@eskimo.com
This is more of a pointer than a tip, but your readers might want to
check out traplayer on sunsite, it lets you play realaudio without
starting up an X server on your screen. Kinda useful if you don't like
to use memory-hog browsers just to listen to realaudio.
The file is available at sunsite.unc.edu/pub/Linux in the Incoming
directory (until it gets moved), and then who knows where. It's called
traplayer-0.5.tar.gz.
_________________________________________________________________
Connecting to dynamic IP via ethernet
Date: Fri, 12 Sep 1997 13:22:06 +0200
From: August Hoerandl hoerandl@elina.htlw1.ac.at
in LG 21 Denny wrote:
"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 address."
There is a program called bootpc (a bootp client for linux). From the
LSM entry (maybe there is a newer version now):
Title: Linux Bootp Client
Version: V0.50
Entered-date: 1996-Apr-16
Description: This is a boot protocol client used to grab the machines
ip number, set up DNS nameservers and other useful information.
Keywords: bootp bootpc net util
Author: ceh@eng.cam.ac.uk (Charles Hawkins)
Maintained-by: J.S.Peatfield@damtp.cam.ac.uk (Jon Peatfield)
Primary-site: ftp.damtp.cam.ac.uk:/pub/linux/bootpc/bootpc.v050.tgz
Alternate-site:
sunsite.unc.edu:/pub/Linux/system/Network/admin/bootpc.v050.tgz
Platform: You need a BOOTP server too.
Copying-policy: This code is provided as-is, with no warrenty, share and
enjoy.
The package inludes a shell script to set up the ethernet card, send
the bootp request, receive the answer and set up everything needed.
I hope this helps
Gustl
_________________________________________________________________
Running commands from X w/out XTerm
Date: Fri, 26 Sep 1997 18:28:51 -0600
From: "Kenneth R. Kinder" Ken@KenAndTed.com
I often found myself running XTerm just to type a single shell
commmand. After a while, you just wish you could run a single command
without even accessing a menu. To solve this problem, I wrote exec. As
the program name would emply, the exec program mearly prompts (in X11)
for a command, and replaces its own process with the shell-orriented
command you type in. Exec can also browse files, and insert the path
in the text box, incase you need a file in your command line. Pretty
simple huh? Exec (of course!) is GPL, and can be downloaded at
http://www.KenAndTed.com/software/exec/ -- I would appreciate it if
someone would modify my source to do more! =)
_________________________________________________________________
Ascii problems with FTP
Date: Wed, 24 Sep 1997 12:42:05 -0400
From: Carl Hohman carl@microserv-canada.com
Andrew, I read your letter to the Linux Gazzette in issue 19. I don't
know if you have an answer yet, but here's my 2 bits...
If I understand correctly, you are using FTP under DOS to obtain Linux
scripts. Now, as you may know, the line terminators in text files are
different between Unix systems and DOS (and Apples, for that matter).
I suspect that what's happening is this: FTP is smart enough to know
about terminator differences between systems involved in an ascii mode
transfer and performs appropriate conversions silently and on the fly.
This give you extra ^M's on each line if you download the file in DOS
and then simply copy it (or use an NFS mount) to see it from Unix. I
suspect that if you use a binary tranfer (FTP> image) the file will
arrive intact for Linux use if it originates on a Unix server.
Hope this helps.
Carl Hohman
_________________________________________________________________
Red Hat Questions
Date: Thu, 18 Sep 1997 14:06:08 -0700
From: James Gilb p27451@am371.geg.mot.com
Signal 11 crashes are often caused by hardware problems. Check out the
The Sig11 FAQ on: http://www.bitwizard.nl/sig11/
James Gilb
_________________________________________________________________
Published in Linux Gazette Issue 22, October 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
_________________________________________________________________
BLINUX Documentation and Development Project
The purpose of The BLINUX Documentation and Development Project is to
serve as a catalyst which will both spur and speed the development of
software and documentation which will enable the blind user to run his
or her own Linux workstation.
Their web site is at:
http://leb.net/blinux/
It contains information about documenting Linux for the Blind and
Visually Impaired, the BLINUX FTP Archive, and where to find Linux
Software for the Blind User.
_________________________________________________________________
Linux "class" via the Internet
There is a Linux "class" being offered on the internet! It's a
beginners class that's using Matt Welsh's "Running Linux" as the
textbook. Lessons are posted to the site, with links to Linux related
urls and reading from the text as additional assignments. I just
checked out the first lesson (history of Linux), looks pretty good.
If anyone's interested (it's free), the url is:
http://www.vu.org/channel25/today/
_________________________________________________________________
WindowMaker and AfterStep themes
Give your X-windows a whole new look with one of the WindowMaker or
AfterStep themes. There are almost 30 different themes for the
WindowMaker and another 30 for AfterStep window manager available at:
http://x.unicom.net/themes
_________________________________________________________________
Software Announcements
_________________________________________________________________
TCD 1.0: New curses-based CD player
TCD is a new curses based CD player for Linux. Here are some of it's
distinct features:
* Nice-looking color (if supported) curses interface.
* Simple, sensible, one-keystroke control. (No more mapping little
icons to your keypad!) :)
* Repeat track, continuous play control.
* Track name database.
* Uses little CPU time while running.
It should still be at
ftp://sunsite.unc.edu/pub/Linux/Incoming/tcd-1.0.tar.gz
But by the time you read this is may have moved to
/pub/Linux/apps/sound/cdrom/curses/
_________________________________________________________________
urlmon -- The URL Monitor
urlmon reports changes to web sites (and ftp sites, too).
urlmon makes a connection to a web site and records the last_modified
time for that url. Upon subsequent calls, it will check the url again,
this time comparing the information to the previously recorded times.
Since the last_modified data is not required to be given by HTTP (it's
optional) and is non-existent for ftp, urlmon will then take an MD5
checksum.
It's real utilitity is evident when running it periodically (from
cron, for example) in batch mode, so as to keep tabs on many different
web pages, reporting on those that have recently changed.
New with 2.1, it can monitor muliple URLs in parallel. It also has
user settable proxy server ability, and user settable timeout lengths.
A few algorithm improvements have been made.
It can be found at
http://sunsite.unc.edu/pub/Linux/apps/www/mirroring/urlmon-21.tgz
http://web.syr.edu/~jdimpson/proj/urlmon-21.tgz
ftp://camelot.syr.edu/pub/web/urlmon-21.tgz
urlmon requires perl 5, the LWP perl modules, the MD5 module, all
available at any CPAN archive http://www.perl.com/perl/CPAN/
_________________________________________________________________
New Netscape Version for Linux
Netscape Communicator 4.03 (Standard and Professional editions) is now
available for Linux.
To download it, go to http://www.netscape.com
_________________________________________________________________
TeamWave Workplace 2.0
TeamWave Workplace is an Internet groupware product that lets you work
together with colleagues in shared Internet rooms using Windows,
Macintosh or Unix platforms.
TeamWave's rooms are customized with shared tools like whiteboards,
chat, calendars, bulletin boards, documents, brainstorming and voting,
so you can fit the rooms to your team's tasks. Team members can work
together in rooms any-time, whether meeting in real-time or leaving
information for others to pick up or add to later.
The support for any-time collaboration and easy customization,
combined with its rich cross-platform support and modest
infrastructure needs, make TeamWave Workplace an ideal communication
solution for telecommuters, branch offices, business teams, road
warriors -- any teams whose members sometimes work apart.
System Requirements: TeamWave Workplace runs on both Windows 95/NT and
Macintosh platforms, as well as SunOS, Solaris, SGI, AIX and Linux. A
network connection (LAN or modem) is also required.
Availability and Pricing
TeamWave Workplace 2.0 is available now. A demonstration version may
be downloaded from TeamWave's web site at http://www.teamwave.com/. A
demo license key, necessary to activate the software, can also be
requested from the web site.
Regular licenses are US$50 per team member, with quantity discounts
available. Licenses can be purchased via postal mail, fax, email or
secure web server. We are making free licenses available for qualified
educational use. Please see our web site for additional information.
_________________________________________________________________
Published in Linux Gazette Issue 22, October 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:
* Faxing and Dialing-Out on the Same Line
* Linux and the 286
* Accessing ext2fs from Windows 95
* chattr +i
* Linux sendmail problem
* POP3 vs. /etc/passwd
* Problem with make
* Swap partition and Modems
* Redhat 4.2/Motif
* E-mail adjustment needed
* REALBIOS?
* X-Windows Libraries
* PC Emulation
* Visual Basic for Linux
* Linux 4.2 software and Hardware compatablity problems
* Moving /usr subdirectory to another drive..
* C++ Integrated Programming Enviroment for X...
* LYNX-DEV new to LYNX
_________________________________________________________________
Faxing and Dialing Out on the Same Line
From: Carlos Costa Portela c.c.portela@ieee.org
Hello, Linux Gazette!
First of all, let me say you that the Gazette is EXCELLENT! Well, you
probably know that, but I must say it!. I have the next problem:
I am using the fax program efax, by Ed Casas. Really good!. When my
system starts, I put the fax in answer mode:
This is the entry in the inittab file: rf:3:respawn:/bin/sh
/usr/bin/fax answer
Another option here would be 'mgetty' -- which provides dial-in
(terminal, PPP, etc) and fax support on the same line. Allegedly the
'vgetty' extension to 'mgetty' will even allow limited "voice" support
on that same line (although the only modem that's currently supported
seems to be certain Zyxel models -- none of the other modem
manufacturers seem to be willing to release the API's for voice
support!).
But sometimes a day (once or twice) I need my modem to connect to my
ISP and, at least, read and send my mail!
Then there is an overlapping between one program -or command- and the
other.
This is a very common situation. That's why Unix communications
programs support various sorts of "device locking."
The only trick is to make sure that all the programs on your system
agree on the name, location, and type of lock files.
On a Linux box this is reasonably easy -- compile them all to use the
/var/lock/ directory. The lock files will be of the form: LCK..$device
(where $device is the base name of the modem device -- like 'ttyS0' or
'modem'). That takes care of the location.
My advice is to ignore everything you've heard about using "cuaXX" as
the call out device and "ttySxx" as the dial-in device. I make a
symlink from /dev/modem to the appropriate /dev/ttyS* node and use
/dev/modem as the device name for EVERYTHING (pppd, chat, uucp,
C-Kermit, minicom, efax, mgetty/sendfax, diald, EVERYTHING). Obviously
that advice applies to situations where you only have one or two
modems. If you're handling whole banks of modems (you're an ISP) than
your situation is different (you probably don't allow much dial-out
via these lines and would probably have one or more lines dedicated to
fax). However, that handles the 'name' issue.
Finally there is the question of lock file "type." There are three
common strategies in Unix for dealing with lock files. The first a
refer to a "touch" -- the mere existence of any file by the correct
name is a flag for all other processes to leave the device/resource
alone. If a process dies and leaves a stale lock file -- there is not
automatic recovery -- an administrator must manually remove the lock
file. This limitation makes this the least useful and least common of
the lockfile types.
With the other sorts of lock files the controlling process (the one
creating the lock) writes its PID into the file. Any other process
seeing the lock file then parses a 'ps' listing to determine the
status of the process that locked the resource. If it's dead or
non-existent (possibly even if it's a zombie) then the new process
removes the "stale" lock file (usually with a message to that effect)
and creates a new one.
Here the only question is: what format should the PID be written in? I
prefer "text" (i.e. the PID is a string of ASCII digits -- like the
printf("%d", int) would generate). Some programs might default to
"binary" -- where the PID is written to the file in the same way that
a program stores it in memory.
The advantage of text format lock files is that you can more easily
write a wrapper script in perl, sh, or whatever -- to provide lock
file support to a program that doesn't use the same sort of lock files
you want. Another advantage is that the admin of a system can read it
-- and use 'ps' or 'top' to check the state of the locking process
manually (useful if a client program is overly timid about removing
the lock file from a "zombie" for example).
The only other problem associated with device lock files involves the
permissions of the /var/lock directory. The simple solution is to make
it world writable. However I consider that to be poor administrative
practice -- particularly on a multi-user or server system. You can't
make this directory "sticky" (as you should with your /tmp/) unless
you make all of your modem using programs SUID. If you did that, no
program would be able to remove a lock file that was created by a
different user -- stale or otherwise.
So, I make this directory group writable by the 'uucp' group and make
all my modem using programs SGID 'uucp'. If you need finer grain
support (for other programs that use the /var/lock directory) then
you'd want to create more specific directories below /var/lock, and
compile all of your programs to use those. On my main Red Hat (3.03)
system all of the other programs that I've see use directories below
/var/lock/ so only my modem programs really need write access.
Obviously any root owned, or suid root or even suid 'bin' programs can
also write to the /var/lock directory -- all we're doing is keeping
out the "riff-raff" (like my personal shell account).
Obviously, this is not a solution:
Turn off the modem, and then turn on.
Kill the efax process.
Because the entry has a "respawn" keyword.
What is the best way to:
- inactivate the fax.
- connect to Internet.
- disconnect.
- activate the fax.
The best way is to avoid the problem. Configure or compile efax to use
a locking mechanism that's compatible with your dial-out programs (or
switch to 'mgetty' or some other enhanced getty).
The 'mgetty' home page is at:
Mgetty+Sendfax Documentation Centre (Gert Doering)
http://www.leo.org/~doering/mgetty/
... and some related resources are at:
ISP Resources - mgetty info (AutoPPP)
http://www.buoy.com/isp/mgetty.html
Coastal Internet - ISP Info! http://www.buoy.com/isp/
Well, one solution is:
go to the /etc/inittab comment the line restart the system Is there a
better one?.
If you really had an insurmountable problem of this sort -- a program
that just wouldn't co-exist with something that you're respawning in
your inittab (like some weird UPS power daemon or data aquisition
service) -- I'd solve it using a new runlevel. The line where you're
loading your fax daemon process specifies that it runs in level 3 (the
default "multi-user with networking" mode). So you could just use the
'telinit 4' command to switch to the (currently undefined or "custom")
runlevel. This should kill the fax process (and any getty's or xdm's
that you have configured for runlevel 3) and start any processes that
you define for runlevel 4.
Read the man page for inittab(5) (that is "the inittab page in section
section 5 of the man tree") for details. I've always been mildly
surprised that the SysV Init programmers didn't put in options for a
full 9 runlevels (where 7, 8, and 9 would all be custom). However I've
never seen a need for such elaborate handling -- so they likely didn't
either.
Hope that clarifies the whole issue of lock files and resolving access
concurrency issues. You can use similar programming techniques (even
in shell scripts) to resolve similar problems with directory, file, or
device locking.
-- Jim
_________________________________________________________________
Linux and the 286
From: tbickl@inreach.com tbickl@inreach.com
Hello,
I am taking a class at community college for introduction to Unix. I
was told I could download Linux, put it on the 286 machine I have, and
that it would function well enough to learn from.
You were told wrong.
Searching thru the downloadables, I have only seen versions that will
run on 386 or above, and I do not have a 386 machine available to me
right now.
Your observations are to be trusted more than the sources of your
rumors.
Do you know if and where I could find a version of Linux that would
suffice?
There is a project to produce an 8086 (and thus 286 compatible) subset
of the Linux kernel (ELK -- embeddable Linux kernel). However it is
probably not far enough along to be of interest to you. More generally
we can say that a kernel is not enough -- there would be considerable
work to porting a large enough set of tools to the subset
architecture.
Moving back a little bit from Linux specifically we can recommend a
couple of Unix like OS' that did run on the 286. Of them, only Minix
is still widely available. It is not free (in the sense of GPL or the
BSD License) -- but is included with copies of Andrew Tanenbaum's
seminal text book on _Operating_Systems_Design_and_Implementation_.
You'll want the 2nd Edition.
The two other implementations of Unix that have run on 286 systems are
Xenix (originally a Microsoft product then handed off to SCO -- Santa
Cruz Operations; which I think Microsoft still owns a good chunk of)
and long since discontinued, and Coherent (by the now defunct Mark
Williams Company).
Neither of these offered any TCP/IP support. I think the latest
versions of Minix do -- although I don't know how robust or extensive
that support is.
For the price of the book you could probably find a 386 motherboard
and 16Mb of RAM to toss on it. I don't like to "push" people into
hardware upgrades -- but the change from 286 to 386 is night and day.
Like I said, it only has to function textually (textually?), no
graphics or other fancies are necessary. Just regular
Unix-command-line based stuff.
The tough nut to crack isn't really the GUI -- Geoworks' Ensemble
provided that (also there used to be a Windows for the 286 and Windows
3.x had a "standard mode" to support the AT). It isn't the
timeslicing/multitasking (DESQview did that). It isn't providing Unix
semantics in a shell and a set of Unix like tools (there's a whole
directory full of GNUish tools on SimTel and there's the earlier
versions of the MKS toolkit).
The hard part of running a "real" Unix on a 286 or earlier processor
is the memory protection model. Prior to the 286 there was simply no
memory protection mechanism at all. Any process could read or write to
any address (I/O or memory) and therefore had complete control of the
machine. These architectures are unsuitable for multi-user interactive
systems. Unix is, at its heart, a multi-user system.
Thank you for any help you can offer . . .
The most bang for your buck is to buy a 386 or better motherboard. If
you are in the SF bay area (Silicon Valley) I can give you one. This
will allow you to run Linux, OpenBSD (or any of the other FreeBSD
derivatives) and will just make more sense than spending any time or
money on the 286.
If that just doesn't work for you -- get a copy of Tanenbaum's book
(with the included CD). In fact, even if that does work for you, get a
copy of his book. If you read that, you'll probably more about Unix
than your instructors.
--Jim
_________________________________________________________________
Accessing ex2fs from Windows 95
From: globus@pathcom.com
Hi:
Just wondering, is there any way (i.e. driver) in existence that would
let me access ext2fs from Win95? I need read and write capabilites.
Try the Linux Software Map (currently courtesy of ExecPC). I used just
the keyword "DOS":
Have you looked at ext2tool:
Database: Linux Software Map
Title: Ext2 tools
Version: 1.1
Entered-date: 09 Jan, 96
Description:
A collection of DOS programs that allow you to read a Linux ext2 file
system from DOS.
Keywords: DOS, ext2
Author: ct@login.dknet.dk (Claus Tondering)
Maintained-by: ct@login.dknet.dk (Claus Tondering)
Primary-site:
login.dknet.dk pub/ct
287706 ext2tool_1_1.zip
Alternate-site:
sunsite.unc.edu pub/Linux/system/Filesystems/ext2
287706 ext2tool_1_1.zip
Platforms:
PC with 386 or better
Copying-policy: GPL
There is also an installale filesystem for OS/2 -- but that probably
won't help you much.
-- Jim
_________________________________________________________________
chattr +i
From: ckkrish@cyberspace.org
Hi Jim, I was going thru the "Tips" document distributed along with
Slackware 3.2. Thanks for the "chattr +i". I used to take pride that I
knew Unix related stuff reasonably well, until I read about
"attribute" in your snippet. If only I had read it a few weeks before!
I have been running Linux for about 2 years now. Only recently I went
for an upgrade. To Slackware 3.2. While exploring the set of four CD's
that came in the pack, I hit upon a language called INTERCAL - a sort
of crazy stuff, the antethe- sis of a good programming language. As
per the documents that ac- companied it, INTERCAL was made by pundits
for fun. Well, I gave a "make install" and after that the usuall
commands failed! The makefile had a line to "rm -f" everything from
the target "bin" directory! I really felt a need for a "chattr +i" at
that time, not really aware that it already exists. Thanks for the
tip. It is a lifesaver.
You're welcome. If you're ever administering a BSD machine (FreeBSD,
OpenBSD, NetBSD or the commercial BSDI/OS) you can use the chflags
+syschg command for the same purpose. That requires the UFS filesystem
(while Linux' chattr is exclusively for ext2 filesystems. If they ever
port ext2fs to other Unix system they'll probably port the lsattr and
chattr commands along with them.
There's a few other tips you should consider following -- which will
also help prevent disasters. First, configure your /usr/ as a separate
filesystem and mount it read-only. You can always issue a 'mount'
command with the 'remount' option when you really need to write to it
(which should be pretty rarely). As part of that -- make sure to
consistently user /usr/local for all new software that you install. It
should also be a separate filesystem which you usually leave mounted
read-only. Developement should be done in home directories, additions
that are not part of a distribution should be in /usr/local/ and the /
and /usr/ should be almost exclusively reserved for things that came
with the initial installation. (you may end up and a /opt as well --
though mine is just a symlink to /usr/local).
Following these conventions helps when you need to do an upgrade --
since you can isolate, even unmount, the portions of your directory
tree that the OS upgrade should NOT touch.
The other suggestion is to avoid doing things as root. You can set the
permission on /usr/local to allow write access to member of a "staff"
or "wheel" or "adm" group (I like to just create one called staff) --
and add your user account to that group. You can also use also use
'sudo' and carefully chosen suidperl scripts (which are also group
executable and not accessible to other) to minimize the time you spend
at the root prompt.
I've read about Intercal before. It's almost as infamous as TECO (the
"tape editing command") which was the language in which EMACS was
originally implemented. EMACS stands for "editor macros." There is a
TECO emulator for GNU emacs now -- which was obviously done to satisfy
some lisp programmer's sick fascination with recursion.
Anyway -- glad my tips were helpful.
-- Jim
_________________________________________________________________
Linux sendmail problem
From: Jason Moore jsmoore@brain.uccs.edu
I have a problem with my linux setup. I have a Linksys Ether16
Ethernet Card(NE2000 compat), and It finds the card fine(with the
correct irg, etc..) but when it boots, the machine freezes when it's
loading send mail. currently I'm using Redhat 4.2, Kernal 2.0.30, and
I don't know anything about sendmail.
Sendmail isn't really hanging. It's blocking while waiting for a DNS
query to time out. If you were to leave it alone long enough it would
eventually timeout and your boot process will continue.
This is because your system can't talk to a name server whereby your
copy of sendmail can look up the names associated with your network
interfaces (using "reverse" DNS resolution). The quick solution is to
remove the symlink from /etc/rc.d/rc3.d/S??sendmail (which points to
/etc/rc.d/init.d/sendmail).
I like to manage these by creating a "disabled" directory under each
of the /etc/rc.d/ directories -- then I can disable any of the startup
scripts by simply moving their symlinks down one directory. The
advantage of this is that is is self-documenting. Also, if I have to
put an entry back in -- I don't have to wonder what numeric sequence
it used to be in, since this "meta information" is encoded in the
symlink's name (that's what the Sxx and Kyy part of the link names are
doing).
Another thing you could do is just start sendmail asynchronously. To
do this just find the line in /etc/rc.d/init.d/sendmail that actually
loads /usr/lib/sendmail -- and put an "&" (ampersand) on the end of
the line. If you do that right then sendmail will do it's waiting (and
timing out) in the background -- and the rest of your startup scripts
will continue.
Obviously this last item is not a solution -- it's just a workaround.
sendmail will still fail to operate properly until it's configured
properly (big surprise, right?).
I'm not going to write a treatise on sendmail configuration here.
First I don't have enough information about your network connections
and your requirements (it would be a monumental waste of our time if
you're planning on reading your e-mail from a different system, for
instance). Also there are a few HOWTO's and Mini-HOWTO's and a couple
of pretty decent books on the topic. Here's the HOWTO's you want to
peruse:
DNS HOWTO
How to set up DNS.
_Updated 3 June 1997._
http://sunsite.unc.edu/LDP/HOWTO/DNS-HOWTO.html
(Like I said -- the real problem is your DNS).
Electronic Mail HOWTO
Information on Linux-based mail servers and clients.
_Updated 29 November 1995. _
http://sunsite.unc.edu/LDP/HOWTO/Mail-HOWTO.html
(This is a bit of an overview).
Mail Queue mini-HOWTO
How to queue remote mail and deliver local mail.
_Updated 22 March 1997. _
http://sunsite.unc.edu/LDP/HOWTO/mini/Mail-Queue
(This is more specific -- and might be how you want to do your mail).
