
Linux Gazette... making Linux just a little more fun!

      Copyright 1996-97 Specialized Systems Consultants, Inc.
      linux@ssc.com
      
   
   
   
     _________________________________________________________________
   
   
   
Welcome to Linux Gazette! (tm)

   
   
   Linux Gazette, a member of the Linux Documentation Project, is an
   on-line WWW publication that is dedicated to two simple ideas:
     * Making Linux just a little more fun
     * Sharing ideas and discoveries
       
   
   
   The basic idea behind these two concepts is that Linux is one cool OS,
   whose price for admission is a willingness to read, learn, tinker
   (aka, hack!), and then share your experiences. The Gazette is a
   compilation of basic tips, tricks, suggestions, ideas and short
   articles about Linux designed to make using Linux fun and easy. LG
   began as a personal project of John M. Fisk, and grew to include
   contributions freely provided by a growing number of authors. Linux
   Journal is now publishing the Gazette using material contributed by
   outside authors (note to potential authors). Without these authors
   there would not be a Gazette, and I thank them all. Drop a note to the
   author of anything that you find helpful or instructive--the author's
   e-mail address is included for this very purpose.
   
   Linux Gazette is a non-commercial publication and will remain that
   way. A tar, gzip file containing all issues of Linux Gazette and one
   containing the current issue can be found at ftp://ftp.ssc.com/pub/lg/
   
   
   Thanks to Matt Welsh, coordinator of the Linux Documentation Project,
   for graciously bringing the Linux Gazette under the auspices of the
   LDP. The material included in these documents is covered by a
   designedly liberal copyright. For information regarding copying and
   distribution of this material read the Copying License.
   
   A new table of contents will appear with each issue that will allow
   you to easily find articles of interest. A search engine is also
   provided to allow you to search all issues for items relating to a
   particular subject.
   
   Have fun!
   
   
     _________________________________________________________________
   
   
   
     * Table of Contents Issue #13
     * Table of Contents Issue #12
     * Table of Contents Issue #11
     * Table of Contents Issue #10
     * Table of Contents Issue #9
     * Table of Contents Issues #1-#8
     * Index of All Issues
       
   
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    For those readers who are accessing Linux Gazette from outside the
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   order to make this possible!
   
   
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   Linux Journal's latest -->
   
  HOT LINUX NEWS! 
  
   
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   -->
   
                             LINUX INFORMATION 
                                       
   Two SSC links that you might find useful. The first is to Linux
   Journal 's "Hot Linux News" page, and the second is to SSC's Linux
   Resources page.
   
   
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  LINUX GAZETTE IS PUBLISHED BY:
  
SSC - Publishers of Linux Journal (tm)

   
   
   
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   Got any great ideas for improvements! Send your comments, criticisms,
   suggestions and ideas.
   
   Linux Gazette, http://www.ssc.com/lg/
   This page written and maintained by the Editor of Linux Gazette,
   gazette@ssc.com
   
   
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                                 LINUX GAZETTE
                                       
      Copyright 1997 Specialized Systems Consultants, Inc.
      For information regarding copying and distribution of this material see
      the Copying License.
      
   
   
   
     _________________________________________________________________
   
   
   
                          TABLE OF CONTENTS ISSUE #13
                                       
   
   
   
     _________________________________________________________________
   
   
   
     * The Front Page
     * The MailBag
          + Help Wanted -- Article Ideas
          + General Mail
     * More 2 Cent Tips
          + Another 2cent Tip for LG
          + Console Trick Follow-up
          + GIF Animations
          + How to close and reopen a new /var/adm/messages file
          + How to truncate /var/adm/messages
          + Info-ZIP encryption code
          + Kernel Compile Woes
          + Letter 1 to LJ Editor re Titlebar
          + Letter 2 to LJ Editor re Titlebar
          + PPP redialer script--A Quick Hack 
          + TABLE tags in HTML
          + Text File undelete
          + Truncating /var/adm/messages
          + 2c Host Trick
          + Use of TCSH's :e and :r Extensions
          + Various notes on 2c tips, Gazette 12
          + Viewing HOWTO Documents
          + Xaw-XPM .Xresources troubleshooting tip
          + Xterm Titlebar
     * News Bytes
          + News in General
          + Software Announcements
     * The Answer Guy, by James T. Dennis
          + Dialup Problem
          + File Referencing
          + Combining Modems for More Speed
          + WWW Server
     * Comdex '96, by Belinda Frasier & Kevin Pierce
     * Filtering Advertisements from Web Pages using IPFWADM, by David
       Rudder
     * Floppy Disk Tips, by Bill Duncan
     * Graphics Muse, by Michael J. Hammel
          + History of Portable Network Graphics Format, by Greg Roelfs
     * Indexing Texts with Smart, by Hans Paijmans
     * Linux Text Editors and A New One, by Oleg L. Machulskiy
     * New Release Reviews, by Larry Ayers
          + Two New X Windows Mail Clients
          + Miscellaneous Notes
     * Petition to Cancel Filed Against Linux Trademark
     * SLEW: Space Low Early Warning, by James T. Dennis
     * The Back Page
          + About This Month's Authors
          + Not Linux
            
