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 André 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
_________________________________________________________________
TWDT 1 (text)
TWDT 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 2˘ 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 " News! " > $INDEX
echo " Internal news archive
" >> $INDEX
echo "Last update: `date`
" >> $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 \ $rfname\<\/a\> >> $INDEX;\
echo \ >> $INDEX;\
grep "Subject:" $f | head -1 >> $INDEX;\
echo \ >> $INDEX;\
echo \ >> $INDEX;\
done
echo "
End of archive" >> $INDEX
echo "" >> $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
/*****************************************************************************/
/*****************************************************************************/
/************************** 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
#include
#include
#include
#include
#include
// 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;isister;
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
\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
# 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 , 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 ." 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:
#
/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
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Copyright © 1997, James T. Dennis
Published in Issue 22 of the Linux Gazette October 1997
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"Linux Gazette...making Linux just a little more fun!"
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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
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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.