Offline Mailing mini-HOWTO
How to set up email addresses without a dedicated Internet
connection.
_Updated 10 June 1997. _
http://sunsite.unc.edu/LDP/HOWTO/mini/Offline-Mailing
(This is another way you might want to do your mail).
ISP Hookup HOWTO
Basic introduction to hooking up to an ISP.
_Updated 9 December 1996. _
http://sunsite.unc.edu/LDP/HOWTO/ISP-Hookup-HOWTO.html
(Your e-mail almost certainly has to go through some sort of ISP to
get anywhere beyond your system. Reading this will determine which of
the mail configuration options are available to you).
PPP HOWTO
Information on using PPP networking with Linux.
_Updated 31 March 1997. _
http://sunsite.unc.edu/LDP/HOWTO/PPP-HOWTO.html
(Most people are connecting to their ISP's via PPP these days. There
are other sorts of connections, like SLIP and various SLIP/PPP
"emulators" (like TIA))
UUCP HOWTO
Information on UUCP software for Linux.
_Updated 29 November 1995. _
http://sunsite.unc.edu/LDP/HOWTO/UUCP-HOWTO.html
(This is another way to get mail and news. It is much older than PPP
and SLIP and doesn't support protocols like HTTP. UUCP is a protocol
that can work over dial up modem lines, or over TCP/IP -- including
PPP and SLIP. I use UUCP for all my mail and news -- because it is
designed for intermittent operation and spooling. However it can be a
hassle to find an ISP that's ever heard of it. Another advantage to a
UUCP feed is that you can control your own e-mail address space --
every user you create on your box can send and receive e-mail and
read/post news. You don't have to have to ask your ISP to do anything
at their end -- and they can't charge you based on the number of
addresses at your end)
Sendmail+UUCP mini-HOWTO
How to use sendmail and UUCP together.
_Updated 15 March 1997. _
http://sunsite.unc.edu/LDP/HOWTO/mini/Sendmail+UUCP
(In the unlikely event that you decide to go out and find a UUCP feed
(or several -- it can handle that) this is what you need to configure
sendmail to talk to UUCP. This isn't difficult (once you have UUCP
working) -- and sendmail and UUCP have been interoperating for over
twenty years. It's just that you have to pay attention to the
details).
Although our whole discussion has been about 'sendmail' -- it's worth
noting that there are a couple of alternatives to it available. The
two that are relatively recent and readily available for Linux are
'smail' and 'qmail.' I'm not going to go into much detail about them
-- but you can find out more about these at:
smail:
FTP Site:
ftp://ftp.uu.net/networking/mail/smail
Newsgroup:
news:comp.mail.smail
qmail:
http://www.qmail.org
-- Jim
_________________________________________________________________
POP3 vs. /etc/passwd
From: Benjamin Peikes benp@npsa.com
The problem with that is that now that person has ftp access. Too many
programs rely on /etc/passwd. What I would like is to be able to set
up users on a per service basis.
Yes -- I understood that from the get go.
I guess what I'm looking for is a way to manage which users can use
which services. i.e. put this person into a no ftp, no samba, yes mail
group. I guess what I really need is to write some scripts to manage
users/services.
This is precisely the intent of PAM/XSSO. Unfortunately PAM isn't
quite done yet -- it's about 60% there and can be used for some of
what you want now.
Under PAM you can configure any service to require membership in a
specific group. You can also limit access to specific users based on
the time of day or the source of the connection -- setup ulimit's and
environment values, and provide/require S/Key (OPIE) one-time
passwords in some cases while allowing plaintext in others.
Under the hood you can use shadowing, pwdb (indexed/hashed
account/password files) to handle large numbers of accounts (without
introducing linear delays for lookups), MD5 or "big DES" to allow long
passwords (some might write an SHA-1 password hashing module now that
MD5 has shown some weakness).
You could write a custom SQL query client if you wanted to allow
database driven access to a particular service. The advantage to PAM
is that you'd write this once -- and an admin could use it on any
service with no coding required.
This gives us the flexibility that previously required very localized
sysadmin hacking -- to reinvent the same wheel at every site and for
every service!
-- Jim
_________________________________________________________________
Problem with make
Date: Thu, 25 Sep 1997 21:17:56 -0700
From: Alfredo Todini mc0736@mclink.it
Jim,
I have a strange problem with make. I have Red Hat 4.0, and I recently
installed GNU make 3.76.1. The compilation went well, and the program
works, except for the fact that it doesn't accept the "short" version
of the command line options. For example, "make --version" works,
"make -v" doesn't; "make --file" works, "make -f" doesn't. All I get
in these cases is the standard "invalid option" error message. It
seems to be a problem related to my particular Linux distribution: I
have also tried it on a Slackware 3.2 distribution, and it worked
well. The old version of make that I have removed to install the new
one worked well.
Could you please help me?
This sounds very odd. What version of GCC did you use? Did you run the
./configure script under this directory? For GNU software this
behavior should be controlled by the getopt libraries (defined in your
/usr/include/getopt.h) -- which I think are linked with your normal
libc (C libraries).
So, are there differences between the getopt.h files between these
systems? What libc's are these linked against (use the 'ldd' command
to see that)? Are there differences between the Makefiles generated by
the ./configure on each of these systems?
If you make the program ('make') on one system, and copy it to the
other system -- do you see the same problem? How about the converse?
What if each is made "statically" (not using shared libraries)?
Obviously, there are many ways to try to isolate the problem.
I just make a copy of this same version -- grabbed it from
prep.ai.mit.edu, ran ./configure and make -- and tested it (in part by
taking the 'make' I just built and using it to remake itself). There
was no problem.
--Jim
_________________________________________________________________
Swap partition and Modems
Date: Thu, 25 Sep 1997 16:50:19 -0700
From: Robert Rambo robert.rambo@yale.edu
I was wondering if it is possible to resize the swap partition in
Linux. I think mine is too small, I keep getting some virtual memory
problem and a friend of mine suggested changing the swap partition.
Resizing is more trouble than its worth. You can add addition swap
partitions or swap files. Must read the 'mkswap' and 'swapon (8)' man
pages for details.
--Jim
_________________________________________________________________
Redhat 4.2/Motif
Date: Thu, 25 Sep 1997 03:11:51 -0700
From: "Victor J. McCoy" vmccoy@kmrmail.kmr.ll.mit.edu
Ok, the details first:
Redhat 4.2 (default installation)
Redhat Motif 2.0.1
Intel p133
64 MB RAM
ATI Graphics Pro Turbo (4MB)
I think that's all the relevant info.
I'm having trouble with pppd and Motif. If I run my connection script,
the Motif stops behaving properly.
Before pppd...popup menus work fine, click anywhere in client window
and focus shifts.
After pppd...popups are non-existent, must click on window border to
get focus.
Are there *any* other symptoms?
This seems awfully specific -- and the PPP connection seems awfully
peripheral to the windowing system.
What if you initiate the PPP session from another virtual console --
or prior to loading X? What if you use the modem for some other form
of dial-up activity? (i.e. is it a particular X client application, is
it something to do with the serial hardware?)
Is this an internal modem? Is it "Plug and Pray?" What if you try an
external modem?
What if you connect another system with PLIP or via ethernet?
What if you use a different Window manager (other than mwm)?
I can't offer much of a suggestion. Just try to isolate it further --
try different screen resolutions, copy your xinitrc and other conf
files off to somewhere else and strip them down to nothing -- etc.
You'll definitely want to post in the newsgroups -- where you might
find someone who's actually used Red Hat's Motif. (I haven't -- I
hardly use X -- and fvwm or twm is fine for the little that I do in
it).
I noticed the behavior quite a while back with previous versions, but
I was unable to duplicate the problem (I connect to work much more
often than I used to so I noticed a pattern).
Has this been trouble for anyone else? I emailed redhat, but their
"bugs@" email address states not to expect an answer.
I might even get involved in a program to provide a better support
infrastructure for Red Hat.
Unfortunately that's probably months away -- and this sort of "no
response" situation is likely to be the norm for RH users for a bit.
--Jim
_________________________________________________________________
E-mail adjustment needed
Date: Mon, 22 Sep 1997 12:52:50 -0700
From: Terrey Cobbtcobb@onr.com
Greetings Answer Guy:
I have a problem with e-mail which you may have already deduced from
the "from:" line of this letter. In brief, I am running RedHat 4.0 on
a home computer. I get onto the Internet by means of a local ISP using
a dynamic ppp connection. I send and read my e-mail through EMACS.
Whenever I send mail to anyone, the "from:" line states that I am
"root <sierra.onr.com>." Even though I always use a "reply to" header
giving my actual e-mail address, it would be nice if I could configure
something so that the "from" header would reflect my true identity.
Any help you could give me on this would be greatly appreciated.
What you want to use is called "masquerading" in the 'sendmail'
terminology. This should not be confused with IP Masquerading (which
everyone outside of the Linux world calls "NAT" -- network address
translation).
The other think you'll want to use is to use M-x customize or M-x
edit-options (in emacs) to customize/override the e-mail address that
emacs' mail readers (RMAIL VM mh-e -- whichever) will put in its
headers).
--Jim
_________________________________________________________________
REALBIOS?
From: Bill Dawson bdawson@abginc.com
Linux Wizard,
I am a newbie to Linux, and it has been a rocky start. Through a
series of trial and error I discovered I needed to use loadlin to get
started. When I ran loadlin I got this message:
"Your current configuration needs interception of "setup.S," but the
setup-code in your image is *very* old (or wrong) Please use BIOSINTV/
REALBIOS or try another image file"
I looked at the reference on your page to REALBIOS, but it did not
tell me where to find this program. Could you tell me where to get it
and how to use it, please?
This happens when you have a memory manager, a disk manager, or any
sort of TSR or device driver that "hooks" into your BIOS controlled
interrupt vectors prior to running LOADLIN.
Short Answer:
-------------
Look for the loadlin.tar.gz package -- it should include that. Here's
the URL for the copy of that on sunsite:
http://sunsite.unc.edu/pub/Linux/distributions/slackware/slakware/a4/l
oadlin.tgz
In this file there should be a copy of a program called REALBIOS.EXE
which you would run as I've described before. It would create a
special "system/hidden" file in the root of your C:\ drive -- which
allows LOADLIN to find all the ROM handlers for each of your hardware
interrupts.
One way you might avoid the problem is to invoke LOADLIN from your
CONFIG.SYS. You can do that by invoking LOADLIN.EXE from a SHELL=
directive in your CONFIG.SYS.
If you're using a version of MS-DOS later than 5.0 you can create a
menu of boot options pretty easily -- see your MS-DOS/Windows '95
manuals for real details. Heres a trivial example:
rem CONFIG.SYS
menuitem WIN
menuitem LINUX
menudefault LINUX
[WINDOWS]
FILES=64
BUFFERS=32
[LINUX]
rem Load my 2.0.30 Linux kernel
SHELL=C:\LINUX\LOADLIN.EXE C:\LINUX\L2030.K root=/dev/hdc1
A bit of Background:
--------------------
PC Interrupt's are similar to Unix signals or Macintosh "traps." They
are a table of pointers (in the first 4K of RAM) to "handlers"
(routines that process verious sorts of events -- like characters
coming in from the keyboard, handshaking signals from modems or
printers, or data-ready events from disk drives). Normally, under
MS-DOS, many of these events are handled by the BIOS. Others are
handled by DOS device drivers. Still others aren't assigned to
hardware events at all. In fact most of the interrupts are reserved
for "service routines" (similar to Unix "system calls").
Linux doesn't use any of these routines. Your system's BIOS is a set
of machine language routines written for the processor's "real mode."
All x86 processor start in real mode. Every processor since the 286
has had a "protected" mode -- which is where all of the cool extended
memory addressing and other features are implemented (actually the 286
only supported 24-bit addressing -- but it's not supported by any
modern operating protected mode OS, the obscure 80186 was never used
as the core processor).
So, your kernel has to shift from "real mode" to "protected mode." It
also has to provide low level device drivers for any device you want
to access -- where it uses I/O port and DMA channels to talk to the
devices. The problem is that something from real mode must load the
Linux kernel.
LILO and LOADLIN.EXE:
---------------------
The two common ways to load a Linux kernel into memory are: LILO and
LOADLIN.EXE.
On any PC hard disk there is a "partition table" which is how multiple
operating systems can share the same disk. This was necessary because
the early design o fthe PC made it very difficult to swap drives.
(Using the sorts of external SCSI drives that are common on other
systems -- and any sort of OpenBoot or other PROM "monitor/debugger"
-- makes it pretty easy to connect external drives with alternative
OS' on them -- but that would have been far too expensive for the
early PC XT's (the first PC's to offer hard drives).
Throughout most of the history of the PC architecture the BIOS for
most machines could only see two hard drives -- any additional hard
drives required additional drivers. Furthermore these two drives had
to be on a single controller -- so you couldn't mix and match (without
resorting to software drivers).
Worse than that -- there were no standard drivers -- each manufacturer
had to write their own -- and none of them followed an particular
conventions.
None of this matters to us, once we get the Linux kernel loaded,
because Linux will recognize as many drives and devices as you attach
to it (assuming you compile in the drivers or load their modules).
However, it does matter *until* we get our kernel loaded. With LILO
this basically requires that we have our kernel somewhere where the
BIOS can reliably find it from real mode. With LOADLIN we have a bit
more flexibility -- since we can put the kernel anywhere where DOS can
find it (after any of those funky drivers is loaded).
The partition table is a small block of data at the end of the master
boot record (the MBR). It's about 40 bytes long and has enough for 4
entries. These are your "primary" partitions. One of them may be
marked "active" that is will be the partition that is "booted" by
default. One of the partitions may be an "extended" partition -- which
is a pointer to another partition table on the same hard disk. The
rest of the MBR (512 bytes total) which precedes the partition table
is a section of real mode machine code called the 'boot loader'.
LILO can replace the MBR boot code (or it can be in the "logical boot
record" -- which is like the "superblock" in Unix terminology -- it
can also be placed in the boot sector of a floppy. If LILO is placed
in "logical boot record" of a Linux partition -- then the DOS (or NT,
or OS/2 or whatever) code must be set to load it (usually by setting
that partition -- with LILO in it -- as the "active" partition).
With LOADLIN all of this is moot. You just boot DOS (or Win '95 in
"command prompt" mode -- using {F8} during the boot sequence or
whatever) -- or you can use the mult-boot configuration I described
earlier.
One of the funny things about Linux is how many different ways you can
load it. You can even shove a Linux kernel unto a floppy (using the dd
command) and boot it that way (though you don't get any chance to pass
it any parameters that way -- as you do with LOADLIN and LILO).
Last Notes:
-----------
Things are improving in the PC world. We no have some SCSI and EIDE
controllers that can boot off of specially formatted CD-ROM disks
(meaning we can use a full featured system for our rescue media,
rather than and to scrimp and fight to get what we need onto one or
two floppies). Most new systems come with at least EIDE -- giving us
support for four devices rather than just two. (That's especially
important when you want to share a system with a couple of OS and you
want to have a CD-ROM drive). Any decent system comes with SCSI -- and
most PCI SCSI controllers support 15 devices, rather than the
traditional limit of seven. There are "removable bay" and drive
adapters for IDE and SCSI -- so having an extra "cold spare" hard
drive is pretty simple (and with SCSI we can have external drives
again).
Conclusion:
-----------
There are still many cases where we need to use LOADLIN.EXE rather
than LILO. I personally recommend that anyone that has DOS installed
on their system make a LINUX directory somewhere and toss a copy of
LOADLIN.EXE and their favorite kernel(s) in there. This makes an
effective "alternative boot" sequence of your partition tables
--Jim
_________________________________________________________________
X-Windows Libraries
Date: Sun, 21 Sep 1997 14:06:26 -0700
From: PATAP!DPFALTZG@patapsco.com
Although I did not get any response from you, I want to follow up with
what I have found in the hopes that it may benefit someone along the
way.
Sorry. The volume of my mail and the nature of my expertise (that is
the fact that I don't know much about X Windows -- meaning I have to
research anything I'm thinking of saying), means that there are
sometimes unfortunate delays in my responses.
By the beginning of next year I hope to entirely revamp the way we do
"The Answer Guy" (it will hopefully become "The Answer Gang").
This is about the problem of the X-Windows System not coming up but
instead gives messages to the effect that it couldn't map the
libraries.
In the process of our playing around, on occasion it would give a
message about being out of memory. This puzzled us in that it was not
consistent and appeared in a small percentage of the cases. However,
on that clue, I found that the swap entry was missing from
'/etc/fstab'. I manually turned on swapping and now the X-Windows
System comes up and runs normally.
After adding the entry to '/etc/fstab', the whole system comes up and
plays as it should. All I can say is that somewhere in the process of
trying to get the system back on the air, the entry got removed!
Although you were not directly involved in the solution, I'd like to
say, "Thanks for being there!"
I'm glad that worked. I'll try remember that next time a similar probl
em comes up.
To the extent that I have "been there" you're welcome. As with most of
the contributors to Linux I must balance my participation against my
paying work. Naturally my contributions are far less significant than
those of our illustrious programmers -- bit I hope to help anyway.
--Jim
_________________________________________________________________
PC Emulation
Date: Sat, 20 Sep 1997 13:07:56 -0700
From: SAFA ISAA safaisaa@swipnet.se
Hi Im working in comp. named Fordons Data our databas is a UNIX
RS/6000.and we use aprogram calld Reflection to emulte pc so we can
use the
That would be the WRQ Reflections to emulate a 3270 or 5150/5250 IBM
terminal.
pc=B4s as aterminal.We use ethernet withe TCP/IP protcol=20 for
com.betwen RS and PC .In pc we use win95.My q. is can we use doslinux
or minilinux to com. withe rs instade of Reflection ??
You could install DOSLinux or MiniLinux and a copy of tn3270 and it
*might* be able to talk to your RS/6000 (AIX) applications.
The problem is that the 3270 and 5150 terminals are very complex --
more of a client/server hardware than a "terminal/host." Essentially
the IBM mainframes and mini's download whole forms to the "terminal"
and the "terminal" then handles all sorts of the processing on its
own.
tn3270 just implements a bare minimum subset of the 3270 protocols
(just the weird EBCDIC character set so far as I know).
Frankly I don't know how this relates to your RS/6000 AIX system. That
should be able to accept standard telnet and terminal connections. The
question be becomes: "Can your database application (frontends) handle
this sort of connection?" Does it provide a curses or tty interface?
If the answer is YES would U tell me where can I gat and how to test
it..We R the bigest comp. in skandinavin for adm the hole car sys THX
This looks pretty mangled. The answer is "I don't know." However,
Linux has the virtual of being free -- so there's very low risk in
setting up a copy and trying it.
The more fundamental question is: What are you trying to accomplish?
If you currently use Win '95 and Reflections why do you want to
switch?
Do you want to save money?
While Win '95 and Reflections are commercial packages -- they aren't
terribly expensive. Your administrative and personnel training costs
are presumably much higher.
Is is for administrative flexibility?
The number one complaint about MS Windows products by Unix sysadmins
(based on my attendance at LISA, USENIX, and similar events) is that
MS products are difficult to administer -- and largely impossible to
administer remotely or in any automated way.
Unix admins are spoiled by rlogin, rcp, rdist, and the fact that
almost *anything* under Unix can be scripted. Most jobs are amenable
to shell or perl scripts run via rlogin or cron -- and some of the
"tough" jobs require expect (or the perl comm.pl) to "overcome those
fits of interactivity."
Mouse driven interfaces with "floating" windows and dialog boxes are
not "automation friendly" and MS Windows is particularly unfriendly in
this regard. (MacOS has an Applescript and a popular third-party
utility called QuickKeys (sp) that reduce its deficiencies in this
area).
So, if you're considering switching from Win '95 to Linux so that you
can centrally administer your client desktops -- it's probably not
quite a compelling reason.
I could go on and on. The point is that you have to make a good
business case for making this switch. Is there some Linux application
that you intend to deploy? Is this suggested by your security needs?
What are the requirements of you database applications? Could you
migrate those to use "thin clients" (HTML/CGI forms) through a web
(intranet) gateway? Could you implement the client on Java?
As for DOSLinux and MiniLinux specifically: Those can be pretty hard
to find. I've sent e-mail to Kent Robotti, the creator of the DOSLinux
distribution, to ask where it's run off to.
There are some other small Linux distributions that are suitable for
installation into a DOS directory and able to be run off of the UMSDOS
filesystem mount on '/' (root).
Mini-Linux is pretty old (1.2.x kernel) and doesn't appear to be
currently maintained.
I'd look at Sunsite's distibutions directory --
http://sunsite.unc.edu/pub/Linux/distributions/
Normally there would be a doslinux directory thereunder -- but Kent
seems to change things pretty rapidly and it may be that this as been
removed while he's doing another upgrade or release.
It may be that you best bet would be the "Monkey" distribution
(there's a directory under the URL above for that). This seems to be a
five diskette base set in a set of split ARJ (Jung Archive) files.
This seems to have been put together by Milan Kerslager of
Czechloslovakia (CZ). There are about nine add-on "packages" that are
ready to roll with it.
This is pretty recent (last March) package -- and one of the packages
for it is a 2.0.30 kernel from the end of April.
A copy of ARJ.EXE doesn't seem to be included, so you'd have to grab
that from someplace like:
Simtel: arj250a.exe -- Robert Jung's Archiver
ftp://ftp.cdrom.com/pub/simtelnet/msdos/arcers/arj250a.exe
* (for those who don't know Simtel used to be at the White Sands
Missile Range on an old TOPS system. It's primary mirror used to be at
oak.oakland.edu -- and it's now hosted by Walnut Creek CD-ROM
(ftp.cdrom.com). If you need any sort of DOS shareware or freeware
(perhaps to run under dosemu or Caldera's OpenDOS) this is the
definitive collection. If you need any significant number of packages
(like you need to test/evaluate a dozen of them to decide which works
for you) I'd suggest springing for the CD. Another invaluable site for
any non-MS DOS users is at http://www.freedos.org -- which in proper
free software tradition has links to other DOS sites like RxDOS. DOS
is truly the OS that wouldn't die -- and the shareware writers have
about a decade headstart on ubiquitous availability over Linux).
--Jim
_________________________________________________________________
Visual Basic for Linux
Date: Thu, 18 Sep 1997 15:34:08 -0700
From: Forzano Forzano@ansaldo.it
I'm looking for a sw that can translate an application developed in
Visual Basic to Unix. Could you help me?
The product you were undoubtedly thinking ofis VBIX by Halcyon
Software (http://www.vbix.com). (408-378-9898).
I haven't used this product personally (since I have no interest in
Visual BASIC). However they do claim to support Microsoft Visual BASIC
source code and they offer some other, related products.
I see a DBIX (which appears to be a database engine with ODBC -- open
database connectivity drivers for Linux/Unix and MS Windows '95 and
NT). Also interesting might be their "BASIC 4 Java." Here's a blurb
from their web pages:
"Halcyon Software Java Products
InstantBasic Script -Written in 100% Pure Java, Halcyon InstantBasic
Script (IBS) is more than just cross-platform BASIC; it is BASIC for
the Internet. Moreover, IBS is available as both a compiler and an
interpreter, thus allowing developers to execute scripts as either
BASIC source code or Java binaries(class file). The engine is
compatible with Microsoft's BASIC Script Edition and provides complete
Java Beans and ActiveX* support. The engine is easily customizable for
quick integration and comes with its own lightweight Interactive
Development Environment (IDE).
InstantBasic 4 Java - InstantBasic 4 Java is a 4GL development
environment written 100% in Java that allows programmers to quickly
and easily migrate their existing VB applications to run under any
Java environments using the VB-like IDE.
--Jim
_________________________________________________________________
Linux 4.2 software and Hardware compatablity problems
Date: Wed, 17 Sep 1997 20:03:54 -0700
From: John Arnold jarnold@hal-pc.org
I purchased a new computer system and 4.2 RedHat Linux Power Tools for
my son, Blake, who is a student at Trinity University in San Antonio,
TX.