   
   
   Weekend Mechanic
   will return next month.
   
   
     _________________________________________________________________
   
   
   
   The Whole Damn Thing 1 (text)
   The Whole Damn Thing 2 (HTML)
   are files containing the entire issue: one in text format, one in
   HTML. They are provided strictly as a way to save the contents as one
   file for later printing in the format of your choice; there is no
   guarantee of working links in the HTML version.
   
   
     _________________________________________________________________
   
   
   
   Got any great ideas for improvements! Send your comments, criticisms,
   suggestions and ideas.
   
   
     _________________________________________________________________
   
   
   
   This page written and maintained by the Editor of Linux Gazette,
   
   
     _________________________________________________________________
   
   
   
    "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
       
   
   
   
   
   
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  HELP WANTED -- ARTICLE IDEAS
  
   
   
   
     _________________________________________________________________
   
   
   
   Date: Sun, 17 Nov 1996 18:49:56 -0600
   Subject: a reply type thing...
   From: Glenn E. Satan, insipid@onramp.net

> Subject: Xwindows depth
> From: James Amendolagine uq274@freenet.victoria.bc.ca
>
> I have recently been messing with my x-server, and have managed
> to get a depth of 16, ie 2^16 colors. This works
> really nice with Netscape, but some programs (doom, abuse, and
> other games) wont work with this many colors. Do
> you know of a fix? I have tried to get X to support multiple
> depths--to no avail. The man-page suggests that some
> video cards support multiple depths and some don't. How do I know
> if mine does.
>
> I would really like to see an article on this subject,

   I would like to say, yes, please someone help.... thought maybe a
   reply would motivate someone a little more to write a article on this.
   
     (All right a second request for help in this area. Anybody out there
     with suggestions and/or wanting to write an article? --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Sun, 01 Dec 1996 00:20:12 +1000
   Subject: Quilting and geometry 
   From: Chris Hennessy, chenness@enterprise.powerup.com.au 
   
   I liked your comment about quilting being an interest. We tend to
   forget that people have interests outside of computers in general (and
   linux in particular).
   
   Just like to say thanks for what is obviously an enormous effort you
   are putting into the gazette. I'm new(ish) to linux and I find it a
   great resource, not to say entertaining.
   
   Has anyone suggested an article on the use of Xresources? As I said
   I'm fairly new and find this a bit confusing... maybe someone would be
   interested in an example or three?
   
   Oh and with the quilting and geometry ... better make sure its not the
   80x25+1-1 variety.
   
     (Thanks, LG is a lot of work, as well as a lot of fun. And yes, I do
     have a life outside of Linux. Anyone interested in writing about
     Xresources? Thanks for writing. It's always nice to know we are
     attracting new readers. --Editor) 
     
   
   
   
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   Date: Wed, 4 Dec 1996 13:33:26 +0200 (EET)
   Subject: security issue! 
   From: Arto Repola, arepola@raahenet.ratol.fi 
   
   
   Hi there!
   
   I was wondering that could you write in some Gazette something about
   Linux security...how to improve it, how to setup firewall,shadow
   password systems etc?
   
   I'm considering to build up my own linux-server and i really would
   like to make it as secure as possible!
   
   Nothing more this time!
   
   http://raahenet.ratol.fi/~arepola
   
     (And another great idea for an article. Any takers? --Editor) 
     
   
   
   
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   Date: Wed, 04 Dec 1996 08:08:06 -0700
   Subject: Reader Response 
   From: James Cannon, cannonj@jads.kirtland.af.mil 
   Organization: JADS JTF
   
   
   Great Resource,
   
   I really like the resource Linux offers new users. I have already
   applied a few tricks to my PC. I wish some one would explain how to
   use the GNU C/C++ compiler with Linux. It is a tool resting in my hard
   drive. With commercial compilers, there is a programming environment
   that links libraries automatically. Are there any tricks to command
   line C/C++ programming with Linux?? Stay online!
   