They were purchased from different vendors.
Neither, Blake, his profs,myself or my vendor knew what we were doing.
The result is a big mess. I believe the basic configuration is
incorrect. That notwithstanding, I need to know which parts are not
supported by Linux and recommended replacements. The following is a
brief description of the system:
Supermicro P5MMS motherboard with 430TX chip set. Ultra DMA 33 Mb/s
Transfer and 512K pipe line burst mode cache
AMD K6 MMX Processor @166 MHz, 6th generation performance, Microsoft
certified.
32 MEG SDRAN-10ns-DIMM Memory
Western Digital 4.0 Gig IDE hard drive. Split 50/50 by vendor
TEAC 1.44 floppy disk drive
MATROX MYSTIQUE 4MEG SGRAM PCI Video card
14" NI SVGA Color monitor by MediaTech,
1024X768-28DPI (I beleive it has a Fixed Frequency)
PIONEER 24X CD ROM Drive
Keytronics keyboard
Microsoft PS2 mouse
US Robotics 28.8/33.6 Sportster modem
Sound Blaster AWE 64 sound card with speakers
Windows 95 & Plus, Service release 2
When I have the correct equipment I will find a professional to
properly configurer it.
Thank you for your assistance.
All of this equipment is fine. However I have to question your
approach. There are several vendors that can ship you a fully
configured system with Linux and Windows '95 pre-installed and
configured (or just Linux, if you prefer).
In fact an upcoming issue of the Linux Journal has a hardware review
of just such a system: the VAR Station II by VA Research
(http://www.varesearch.com).
This system is very similar to the one you described (using the same
video card, keyboard, and sound card and a very similar 24X CDROM).
The big difference between the configuration you list and the one I
reviewed is that the VAR Station came with a 4Gb SCSI hard drive, a
Toshiba SCSI CD-ROM, and a SymBIOS SCSI adapter (in lieu of the IDE
equipment you listed). Also the system I reviewed had a 3Com PCI
ethernet card rather than any sort of modem (I already have some modem
on my LAN). The other thing is that this motherboard is an Intel and
uses a 266 Pentium II.
For about the same as you have spent on these parts separately you
could probably get a system from VA Research or several others.
Here's a short list in no particular order:
PromoX (http://www.promox.com)
Aspen Systems (http://www.aspsys.com)
Linux Hardware Solutions (http://www.linux-hw.com)
SW Technology (http://www.swt.com)
Apache Digital (http://www.apache.com
Telenet Systems Solutions (http://www.tesys.com)
... and that doesn't include the ones that specialize in Alphas or
SPARC based systems.
So, you have many choices for getting system with Linux preconfigured.
Now, if you're stuck with the system you've got, and you just want it
all to work, you could pay a consultant to install and configure on
the existing hardware. At typical rates of $50 to $150 per hour (mine
are usually set at $91/hr) you'd rapidly spend more on this than on
getting system from any of these vendors (who presumably have most of
the installation and configuraiton process automated).
I cannot, in good conscience, recommend that you hire me to configure
a system like this. It's just too expensive that way.
If you made it clear to your vendor that you intended to run Linux on
the system, and they were unable to adequately install and configure
it -- I personally think you are fully justified in returning
everything and starting over. (If not then yo are still probably
within your rights -- and you may still want to consider it).
Another approach you might try is to get just a hard disk with Linux
pre-installed on it. This is the popular LOAD (Linux on a Disk)
product from Cosmos Engineering (http://www.cosmoseng.com). This isn't
quite a neat as getting the whole box pre-configured -- you still have
to tell it what sort of video, sound, and other cards you want it to
use (and you have to be able to support the extra drive -- which may
be tricky if you have an IDE HD and an IDE CD-ROM drive already on
your IDE controller. Many new IDE controller have two "channels"
(enough to support four IDE devices) and some don't.
Another approach is to just let Blake fend for himself. He can wander
around the campus a bit and look for fellow students who use and
understand Linux. Who knows, he may meet some great people that way --
maybe even get a date in the process. Linux is very popular at
colleges and universities -- and students are generally pretty
enthusiastic about helping one another use any sort of toys --
computers especially.
--Jim
_________________________________________________________________
Moving /usr subdirectory to another drive..
Date: Wed, 17 Sep 1997 18:11:32 -0700
From: Ben Bullock bullock@toolcity.net
My entire Linux filesystem currently resides on /dev/hda2 and uses up
almost 90% of this partition. Because I am quickly running out of disk
space on my original hard drive, I recently added a second hard drive
and created a Linux partition on it which the system sees as
/dev/hdb1. The /usr subdirectory of my filesystem has swollen to over
300MB, so I would like to copy all the directories and files under
/usr over to /dev/hdb1 and then edit /etc/fstab so that this partition
will then be mounted on /usr in the filesystem when I boot up.
I've given a lot of thought about how to do this, but I am very
concerned about making this change because of the potential problems
it might cause if not done properly. I would, therefore, appreciate
your advice on how to proceed and what steps I should take to
safeguard the integrity of my filesystem. BTW, I have a second, unused
partition (/dev/hdb2) available on the new drive that could be used to
store a "backup copy" of all the directories and files currently under
/usr on /dev/hda2, and I also have an emergency boot/root floppy disk
set that provides basic utilties.
Thanks very much for any help you can give me on this. Also, I want
you to know that I enjoy your column in the Linux Gaxette and have
found it to be very helpful.
Re: my previous columns and articles.
You're welcome.
Re: how to move (migrate) trees full of files:
I can understand you concerns. Under DOS and Windows this sort of
operation is hairy, tricky, painful, and often terribly destructive.
The good news is that Unix is *much* better at this.
Here's the overview:
Mount the new filesytem to a temporary location Use a cpio or tar
command to copy everything * (optionally) Make all these files
"immutable" Boot from an alternate partition or a rescue disk Rename
the source directory Make a new directory by that name (a mount point)
Mount the new fs on the new mount point Update your /etc/fstab to make
this permanent * (optionally) Update your tripwire database Test
Remove the old tree at your leisure.
That's all there is to it. Now we'll go back over those steps in
greater detail -- with same commands and some commentary.
Mount the new filesytem to a temporary location:
I like to use /mnt/tmp for this. So the command is:
mount /dev/hdb1 /mnt/tmp
Use a cpio or tar command to copy everything
I used to use tar for this -- but I've found that cpio is better. So
here's the tricky command that's really the core of your question:
cd /usr/ && find . -print0 | cpio -p0vumd /mnt/tmp
* note: must do this as root -- to preserve permissions and ownership!
I realize this is an ugly looking command. However, we'll explain it
step by step:
cd /usr/ && -- this cd's to the user directory and (if that goes O.K.)
executes the following. If you typed /usr/ wrong you won't end up with
a mess.
find . -print0 -- this provides a list of filenames as "null
terminated strings" -- this will work *even if some of the files have
spaces, newlines, or other dubious characters in them*. The results
are written into a pipe -- and the program reading them must be
capable of using this list. Luckily the GNU cpio and xargs command
have this feature, as we'll see.
| cpio -p0vmd /mnt/tmp -- here's the tricky part. This is the
"passthrough" mode of cpio. cpio normally copies files "in" or "out"
-- but it can do "both" using the "passthrough" mode. cpio expects a
list of filenames for its standard input (which we are providing with
the 'find' command). It then copies the corresponding file "in" from
the path specified (as part of the input line) and "out" to the the
path specified as one of cpio's arguments (/mnt/tmp in this case).
The rest of the switches on this cpio command are: 0 -- expect the
input records (lines) to be null terminated, v -- be verbose, m --
preserve the modification time of the files (so your next incremental
backup does think that everything under /usr/ has suddenly changed),
and d -- make leading directories as needed.
The last argument to this cpio command is simply the target directory
we supply to the -p switch.
* (optionally) Make all these files "immutable"
One obscure feature of Linux' ext2 filesystem that I like to suggest
is the "immutable attribute." This prevents *any* change to a given
file or directory until the file is made "mutable" again. It goes way
beyond simply removing write permissions via the standard Unix chmod
command.
To do this use the command:
cd /mnt/tmp && chattr -R +i *
... or (to just do the files and not the directories):
find /mnt/tmp -type f -print0 | xargs -0 chattr +i
Ultimately this protects the sysadmin from his or her own 'rootly'
powers. Even 'root' gets an "operation not permitted" error on any
attempt to modify any feature of an immutable file.
Under normal circumstances this only marginally improves the system's
security (any attackers who get a 'root' shell can just 'chattr' the
files back to "-i" (mutable), and then have their way with your
files). However, with the addition of the "sysctl securelevel"
features that are expected in the 2.2 kernel (and may already be in
the current 2.0 and 2.1 kernels) -- this will actually be a real
security feature. (Discussion of "securelevel" is for a different
article).
The point is that you can save yourself from many sorts of mistakes by
making files immutable. This is particularly handy when running 'make'
as root -- when you may have missed some problem in the file that
would otherwise wipe out some of your important files. I suspect it's
also handy if you get a bogus RPM package -- for basically the same
reason.
(Many sysadmin's I've talked to and exchanged mail and news postings
with fervently rail about the dangers of running make as root or using
any sort of package management system. I understand their concerns but
also recognize that the number of new inexperienced SA's -- and the
sheer amount of work that many SA's are expected to complete --
practically require us all to take shortcuts and place some trust in
some of the packages we're installing. So this "immutable" feature is
a reasonable compromise).
Boot from an alternate partition or a rescue disk
Now we've done the hard part. All we have to do now is use the new
copy of /usr. The only problem is that many of the commands we want to
use require access to the shared libraries in /usr/lib. If you ever
accidentally remove or damage /usr/lib/libc.so you'll have first hand
experience with the problem.
So, we boot from an alternative boot partition or from a rescue disk,
mount our normal root partition and continue. I'll leave out the
details on this -- since the details vary from one distribution and
site to another.
* Note to distributors and installation script maintainers: PLEASE
INCLUDE AN OPTION TO CREATE AN ALTERNATIVE BOOT PARTITION IN YOUR
PRODUCTS
Rename the source directory
Now we've copied the whole /usr/ tree to /mnt/tmp. We could just
modify the /etc/fstab, and reboot the system. Your rc scripts would
blithely mount the new /dev/hdb1 right over the existing /usr -- in
effect "hiding" the old usr files. However this wouldn't be very
useful -- it does free up any disk space.
So we issue a command like:
cd $NORMALROOT # (wherever you mounted
# your normal root filesystem)
mv usr usr.old
Make a new directory by that name (a mount point)
Now we need to make a new /usr directory. We just issue the "mkdir
/usr" command. However -- we're not quite done. We also want to chown
and chmod this new directory to match the old one.
So we use "ls -ld usr.old" to see the owner, group, and permissions --
whice are typically like:
drwxr-xr-x 20 root root 1024 Aug 1 22:10 usr
... and we use the commands:
chown root.root usr
chmod 755 usr
... to finish the new mount point.
(Personally I like to make /usr/ owned by root.bin and mode 1775 --
sticky and group writable. However, I also mount the whole thing
read-only so I'm not sure this is comparable to any of the FSSTND (the
filesystem standard) or the conventions used by any distribution).
I get a bit of confused about how the mount command works -- because
it seems that the mount command actually over-rides the underlying
ownership and permissions of the mount point. However I have seen
problems that only seemed to go away when I make the underlying mount
point match my intended permissions -- so I do it without
understanding it completely.
Mount the new fs on the new mount point
I like to do this just to test things.
Update your /etc/fstab to make this permanent
Now you can edit your /etc/fstab (which should actually be under
whatever mount point your using during this "alternative root/rescue"
session)
You'll add a line like:
/dev/sdb1 /usr ext2 defaults,ro 1 2
... to it.
(Note, I like to mount /usr/ in "read-only" mode. this provide one
extra layer of protection from the occasional root 'OOOOPS!' It also
helps enforce my policy that all new packages are installed under
/usr/local, or /usr/local/opt (to which my /opt is a symlink), or
under a home directory (which, on some of my systems are under
/usr/local/home). The idea of maintaining this policy is that I know
what files and packages are not part of the base OS).
* (optionally) Update your tripwire database
Tripwire is a program that maintains a detailed database of your
files, their permissions, ownership, dates, sizes, and several
different checksums and hashes. The intent is to detect modifications
to the system -- in particular these would be signs of corruption, or
tampering (security breaches or the work of a virus or trojan horse).
I won't go into details here. If you have tripwire installed, you want
to update the database and store it back on it's read-only media.
For more info about tripwire see:
Tripwire (ftp://coast.cs.purdue.edu/pub/COAST/Tripwire)
To get it to compile cleanly under Linux look at the patch I wrote for
it:
Tripwire Patch for Linux
(http://www.starshine.org/linux/tripwire-linux.patch)
(no .html extension on that -- its just a text file).
(* one of these days I'll get around to writing up a proper web page
for Tripwire and for my patch -- I submitted it to Gene and Gene and
they never integrated it into their sources).
Test
Now you simply reboot under your normal configuration and test to your
hearts content. You haven't removed the old /usr.old yet -- so you can
back out of all your changes if anything is broken.
Remove the old tree at your leisure.
When you're satisfied that everthing was copied O.K. -- you can simply
remove all the old copies using the command:
rm -fr /usr.old
Now you finally have all that extra disk space back.
Obviously this process can be done for other parts of your filesystems
as well. Luckily any other filesystem (that doesn't include the /
(root) and /usr/lib/ trees) is less involved. You shouldn't have to
reboot or even switch to single user mode for any other migrations
(though it won't hurt to do so).
I like to put /tmp, /var, and /usr/local all on their own filesystems.
On news servers I put /var/spool/news on it's own. Here's a typical
fstab from one of my systems:
# <device> <mountpoint> <filesystemtype> <options> <dump> <fsckorder>
/dev/sdc1 / ext2 defaults 1 1
/dev/sda6 /tmp ext2 defaults 1 2
/dev/sda10 /usr ext2 defaults,ro 1 2
/dev/sda7 /var ext2 defaults 1 3
/dev/sda8 /var/log ext2 defaults 1 3
/dev/sda9 /var/spool ext2 defaults 1 3
/dev/sdb5 /usr/local ext2 defaults 1 3
/proc /proc proc defaults
/dev/sda2 none swap sw
/dev/fd0 /mnt/a umsdos noauto,rw,user 0 0
/dev/fd1 /mnt/b umsdos noauto,rw,user 0 0
/dev/hda1 /mnt/c umsdos defaults 0 0
/dev/scd1 /mnt/cd iso9660 noauto,ro,user,nodev,nosuid 0 0
/dev/scd0 /mnt/cdwr iso9660 noauto,ro,user,nodev,nosuid 0 0
/dev/fd0 /mnt/floppy minix noauto,rw,user,noexec,nodev,nosuid 0 0
/dev/fd0 /mnt/e2floppy ext2 noauto,rw,user,noexec,nodev,nosuid 0 0
/dev/sdd1 /mnt/mo ext2 noauto,rw,user,nodev,nosuid 0 0
/dev/sdd1 /mnt/mo.offline ext2 noauto,rw,user,nodev,nosuid 0 0
/dev/sdd1 /mnt/modos umsdos defaults,noauto 0 0
tau-ceti:/ /mnt/tau-ceti nfs ro
Note all the noauto and user point points. These allow users to access
these removable devices without switching to 'root.' To protect
against potential problems with the 'mount' command (being SUID
'root') I have it configured with the following ownership and
permissions:
-r-sr-x--- 1 root wheel 26116 Jun 3 1996 /bin/mount
Thus, only members of the "wheel" group are allowed to use the mount
command (and I only put a few people in that). So I balance the risk
of one of the "wheel" members finding and exploiting a bug in 'mount'
vs. the expense having to do all mount's myself and risk of my typing
*bad things* at the root shell prompt. I could also accomplish the
same sorts of things with 'sudo' (and I use that for many other
cases).
For more info about sudo see:
Sudo Home Page (http://www.courtesan.com/courtesan/products/sudo/)
FTP sudo: (ftp://ftp.cs.colorado.edu/pub/sysadmin/sudo
I hope that I've done more than answer your question. I hope I've
given you some ideas for how to make your system more robust and
secure -- how to apply some of the principles of "best practice" to
administering your Linux box.
--Jim
_________________________________________________________________
C++ Integrated Programming Enviroment for X...
Date: Wed, 17 Sep 1997 17:56:30 -0700
From: trustno1@kansas.net
Dear Answer Guy,
I am a student in Information Systems at Kansas State University. As a
relatively new user of Liunx, I was wondering if there exists a
software package for X which could be comparable to something like
Borland's C++ IDE? I've heard of something called Wipeout, but I'm not
running Xview, is there anything else that I should check out?
I've never heard of "Wipeout" -- but it sounds suspicously like a
slurred pronunciation of "wpe" -- which would be the "Window
Programming Environment" by Fred Kruse. This has a console mode (wpe)
and an X mode (xwpe) which are just links to the same binary.
I don't know that it requires Xview. Certainly on the rare occasions
when I've run it I didn't have to do anything special -- just type the
appropriate command for the mode I wanted and it just appears. So, I
didn't have to install any special libraries or run a particular
window manager or anything silly like that.
t typing 'xwpe &' from any xterm and see if that's already installed
for you. If so you can add it to your window manager's menu tree, or
to whatever sort of desktop manager or program/applications manager
you use (or just always launch if from an xterm -- which is what I do
for 90% of the things I run under X).
--Jim
_________________________________________________________________
LYNX-DEV new to LYNX
Date: Tue, 16 Sep 1997 22:06:45 -0700
Will I be able to browse the FULL INTERNET using LYNX? I am using LYNX
at my job, and the computer does not have window!
The web is not the FULL INTERNET!
Web browsers (such as Lynx, Mosaic, Netscape and MSIE) only access the
web, ftp, and gopher. These are only a few of the services and
protocols supported by the Internet.
There is no such thing as "browsing" the "full Internet." Indeed, the
phrase "full Internet" is meaningless.
As to your implicit question:
Will you be able to browse all public web sites using Lynx?
... the answer is no.
Lynx is a browser that complies with as much of the HTTP and HTML
specifications (the protocols and data representation (file formats)
used by the "web") as possible -- within the constraints of it various
platforms (text only -- no "inline" graphics, no sound, no support for
"Java" or "JavaScript" (which aren't part of these specifications
anyway).
Therein lies the rub. The client (Lynx) is able -- but many of the
servers aren't willing. (In this case, by "servers" I'm referring to
the people and the sites -- not the software).
Basically there are some sites that are "unfriendly." They make
gratuitous use of tables, imagemaps, frames, Java applets, embedded
JavaScript, cookies, ActiveX, active server pages (ASP) and ISAPI, and
other extensions. They hope to win in some "one-up-manship" contest of
"coolness."
Most of these extensions were introduced or promoted by one or another
company (mostly Microsoft or Netscape) in their efforts to "capture"
the "mindshare" -- which they hope will lead to increased
*market*-share for their browsers and "web developement tools" (at the
expense of standards, interoperability, and -- most especially --
their competitors).
The "web development tools" are the most insidious power piece in this
little chess game. These tools (mostly Microsoft's "FrontPage") seem
to include these non-standard extensions wherever possible -- with no
warning, commentary, and mostly with no option to avoid them. Anyone
who wants to produce "clean," friendly, standards conformant code is
basically reduced to using a bare text editor -- and knowing the
syntax inside and out.
In some particularly notorious cases there are "active" or "dynamic
content" sites that will slam the door shut on your browser just based
on a prejudice about it's name. By default your browser identifies
itself to the server when fetching pages. Some sites are "just too
cool" to have any textual content -- and shove a message down your
throat:
"Go get a 'real' browser, punk!"
... (the sheer effrontery of telling your "customers" what sort of
vehicle to drive around on the "stupor hypeway" -- it simply boggles
the mind and gasts the flabber!).
I've even encountered a couple of cases where some "dynamic sites"
would shove hundreds of kilobytes of "search engine spam" to my copy
of Lynx. This was a crude effort to seed the databases maintained by
Yahoo!, InfoSeek, HotBot, and others with excessively favorable
content rating (based on the notion that most of these sites used
"bots" (web robots, or "spiders") that identify themselves as "Lynx"
(to avoid using the extra bandwidth on graphics that they couldn't
use).
There are also an increasing number of sites that require SSL even for
their non-secure information. SSL is a set of encryption protocols
which are primarily used to provide for server-authenticated (or
mutually authenticated) and "secure" (encrypted) access to web forms
(mostly for order Pizzas without shouting your credit card number to
every router in fifty states and a few countries).
So, there are a number of places on the "full Internet" that you can't
adequately or comfortably browse with Lynx.
The good news is that Lynx does support features to address most of
these problems. You can get an SSL proxy (which you'd run on the same
machine as you run Lynx), the current versions of Lynx will list all
the "frames" (which are a Netscape extension for displaying multiple
separate HTML files concurrently), and can fetch some sorts of "map"
files (the text files which describe the "hot" (clickable) regions of
an IMAGEMAP -- which is a picture with "clickable" point therein) --
so you can browse them. Lynx can offer to accept cookies *(see note:
cookies) for a given session -- and, eventually, may offer options to
save them.
The bad news, again from the site maintainers and devlopers, is that
they often don't provide meaningful names for their frames, or within
their image map files. These are intended to be "seen" by a site's
users -- and often aren't "seen" by the site's developers (remember
the "integrated web developer software we mentioned earlier?).
The final bit of good news is this:
"Most sites that are particularly "Lynx-unfriendly" have not real
content. When I succumb to curiosity and view them in a GUI browser --
they are all flash and no substance."
When we say "hypertext" they seem to hear "hype OR text"
So, Lynx acts as a bit of a twit filter. Visit a site first with a
text browser (Lynx or emacs' W3 mode) and you'll know immediately
whether their webmasters are hard of hearing or whether they "get it."
"* Cookies are another Netscape extension which are intended to allow
web site developers a crude and unreliable way to "maintain state"
(distinguish between users who might be at the same site -- like all
of the AOL, CompuServe, and Netcom users going through their
respective gateways). Marketing people drool over statistics based on
"cookies" which can purport to tell how many *new* and *returning*
users there are to a site, *who* read *which* documents other
nonsense. However, for those statistics to be even close enough for a
marketeer, the use of them must be almost universal (so we stop
non-cookies browsers at the front home page) and we have to rely on
them being so obscure in the browser software that no one tampers with
them (they essentially must be "sneaky")."
PS: I've copied this to my editor at the Linux Gazette -- since I
think it's a article for them to consider. Maybe they'll reprint it in
"Websmith" (a feature of the Linux Journal, which is published by SSC,
the maintainers for the Linux Gazette webazine). Interested parties
can view all of the back issues of LG the URL in my sig. - -- a site
that is emminently "Lynx Friendly"
-- Jim
_________________________________________________________________
Copyright © 1997, James T. Dennis
Published in Issue 22 of the Linux Gazette October 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Welcome to the Graphics Muse
Set your browser as wide as you'd like now. I've fixed the Muse to
expand to fill the aviailable space!
© 1997 by mjh
______________________________________________________________________
Button Bar muse:
1. v; to become absorbed in thought
2. n; [ fr. Any of the nine sister goddesses of learning and the arts
in Greek Mythology ]: a source of inspiration
W elcome to the Graphics Muse! Why a "muse"? Well, except for the
sisters aspect, the above definitions are pretty much the way I'd
describe my own interest in computer graphics: it keeps me deep in
thought and it is a daily source of inspiration.
[Graphics Mews] [WebWonderings][Musings] [Resources]
T his column is dedicated to the use, creation, distribution, and
discussion of computer graphics tools for Linux systems.