   James Cannon
   
     (Thanks for the tip. Online is the best place to be. Anyone out
     there got some C++ help for this guy? --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Mon, 9 Dec 1996 23:27:21 +0000 (GMT)
   Subject: Linux InfraRed Support 
   From: Hong Kim, kimh@domp04.adm.intelsat.int 
   
   
   Hi,
   
   I have been so far unsuccessful in finding information for InfraRed
   support on Linux.
   
   I am particularly interested in hooking up Caldera Linux on a Thinkpad
   560 using Extended Systems JetEye Net Plus. Caldera on Thinkpad I can
   handle but the JetEye allows connection to ethernet or token ring
   networks via IR.
   
   My searches of Linux Resources page come up negative. I have posted to
   USENET and also emailed any web master that has any mention of
   ThinkPad or IR on their pages. Still no answer.
   
   Can you help me to find information. If I am successful, I would be
   willing to write an article about it.
   
   Hong
   
     (I have sent your question on to Linux Journal's Tech Support
     Column. Answers from this source can be slow as author contacts
     companys involved. Sounds like you have covered all the bases in
     your search -- can anyone out there help him? If you write the
     article, I'll be happy to post it in the LG so next person who
     needs this information will have a quicker answer. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Thu, 5 Dec 96 13:00:01 MET
   Subject: Linux networking problem ...
   From: Tauche%fbm%mfh@mfhdvzis.mfh-iserlohn.de 
   
   
   Hi there,
   
   First I have to apologize for writing to this address with my problem,
   but I don't no where to search for an answer and university's network
   is so damned slow that surfing through the net searching for an answer
   makes no fun. Another reason is that I've got no access to Usenet...
   means can't post in comp.os.linux.networking... 8-((
   
   I tried to find a news server near to Germany which allows posting
   without using that damned -> identd Here's the problem:
   I want to setup Linux in our University's LAN but ran into problems,
   because the LAN is VINES-IP based so that normal TCP/IP packet drivers
   won't work. The admin says I do need a driver which can tunnel the
   normal Linux TCP/IP packets into those VINES-IP packets, so that they
   can be send over the LAN to that box which has Internet connection....
   
   
   Maybe you know if such thing is available and/or where I can get it.
   Or maybe you can give some Email-addresses for asking people which
   real knowledge 'bout Linux (maybe even that of Linus T. himself) and
   it's drivers.
   
   Hope you can help me 8-))
   
   Thanks in advantage
   Stefan 8-))
   
     (I've sent your problem on to Linux Journal's Technical Support
     column and will post it in Linux Gazette's Mailbag next month.
     Neither one will give you a fast answer.
     
     I did a search of LG, LJ and SSC's Linux Resources using VINES as
     the keyword. I found only one entry from an author's biography.
     It's old -- March 1995 -- and the guy was in the marine corp then
     so may or may not be a good address. Anyway here's what it said:
     "Jon Frievald ... manages Wide Area Network running Banyan VINES.
     ... e-mail to jaf@jaflrn.liii.com"
     
     Anyway you might give him a try for help ideas.
     
     For faster access to LG have you tried any of LG's mirror sites in
     Germany:
   
     * http://www.cs.uni-dusseldorf.de/~stein/lg 
     * http://vina12.va.htw-dresden.de/lg 
     * http://www.fokus.gmd.de/linux/lg 
       
     
     
     Please note that mirror sites wont help search time -- all
     searching is done on SSC site. --Editor) 
     
   
   
   
   
   
     _________________________________________________________________
   
   
   
  GENERAL MAIL
  
   
   
   
     _________________________________________________________________
   
   
   
   Date: Sat, 30 Nov 1996 20:35:17 -0600 (CST)
   Subject: Re: Slang Applications for Linux 
   From: Duncan Hill, dhill@sunbeach.net
   To: Larry Ayers, layers@vax2.rain.gen.mo.us 
   
   
   On Sat, 30 Nov 1996, Duncan Hill wrote:
   
   Greetings. I was reading your article in the Linux Gazette, and
   thought you might be interested to know that Lynx also has its own web
   site now at:
   http://lynx.browser.org/ 
   It's up to version 2.6 now, and is rather nice, specially with slang
   included :)
   
   Duncan Hill, Student of the Barbados Community College
   
     (Thanks for the tip! I really appreciate responses from readers;
     confirms that there are really readers out there! --Larry Ayers) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Sat, 30 Nov 96 16:42:58 0200
   Subject: Linux Gazette 
   From: Paul Beard, paulb@id.co.zw 
   
   
   Hello from Zimbabwe.
   