As expected, two months of material piled up while I was out wondering
the far reaches of the US in August. My travels took me to California
for SIGGRAPH, Washington DC for vacation (honest), Huntsville Alabama
for work (they kind that pays the rent) and just last week I was in
Dallas for a wedding. All that plane travel gave me lots of time to
ponder just where the Muse has come in the past year and where it
should go from here. Mixed with a good dose of reality from SIGGRAPH,
I came up with the topics for this month. [INLINE]
First, there are two new sections: Reader Mail and Web Wonderings.
Reader Mail is an extension of Did You Know and Q and A. I'm getting
much more mail now than I did when I first started this column and
many of the questions are worthy of passing back to the rest of my
readers. I've also gotten many suggestions for topics. I wish I had
time to cover them all.
Web Wonderings is new but may be temporary. I know that many people
are reading my column as part of learning how to do Web page
graphics. Its hard to deny how important the Web has become or how
much more important it will become in the future. I started reading a
bit more on JavaScript to see if the language is sufficient to support
a dynamically changing version of my Linux Graphics mini-Howto. Well,
it is. I'll be working (slowly, no doubt) on converting the LGH to a
JavaScript based set of pages. My hope is to make it easier to search
for tools of certain types. I can do this with JavaScript, although
the database will be psuedo static as an JavaScript array. But it
should work and requires no access to a Web server.
Readers with Netscape 3.x or later browsers should notice a lot more
color in this column. The Netscape 4.x Page Composer makes it pretty
easy to add color to text and tables so I make greater use of color
now. Hopefully it will add more than it distracts. We'll see. I may
do a review of Netscape 4.x here or maybe for Linux Journal soon.
There are some vast improvements to this release of Netscape, although
the new reader (known as Collabra Discussions) is not one of them.
In this months column I'll be covering ...
* Browser detection using JavaScript
* SIGGRAPH 97 - what I saw, what I learned
* Designing Multimedia applications for Linux
Oh yeah, one other thing: Yes, I know I spelled "Gandhi" wrong in the
logo used in the September 1997 Linux Gazette. I goofed. I was more
worried about getting the quote correct and didn't pay attention to
spelling. Well, I fixed it and sent a new version to our new editor,
Viki. My apologies to anyone who might have been offended by the
misspelling. Note: the logo has been updated at the SSC site.
Graphics Mews Disclaimer: Before I get too far into this I
should note that any of the news items I post in this section are just
that - news. Either I happened to run across them via some mailing
list I was on, via some Usenet newsgroup, or via email from someone.
I'm not necessarily endorsing these products (some of which may be
commercial), I'm just letting you know I'd heard about them in the
past month.
indent
VRML 98
The third annual technical symposium focusing upon the research,
technology and applications of VRML, the Vritual Reality Modeling
Language will be held Feb 16-19, 1998 in Monterey, California. VRML
98 is sponsored by ACM SIGGRAPH and ACM SIGCOMM in cooperation with
the VRML Consortium. Deadlines for submission are as follows:
Papers Mon. 22 Sep
Panels Fri. 3 Oct
Workshops
Courses
Video Mon. 2 Feb
Contact Information:
VRML 98 Main Web Site http://ece.uwaterloo.ca/vrml98
Courses vrml98-courses@ ece.uwaterloo.ca
Workshops vrml98-workshops@ ece.uwaterloo.ca
Panels vrml98-panels@ ece.uwaterloo.ca
Papers vrml98-papers@ ece.uwaterloo.ca
Video Submissions vrml98-video@ ece.uwaterloo.ca
Demo Night vrml98-demos@ ece.uwaterloo.ca indent
Iv2Rib
Cow House Productions is please to present the first release of
Iv2Rib, an Inventor 2.0 (VRML 1.0) to Renderman / BMRT converter.
Source (C++) and an Irix 5.3 binary are available at:
http://www.cowhouse.com/ Home/Converters/converters.html
Additionally, new updates (V0.12, 30-Jul-97) of both Iv2Ray (the
Inventor to Rayshade converter) and Iv2POV (the inventor to POVRAY
converter) are also available on the same page, as both source (C++)
and binaries for Irix 5.3
[INLINE]
Crack released the Abuse source code to the public domain recently.
Abuse was a shareware and retail game released for DOS, MacOS, Linux,
Irix, and AIX platforms.
The source is available at
http://games.3dreview.com/abuse/files/abuse_pd.tgz
and
http://games.3dreview.com/abuse/files/abuse_pd.zip
If you don't know the 1st thing about Abuse,
http://crack.com/games/abuse
and
http://games.3dreview.com/abuse
Lastly, if you want to discuss the source (this is a just-in-case
thing-it may very well not get used), we put a small newsgroup up at
news://addicted.to.crack.com/crack.technical. That is also where we'll
prolly host a newsgroup about Golgotha DLL's, mods, editting, movies
and stuff like that later on.
Dave Taylor
[INLINE] [INLINE]
Version 0.2.0 of DeltaCine
DeltaCine is a software implemented MPEG (ISO/IEC 11172-1 and 11172-2)
decompressor and renderer for GNU/Linux and X-Windows. It is available
from ftp://thumper.moretechnology.com/pub/deltacine.
This project aims to provide portable C++ source code that implements
the system and video layers of the MPEG standard. This first release
will interpret MPEG 1 streams, either 11172-1 or raw 11172-2, and
render them to an X-Windows display. The project emphasizes
correctness and source code readability, so the performance suffers.
It cannot maintain synchronized playback on a 166MHz Pentium.
Still, the source code contains many comments about the quality of the
implementation and the problems encountered when interpreting the
standard. All of the executing code was written from scratch, though
there is an IDCT (Inverse Discrete Cosine Transform) implementation
adapted from Tom Lane's IJG project that was used during development.
This is an ALPHA release which means that the software comes with no
warranties, expressed or implied. It is being released under the GNU
Public License for the edification of the GNU/Linux user community.
Limitations:
* Requires ix86
* No playback synchronization. Movies play as fast as the decoder
can render the frames.
* Requires X-Windows server in 16bpp mode.
Features:
* Full decode of Part 1 (System) and Part 2 (Video) specification
for ISO/IEC 11172. Full implementation except for
synchronization.
* Reference quality output as compared to the Stanford
implementation.
* User-mode multi-threading implemented as part of the decoder.
RenderMan Module v0.01 for PERL 5
This module acts as a Perl5 interface to the Blue Moon Rendering Tools
(BMRT) RenderMan-compliant client library, written by Larry Gritz:
http://www.seas.gwu.edu/student/gritz/bmrt.html
REQUIREMENTS
This module requires Perl 5, a C compiler, and BMRT.
EXAMPLES
Some extra code has been added to the examples directory that should
enable you to convert LightWave objects to RIB or to a Perl script
using the RenderMan binding. More useful examples will be provided in
future releases.
Updates will hopefully be uploaded to PAUSE once I am authorized to
upload there, and will be posted to my personal home page at:
http://www.gmlewis.com/
AUTHOR
Glenn M. Lewis | glenn@gmlewis.com
[INLINE]
Sven Neumann released two more GIMP scripts for the megaperls script
collection. You can find them as usual at:
http://www-public.rz.uni-duesseldorf.de/ ~neumanns/gimp/megaperls
You'll need to patch the waves-plug-in if you want to use the
waves-anim script. The patch was posted a while ago on the list but
hasn't made its way into any semi-official release yet. It is also
available from the web-site mentioned above.
Ed. Note: Please note that the current release of the GIMP is a
developers only release and not a public release. If you plan on
using it you should be very familiar with software development and C.
A public release is expected sometime before the end of the year.
Sven Neumann
<neumanns@uni-duesseldorf.de>
[INLINE]
t1lib-0.3-beta
t1lib is a library for generating character- and string-glyphs from
Adobe Type 1 fonts under UNIX. t1lib uses most of the code of the X11
rasterizer donated by IBM to the X11-project. But some disadvantages
of the rasterizer being included in X11 have been eliminated. Here are
the main features:
* t1lib is completely independent of X11 (although the program
provided for testing the library needs X11)
* fonts are made known to library by means of a font database file
at runtime
* searchpaths for all types of input files are configured by means
of a configuration file at runtime
* characters are rastered as they are needed
* characters and complete strings may be rastered by a simple
function call
* when rastering strings, pairwise kerning information from
.afm-files may optionally be taken into account
* an interface to ligature-information of afm-files is provided
* rotation is supported at arbitrary angles
* there's full support for extending and slanting fonts
* new encoding vectors may be loaded at runtime and fonts may be
reencoded using these encoding vectors
* antialiasing is implemented using three gray-levels between black
and white
* a logfile may be used for logging runtime error-, warning- and
other messages
* an interactive test program called "xglyph" is included in the
distribution. This program allows to test all of the features of
the library. It requires X11.
For X11-users a special set of functions exists which:
* draw directly into X11 drawbles
* respect fore- and background color of the graphics context
* provide opaque and transparent drawing mode
* provide automatic colored antialiasing
Author: Rainer Menzner (rmz@neuroinformatik.ruhr-uni-bochum.de)
You can get t1lib by anonymous ftp at:
ftp://ftp.neuroinformatik.ruhr-uni-bocum.de/pub/software/t1lib/t1lib-0
.3-beta.tar.gz
An overview on t1lib including some screenshots of xglyph can be found
at:
http://www.neuroinformatik.ruhr-uni-bochum.de/ini/PEOPLE/rmz/t1lib.htm
l
[INLINE]
GTK Needs A Logo!
GTK, the GIMP Toolkit (I think, at least thats what it used to stand
for) is looking a for a logo. Something that defines the essence of
GTK, something that captures its soul and personality. A frozen image
of everything that GTK stands for. Or maybe just something cool.
The Prize
The prize for submitting the winning logo is a very cool
yourname@gimp.org email alias. Thats right, if you win, you can be the
envy of your friends with your sparkling @gimp.org email alias.
See http://www.gimp.org/contest.html for more details.
[INLINE]
Announcing MpegTV SDK 1.0 for Unix
MpegTV SDK 1.0 is the first toolkit that allows any X-windows
application to support MPEG video without having to include the
complex code necessary to decode and play MPEG streams.
MpegTV SDK 1.0 is currently available for:
* Solaris 2.5 SPARC
* Solaris 2.5 x86
* IRIX 6.2
* Linux x86
* BSD/OS 3.0
MpegTV also announces more good news: MpegTV Player 1.0 for Unix is
now free for non-commercial use!
For more information on MpegTV products and to download MpegTV
software, please visit the MpegTV website:
http://www.mpegtv.com
Regards,
Tristan Savatier - President, MpegTV LLC [INLINE]
Announcing MpegTV Plug-in 1.0 for Unix
MpegTV Plug-in 1.0 is a streaming-capable Netscape Plug-in that allows
you to play MPEG movie embedded inside HTML documents.
Unlike other similar Netscape Plug-ins (e.g. the Movieplayer Plug-in
on SGI), MpegTV Plug-in is capable of streaming from the network, i.e.
you can play a remote MPEG stream immediately, without having to wait
for the MPEG file to be downloaded on your hard disk.
MpegTV Plug-in 1.0 is currently available for:
* Solaris 2.5 SPARC
* IRIX 6.2
* Linux x86
* Solaris 2.5 x86 (coming soon)
* BSD/OS 3.0 (coming soon)
Get it now at http://www.mpegtv.com/plugin.html !
Regards, -- Tristan Savatier (President, MpegTV LLC)
MpegTV: http://www.mpegtv.com
MPEG.ORG: http://www.mpeg.org
[INLINE]
USENIX 1998 Annual Technical Conference
The 1998 USENIX Technical Conference Program Committee seeks original
and innovative papers about the applications, architecture,
implementation, and performance of modern computing systems. Papers
that analyze problem areas and draw important conclusions from
practical experience are especially welcome. Some particularly
interesting application topics are:
ActiveX, Inferno, Java, and other embeddable environments
Distributed caching and replication
Extensible operating systems
Freely distributable software
Internet telephony
Interoperability of heterogeneous systems
Nomadic and wireless computing
Privacy and security
Quality of service
Ubiquitous computing and messaging
A major focus of this conference is the challenge of technology: What
is the effect of commodity hardware on how we build new systems and
applications? What is the effect of next-generation hardware? We seek
original work describing the effect of hardware technology on
software. Examples of relevant hardware include but are not limited
to:
Cheap, fast personal computers
Cheap, large DRAM and disks
Flash memory
Gigabit networks
Wireless networks
Cable modems
WebTV
Personal digital assistants
Network computers
The conference will also feature tutorials, invited talks, BOFs,
and Vendor Exhibits.
For more information about this event:
* Visit the USENIX Web site:
http://www.usenix.org/events/no98/index.html
* Send email to the USENIX mailserver at info@usenix.org. Your
message should contain the line: "send usenix98 conferences".
* Or watch comp.org.usenix for full postings
The USENIX Association brings together the community of engineers,
system administrators, scientists, and technicians working on the
cutting edge of computing. Its technical conferences are the essential
meeting grounds for the presentation and discussion of the most
advanced information on new developments in all aspects of advanced
computing systems. [INLINE]
Ra-vec version 2.1b - convert plan drawings to 3D vector format
Ra-vec is a program which can convert plan drawings of buildings into
a vector format suitable for the creation of 3D models using the
popular modelling package AC3D. It is freely avalible for linux from
http://www.comp.lancs.ac.uk/ computing/users/aspinr/ra-vec.html
[INLINE]
xfpovray 1.2.4
A new release of the graphical interface to the cool ray-tracer
POV-Ray called xfpovray is now available. It requires the most recent
(test) version of the XForms library (0.87), and supports most of the
numerous options of POV-Ray. Hopefully 0.87 will migrate from test
release to public release soon.
This version of xfpovray adds a couple nice features, such as POV-Ray
templates to aid in writing scene files. Binary and source RPMs are
also available. Since xforms does not come in rpm, you may get a
failed dependency error. If you get this, just use the --nodeps
option.
You can view an image of the interface and get the RPMs and source
code from
http://cspar.uah.edu/~mallozzir/
There is a link there to the XForms home page if you don't yet have
this library installed.
Bob Mallozzi <mallozzir@cspar.uah.edu>
[INLINE]
WSCG'98 - Call for Papers and Participation
Just a reminder:
The Sixth International Conference in Central Europe on Computer
Graphics and Visualization 98, in cooperation with EUROGRAPHICS and
IFIP working group 5.10 on Computer Graphics and Virtual Worlds, will
be held in February 9 - 13, 1998 in Plzen at the University of West
Bohemia close to PRAGUE, the capital of Czech Republic
Information for authors: http://wscg.zcu.cz select WSCG'98
Contribution deadline: September 30, 1997
[INLINE]
ivtools 0.5.7
ivtools contains, among other things, a set of drawing editors written
in C++ for Unix/X11. They extend idraw with networked export/import,
multi-frame flipbook editing, and node/graph topology editing. A new
release, 0.5.7, is now available.
Source code at:
http://www.vectaport.com/pub/src/ivtools-0.5.7.tar.gz
ftp://sunsite.unc.edu/pub/Linux/apps/graphics/draw/ivtools-0.5.7.tar.g
z
Linux elf binaries at:
http://www.vectaport.com/pub/src/ivtools-0.5.7-LINUXx.tar.gz
ftp://sunsite.unc.edu/pub/Linux/apps/graphics/draw/ivtools-0.5.7-LINUX
.tar.gz
Web page at:
http://www.vectaport.com/ivtools/
Vectaport Inc.
http://www.vectaport.com
info@vectaport.com
[INLINE]
Pixcon & Anitroll 1.04
New features since version 1.04:
* added DOS binaries to the distribution
* 3DSMAX import/export plugin for Pixcon data files
* 25% increase in rendering speed
Pixcon 3D rendering package that creates high quality images by using
a combination of 11 rendering primitives. Anitroll is a forward
kinematic hierarchical based animation system that has some support
for some non-kinematic based animation (such as flock of birds, and
autonomous cameras). These tools are based upon the Graph library
which is full of those neat rendering and animation algorithms that
those 3D faqs keep mentioning.
Why Pixcon & Anitroll? Well, systems like Alias, Renderman,
3DS/3DSMAX, Softimage, Lightwave, etc are too expensive for average
users (anywhere from $1000 - $5000 US) and require expensive hardware
to get images in a reasonable amount of time. Conventional freeware
systems, such as BMRT, Rayshade, and POV are too slow (they're
raytracers...). Pixcon & Anitroll is FREE, and doesn't take a long
time to render a frame (true, its not real time... but I'm working on
it). It also implements some rendering techniques that were presented
at Siggraph 96 by Ken Musgrave and was used to generate an animation
for Siggraph '95.
The Pixcon & Anitroll Home page is at:
http://www.radix.net/~dunbar/index.html
Comments to dunbar@saltmine.radix.net
Availabe from: ftp://sunsite.unc.edu/incoming/Linux/pixcon-105.tgz
and will be moved to:
ftp://sunsite.unc.edu/pub/Linux/apps/graphics/rays/pixcon-105.tgz
[INLINE]
Glide 2.4 ported to Linux
Glide version 2.4 has now been ported to Linux and is available free
of charge. This library enables Linux users with 3Dfx Voodoo Graphics
based cards such as the Orchid Righteous 3D, Diamond Monster 3D,
Canopus Pure 3D, Realvision Flash 3D, and Quantum Obsidian to write 3D
applications for the cards. The Voodoo Rush is not yet supported. The
library is available only in binary form.
To quote 3Dfx's web page:
Glide is an optimized rasterization library that serves as a
software 'micro-layer' to the 3Dfx Voodoo accelerators. With Glide,
developers can harness the power of the Voodoo to provide
perspective correct, filtered, and MIP mapped textures at real-time
frame rates - without having to work directly with hardware
registers and memory, enabling faster product development and
cleaner code.
As a separate effort, a module for Mesa is also under development to
provide an OpenGL like interface for the Voodoo Graphics cards.
For more information on Glide please see:
http://www.3dfx.com/download/sdk/index.html
For more download informtion for Glide see:
http://www.3dfx.com/download/sdk/index.html
For more information on Mesa see:
http://www.ssec.wisc.edu/~brianp/Mesa.html
For an FAQ on 3Dfx on Linux see:
http://www.gamers.org/~bk/xf3D/
Finally, if you need to discuss all this, try the 3Dfx newsgroup:
news://news.3dfx.com/3dfx.glide.linux
[INLINE]
Did You Know?
Q and A
Q: Let me ask a graphic related question: is there a software which
converts GIF/JPEG file to transparent GIF/JPEG file? Raju Bathija
<bathija@sindhu.theory.tifr.res.in>
A: JPEG, to my knowledge, doesn't support transparency. You have to
use GIF (or PNG). GIF files can have a transparency added by picking
the color you want to be transparent. One of the colors, and only
one, can be specified as transparent. You can use xv to pick the
color. Then you can use the NetPBM tools to convert the image to a
transparent GIF. You would do something like
giftopnm file.gif | ppmtogif -transparent rgb:ff/ff/ff > newfile.gif
Check the man page for ppmtogif for how to specify the color to use.
[INLINE]
Reader Mail
Chris Bentzel <cbentzel@rhythm.com> wrote:
At the end of your gamma correction discussion of graphics muse
issue 17, you mention that you were unable to find contact info for
Greg Ward. He is at gregl@sgi.com (he is now Greg Ward Larson->
believes in reciprocating on the maiden-married name
thing).However, a better link is to the radiance page: a high-end,
physically correct ray-tracing/radiosity renderer used mostly for
architectural design (and runs on Linux! Free source!)
http://radsite.lbl.gov/radiance/HOME.html
Jean Francois Martinez <jfm2@club-internet.fr> wrote:
I had just finished reading your article in LJ about Megahedron and
I was reading some of the examples and playing with them. I looked
in mhd/system/smpl_prims and found the following:
coord_system=right_handed;
so you can do this
picture smokey_train_pic with
coord_system=left_handed;
Notice than I put it just under the declaration of the top level
object (the one called by do). Of course if you use this for the
examples provided you will notice that now the camera is not
focusing on the subject.
John P. Pomeroy <pomerojp@ttc2.lu.farmingdale.edu> wrote:
Usually I skip over the Graphics Muse, (I'm a bit head, not a
graphic artist) but something drew me in this time. Perhaps it's
because I'm investigating the development of a Linux based Distance
Learning platform for for use in my networking classes.Anyway, one
of the least expensive resources I've found over time has been the
Winnov Videum-AV. An outstanding card but near as I can tell,
there are no Linux drivers . I contacted Winnov a while back and
they're not interested in Linux at all, but after reading about the
efforts of the QuickCam folks I was wondering if you could just
mention that the Videum card exists, perhaps simply asking if
anyone is working on a driver? (And, no, I don't own stock in
Winnov nor know anyone that does.)Perhaps some of the programmers
out there are working on something, or maybe Winnov will take the
hint. I'm certain that a Videum card on Linux would outperform the
same card under NT. Imagine a streaming video service (Either Java
based or using the just released 60 stream Real Video Linux server)
with a live feed under Linux. Sure wish the folks at Winnov
could!Anyway, thanks. The 'Muse has a good balance of technical
material and artistic issues. I'll be reading the 'Muse a lot more
often, but first...... the back issues!
'Muse: Well? Anyone working on a driver for this?
Jim Tom Polk <jtpolk@camalott.com> http://camalott.com/~jtpolk/
wrote:
Reading your column I noticed that you state that you don't know of
any animated GIF viewers for Linux. I use xanim. I usually use
gifmerge to create the image, and then load up the image and step
through it with xanim. I also find it useful to see just how some
animations are composed / created. The version I have installed
is: XAnim Rev 2.70.6.4 by Mark Podlipec (c) 1991-1997 I only found
it out by accident when I loaded an animated GIF by accident (I was
clicking on an mpeg file and missed it). You can start/stop/pause.
Go forward and backwards one frame at a time, and speed up or slow
down the entire sequence. You still have to use another utility to
create the GIF, but I use it all the time.Really enjoy your column.
'Muse: I got a number of replies like this. I never tried xanim for
animated GIFs. Sure enough, it works. It just goes to show how much
this wonderful tool can do.
Alf Stockton <stockton@acenet.co.za> wrote:
I have a number of JPEGs that I want to add external text to. ie
Comments on photographs I have taken with my QV-10 digital camera.
Now I don't want the text to appear on the picture. It must appear
either next to or below same. So in other words I want to create a
large JPEG consisting of some text and my picture. Of course it
does not necessarily have to be a JPEG but it must be something
that a web browser can display as I intend uploading same to my
ISP.The thought was that I would create a HTML document for each
image and this would work but now I have a large number of images &
I don't want to create an equal amount of HTMLs.
'Muse: I'm a little confused here. Do you want the text visible at
all? Or just include the text as unprintable info (like in the header
of the image)? If you want the text in the header I'm not sure how to
do this. I'm pretty sure it can be done, but I've never messed with
it.
If you want the text visible but not overlapping the original image
there are lots of ways to get it done. I highly recommend the GIMP,
even though you feel its overkill - once you've learned to use it
you'll find it makes life much easier. However, if you just want a
shell script to do it you can try some of the NetPBM tools. NetPBM is
a whole slew of simple command line programs that do image conversion
and manipulations. One of the tools is pnmcat. To use this you'd
take two images and convert them to pnm files. For GIFs that would be
like
giftoppm file1.gif > file1.pnm
Then you use pnmcat like this:
pnmcat -leftright file1.pnm file2.pnm > final-image.pnm
This would place the two images side by side. You could then convet
this back to a GIF file for placing on the Web page. pnmcat has other
options allowing you to stack the images (-topbottom) and specify the
way to justify the smaller image if the images are not the same
width/height. There is a man page for pnmcat that comes with NetPBM.
Note that the NetPBM tools do not have tools for dealing with JPEG
images. However, there are some tools called jpegtoppm and ppmtojpeg
available from the JPEG web site (I think). I'm not positive abou
that. I don't use these specific tools for dealing with JPEGs.
If you want, you can always read in the JPEG with xv first and save it
as a PPM/PNM (these two formats are essentially the same) file first,
then use the NetPBM tools.
Jeff Taylor <jeff@adeno.wistar.upenn.edu> wrote:
1) You mentioned [in your review of Megahedron in the September
issue of Linux Journal]some difficulty in writing the model
information to a file for rendering with an alternative renderer.
This is important to me as I would like to use PVMPOV for the final
rendering. It wasn't clear from what you wrote, is it difficult to
do or impossible?
'Muse: Difficult, but not impossible. I think you can get model
information via polygon data (vectors), but you'll have to do the work
of getting that out to the file format of interest. I'm no expert,
however. I used it only for a little while, to get modestly familiar
with it. The best thing to do is write to them and ask the same
question. It will get a better answer (one would hope, anyway) and
also show that the Linux community is interested in supporting
commercial products.
2) Does the modeller allow 2D images to be printed? I'm thinking
of CAD type 3-angle-view drawings. I'd like to use it for CAD
applications where a model is created and scale drawing can be
printed.
'Muse: There isn't a print function for the 2D images, but you can
save the images to a file and then print them using some other tool,
like xv or the GIMP. The manual has a section on how to save the
images. BTW, I'm assuming you mean the images that have been
rendered. These images can be saved in RAW or TGA format using
functions provided in the SMPL language.
Daniel Weeks <danimal@blueskystudios.com> wrote:
I just want to start of by telling you that you are doing a great
job with the Graphic Muse and on the current article in the Linux
Jornal on Megahedron. This is where my questions come from.
'Muse: Thanks for the compliments!
First, with Megahedron I noticed that it is a progamatic/procedural
language for modeling (interestingly enough the language itself is
not that dissimilar to our cgiStudio language in structure and
function {except for that wierd commenting style}, in fact I
already have a perl script that translates most of SPML to
cgiStudio :). The question here is does Megahedron have any sort
of interface over the demo mode, I guess I mean something like (but
it doesn't have to be as fully functional or bloated as) SoftImage
or Alias|Wavefront. Second can Megahedron support NURBS patches
and deforming geometry.
'Muse: Megahedron is a programming API - actually a scripting API.
The CD I got (which is the $99 version they sell from their web pages)
wasn't a demo, although it had lots of demos on it. There is no X
interface to the language (ie no graphical front end/modeler). I
suppose if there was enough interest they'd look into it. Best thing
to do is check their web page and get an email address to ask for it.
There might be a non-Unix graphical front end, but I didn't check on
that. As for Nurbs, there wasn't any mention of support for it on the
disk I got. In fact, I don't think I've come across any modellers (or
modelling languages) aside from BMRT that has support for NURBS on
Linux. But Linux is just beginning to move into this arena anyway, so
its just a matter of time.
BTW: for those that don't know it, Blue Sky Studios is the special
effects house that is doing, among other things, the special effects
for the upcoming Alien Resurrection movie. Yes, it appears Ripley may
live forever.
Hap Nesbitt <hap@handmadesw.com>, of Handmade Software wrote in reply
to my review of Image Alchemy:
A very nice review thanks. BTW we do 81 formats now. The new
formats are documented in addendum.pdf. The Mews seems quite
ambitious. Is this all your work or do you get some help?
'Muse: Its all mine, although I've had a couple of people write
articles on two separate occassions. And Larry Gritz offered lots of
help when I did the BMRT write ups. I still owe the readers an
advanced version of that series.
We've found a tool for porting Mac libraries to X. Our Mac
interface is beautiful and we should get it ported sometime in the
next 6 months or so. I'll keep you posted. BTW people don't really
buy much Image Alchemy, they buy Image Alchemy PS to RIP PostScript
files out to large format inkjet plotters in HP-RTL format. If you
give me your mailing address I'll send you a poster done this way.
I think you might enjoy it.
'Muse: Sounds great. Thanks for the info Hap!
G. Lee Lewis <GLLewis@ecc.com> wrote:
Your web pages look really nice.
'Muse: Thanks.
Did you use Linux software to create your web pages?
'Muse: Yes. In fact, thats all I use - Linux. I don't use MS for
anything anymore. All the software used to create the graphic images
on my pages runs on Linux.
Can you say what you used?.
'Muse: Mostly the GIMP, a Photoshop clone for Unices. "GIMP" stand
for GNU Image Manipulation Program, but the acronym kinda stinks
(IMHO, of course). Its quite a powerful program though. I also use xv
quite a bit, along with tools like the NetPBM toolkit (a bunch of
little command line programs for doing various image processing
tasks), MultiGIF (for creating GIF animations) and Netscape's 4.x Page
Composer for creating HTML. I just started using the latter and not
all my pages were created with it, but eventually I'll probably switch
from doing the HTML by hand (through vi) to only using the Page
Composer. For 3D images I use POV-Ray and BMRT. These require a bit
more understanding of the technology than a tool like the GIMP, but
then 3D is at a different state of development than 2D tools like the
GIMP.
What flavor of Linux do you like, redhat, debian, etc..??
'Muse: Right now two of my 3 boxes at home are WGS Linux Pro's (which
is really a Red Hat 3.x distribution) and one is a Slackware (on my
laptop). I like the Red Hat 4.2 distribution, but it lacks support
for network installs using the PCMCIA ethernet card I have for my
laptop. I plan on upgrading all my systems to the RH4.2 release by
the end of the year.
I've not seen the Debian distribution yet. Slackware is also quite
good. I liked their "setup" tool for creating packages for
distribution because it used a simple tar/gzip/shell script
combination that was easy to use and easy to diagnose. However, its
not a real package management system like RPM. "Consumers" (not
hackers) will probably appreciate RPM more than "setup".
I also use commercial software for Linux when possible. I run
Applixware, which I like very much, and Xi Graphics AcceleratedX
server instead of the XFree86 servers. The Xi server is much easier
to install and supports quite a few more video adapters. However, it
doesn't yet support the X Input Extension unfortunately. The latest
XFree86 servers do, and thats going to become important over the next
year with respect to doing graphics.
What do you think of Caldera OpenLinux?
'Muse: I haven't had a chance to look it over. However, I fully
support the commercial distributions. I'm an avid supporter of
getting Linux-based software onto the shelves of software reseller
stores like CompUSA or Egghead Software. Caldera seems the most
likely candidate to be able to get that done the quickest. After
that, we'll start to see commercial applications on the shelves too.
And thats something I'd love to see happen. I did buy the Caldera
Network Desktop last year but due to some hardware limitations decided
to go back to the Slackware distributions I had then.
Of all the distributions Caldera probably has a better understanding
of what it takes to make a "product" out of Linux - something beyond
just packing the binaries and sticking them on a CD. A successful
product will require 3rd party products (ones with full end-user
quality, printed documentation and professional support organizations)
and strategic alliances to help prevent fragmentation. Fragmentation
is part of what hurt the early PC Unix vendors (like Dell and Everex)
and what has plagued Unix workstation vendors for years.
So, in summary, I strongly support the efforts of Caldera, as well as
Red Hat, Xi Graphics, and all vendors who strive to productize Linux.
<veliath@jasmine.hclt.com> wrote:
Is there some documentation available on GIMP - please, please say
there is and point me towards it.
'Muse: No, not yet. A couple of books are planned, but nothing has
been started officially. No online documentation exists yet. Its a
major flaw in free software in general which annoys me to no end, but
even in commercial organizations the documentation is usually the last
thing to get done.
There will be a 4 part series on the GIMP in the Linux Journal
starting with the November issue. I wrote this series. It is very
introductory but should help a little. I also did the cover art for
that issue. Let me know what you think!
You can also grab any Photoshop 3 or Photoshop 4 book that covers the
basics for that program. The Toolbox (the main window with all the
little icons in it) is nearly exactly the same in both programs (GIMP
and Photoshop). Layers work the same (with some minor differences in
the way the dialog windows look). I taught myself most of what I know
based on "The Photoshop 3 Wow! Book" and a couple of others.
______________________________________________________________________
[INLINE]
Browser Detection with JavaScript
I recently started reading up on the latest features that will be
supported in the upcoming releases of the Netscape and MSIE Web
browsers through both the C|Net web site known as Builder.com and
another site known as Developer.com. A couple of the more interesting
features are Cascading Style Sheets, which you'll often see referred
to as CSS, and layers. CSS will allow HTML authors to define more
definitive characteristics to their pages. Items such as the font
family(Ariel, Helvetica, and so forth), style (normal, italic,
oblique), size, and weight can be specified for any text on the page.
Browsers will attempt to honor these specifications and if they can't
do so they will select appropriate defaults. CSS handles most of the
obvious characteristics of text on a page plus adds the ability to
position text in absolute or relative terms. You can also clip,
overflow, and provide a z-index to the position of the text. The
z-index positioning is useful because it provides a means of accesing
text and graphics in layers. By specifying increasing values of z to
a position setting you can effectively layer items on a page.
Builder.com and Developer.com both have examples of these extensions
to HTML that are fairly impressive. There is a table of the new CSS
features available at
http://www.cnet.com/Content/Builder/Authoring/CSS/table.html. You
will need Netscape 4.x to view these pages.
CSS is about to make web pages a whole lot more interesting.
The down side to CSS is that its new. Any new technology has a
latency period that must pass before the technology is sufficiently
distributed to be useful to the general populace. In other words, the
browsers aren't ready yet, or will just be released at the time this
goes to print, so adding CSS elements to your pages will pretty much
go unnoticed for some time. I would, however, recommend becoming
familiar with them if you plan on doing any serious Web page design in
the future. In the meantime we still have our JavaScript 1.1 and good
ol' HTML 3.0.
Ok, enough philosophizing, down to some nitty gritty.
I just updated my GIMP pages to reflect the fact that the 0.54 version
is pretty much dead and the 0.99 version is perpetually "about to
become 1.0". What that means is I've dropped most of my info and
simply put up a little gallery with some of the images I've created
with the GIMP. Along with the images, including a background image
that was created using nothing more than a set of gradients created or
modified with the gradient editor in the GIMP, I've added some
Javascript code to spice up my navigation menus and a couple of simple
animated GIFs. It was probably more fun to do than it is impressive.
If you check out these pages you'll find its a little more attractive
with Netscape 4.x since I'm using a feature for tables that allows me
to specify background images for tables, rows and even individual
cells. Netscape 3.x users can still see most of the effects, but a
few are lost.
I had added some JavaScript code to the main navigation page of my
whole site some time back. I sent email to my brother, who does NT
work at Compaq, and a Mac-using friend asking them to take a look at
it and see what they thought. It turned out MSIE really disliked that
code and the Netscape browser on the Mac didn't handle the image
rollers correctly (image rollovers cause one image to be replaced by
another due to some user initiated action - we'll talk about those in
a future Web Wonderings). Shocking - JavaScript wasn't really cross
platform as was first reported. Well, its a new technology too. The
solution is to add code to determine if the rest of the code should
really execute or not. I needed to add some browser detection code.
That was .... a year ago? I can't remember, its been so long now.
Well, while scanning the CSS and other info recently I ran across a
few JavaScript examples that explained exactly how to do this. I now
take this moment to share it with my readers. Its pretty basic, so
I'll show it first, then explain it. Note: the following columns
might be a little hard to read in windows less than about 660 pixels
wide. Sorry 'bout that.
<SCRIPT LANGUAGE="JavaScript1.1">
<!-- // Activate Cloaking Device
//***************************************
// Browser Detection - check which browse
// we're working with.
// Based loosely on code from both Tim
// Wallace and the Javascript section of
// www.developer.com.
//***************************************
browserName = navigator.appName;
browserVersion = parseInt(navigator.appVersion);
browserCodeName = navigator.appCodeName;
browserUserAgent = navigator.appUserAgent;
browserPlatform = navigator.platform;
// Test for Netscape browsers
if ( browserName == "Netscape" &&
browserVersion >= 4 )
bVer = "n4";
if ( browserName == "Netscape" &&
browserVersion == 3 )
bVer = "n3";
if ( browserName == "Netscape" &&
browserVersion == 2 )
bVer = "n1";
// Test for Internet Explorer browsers
if ( browserName == "Microsoft Internet Explorer" &&
browserVersion == 2 ) bVer = "e2";
if ( browserName == "Microsoft Internet Explorer" &&
browserVersion == 3 ) bVer = "e3";
if ( browserName == "Microsoft Internet Explorer" &&
browserVersion >= 4 ) bVer = "e4";
// Deactivate Cloaking -->
</SCRIPT>
The first line tells browsers that a script is about to follow. The
LANGUAGE construct is supposed to signify the scripting language, but
is not required. If the LANGUAGE tag is left off browsers are supposed
to assume the scripting language to be JAVASCRIPT. The only other
language available that I'm aware of currently is VBSCRIPT for MSIE
Browsers that do not understand this HTML element simply ignore it.
The next line starts the script. All scripts are enclosed in HTML
comment structures. By doing this the script can be hidden from
browsers that don't understand them (thus the comment on "cloaking").
Note that scripts can start and stop anywhere in your HTML document.
Most are placed in the <HEAD> block at the top of the page to make
debugging a little easier, but thats not required.
Comments in scripts use the C++ style comment characters, either
single lines prefixed with // or multiple lines that start with /* and
end with */. I placed the comments in the example in a purple color
for those with browsers that support colored text, just to make them
stand out from the real code a little.
The next five lines grab identification strings from the browser by
accessing the navigator object. The first two, which set the
browserName and browserVersion variables, are obvious and what you
will use most often to identify browsers in your scripts. The
appCodeName is "Mozilla" for Netscape and may not be set for MSIE.
The appUserAgent is generally a combination of the appCodeName and the
appVersion, although it doesn't have to be. Often you can use grab
this string and parse out the information you are really looking for.
The last item, the platform property for the navigator object, was
added in Javascript 1.2. Be careful - this code tries to access a
property that not all browsers can handle! You may want to embed the
browserPlatform assignment inside one of the IF statements below it to
be safe.
Now we do some simple tests for the browsers our scripts can support.
Note that the tests are fairly simply - we just test the string values
that we grabbed for our browserName and browserVersion variables. In
the first set of tests we check for Netscape browsers. The second set
of tests test for MSIE browsers. We could add code inside these tests
to do platform specific things (like special welcome messages for
Linux users!) but in practice you'll probably want this particular
script to only set a global flag that can be tested later, in other
scripts where the real work will be done. Remember - you can have
more than one script in a single HTML page and each script has access
to variables set in other scripts.
Why is it important to test for browers versions? Simple -
JavaScript is a new technology, introduced in Netscape's 2.0 release
of their Navigator browser. Microsoft, despite whining that
JavaScript isn't worth supporting, added support for the language in
their 3.0 browser. The problem is that each version, for either
browser, supports the language to different extents. For example, one
popular use of the language is "image rollovers". These allow images
to change in the display based when the mouse is placed over the
image. Various versions of Netscape from 2.0 handled this just fine.
The Mac version had a bug in 3.0 that would not clear the original
image before updating with the new image. MSIE 2.0 and 3.0 didn't
like this bit of JavaScript at all, popping up error windows in
protest. Knowing the browser and platform information can help you
design your JavaScript to work reasonably well on any platform.
______________________________________________________________________
Musings
SIGGRAPH 97
Unfortunately I'm not able to bring you my experiences at
SIGGRAPH this month. On my trip I took notes in my NEC Versa notebook
(running Linux, of course). Unfortunately I left the power supply and
power cable in my motel room and by the time I realized it after I
returned the motel could not find it. Its probably on some used
computer resellers shelves now. Anyway, I just ordered a
replacement. I'll have my SIGGRAPH report for you next month. Sorry
about that. I am, of course, taking donations to cover the cost of
replacement. <grin>
[INLINE]
Designing Multimedia Applications
I recently picked up a copy of Design Graphics from my local computer
bookstore. This is a monthly magazine with a very high quality layout
that covers many areas of computer graphics in great detail. The
magazine is rather pricey, about $9US, but so far has proven to be
worth the price. If you are into Graphic Design and/or User Interface
Design it might be worth your time and money to check out this
magazine.
The July issue focused on MetaCreations, the company that was created
from the merger of MetaTools and Fractal Design. MetaTools founders
includeKai Krause, a unique designer and software architect, the man
responsible for the bold interfaces found in MetaTools products like
Soap and GOO. This issue also included very detailed shots of the
interface for Soap. It was while reading this issue and studying the
interface for Soap that I realized something basic: Multimedia
applications can look like anything you want. You just have to
understand a little about how Graphical Interfaces work and a lot
about creating graphical images.
Graphical Interfaces are simply programs which provide easily
recognizable displays that permit users to interact with the program.
These interfaces are event driven, meaning they sit in a loop waiting
for an event such as a mouse click or movement and then perform some
processing based on that event. There are two common ways to create
programs like this. You can use a application programming interface,
often referred to as an API, like Motif or OpenGL. Or you can use a
scripting interface like HTML with Java/JavaScript or VRML. Which
method you choose depends on the applications purpose and target
audience.
So, who is the target audience? My target audience for this column is
the multitudes of Linux users who want to do something besides run Web
servers. Your target audience will either be Linux/Unix users or
anyone with access to a computer no matter what platform they use. In
the first case you have a choice: you can use either the API's or you
can make use of HTML/VRML and browser technology. If you are looking
for cross-platform support you will probably go with browser
technology. Note that a third alternative exists - native Java which
runs without the help of a browser - but that this is even newer than
browser technology. You'll have about a year to wait till Java can be
used easily across platforms. Browser technology, although a little
shakey in some ways, is already here.
In order to use an API for your multimedia application you need to
choose a widget set. A widget set is the part of the API that handles
windowing aspects for you. Motif has a widget set that provides 3D
buttons, scrollbars, and menus. Mutlimedia applications have higher
demands than this, however. The stock Motif API cannot handle
MPEG movies, sound, or even colored bitmaps. It must be used in
conjunction with OpenGL, MpegTV's library, the OSS sound interface and
the XPM library to provide a full multimedia development environment.
The advantage to the API method is control - the tools allow the
developer the ability to create applications that are much more
sophisticated and visually appealing than with browser based
solutions. An API solution, for example, can run in full screen mode
without a window manager frame, thus creating the illusion that it is
the only application running on the X server. In order to get the
effects you see in MetaTool's Soap you will need to create 2D and
3D pixmaps to be used in Motif label and button widgets. If you do
this you should turn off the border areas which are used to create
Motif's 3D button effects. You will also need to write special
callbacks (routines called based on an event which you specify) to
swap the pixmaps quickly in order to give the feeling of motion or
animation.
Even with the use of 3D pixmaps in Motif you still won't have the
interactivity you desire in your multimedia application. To add
rotating boxes and other 3D effects with which the user can interact
you will need to embed the OpenGL widget, available from the
MesaGL package, into your Motif program. By creating a number of
OpenGL capable windows you can provide greater 3D interactivity than
you can by simply swapping pixmaps in Motif labels and buttons. The
drawback here is that you will be required to write the code which
registers events within given areas of the OpenGL widget. This is not
a simple task, but it is not impossible. Using OpenGL with Motif is a
very powerful solution for multimedia applications, but it is not for
the faint of heart developer.
Using browser technology to create a multimedia application is a
little different. First, the browser will take care of the event
catching for you. You simply need to tell it what part of a page
accepts events, which events it should watch for and what to do when
that event happens. This is, conceptually, just like using the
API method. In reality, using a browser this way is much simpler
because the browser provides a layer of abstraction to simplify the
whole process. You identify what parts of the page accept input via
HTML markup using links, anchors, and forms and then use JavaScript's
onEvent style handlers, such as onClick or onMouseOver, to call an
event handler. Formatting your application is easier using the
HTML markup language than trying to design the interface using the
API. You can have non-rectangular regions in imagemaps, for example,
that accept user input. API's can also have non-rectangular regions,
but HTML only requires a single line of code to specify the region.
An API can use hundreds of lines of code.
-Top of next column-
[INLINE]
More Musings...
No other musings - what? This wasn't enough for you? <grin>
[INLINE]
Ok, since we know using API's can be complex, and because I'm going to
run out of room long before I can cover how to use an API to do a
multimedia application, lets look at creating an application using
browser technology.
Creating web pages is pretty easy. If you haven't had a chance yet,
take a look at Netscape 4.0. It includes a tool called the Page
Composer which allows for WYSIWYG creations of web pages. This column
was created using Page Composer. Web pages are not enough, of
course. We need graphics, animations and sound. Not to mention
interaction with files on disk.
Graphics, animations and sound can easily be embedded in a web page
with links. Your application will probably need to provide players
for any animations or sounds you provide unless you feel really
confident users will already have players. For animations on Linux
systems, other than animated GIFs which are supported natively in most
browsers these days, you can try xanim. Your installation process
will have to explain how to install the players. JavaScript does
permit you to query what players and plug-ins are available but
doesn't appear to give you the ability to automatically launch them
without having first registered them with the browser.
Sound can be added just like the graphics and animations. You simply
have links to the sound files. Not all Linux systems will have sound
available. You might want to consider writing a plug-in which checks
for the sound devices before trying to play sounds and having this
plug-in installed for your sound files. Security issues may prevent a
plug-in from opening a device file. You should check the Netscape
plug-in API to find out what files you can and cannot open.
You might be wondering how you can use a browser for a multimedia
application on a CD. Don't forget - both MSIE and Netscape allow you
to view HTML documents on the native system. On Netscape you can just
use something like file:/cdrom/start.html to open up the main page of
the application. Any links - sound, graphics, or animations - can be
displayed or played when the page is first loaded using JavaScript's
onLoad event handler. Graphics, animations, sound and Java applets do
not have to be served via a Web server to be viewed or run by the
browser. And JavaScript is embedded in the HTML page so it doesn't
require a Web server either. As long as you use relative links
(relative to the directory where your applications start page is
located) your users won't need access to a Web server to use your
HTML-based multimedia application.
Well, we've covered just about all the things you'll want to do in
your program except how to access files. Security in browsers and
with Java has traditionally been rather zealous - the systems were
secure by denying all access to your hard drives. Thats still the
case even with JavaScript 1.2. There are no real file I/O commands in
the JavaScript language. In order to place data in your application
you will need to place it all in static arrays embedded in JavaScript
code in a page. Fortunately you can place this data in separate files
and link to them when the page is loaded. To do this you would use
the SRC= attribute of the SCRIPT tag. Netscape 3.0 or later browsers
will read this and load the script file as if it were embedded at the
SCRIPT tag of the original page. This will not work for pre-3.0
browsers, some of the beta 4.0 browsers or (apparently) any of the
MSIE browsers.
The SCR attribute provides some level of control for maintaining your
data files, but it also means your data is in user readable files on
the CD. If you use Java applets instead you have the ability to
compile this data into an object file but you still don't have access
to your file system. It may be possible to read data from files using
plug-ins in order to perform some interactive operations but I'm not
familiar with the Netscape or MSIE plug-in API's and suspect they also
have some measure of security that may prevent this. Reading files
seems harmless enough, but there are reasons to disallow this
practice. There is a way to get read/write access to the users
filesystem from a JavaScript or Java application - certificates. This
is a new technology and I'm not that familiar with its use yet. The
Official Netscape JavaScript 1.2 Book describes certificates and how
to obtain and create them. I suggest taking a look at this book (at
the end of chapter 14) if you are interested in this.
As I reread this article I realize what is so crystal clear in my mind
now is probably still a muddy swamp to my readers. Don't fret.
I covered a lot of material in a rather short space. What you should
do is first pick a method - API or browsers. Then pick one part of
that method and start reading all you can about it. Personally,
I understand the API methods better since I'm a programmer by trade.
The browser technology is interesting in that it provides the User
Interface (UI) that is filled in by the developer with images and
sound. Abstrasting the UI in this manner is the future of
applications but its still in its early days of development. In
either case you still need an understanding of what each piece of the
puzzle does for you. The API method will give you more control and
access to databases without the need for servers (you can embed the
database code in the application). The browser method is easier to
prototype and develop but has limited access to the system for
security reasons. Either method can produce stunning effects, if you
understand how all the pieces fit together. And when you look at
MetaCreations products, like Soap and GOO, you can see the kinds of
effects that are possible.
[INLINE]
Resources The following links are just starting points for finding
more information about computer graphics and multimedia in general for
Linux systems. If you have some application specific information for
me, I'll add them to my other pages or you can contact the maintainer
of some other web site. I'll consider adding other general references
here, but application or site specific information needs to go into
one of the following general references and not listed here.
Linux Graphics mini-Howto
Unix Graphics Utilities
Linux Multimedia Page
Some of the Mailing Lists and Newsgroups I keep an eye on and where I
get alot of the information in this column:
The Gimp User and Gimp Developer Mailing Lists.
The IRTC-L discussion list
comp.graphics.rendering.raytracing
comp.graphics.rendering.renderman
comp.graphics.api.opengl
comp.os.linux.announce [INLINE]
Future Directions
Next month:
* Web Wonderings - Adding JavaScript Rollovers to simulate dynamic
images
* My SIGGRAPH notes, if I can get my notebook running again.
* Maybe a look at libgr, if I have time.
Let me know what you'd like to hear about!
_________________________________________________________________
Copyright © 1997, Michael J. Hammel
Published in Issue 22 of the Linux Gazette, August 1997
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[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Linux Benchmarking - Concepts
by Andrй D. Balsa andrewbalsa@usa.net
With corrections and contributions by Uwe F. Mayer mayer@math.vanderbilt.edu
and David C. Niemi bench@wauug.erols.com
_________________________________________________________________
This is the first article in a series of 4 articles on Linux
Benchmarking, to be published by the Linux Gazette. This article deals
with the fundamental concepts in computer benchmarking, as they apply
to the Linux OS. An example of a classic benchmark, "Whetstone", is
analyzed in more detail.
_________________________________________________________________
1. Basic concepts and definitions
* 1.1 Benchmark
* 1.2 Benchmark results
* 1.3 Index figures
* 1.4 Performance metrics
* 1.5 Elapsed wall-clock time vs. CPU time
* 1.6 Resolution and precision
* 1.7 Synthetic benchmark
* 1.8 Application benchmark
* 1.9 Relevance
2. A variety of benchmarks
3. FPU tests: Whetstone and Sons, Ltd.
* 3.1 Whetstone history and general features
* 3.2 Getting the source and compiling it
* 3.3 Running Whetstone and gathering results
* 3.4 Examining the source code, the object code and interpreting
the results
4. References
_________________________________________________________________
1. Basic concepts and definitions
1.1 Benchmark
A benchmark is a documented procedure that will measure the time
needed by a computer system to execute a well-defined computing task.
It is assumed that this time is related to the performance of the
computer system and that someh ow the same procedure can be applied to
other systems, so that comparisons can be made between different
hardware/software configurations.
1.2 Benchmark results
From the definition of a benchmark, one can easily deduce that there
are two basic procedures for benchmarking:
1. Measuring the time it takes for the system being examined to loop
through a fixed number of iterations of a specific piece of code.
2. Measuring the number of iterations of a specific piece of code
executed by the system under examination in a fixed amount of
time.
If a single iteration of our test code takes a long time to execute,
procedure 1 will be preferred. On the other hand, if the system being
tested is able to execute thousands of iterations of our test code per
second, procedure 2 should be chosen.
Both procedures 1 and 2 will yield final results in the form
"seconds/iteration" or "iterations/second" (these two forms are
interchangeable). One could imagine other algorithms, e.g.
self-modifying code or measuring the time needed to reach a steady s
tate of some sort, but this would increase the complexity of the code
and produce results that would probably be next to impossible to
analyze and compare.
1.3 Index figures
Sometimes, figures obtained from standard benchmarks on a system being
tested are compared with the results obtained on a reference machine.
The reference machine's results are called the baseline results. If we
divide the results of the system under examination by the baseline
results, we obtain a performance index. Obviously, the performance
index for the reference machine is 1.0. An index has no units, it is
just a relative measurement.
1.4 Performance metrics
The final result of any benchmarking procedure is always a set of
numerical results which we can call speed or performance (for that
particular aspect of our system effectively tested by the piece of
code).
Under certain conditions we can combine results from similar tests or
various indices into a single figure, and the term metric will be used
to describe the "units" of performance for this benchmarking mix.
1.5 Elapsed wall-clock time vs. CPU time
Time measurements for benchmarking purposes are usually taken by
defining a starting time and an ending time, the difference between
the two being the elapsed wall-clock time. Wall-clock means we are not
considering just CPU time, but the "real" time usually provided by an
internal asynchronous real-time clock source in the computer or an
external clock source (your wrist-watch for example). Some tests,
however, make use of CPU time: the time effectively spent by the CPU
of the system being test ed in running the specific benchmark, and not
other OS routines.
1.6 Resolution and precision
Resolution and precision both measure the information provided by a
data point, but should not be confused.
Resolution is the minimum time interval that can be (easily) measured
on a given system. In Linux running on i386 architectures I believe
this is 1/100 of a second, provided by the GNU C system library
function times (see /usr/include/time .h - not very clear, BTW).
Another term used with the same meaning is "granularity". David C.
Niemi has developed an interesting technique to lower granularity to
very low (sub-millisecond) levels on Linux systems, I hope he will
contribute an explanation of his algorithm in the next article.
Precision is a measure of the total variability in the results for any
given benchmark. Computers are deterministic systems and should always
provide the same, identical benchmark results if running under
identical conditions. However, since Linux is a multi-tasking,
multi-user system, some tasks will be running in the background and
will eventually influence the benchmark results.
This "random" error can be expressed as a time measurement (e.g. 20
seconds + or - 0.2 s) or as a percentage of the figure obtained by the
benchmark considered (e.g. 20 seconds + or - 1%). Other terms
sometimes used to describe variations in results ar e "variance",
"noise", or "jitter".
Note that whereas resolution is system dependent, precision is a
characteristic of each benchmark. Ideally, a well-designed benchmark
will have a precision smaller than or equal to the resolution of the
system being tested. It is very important to iden tify the sources of
noise for any particular benchmark, since this provides an indication
of possibly erroneous results.
1.7 Synthetic benchmark
A program or program suite specifically designed to measure the
performance of a subsystem (hardware, software, or a combination of
both). Whetstone is an example of a synthetic benchmark.
1.8 Application benchmark
A commonly executed application is chosen and the time to execute a
given task with this application is used as a benchmark. Application
benchmarks try to measure the performance of computer systems for some
category of real-world computing task. Measu ring the time your Linux
box takes to compile the kernel can be considered as a sort of
application benchmark.
1.9 Relevance
A benchmark or its results are said to be irrelevant when they fail to
effectively measure the performance characteristic the benchmark was
designed for. Conversely, benchmark results are said to be relevant
when they allow an accurate prediction of re al-life performance or
meaningful comparisons between different systems.
_________________________________________________________________
_________________________________________________________________
2. A variety of benchmarks
The performance of a Linux system may be measured by all sorts of
different benchmarks:
1. Kernel compilation performance.
2. FPU performance.
3. Integer math performance.
4. Memory access performance.
5. Disk I/O performance.
6. Ethernet I/O performance.
7. File I/O performance.
8. Web server performance.
9. Doom performance.
10. Quake performance.
11. X graphics performance.
12. 3D rendering performance.
13. SQL server performance.
14. Real-time performance.
15. Matrix performance.
16. Vector performance.
17. File server (NFS) performance.
Etc...
* Conclusion I: it's obvious that no single benchmark can provide
results for all the above items.
* Conclusion II: you must first decide what you are trying to
measure, then choose an appropriate benchmark (or write your own).
* Conclusion III: it's impossible to come up with a single figure
(called Single Figure of Merit in benchmarking terminology) that
will summarize the performance of a Linux system. Hence, no
"Lhinuxstone" metric exists.
* Conclusion IV: benchmarking always takes more time than you
thought it would.
_________________________________________________________________
3. FPU tests: Whetstone and Sons, Ltd.
Floating-point (FP) instructions are among the least used while
running Linux. They probably represent < 0.001% of the instructions
executed on an average Linux box, unless one deals with scientific
computations. Besides, if you really want to know how well designed
the FPU in your processor is, it's easier to have a look at its data
sheet and check how many clock cycles it takes to execute a given FPU
instruction. But there are more benchmarks that measure FPU
performance than anything else. Why ?
1. RISC, pipelining, simultaneous issuing of instructions,
speculative execution and various other CPU design tricks make the
CPU performance, specially FPU performance, difficult to measure
directly and simply. The execution time of an FPU instruction
varies depending on the data, and a continuous stream of FPU
instructions will execute under special circumstances that make
direct predictions of performance impossible in most cases.
Simulations (synthetic benchmarks) are needed.
2. FPU tests are easier to write than other benchmarks. Just put a
bunch of FP instructions together and make a loop: voilа !
3. The Whetstone benchmark is widely (and freely) available in Basic,
C and Fortran versions, in case you don't want to write your own
FPU test.
4. FPU figures look good for marketing purposes. Here is what Dave
Sill, the author of the comp.benchmarks FAQ, has to say about
MFLOPS: "Millions of Floating Point Operations Per Second.
Supposedly the rate at which the system can execute floating point
instructions. Varies widely between different benchmarks and
different configurations of the same benchmarks. Popular with
marketing types because it's sounds like a "hard" value like miles
per hour, and represents a simple concept."
5. If you are going to buy a Cray, you'd better have an excuse for
it.
6. You can't get a data sheet for the Cray (or don't believe the
numbers), but still want to know its FP performance.
7. You want to keep your CPU busy doing all sorts of useless FP
calculations, and want to check that the chip gets very hot.
8. You want to discover the next big bug in the FPU of your
processor, and get rich speculating with the manufacturer's
shares.
Etc...
3.1 Whetstone history and general features
The original Whetstone benchmark was designed in the 60's by Brian
Wichmann at the National Physical Laboratory, in England, as a test
for an ALGOL 60 compiler for a hypothetical machine. The compilation
system was named after the small town of Whetstone, where it was
designed, and the name seems to have stuck to the benchmark itself.
The first practical implementation of the Whetstone benchmark was
written by Harold Curnow in FORTRAN in 1972 (Curnow and Wichmann
together published a paper on the Whetstone benchmark in 1976 for The
Computer Journal). Historically it is the first major synthetic
benchmark. It is designed to measure the execution speed of a variety
of FP instructions (+, *, sin, cos, atan, sqrt, log, exp) on scalar
and vector data, but also contains some integer code. Results are
provided in MWIPS (Millions of Whetstone Instructions Per Second). The
meaning of the expression "Whetstone Instructions" is not clear,
though, at least after close examination of the C source code.
During the late 80's and early 90's it was recognized that Whetstone
would not adequately measure the FP performance of parallel
multiprocessor supercomputers (e.g. Cray and other mainframes
dedicated to scientific computations). This spawned the development of
various modern benchmarks, many of them with names like Fhoostone, as
a humorous reference to Whetstone. Whetstone however is still widely
used, because it provides a very reasonable metric as a measure of
uniprocessor FP performance.
Whetstone has other interesting qualities for Linux users:
* Its source code is short and relatively easy to understand, with a
clean, self-explanatory structure.
* The C version compiles cleanly on Linux boxes with gcc.
* Execution time is short: 100 seconds (by design).
* It is very precise (small variations in the results).
* CPU architecture digression: for the Whetstone benchmark, the
object code that gets looped through is very small, fitting
entirely in the L1 cache of most modern processors, hence keeping
the FPU pipeline filled and the FPU permanently busy. This is
desirable because Whetstone is doing exactly what we want it to
do: measuring FPU performance, not CPU/L2 cache/main memory
coupling, integer performance or any other feature of the system
under test. Note however that David C. Niemi has provided some
conclusive evidence that at least some interaction with the L2
cache or main memory is taking place on Pentium (R) systems
(Pentium CPUs have a sophisticated FPU instruction pipeline and
can dispatch two FPU instructions on a single clock cycle. One
pipe can execute all integer and FP instructions, while the other
pipe can execute simple integer instructions and the FXCH FP
instructions. This is quoted from Intel's datasheet on the Pentium
processor, available at Intel's developers site). I wish somebody
with a Pentium ICE equipment could investigate this a little
further...
3.2 Getting the source and compiling it
Getting the standard C version by Roy Longbottom.
The version of the Whetstone benchmark that we are going to use for
this example was slightly modified by Al Aburto and can be downloaded
from his excellent FTP site dedicated to benchmarks. After downloading
the file whets.c, you will have to edit slightly the source: a)
Uncomment the "#define POSIX1" directive (this enables the Linux
compatible timer routine). b) Uncomment the "#define DP" directive
(since we are only interested in the Double Precision results).
Compiling
This benchmark is extremely sensitive to compiler optimization
options. Here is the line I used to compile it: cc whets.c -o whets
-O2 -fomit-frame-pointer -ffast-math -fforce-addr -fforce-mem -m486
-lm.
Note that some compiler options of some versions of gcc are buggy,
most notably one of -O, -O2, -O3, ... together with -funroll-loops can
cause gcc to emit incorrect code on a Linux box. You can test your gcc
with a short test program available at Uwe Mayer's site. Of course, if
your compiler is buggy, then any test results are not written in
stone, to say the least (pun intended). In short, don't use
-funroll-loops to compile this benchmark, and try to stick to the
optimization options listed above.
3.3 Running Whetstone and gathering results
First runs
Just execute whets. Whetstone will display its results on standard
output and also write a whets.res file if you give it the information
it requests. Run it a few times to confirm that variations in the
results are very small.
With L1, L2 or both L1 and L2 caches disabled
Some motherboards allow you to disable the L1 (internal) or L2
(external) caches through the BIOS configuration menus (take a look at
the motherboard's manual; the ASUS P55T2P4 motherboard, for example,
allows disabling both caches separately or together). You may want to
experiment with these settings and/or main memory (DRAM) timing
settings.
Without optimization
You can try to compile whets.c without any special optimization
options, just to verify that compiler quality and compiler
optimization options do influence benchmark results.
3.4 Examining the source code, the object code and interpreting the results
General program structure
The Whetstone benchmark main loop executes in a few milliseconds on an
average modern machine, so its designers decided to provide a
calibration procedure that will first execute 1 pass, then 5, then 25
passes, etc... until the calibration takes more than 2 seconds, and
then guess a number of passes xtra that will result in an approximate
running time of 100 seconds. It will then execute xtra passes of each
one of the 8 sections of the main loop, measure the running time for
each (for a total running time very near to 100 seconds) and calculate
a rating in MWIPS, the Whetstone metric. This is an interesting
variation in the two basic procedures described in Section 1.
Main loop
The main loop consists of 8 sections each containing a mix of various
instructions representative of some type of computational task. Each
section is itself a very short, very small loop, and has its own
timing calculation. The code that gets looped through for section 8
for example is a single line of C code:
x = sqrt(exp(log(x)/t1); where x = 0.75 and t1=0.50000025, both
defined as doubles.
Executable code size, library calls
Compiling as specified above with gcc 2.7.2.1, the resulting ELF
executable whets is 13 096 bytes long on my system. It calls libc and
of course libm for the trigonometric and transcendental math
functions, but these should get compiled to very short executable code
sequences since all modern CPUs have FPUs with these functions
wired-in.
General comments
Now that we have an FPU performance figure for our machine, the next
step is comparing it to other CPUs. Have you noticed all the data that
whets.c asked you after you had run it for the first time? Well, Al
Aburto has collected Whetstone results for your convenience at his
site, you may want to download the data file and have a look at it.
This kind of benchmarking data repository is very important, because
it allows comparisons between various different machines. More on this
topic in one of my next articles.
Whetstone is not a Linux specific test, it's not even an OS specific
test, but it certainly is a good test for the FPU in your Linux box,
and also gives an indication of compiler efficiency for specific kinds
of applications that involve FP calculations.
I hope this gave you a taste of what benchmarking is all about.
_________________________________________________________________
4. References
Other references for benchmarking terminology:
* The comp.benchmarks FAQ by Dave Sill.
* The On-Line Computing Dictionary.
* The Linux Benchmarking HOWTO available from the LDP site and
mirrors.
_________________________________________________________________
Copyright © 1997, Andrй D. Balsa
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
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_________________________________________________________________
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Word Processing and Text Processing
by Larry Ayers
_________________________________________________________________
One of the most common questions posted in the various Linux
newsgroups is "Where can I find a good word-processor for Linux?".
This question has several interesting ramifications:
* There is an unspoken assumption that a word processor is a vital
application for an operating system.
* The query implies that the questioner has investigated the text
processing capabilities readily available for Linux and has either
found them too daunting to learn and/or not suited to the tasks at
hand, or...
* The questioner is a recent migrant from one of the commercial OS's
and is accustomed to a standard word processor.
_________________________________________________________________
Vital For Some...
A notion has become prevalent in the minds of many computer users
these days: the idea that a complex word processor is the only tool
suitable for creating text on a computer. I've talked with several
people who think of an editor as a primitive relic of the bad old DOS
days, a type of software which has been superseded by the modern
word-processor. There is an element of truth to this, especially in a
business environment in which even the simplest memos are distributed
in one of several proprietary word-processor formats. But when it is
unnecessary to use one of these formats, a good text editor has more
power to manipulate text and is faster and more responsive.
The ASCII format, intended to be a universal means of representing and
transferring text, does have several limitations. The fonts used are
determined by the terminal type and capability rather than by the
application, normally a fixed, monospace font. These limitations in
one sense are virtues, though, as this least-common-denominator
approach to representing text assures readability by everyone on all
platforms. This is why ASCII is still the core format of e-mail and
usenet messages, though there is a tendency in the large software
firms to promote HTML as a replacement. Unfortunately, HTML can now be
written so that it is essentially unreadable by anything other than a
modern graphical browser. Of course, HTML is ASCII-based as well, but
is meant to be interpreted or parsed rather than read directly.
Working with ASCII text directly has many advantages. The output is
compact and easily stored, and separating the final formatting from
actual writing allows the writer to focus on content rather than
appearance. An ASCII document is not dependent on one application; the
simplest of editors or even cat can access its content. There is an
interesting parallel, perhaps coincidental, between the Unix use of
ASCII and other OS's use of binary formats. All configuration files in
a Linux or any Unix system are generally in plain ASCII format:
compact,editable, and easily backed-up or transferred. Many
programmers use Linux; source code is written in ASCII format, so
perhaps using the format for other forms of text is a natural
progression. The main configuration files for Win95, NT and OS/2 are
in binary format, easily corruptible and not easily edited. Perhaps
this is one reason users of these systems tend towards proprietary
word-processing formats which, while not necessarily in binary format,
aren't readable by ASCII-based editors or even other word-processors.
But I digress...
There are several methods of producing professional-looking printable
documents from ASCII input, the most popular being LaTeX, Lout, and
Groff.
_________________________________________________________________
Text Formatting with Mark-Up Languages
LaTeX
LaTeX, Leslie Lamport's macro package for the TeX low-level formatting
system, is widely used in the academic world. It has become a
standard, and has been refined to the point that bugs are rare. Its
ability to represent mathematical equations is unparalleled, but this
very fact has deterred some potential users. Mentioning LaTeX to
people will often elicit a response such as: "Isn't that mainly used
by scientists and mathematicians? I have no need to include equations
in my writing, so why should I use it?" A full-featured word-processor
(such as WordPerfect) also includes an equation editor, but (as with
LaTeX) just because a feature exists doesn't mean you have to use it.
LaTeX is well-suited to creating a wide variety of documents, from a
simple business letter to articles, reports or full-length books. A
wealth of documentation is available, including documents bundled with
the distribution as well as those available on the internet. A good
source is this ftp site, which is a mirror of CTAN, the largest
on-line repository of TeX and LaTeX material.
LaTeX is easily installed from any Linux distribution, and in my
experience works well "out of the box". Hardened LaTeX users type the
formatting tagging directly, but there are several alternative
approaches which can expedite the process, especially for novices.
There is quite a learning curve involved in learning LaTeX from
scratch, but using an intermediary interface will allow the immediate
creation of usable documents by a beginner.
AucTeX is a package for either GNU Emacs or XEmacs which has a
multitude of useful features helpful in writing LaTeX documents. Not
only does the package provide hot-keys and menu-items for tags and
environments, but it also allows easy movement through the document.
You can run LaTeX or TeX interactively from Emacs, and even view the
resulting output DVI file with xdvi. Emacs provides excellent syntax
highlighting for LaTeX files, which greatly improves their
readability. In effect AucTeX turns Emacs into a "front-end" for
LaTeX. If you don't like the overhead incurred when running Emacs or
especially XEmacs, John Davis' Jed and Xjed editors have a very
functional LaTeX/TeX mode which is patterned after AucTeX. The
console-mode Jed editor does syntax-highlighting of TeX files well
without extensive fiddling with config files, which is rare in a
console editor.
If you don't use Emacs or its variants there is a Tcl/Tk based
front-end for LaTeX available called xtem. It can be set up to use any
editor; the September 1996 issue of Linux Journal has a good
introductory article on the package. Xtem has one feature which is
useful for LaTeX beginners: on-line syntax help-files for the various
LaTeX commands. The homepage for the package can be visited if you're
interested.
It is fairly easy to produce documents if the default formats included
with a TeX installation are used; more knowledge is needed to produce
customized formats. Luckily TeX has a large base of users, many of
whom have contributed a variety of style-formatting packages, some of
which are included in the distribution, while others are freely
available from TeX archive sites such as CTAN.
At a further remove from raw LaTeX is the LyX document processor. This
program (still under development, but very usable) at first seems to
be a WYSIWYG interface for LaTeX, but this isn't quite true. The text
you type doesn't have visible LaTeX tagging, but it is formatted to
fit the window on your screen which doesn't necessarily reflect the
document's appearance when printed or viewed with GV or Ghostscript.
In other words, the appearance of the text you type is just a user
convenience. There are several things which can be done with a
document typed in LyX. You can let LyX handle the entire LaTeX
conversion process with a DVI or Postscript file as a result, which is
similar to using a word-processor. I don't like to do it this way; one
of the reasons I use Linux is because I'm interested in the underlying
processes and how they work, and Linux is transparent. If I'm curious
as to how something is happening in a Linux session I can satisfy that
curiosity to whatever depth I like. Another option LyX offers is more
to my taste: LyX can convert the document's format from the
LaTeX-derived internal format to standard LaTeX, which is readable and
can be loaded into an editor.
Load a LyX-created LaTeX file into an Emacs/Auctex session (if you
have AucTeX set up right it will be called whenever a file with the
.tex suffix is loaded), and your document will be displayed with new
LaTeX tags interspersed throughout the text. The syntax-highlighting
can make the text easier to read if you have font-locking set up to
give a subdued color to the tagging (backslashes (\) and $ signs).
This is an effective way to learn something about how LaTeX documents
are written. Changes can be made from within the editor and you can
let AucTeX call the LaTeX program to format the document, or you can
continue with LyX. In effect this is using LyX as a preprocessor for
AucTeX. This expands the user's options; if you are having trouble
convincing LyX to do what you want, perhaps AucTeX can do it more
easily.
Like many Linux software projects LyX is still in a state of flux. The
release of beta version 0.12 is imminent; after that release the
developers are planning to switch to another GUI toolkit (the current
versions use the XForms toolkit). The 0.11.38 version I've been using
has been working dependably for me (hint: if it won't compile, give
the configure script the switch --disable-nls. This disables the
internationalization support).
_________________________________________________________________
YODL
YODL (Yet One-Other Document Language) is another way of interacting
with LaTeX. This system has a simplified tagging format which isn't
hard to learn. The advantage of YODL is that from one set of marked-up
source documents, output can be generated in LaTeX, HTML, and Groff
man and ms formats. The package is well-documented. I wrote a short
introduction to YODL in issue #9 of the Gazette. The current source
for the package is this ftp site.
_________________________________________________________________
Lout
About thirteen years ago Jeffrey Kingston (of the University of
Sydney, Australia) began to develop a document formatting system which
became known as Lout. This system bears quite a bit of resemblance to
LaTeX: it uses formatting tags (using the @ symbol rather than \) and
its output is Postscript. Mr. Kingston calls Lout a high-level
language with some similarities to Algol, and claims that user
extensions and modifications are much easier to implement than in
LaTeX. The package comes with hundreds of pages of Postscript
documentation along with the Lout source files which were used to
generate those book-length documents.
The Lout system is still maintained and developed, and in my trials
seemed to work well, but there are some drawbacks. I'm sure Lout has
nowhere near as many users as LaTeX. LaTeX is installed on enough
machines that if you should want to e-mail a TeX file to someone
(especially someone in academia) chances are that that person will
have access to a machine with Tex installed and will be able to format
and print or view it. LaTeX's large user-base also has resulted in a
multitude of contributed formatting packages.
Another drawback (for me, at least) is the lack of available
front-ends or editor-macro packages for Lout. I don't mind using
markup languages if I can use, say, an Emacs mode with key-bindings
and highlighting set up for the language. There may be such packages
out there for Lout, but I haven't run across them.
Lout does have the advantage of being much more compact than a typical
Tex installation. If you have little use for some of the more esoteric
aspects of LaTeX, Lout might be just the thing. It can include tables,
various types of lists, graphics, foot- and marginal notes, and
equations in a document, and the Postscript output is the equal of
what LaTeX generates.
Both RedHat and Debian have Lout packages available, and the
source/documentation package is available from the Lout home FTP site.
_________________________________________________________________
Groff
Groff is an older system than TeX/LaTeX, dating back to the early days
of unix. Often a first-time Linux user will neglect to install the
Groff package, only to find that the man command won't work and that
the man-pages are therefore inaccessible. As well as in day-to-day
invocation by the man command, Groff is used in the publishing
industry to produce books, though other formatting systems such as
SGML are more common.
Groff is the epitome of the non-user-friendly and cryptic unix
command-line tool. There are several man-pages covering various of
Groff's components, but they seem to assume a level of prior knowledge
without any hint as to where that knowledge might be acquired. I found
them to be nearly incomprehensible. A search on the internet didn't
turn up any introductory documents or tutorials, though there may be
some out there. I suspect more complete documentation might be
supplied with some of the commercial unix implementations; the
original and now-proprietary version is called troff, and a later
version is nroff; Groff is short for GNU roff.
Groff can generate Postscript, DVI, HP LaserJet4, and ASCII text
formats.
Learning to use Groff on a Linux system might be an uphill battle,
though Linux software developers must have learned enough of it at one
time or other, as most programs come with Groff-tagged man-page files.
Groff's apparent opacity and difficulty make LaTeX look easy in
contrast!
_________________________________________________________________
A Change in Mind-Set
Processing text with a mark-up language requires a different mode of
thought concerning documents. On the one hand, writing blocks of ASCII
is convenient and no thought needs to be given to the marking-up
process until the end. A good editor provides so many features to deal
with text that using any word-processor afterwards can feel
constrictive. Many users, though, are attracted by the integration of
functions in a word processor, using one application to produce a
document without intermediary steps.
Though there are projects underway (such as Wurd) which may eventually
result in a native Linux word-processor, there may be a reason why
this type of application is still rare in the Linux world. Adapting
oneself to Linux, or any unix-variant, is an adaptation to what has
been called "the Unix philosophy", the practice of using several
highly-refined and specific tools to accomplish a task, rather than
one tool which tries to do it all. I get the impression that
programmers attracted to free software projects prefer working on
smaller specialized programs. As an example look at the plethora of
mail- and news-readers available compared to the dearth of all-in-one
internet applications. Linux itself is really just the kernel, which
has attracted to itself all of the GNU and other software commonly
distributed with it in the form of a distribution.
Christopher B. Browne has written an essay titled An Opinionated Rant
About Word-Processors which deals with some of the issues discussed in
this article; it's available at this site.
The StarOffice suite is an interesting case, one of the few instances
of a large software firm (StarDivision) releasing a Linux version of
an office productivity suite. The package has been available for some
time now, first in several time-limited beta versions and now in a
freely available release. It's a large download but it's also
available on CDROM from Caldera. You would think that users would be
flocking to it if the demand is really that high for such an
application suite for Linux. Judging by the relatively sparse usenet
postings I've seen, StarOffice hasn't exactly swept the Linux world by
storm. I can think of a few possible reasons:
* Many hard-core Linux users aren't working in a corporate office
setting in which such a product would be valuable; they are
scientists, engineers or academics who are perfectly happy with
LaTeX, Lout, Groff, et al.
* Then there are the users who have dual or multiple-boot set-ups;
if they need to use MS Word they just boot from their Win95 or NT
partitions.
* Another group of users run Linux at home and whatever OS their job
requires at work.
* StarOffice is written with a cross-platform development tool-kit;
this may be responsible for its bulk and lack of speed.
_________________________________________________________________
I remember the first time I started up the StarOffice word-processor.
It was slow to load on a Pentium 120 with 32 mb. of RAM (and I thought
XEmacs was slow!), and once the main window appeared it occurred to me
that it just didn't look "at home" on a Linux desktop. All those icons
and button-bars! It seemed to work well, but with the lack of English
documentation (and not being able to convince it to print anything!) I
eventually lost interest in using it. I realized that I prefer my
familiar editors, and learning a little LaTeX seemed to be easier than
trying to puzzle out the workings of an undocumented suite of
programs. This may sound pretty negative, and I don't wish to
denigrate the efforts of the StarDivision team responsible for the
Linux porting project. If you're a StarOffice user happy with the
suite (especially if you speak German and therefore can read the docs)
and would like to present a dissenting view, write a piece on it for
the Gazette!
Two other commercial word-processors for Linux are Applix and
WordPerfect. Applix, available from RedHat, has received favorable
reviews from many Linux users.
A company called SDCorp in Utah has ported Corel's WordPerfect 7 to
Linux, and a (huge!) demo is available now from both the SDCorp ftp
site and Corel's. Unfortunately both FTP servers are unable to resume
interrupted downloads (usually indicating an NT server) so the CDROM
version, available from the SDCorp website, is probably the way to go,
if you'd like to try it out. The demo can be transformed into a
registered program by paying for it, in which case a key is e-mailed
to you which registers the program, but only for the machine it is
installed on.
Addendum: I recently had an exchange of e-mail with Brad Caldwell,
product manager for the SDCorp WordPerfect port. I complained about
the difficulty of downloading the 36 mb. demo, and a couple of days
later I was informed that the file has been split into nine parts, and
that they were investigating the possibility of changing to an FTP
server which supports interrupted downloads. The smaller files are
available from this web page.
_________________________________________________________________
There exists a curious dichotomous attitude these days in the Linux
community. I assume most people involved with Linux would like the
operating system to gain more users and perhaps move a little closer
to the mainstream. Linux advocates bemoan the relative lack of
"productivity apps" for Linux, which would make the OS more acceptable
in corporate or business environments. But how many of these advocates
would use the applications if they were more common? Often the change
of mindset discussed above mitigates against acceptance of
Windows-like programs, with no source code available and limited
access to the developers. Linux has strong roots in the GNU and free
software movements (not always synonymous) and this background might
be a barrier towards development of a thriving commercial software
market.
_________________________________________________________________
Copyright © 1997, Larry Ayers
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
GNU Emacs 20.1
by Larry Ayers
_________________________________________________________________
Introduction
Richard Stallman and the other members of the GNU Emacs development
team are a rather reticent group of programmers. Unlike many other
development projects in the free-software world, the Emacs beta
program is restricted to a closed group of testers, and news of what
progress is being made is scanty. In the past couple of months hints
found in various usenet postings seemed to intimate that a new release
of GNU Emacs was imminent, so every now and then I began to check the
GNU main FTP site on the off-chance that a release had been made.
Early on the morning of September 17 I made a quick check before
beginning my day's work, and there it was, a new Emacs 20.1 source
archive. As with all Emacs source packages, it was large (over 13
megabytes) so I began the download with NcFtp and left it running.
Building It
There is always a delay between the release of a new version of a
software package and the release of a Linux distribution's version,
such as a Debian or RedHat binary package. Even if you usually use
RPMs or *.deb releases (in many cases it's preferable) a source
release of a major team-developed piece of software such as GNU Emacs
will usually build easily on a reasonably up-to-date Linux machine.
The included installation instructions are clear: just run the
configure script, giving your machine-type and preferred installation
directory as switches. In my case, this command did the trick:
./configure i586-Debian-linux-gnu --prefix=/mt
The script will generate a Makefile tailored to your machine; make,
followed by make install and you're up and running.
_________________________________________________________________
So What's New?
It's been about a year since the last public GNU Emacs release, so
there have been quite a few changes. One of the largest is the
incorporation of the MULE (MUltiLingual Emacs) extensions, which give
Emacs the capability of displaying extended character sets necessary
for languages such as Chinese and Japanese. This won't be of interest
to most English-speaking users, but if you're interested the necessary
files are in a separate archive at the GNU site.
Here's a partial list of changes and updated packages:
* For some reason, the scroll-bar is now on the left, but it can be
changed back to its old position on the right with the new
Customize facility. Some day it would be nice if someone
implemented a real scrollbar for GNU Emacs, with the usual buttons
or arrows at top and bottom which allow smooth scrolling rather
than paging, but it seems this is a low priority for the
developers.
* Per Abrahamsen's Customize package is now thoroughly integrated
with the majority of the included LISP packages, allowing easy
customization of all sorts of options, with the results appended
to your ~.emacs file. This so much easier than hacking on the
.emacs file; I don't know how many times I've had a misplaced or
unbalanced parentheses, causing Emacs to quit loading the file and
giving me the dread message: Error in init file.
* Viper, CC-Mode, the GNUS newsreader, and many other extension
packages have been updated.
* The default values for many configuration parameters have been
changed to values more likely to be acceptable to most users, the
sort of thing which would be entered in an ~/.emacs file.
* The syntax-highlighting color default values are now sensitive to
whether you have a dark or light screen background; for the most
part the dark-background default colors are readable, with enough
contrast.
* The text-filling commands now handle indented and bulleted
paragraphs more effectively.
* The word Emacs no longer is shown in the mode-line, allowing more
room for line and column numbers, mode specifications, time of
day, etc.
* For programmers, there are new commands for looking up symbols or
files in the Info documentation files. As an example, in C mode
the GNU libc Info files would be searched for a reference to the
symbol or file at the cursor position in the current buffer.
* Another programmer's feature: Alt-tab (with a numeric argument)
will now perform completion on a symbol name in the current
buffer, using Info files as above.
* The main /lisp directory has been subdivided into several
sub-directories, which makes individual files much easier to find.
Have you ever been puzzled or annoyed by the peculiar way the Emacs
screen scrolls when using the up- or down- arrow keys? It's a jerky
scroll, difficult for the eye to follow, which could only be partially
alleviated by setting scroll-step to a small value. In 20.1 this has
been changed, so that if you set scroll-step to 2 (setq scroll-step 2)
the screen actually scrolls up and down smoothly, without the
disorienting jerks. This feature alone makes the upgrade worthwhile!
Another Emacs quirk has been addressed with a new variable,
scroll-preserve-screen-position. This variable, if set to t (which
means "yes"), will allow the user to page-up and page-down and then
returns the cursor to its original position when the starting page is
shown again. I really like this. With the default behavior you have to
find the cursor on the screen and manually move it back to where it
was. This variable can be enabled with the line
(setq scroll-preserve-screen-position t)
entered into your ~.emacs init file.
_________________________________________________________________
The Customization Utility
What a labor-saver! Rather than searching for the documentation which
deals with altering one of Emacs' default settings, the user is
presented with a mouse-enabled screen from which changes can be made,
either for the current session or permanently, in which case the
changes are recorded in the user's ~.emacs file. It appears that a
tremendous amount of work went into including the customization
framework in the LISP files for Emacs' countless modes and add-on
packages. A Customize screen can be summoned from the Help menu; the
entries are in a cascading hierarchy, allowing an easy choice of the
precise category a user might want to tweak. Here's a screenshot of a
typical Customization screen:
Customizing screen
_________________________________________________________________
Per Abrahamsen is to be congratulated for writing this useful utility,
and for making it effective both for XEmacs and GNU Emacs users.
_________________________________________________________________
Musings
Emacs used to be thought of as a hefty, memory-intensive editor which
tended to strain a computer's resources. Remember the old
mock-acronym, Eight Megabytes And Constantly Swapping? These days it
seems that the hardware has caught up with Emacs; today a mid-range
machine can run Emacs easily, even with other applications running
concurrently. Memory and hard-disk storage have become less expensive
which makes Emacs usable for more people.
Some people are put off by the multiple keystrokes for even the most
common commands. It's easy to rebind the keys, though. The function
keys are handy, as they aren't in use by other Emacs commands. As
examples, I have F1 bound to Kill-Buffer, F2 bound to Ispell-Word
(which checks the spelling of the word under the cursor), F3 and F4
put the cursor at the beginning or end of the current file, and F7 is
bound to Save-Buffer. Of course, these operations are on the menu-bar,
but using the keyboard is quicker. If you are accustomed to a Vi-style
editor, the Viper package allows toggling between the familiar Vi
commands (which are extraordinarily quick, as most are a single
keystroke) and the Emacs command set. This emulation mode has been
extensively improved lately, and is well worth using.
Even with the exhaustively detailed Info files, the tutorial, etc. I
would hesitate to recommend Emacs for a novice Linux user. There is
enough to learn just becoming familiar with basic Linux commands
without having to learn Emacs as well. I think Nedit would be a more
appropriate choice for a new user familiar with Windows, OS/2, or the
Macintosh, since its mouse-based operation and menu structure are
reminiscent of editors from these operating systems.
Emacs has a way of growing on you; as your knowledge of its traits and
capabilities increases the editor gradually is molded to your
preferences and work habits. It is possible to use the editor at a
basic level, (using just the essential commands), but it's a waste to
run a large editor like Emacs without using at least some of its
manifold capabilities.
_________________________________________________________________
Copyright © 1997, Larry Ayers
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
A True "Notebook" Computer?
by Larry Ayers
_________________________________________________________________
Introduction
Recently I happened across an ingeniously designed add-on LISP package
for the GNU Emacs editor. It's called Notes-Mode, and it helps
organize and cross-reference notes by subject and date. It was written
by John Heidemann. Here's his account of how he happened to write the
package:
Briefly, I started keeping notes on-line shortly after I got a
portable computer in January, 1994. After a month-and-a-half of
notes, I realized that one does not live by grep alone, so I
started adding indexing facilities. In June of 1995 some other
Ficus-project members started keeping and indexing on-line notes
using other home-grown systems. After some discussion, we
generalized my notes-mode work and they started using it. Over the
next 18 months notes-mode grew. Finally, in April, 1996 I wrote
documentation, guaranteeing that innovation on notes-mode will now
cease or the documentation will become out of date.
_________________________________________________________________
Using Notes-Mode
Here's what one of my smaller notes files looks like:
_________________________________________________________________
25-Jul-97 Friday
----------------
* Today
-------
prev: <file:///~/notes/199707/970724#* Today>
next: <file:///~/notes/199707/970728#* Today>
* Prairie Plants
----------------
prev: <file:///~/notes/199707/970724#* Prairie Plants>
next: <none>
So far the only results I've seen in response to the various desultory
efforts I've made to direct-seed prairie plants in the west prairie:
1: Several rattlesnake-master plants in a spot where we burned a
brush-pile. Two are blooming this summer. 2: One new-england aster
near the above. There are probably others which are small and haven't
flowered yet. * Linux Notes ------------- prev:
<file:///~/notes/199707/970724#* Linux Notes> next:
<file:///~/notes/199708/970804#* Linux Notes> I noticed today that a
new version of e2compress was available, and I've patched the 2.0.30
kernel source but haven't compiled it yet. I've been experimenting
with the color-syntax-highlighting version of nedit 4.03 lately; it
has a nifty dialog-box interface for creating and modifying modes.
Easier than LISP!
_________________________________________________________________
The first entry,Today, contains nothing; it just serves as a link to
move from the current notes file to either the previous day's file or
the next day's. Any other word preceded by an asterisk and a space
will serve as a hyper-link to previous or next entries with the same
subject. Type in a new (or previously-used) subject with the asterisk
and space, press enter, and the dashed line and space will
automatically be entered into the file; this format is what the Perl
indexing script uses to identify discrete entries.
While in Emacs with a notes-mode file loaded, several keyboard
commands allow you to navigate between successive entries, either by
day or by subject, depending on where the cursor is when the keystroke
is executed. A handy key-binding for notes-mode is Control-c n, which
will initialize a new notes file for the day if the following LISP
code is entered into your ~.emacs file:
(define-key global-map "^Cn" 'notes-index-todays-link). The "^C" part
is entered into the file by entering Control-q Control-c.
When Notes-Mode is installed a subdirectory is created in your home
directory called Notes. As you use the mode a subdirectory for each
month is created as well as a subdirectory under each month's
directory for each week in the month. The individual note files, one
for each day the mode is used, are given numerical names; the format
of the path and filename can be seen in the above example.
The ability to navigate among your notes is enabled by means of a Perl
script called mkall, which is intended to be run daily by cron. Mkall
in turn calls other Perl scripts which update the index file with
entries for any new notes you may have made. This system works well,
making good use of Linux's automation facilities. Once you have it set
up you never have to think about it again.
While this mode is designed for an academic environment in which
voluminous notes are taken on a variety of subjects, it can also be
useful for anyone who wants to keep track of on-line notes. It could
even be used as a means of organizing diary or journal entries. The
only disadvantage I've seen is that, though the notes-files are ASCII
text readable by any editor, the navigation and hyper-linking features
are only available from within Emacs. This is fine if you use Emacs as
your main editor but makes the package not too useful for anyone else.
XEmacs users are out of luck as well, as the package doesn't work
"out-of-the-box" with XEmacs. I imagine a skilled LISP hacker could
modify Notes-Mode for XEmacs; I've made some tentative attempts but
without success.
Availability
The only source I've seen for this package is from the author's web
page, at this URL:
http://gost.isi.edu/~johnh/SOFTWARE/NOTES_MODE/index.html
The documentation for Notes-Mode can be browsed on-line at this site
if you'd like to read more before trying it out.
_________________________________________________________________
Copyright © 1997, Larry Ayers
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next
_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Using m4 to write HTML.
By Bob Hepple bhepple@pacific.net.sg
_________________________________________________________________
Contents:
* 1. Some limitations of HTML
* 2. Using m4
* 3. Examples of m4 macros
* 3.1 Sharing HTML elements across several page
* 3.2 Managing HTML elements that often change
* 3.3 Creating new text styles
* 3.4 Typing and mnemonic aids
* 3.5 Automatic numbering
* 3.6 Automatic date stamping
* 3.7 Generating Tables of Contents
* 3.7.1 Simple to understand TOC
* 3.7.2 Simple to use TOC
* 3.8 Simple tables
* 4. m4 gotchas
* 4.1 Gotcha 1 - quotes
* 4.2 Gotcha 2 - Word swallowing
* 4.3 Gotcha 3 - Comments
* 4.4 Gotcha 4 - Debugging
* 5. Conclusion
* 6. Files to download
_________________________________________________________________
This page last updated on Thu Sep 18 22:46:54 HKT 1997
$Revision: 1.4 $
_________________________________________________________________
1. Some limitations of HTML
It's amazing how easy it is to write simple HTML pages - and the
availability of WYSIWYG HTML editors like NETSCAPE GOLD lulls one into
a mood of "don't worry, be happy". However, managing multiple,
interrelated pages of HTML rapidly gets very, very difficult. I
recently had a slightly complex set of pages to put together and it
started me thinking - "there has to be an easier way".
I immediately turned to the WWW and looked up all sorts of tools - but
quite honestly I was rather disappointed. Mostly, they were what I
would call Typing Aids - instead of having to remember arcane
incantations like <a href="link">text</a>, you are given a button or a
magic keychord like ALT-CTRL-j which remembers the syntax and does all
that nasty typing for you.
Linux to the rescue! HTML is built as ordinary text files and
therefore the normal Linux text management tools can be used. This
includes the revision control tools such as RCS and the text
manipulation tools like awk, perl, etc. These offer significant help
in version control and managing development by multiple users as well
as in automating the process of extracting from a database and
displaying the results (the classic "grep |sort |awk" pipeline).
The use of these tools with HTML is documented elsewhere, e.g. see Jim
Weinrich's article in Linux Journal Issue 36, April 1997, "Using Perl
to Check Web Links" which I'd highly recommend as yet another way to
really flex those Linux muscles when writing HTML.
What I will cover here is a little work I've done recently with using
m4 in maintaining HTML. The ideas can probably be extended to the more
general SGML case very easily.
Contents
2. Using m4
I decided to use m4 after looking at various other pre-processors
including cpp, the C front-end. While cpp is perhaps a little too
C-specific to be very useful with HTML, m4 is a very generic and clean
macro expansion program - and it's available under most Unices
including Linux.
Instead of editing *.html files, I create *.m4 files with my favourite
text editor. These look something like this:
m4_include(stdlib.m4)
_HEADER(`This is my header')
<P>This is some plain text<P>
_HEAD1(`This is a main heading')
<P>This is some more plain text<P>
_TRAILER
The format is simple - just HTML code but you can now include files
and add macros rather like in C. I use a convention that my new macros
are in capitals and start with "_" to make them stand out from HTML
language and to avoid name-space collisions.
The m4 file is then processed as follows to create an .html file e.g.
m4 -P <file.m4 >file.html
This is especially easy if you create a "makefile" to automate this in
the usual way. Something like:
.SUFFIXES: .m4 .html
.m4.html:
m4 -P $*.m4 >$*.html
default: index.html
*.html: stdlib.m4
all: default PROJECT1 PROJECT2
PROJECT1:
(cd project2; make all)
PROJECT2:
(cd project2; make all)
The most useful commands in m4 include the following which are very
similar to the cpp equivalents (shown in brackets):
m4_include:
includes a common file into your HTML (#include)
m4_define:
defines an m4 variable (#define)
m4_ifdef:
a conditional (#ifdef)
Some other commands which are useful are:
m4_changecom:
change the m4 comment character (normally #)
m4_debugmode:
control error disgnostics
m4_traceon/off:
turn tracing on and off
m4_dnl:
comment
m4_incr, m4_decr:
simple arithmetic
m4_eval:
more general arithmetic
m4_esyscmd:
execute a Linux command and use the output
m4_divert(i):
This is a little complicated, so skip on first reading. It is a
way of storing text for output at the end of normal processing
- it will come in useful later, when we get to automatic
numbering of headings. It sends output from m4 to a temporary
file number i. At the end of processing, any text which was
diverted is then output, in the order of the file number i.
File number -1 is the bit bucket and can be used to comment out
chunks of comments. File number 0 is the normal output stream.
Thus, for example, you can `m4_divert' text to file 1 and it
will only be output at the end.
Contents
3. Examples of m4 macros
3.1 Sharing HTML elements across several page
In many "nests" of HTML pages, each page shares elements such as a
button bar like this:
[Home] [Next] [Prev] [Index]
This is fairly easy to create in each page - the trouble is that if
you make a change in the "standard" button-bar then you then have the
tedious job of finding each occurance of it in every file and then
manually make the changes.
With m4 we can more easily do this by putting the shared elements into
an m4_include statement, just like C.
While I'm at it, I might as well also automate the naming of pages,
perhaps by putting the following into an include file, say
"button_bar.m4":
m4_define(`_BUTTON_BAR',
<a href="homepage.html">[Home]</a>
<a href="$1">[Next]</a>
<a href="$2">[Prev]</a>
<a href="indexpage.html">[Index]</a>)
and then in the document itself:
m4_include button_bar.m4
_BUTTON_BAR(`page_after_this.html',
`page_before_this.html')
The $1 and $2 parameters in the macro definition are replaced by the
strings in the macro call.
Contents
3.2 Managing HTML elements that often change
It is very troublesome to have items change in multiple HTML pages.
For example, if your email address changes then you will need to
change all references to the new address. Instead, with m4 you can do
something like this in your stdlib.m4 file:
m4_define(`_EMAIL_ADDRESS', `MyName@foo.bar.com')
and then just put _EMAIL_ADDRESS in your m4 files.
A more substantial example comes from building strings up with
multiple components, any of which may change as the page is developed.
If, like me, you develop on one machine, test out the page and then
upload to another machine with a totally different address then you
could use the m4_ifdef command in your stdlib.m4 file (just like the
#ifdef command in cpp):
m4_define(`_LOCAL')
.
.
m4_define(`_HOMEPAGE',
m4_ifdef(`_LOCAL', `//127.0.0.1/~YourAccount',
`http://ISP.com/~YourAccount'))
m4_define(`_PLUG', `<A REF="http://www.ssc.com/linux/">
<IMG SRC="_HOMEPAGE/gif/powered.gif"
ALT="[Linux Information]"> </A>')
Note the careful use of quotes to prevent the variable _LOCAL from
being expanded. _HOMEPAGE takes on different values according to
whether the variable _LOCAL is defined or not. This can then ripple
through the entire project as you make the pages.
In this example, _PLUG is a macro to advertise Linux. When you are
testing your pages, you use the local version of _HOMEPAGE. When you
are ready to upload, you can remove or comment out the _LOCAL
definition like this:
m4_dnl m4_define(`_LOCAL')
... and then re-make.
Contents
3.3 Creating new text styles
Styles built into HTML include things like <EM> for emphasis and
<CITE> for citations. With m4 you can define your own, new styles like
this:
m4_define(`_MYQUOTE',
<BLOCKQUOTE><EM>$1</EM></BLOCKQUOTE>)
If, later, you decide you prefer <STRONG> instead of <EM> it is a
simple matter to change the definition and then every _MYQUOTE
paragraph falls into line with a quick make.
The classic guides to good HTML writing say things like "It is
strongly recommended that you employ the logical styles such as
<EM>...</EM> rather than the physical styles such as <I>...</I> in
your documents." Curiously, the WYSIWYG editors for HTML generate
purely physical styles. Using these m4 styles may be a good way to
keep on using logical styles.
Contents
3.4 Typing and mnemonic aids
I don't depend on WYSIWYG editing (having been brought up on troff)
but all the same I'm not averse to using help where it's available.
There is a choice (and maybe it's a fine line) to be made between:
<BLOCKQUOTE><PRE><CODE>Some code you want to display.
</CODE></PRE></BLOCKQUOTE>
and:
_CODE(Some code you want to display.)
In this case, you would define _CODE like this:
m4_define(`_CODE',
<BLOCKQUOTE><PRE><CODE>$1</CODE></PRE></BLOCKQUOTE>)
Which version you prefer is a matter of taste and convenience although
the m4 macro certainly saves some typing and ensures that HTML codes
are not interleaved. Another example I like to use (I can never
remember the syntax for links) is:
m4_define(`_LINK', <a href="$1">$2</a>)
Then,
<a href="URL_TO_SOMEWHERE">Click here to get to SOMEWHERE </a>
becomes:
_LINK(`URL_TO_SOMEWHERE', `Click here to get to SOMEWHERE')
Contents
3.5 Automatic numbering
m4 has a simple arithmetic facility with two operators m4_incr and
m4_decr which act as you might expect - this can be used to create
automatic numbering, perhaps for headings, e.g.:
m4_define(_CARDINAL,0)
m4_define(_H, `m4_define(`_CARDINAL',
m4_incr(_CARDINAL))<H2>_CARDINAL.0 $1</H2>')
_H(First Heading)
_H(Second Heading)
This produces:
<H2>1.0 First Heading</H2>
<H2>2.0 Second Heading</H2>
Contents
3.6 Automatic date stamping
For simple, datestamping of HTML pages I use the m4_esyscmd command to
maintain an automatic timestamp on every page:
This page was updated on m4_esyscmd(date)
which produces:
This page was last updated on Fri May 9 10:35:03 HKT 1997
Of course, you could also use the date, revision and other facilities
of revision control systems like RCS or SCCS, e.g. $Date$.
Contents
3.7 Generating Tables of Contents
Using m4 allows you to define commonly repeated phrases and use them
consistently - I hate repeating myself because I am lazy and because I
make mistakes, so I find this feature absolutely key.
A good example of the power of m4 is in building a table of contents
in a big page (like this one). This involves repeating the heading
title in the table of contents and then in the text itself. This is
tedious and error-prone especially when you change the titles. There
are specialised tools for generating tables of contents from HTML
pages but the simple facility provided by m4 is irresistable to me.
3.7.1 Simple to understand TOC
The following example is a fairly simple-minded Table of Contents
generator. First, create some useful macros in stdlib.m4:
m4_define(`_LINK_TO_LABEL', <A HREF="#$1">$1</A>)
m4_define(`_SECTION_HEADER', <A NAME="$1"><H2>$1</H2></A>)
Then define all the section headings in a table at the start of the
page body:
m4_define(`_DIFFICULTIES', `The difficulties of HTML')
m4_define(`_USING_M4', `Using <EM>m4</EM>')
m4_define(`_SHARING', `Sharing HTML Elements Across Several Pages')
Then build the table:
<UL><P>
<LI> _LINK_TO_LABEL(_DIFFICULTIES)
<LI> _LINK_TO_LABEL(_USING_M4)
<LI> _LINK_TO_LABEL(_SHARING)
<UL>
Finally, write the text:
.
.
_SECTION_HEADER(_DIFFICULTIES)
.
.
The advantages of this approach are that if you change your headings
you only need to change them in one place and the table of contents is
automatically regenerated; also the links are guaranteed to work.
Hopefully, that simple version was fairly easy to understand.
Contents
3.7.2 Simple to use TOC
The Table of Contents generator that I normally use is a bit more
complex and will require a little more study, but is much easier to
use. It not only builds the Table, but it also automatically numbers
the headings on the fly - up to 4 levels of numbering (e.g. section
3.2.1.3 - although this can be easily extended). It is very simple to
use as follows:
1. Where you want the table to appear, call Start_TOC
2. at every heading use _H1(`Heading for level 1') or _H2(`Heading
for level 2') as appropriate.
3. After the very last HTML code (probably after </HTML>), call
End_TOC
4. and that's all!
The code for these macros is a little complex, so hold your breath:
m4_define(_Start_TOC,`<UL><P>m4_divert(-1)
m4_define(`_H1_num',0)
m4_define(`_H2_num',0)
m4_define(`_H3_num',0)
m4_define(`_H4_num',0)
m4_divert(1)')
m4_define(_H1, `m4_divert(-1)
m4_define(`_H1_num',m4_incr(_H1_num))
m4_define(`_H2_num',0)
m4_define(`_H3_num',0)
m4_define(`_H4_num',0)
m4_define(`_TOC_label',`_H1_num. $1')
m4_divert(0)<LI><A HREF="#_TOC_label">_TOC_label</A>
m4_divert(1)<A NAME="_TOC_label">
<H2>_TOC_label</H2></A>')
.
.
[definitions for _H2, _H3 and _H4 are similar and are
in the downloadable version of stdlib.m4]
.
.
m4_define(_End_TOC,`m4_divert(0)</UL><P>')
One restriction is that you should not use diversions within your
text, unless you preserve the diversion to file 1 used by this TOC
generator.
Contents
3.8 Simple tables
Other than Tables of Contents, many browsers support tabular
information. Here are some funky macros as a short cut to producing
these tables. First, an example of their use:
<CENTER>
_Start_Table(BORDER=5)
_Table_Hdr(,Apples, Oranges, Lemons)
_Table_Row(England,100,250,300)
_Table_Row(France,200,500,100)
_Table_Row(Germany,500,50,90)
_Table_Row(Spain,,23,2444)
_Table_Row(Denmark,,,20)
_End_Table
</CENTER>
Apples Oranges Lemons
England 100 250 300
France 200 500 100
Germany 500 50 90
Spain 23 2444
Denmark 20
...and now the code. Note that this example utilises m4's ability to
recurse:
m4_dnl _Start_Table(Columns,TABLE parameters)
m4_dnl defaults are BORDER=1 CELLPADDING="1" CELLSPACING="1"
m4_dnl WIDTH="n" pixels or "n%" of screen width
m4_define(_Start_Table,`<TABLE $1>')
m4_define(`_Table_Hdr_Item', `<th>$1</th>
m4_ifelse($#,1,,`_Table_Hdr_Item(m4_shift($@))')')
m4_define(`_Table_Row_Item', `<td>$1</td>
m4_ifelse($#,1,,`_Table_Row_Item(m4_shift($@))')')
m4_define(`_Table_Hdr',`<tr>_Table_Hdr_Item($@)</tr>')
m4_define(`_Table_Row',`<tr>_Table_Row_Item($@)</tr>')
m4_define(`_End_Table',</TABLE>)
Contents
4. m4 gotchas
Unfortunately, m4 is not unremitting sweetness and light - it needs
some taming and a little time spent on familiarisation will pay
dividends. Definitive documentation is available (for example in
emacs' info documentation system) but, without being a complete
tutorial, here are a few tips based on my fiddling about with the
thing.
4.1 Gotcha 1 - quotes
m4's quotation characters are the grave accent ` which starts the
quote, and the acute accent ' which ends it. It may help to put all
arguments to macros in quotes, e.g.
_HEAD1(`This is a heading')
The main reason for this is in case there are commas in an argument to
a macro - m4 uses commas to separate macro parameters, e.g. _CODE(foo,
bar) would print the foo but not the bar. _CODE(`foo, bar') works
properly.
This becomes a little complicated when you nest macro calls as in the
m4 source code for the examples in this paper - but that is rather an
extreme case and normally you would not have to stoop to that level.
Contents
4.2 Gotcha 2 - Word swallowing
The worst problem with m4 is that some versions of it "swallow" key
words that it recognises, such as "include", "format", "divert",
"file", "gnu", "line", "regexp", "shift", "unix", "builtin" and
"define". You can protect these words by putting them in m4 quotes,
for example:
Smart people `include' Linux in their list
of computer essentials.
The trouble is, this is a royal pain to do - and you're likely to
forget which words need protecting.
Another, safer way to protect keywords (my preference) is to invoke m4
with the -P or --prefix-builtins option. Then, all builtin macro names
are modified so they all start with the prefix m4_ and ordinary words
are left alone. For example, using this option, one should write
m4_define instead of define (as shown in the examples in this
article).
The only trouble is that not all versions of m4 support this option -
notably some PC versions under M$-DOS. Maybe that's just another
reason to steer clear of hack code on M$-DOS and stay with Linux!
Contents
4.3 Gotcha 3 - Comments
Comments in m4 are introduced with the # character - everything from
the # to the end of the line is ignored by m4 and simply passed
unchanged to the output. If you want to use # in the HTML page then
you would need to quote it like this - `#'. Another option (my
preference) is to change the m4 comment character to something exotic
like this: m4_changecom(`[[[[') and not have to worry about `#'
symbols in your text.
If you want to use comments in the m4 file which do not appear in the
final HTML file, then the macro m4_dnl (dnl = Delete to New Line) is
for you. This suppresses everything until the next newline.
m4_define(_NEWMACRO, `foo bar') m4_dnl This is a comment
Yet another way to have source code ignored is the m4_divert command.
The main purpose of m4_divert is to save text in a temporary buffer
for inclusion in the file later on - for example, in building a table
of contents or index. However, if you divert to "-1" it just goes to
limbo-land. This is useful for getting rid of the whitespace generated
by the m4_define command, e.g.:
m4_divert(-1) diversion on
m4_define(this ...)
m4_define(that ...)
m4_divert diversion turned off
Contents
4.4 Gotcha 4 - Debugging
Another tip for when things go wrong is to increase the amount of
error diagnostics that m4 emits. The easiest way to do this is to add
the following to your m4 file as debugging commands:
m4_debugmode(e)
m4_traceon
.
.
buggy lines
.
.
m4_traceoff
Contents
5. Conclusion
"ah ha!", I hear you say. "HTML 3.0 already has an include statement".
Yes it has, and it looks like this:
<!--#include file="junk.html" -->
The problem is that:
* The work of including and interpreting the include is done on the
server-side before downloading and adds a big overhead as the
server has to scan files for `include' statements.
* Consequently most servers (especially public ISP's) deactivate
this feature.
* `include' is all you get - no macro substitution, no parameters to
macros, no ifdef, etc, etc.
There are several other features of m4 that I have not yet exploited
in my HTML ramblings so far, such as regular expressions and doubtless
many others. It might be interesting to create a "standard" stdlib.m4
for general use with nice macros for general text processing and HTML
functions. By all means download my version of stdlib.m4 as a base for
your own hacking. I would be interested in hearing of useful macros
and if there is enough interest, maybe a Mini-HOWTO could evolve from
this paper.
There are many additional advantages in using Linux to develop HTML
pages, far beyond the simple assistance given by the typical Typing
Aids and WYSIWYG tools.
Certainly, this little hacker will go on using m4 until HTML catches
up - I will then do my last make and drop back to using pure HTML.
I hope you enjoy these little tricks and encourage you to contribute
your own. Happy hacking!
6. Files to download
You can get the HTML and the m4 source code for this article here (for
the sake of completeness, they're copylefted under GPL 2):
using_m4.html :this file
using_m4.m4 :m4 source
stdlib.m4 :Include file
makefile
Contents
_________________________________________________________________
Copyright © 1997, Bob Hepple
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
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_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
An introduction to The Connecticut Free Unix Group
by Lou Rinaldi lou@cfug.org, CFUG Co-Founder
_________________________________________________________________
October of 1996 was when Nate Smith and I first began discussing the
creation of a local-area unix users' group here in Connecticut,
something we felt the area was desperately in need of. We bantered
around some initial ideas; some great, some not so great. Finally we
decided on creating a group whose focus was on the "free unix"
community. CFUG, The Connecticut Free Unix Group, was born in November
of 1996. Both of us had very busy schedules, so all of the time we
were going to invest in this project came directly from our
ever-decreasing periods of leisure activity. We agreed upon three
major goals for CFUG: The first was the wide distribution and
implementation of free, unix-like operating systems and software. The
second was educating the public about important developments in the
evolution of free operating systems. Finally, we strove to provide an
open, public forum for debate and discussion about issues related to
these topics. After writing to several major vendors and asking for
donations of their surplus stock and/or older software releases, the
packages began rolling in. (After all, we wanted to create some sort
of incentive for people to come to the first meeting)! We then got
started doing some heavy advertising on the newsgroups, in local
computer stores and also on local college campuses. Finally, after
securing an honored guest speaker for our first meeting, (Lar Kaufman,
co-author of the seminal reference book "Running Linux"), we were
ready to set a date. December 9th, 1996 marked the first official CFUG
gathering, which took place at a local public library. We've held
meetings on the second Monday of each month ever since, and are now
widely recognized as Connecticut's only organization dedicated to the
entire free unix community. We've since lost Nate Smith to the
lucrative wiles of Silicon Valley, but we continue to carry on with
our original goals. We have close relations with companies such as
Caldera Inc., InfoMagic Inc., and Red Hat Software, as well as such
non-commercial entities as The FreeBSD Project, Software In The Public
Interest (producers of Debian GNU/Linux), The OpenBSD Project and The
Free Software Foundation. We were also featured on the front page of
the Meriden Record-Journal, a major local newspaper, on May 26th of
this year. Our future plans include more guest speakers, as well as
trips to events of pertinence throughout New England.
For more information, please check our website - http://www.cfug.org
There is a one-way mailing list for announcements concerning CFUG. You
can sign up by emailing cfug-announce-request@cfug.org with
"subscribe" as the first line of the message body (without the
quotes).
_________________________________________________________________
Copyright © 1997, Lou Rinaldi
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
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_________________________________________________________________
"Linux Gazette...making Linux just a little more fun!"
_________________________________________________________________
Review: The Unix-Hater's Handbook
by Andrew Kuchling amk@magnet.com
_________________________________________________________________
I've written a review of an old (1994-vintage) book that may be of
interest to Linuxers. While even just its title will annoy people,
there actually is material of interest in the book to Linux developers
and proponents.
Andrew Kuchling
amk@magnet.com
http://starship.skyport.net/crew/amk/
_________________________________________________________________
The UNIX-HATERS Handbook (1994)
by Simson Garfinkel, Daniel Weise, and Steven Strassman.
Foreword by Donald Norman
Anti-Forward by Dennis Ritchie.
Summary: A sometimes enraging book for a Linux fan, but there are
valuable insights lurking here.
In his Anti-Forward to this book, Dennis Ritchie writes "You claim to
seek progress, but you succeed mainly in whining." That's a pretty
accurate assessment of this book; it's one long complaint about work
lost due to crashes, time wasted finding workarounds for bugs, unclear
documentation, and obscure command-line arguments. Similar books could
be written about any operating system. Obviously, I don't really agree
with this book; I wouldn't be using Linux if I did. However, there is
informative material here for people interested in Linux development,
so it's worth some attention.
The book describes problems and annoyances with Unix; since it was
inspired by a famous mailing list called UNIX-HATERS, there are lots
of real-life horror stores, some hilarious and some wrenching. The
shortcomings described here obviously exist, but in quite a few cases
the problem has been fixed, or rendered irrelevant, by further
development. Two examples:
* On the Unix file system: "...since most disk drives can transfer up
to 64K bytes in a single burst, advanced file systems store files in
contiguous blocks so they can be read and written in a single
operation ... All of these features have been built and fielded in
commercially offered operating systems. Unix offers none of them." But
the ext2 file system, used on most Linux systems, does do this;
there's nothing preventing the implementation of better filesystems.
* "Unix offers no built-in system for automatically encrypting files
stored on the hard disk." (Do you know of any operating system that
has such capability out of the box? Can you imagine the complaints
from users who forget their passwords?) Anyway, software has been
written to do this, either as an encrypting NFS server (CFS) or as a
kernel module (the loopback device).
There are some conclusions that I draw from reading this book:
First, when the book was written in 1994, the free Unixes weren't very
well known, so the systems described are mostly commercial ones.
Proponents of free software should notice how many of the problems
stem from the proprietary nature of most Unix variants at the time of
writing. The authors point out various bugs and missing features in
shells and utilities, flaws which could be *fixed* if the source code
was available.
Better solutions sometimes didn't become popular, because they were
owned by companies with no interest in sharing the code. For example,
the book praises journalled file systems such as the Veritas file
system, because they provide faster operation, and are less likely to
lose data when the computer crashes. The authors write, "Will
journaling become prevalent in the Unix world at large? Probably not.
After all, it's nonstandard." More importantly, I think, the file
system was proprietary software, and companies tend to either keep the
code secret (to preserve their competitive advantage), or charge large
fees to license the code (to improve their balance sheets).
The chapter on the X Window System is devastating and accurate; X
really is an overcomplicated system, and its division between client
and server isn't always optimal. An interesting solution is suggested;
let programs extend the graphics server by sending it code. This
approach was used by Sun's NeWS system, which used PostScript as the
language. Unfortunately NeWS is now quite dead; it was a proprietary
system, after all, and was killed off by X, which was freely available
from MIT. (Trivia: NeWS was designed by James Gosling, who is now
well-known for designing Java. Sun seems determined not to make the
same mistake with Java... we hope.)
Second, many of the problems can be fixed by integrating better tools
into the system. The Unix 'find' command has various problems which
are described in chapter 8 of the book, and are pretty accurate,
though they seem to have been fixed in GNU find. Someone has also
written GNU locate, an easier way to find files. It runs a script
nightly to build a database of filenames, and the 'locate' command
searches through that database for matching files. You could make this
database more than just a list of filenames; add the file's size and
creation time, and you can do searches on those fields. One could
envision a daemon which kept the database instantly up to date with
kernel assistance. The source is available, so the idea only needs an
author to implement it...
Chapter 8 also points out that shell programming is complex and
limited; shell scripts depend on subprograms like 'ls' which differ
from system to system, making portability a problem, and the quoting
rules are elaborate and difficult to apply recursively. This is true,
and is probably why few really sizable shell scripts are written
today; instead, people use scripting language like Perl or Python,
which are more powerful and easier to use.
Most important for Linux partisans, though, it's very important to
note that not all of the flaws described have been fixed in Linux yet!
For example, most Linux distributions don't really allow you to
undelete files, though the Midnight Commander program apparently
supports undeletes. As the authors say, 'sendmail' really is very
buggy, and Unix's security model isn't very powerful. But people are
working on new programs that do sendmail's job, and they're coding
security features like the immutable attributes, and debating new
security schemes.
For this reason, the book is very valuable as a pointer to things
which still need fixing. I'd encourage Linux developers, or people
looking for a Linux project, to read this book. Your blood pressure
might soar as you read it, but look carefully at each complaint and
ask "Is this complaint really a problem? If yes, how could it be
fixed, and the system improved? Could I implement that improvement?"
_________________________________________________________________
Copyright © 1997, Andrew Kuchling
Published in Issue 22 of the Linux Gazette, October 1997
_________________________________________________________________
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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.
_________________________________________________________________
Contents:
* About This Month's Authors
* Not Linux
_________________________________________________________________
About This Month's Authors
_________________________________________________________________
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.
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.
John M. 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.
Michael J. Hammel
Michael J. Hammel, is a transient software engineer with a background
in everything from data communications to GUI development to
Interactive Cable systems--all based in Unix. His interests outside of
computers include 5K/10K races, skiing, Thai food and gardening. He
suggests if you have any serious interest in finding out more about
him, you visit his home pages at http://www.csn.net/~mjhammel. You'll
find out more there than you really wanted to know.
Bob Hepple
Bob Hepple has been hacking at Unix since 1981 under a variety of
excuses and has somehow been paid for it at least some of the time.
It's allowed him to pursue another interest - living in warm, exotic
countries including Hong Kong, Australia, Qatar, Saudi Arabia, Lesotho
and (presently) Singapore. His initial aversion to the cold was
learned in the UK. Ambition - to stop working for the credit card
company and taxman and to get a real job - doing this, of course!
_________________________________________________________________
Not Linux
_________________________________________________________________
Thanks to everyone who contributed to this month's issue!
I'm very excited to edit the Linux Gazette for October.
At my last job, where I fixed computers for a big company, I was
talking with a woman about life in general while fixing her computer,
and suddenly she blurted: "Oh my God! You're really a computer geek!"
She immediately apologized and explained that she didn't mean any
offense, even though I had a huge smile on my face and was trying to
explain that I appreciated the compliment.
After many experiences like that, working with SSC has been a welcome
change. And since Linux Gazette is one of the places where geeks come
home to roost, I'm happy to be a part of it.
I just came back from the Grace Hopper Celebration for Women in
Computing, which was held in San Jose, California this year. To quote
Bill and Ted, it was totally awesome! I got to meet the illustrious
Anita Borg, the amazing Ruzena Bajcny, and the inspiring Fran Allen
from IBM, as well as many many many others who came from all over the
country, and from dozens of countries from around the world. It was
the most incredible even that I have ever attended, and I encourage
everyone to go to the next one which will be in the year 2000.
Margie Richardson will return next month as Editor-In-Chief, and I'll
be helping out on the sidelines. I'm really glad that I got the chance
to be the Big Cheese for a month. :)
Keep sending those articles to gazette@ssc.com!
Until next month, keep reading and keep hacking!
_________________________________________________________________
Viktorie Navratilova
Editor, Linux Gazette gazette@ssc.com
_________________________________________________________________
[ TABLE OF CONTENTS ] [ FRONT PAGE ] Back
_________________________________________________________________
Linux Gazette Issue 22, October 1997, http://www.ssc.com/lg/
This page written and maintained by the Editor of Linux Gazette,
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