   Very nice production. Keep up the good work.
   
   Regards,
   Paul Beard.
   
     (Thanks. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Thu, 28 Nov 1996 23:54:38 +0000
   Subject: Thanks! 
   From: Russ Spooner, russ1@rmplc.co.uk 
   Organization: Kontagx
   
   
   Hi,
   I have been an avid reader of Linux Gazette since its inception! I
   would just like to say that it has helped me a lot and that I am
   really glad that it has become more regular :-)
   
   The Image you have developed now has come a long way and it is now one
   of the best organized sites I visit!
   
   Also I would like to thank you for the link to my site :-) it was a
   real surprise to "see myself up in lights" :)
   
   Best regards!
   Russ Spooner, http://www.pssltd.co.uk/kontagx
   
   
     _________________________________________________________________
   
   
   
   Date: Thu, 28 Nov 1996 12:49:12 -0500
   Subject: LG Width 
   From: frank haynes, frank@vatmom.com 
   Organization: The Vatmom Organization
   
   
   Re: LG page width complaint, LG looks great here, and I don't think my
   window is particularly large. Keep up the fine work.
   
   --Frank, http://www.mindspring.com/~fmh
   
     (Good to hear. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Fri, 29 Nov 1996 10:30:32 +0000
   Subject: LG #12 
   From: Adam D. Moss. adam@uunet.pipex.com
   
   
   Nice job on the Gazette, as usual. :)
   
   Adam D. Moss / Consulting
   
     ( :-) --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Tue, 3 Dec 1996 12:55:18 -0800 (PST)
   Subject: Re: images in tcsh article 
   From: Scott Call, scall@ccnet.com
   
   
   Most of the images in the TCSH article in issue 12 are broken
   
   -Scott
   
     (You must be looking at one of the mirror sites. I inadvertently
     left those images out of the issue12 tar file that I made for the
     mirror sites. When I discovered it yesterday, I made an update file
     for the mirrors. Unfortunately, I have found that not all the
     mirrors are willing to update LG more than once a month, so my
     mistakes remain until the next month. Sorry for the inconvenience
     and thanks for writing. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Fri, 06 Dec 1996 21:21:00 +0600
   Subject: 12? why can you make so bad distributive????????????? 
   From: Sergey A. Panskih, serg@cnti.chel.su
   
   
   i ftpgeted lg12 and untar.gz it as made with lg11. lg11 was read as
   is: with graphics and so, but lg12... all graphics was loosed. i've
   verified hrefs and found out that href was written with principial
   errors : i must copy all it to /images in my httpd server!!!!
   
   this a pre-alpha version!!!
   
   i can't do so unfixed products!!!
   
   i'm sorry, but you forgotten how make a http-ready distrbutions... :)
   
   Sergey Panskih
   
   P.S. email me if i'm not true.
   
     (I'm having a little trouble with your English and don't quite
     understand what "all graphics was loosed" means. You shouldn't have
     to copy anything anywhere: what are you copying to /images?
     
     There is one problem I had that may apply to you. Are you throwing
     away previous issues and only getting the current one? If so, I
     apologize most humbly. I was not aware until this month that people
     were doing this and when I made the tar file I included only new
     files and those that had been changed since the last month. To
     correct this problem I put a new tar file on the ftp site called
     standard_gifs.html. It's not that I've forgotten how to make
     http-ready distributions, it's that I'm just learning all the
     complexities. In the future I will make the tar file to include all
     files needed for the current single issue, whether they were
     changed or not.
     
     I am very sorry to have caused you such problems and distress.
     --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Mon, 02 Dec 96 18:13:48
   Subject: spiral trashes letters 
   From: jep@jephill.com 
   
   
   It's clever and pretty, but the spiral notebook graphic still trashes
   the left edge of letters printed in the issue 12 Mailbag.
   
   Problem occurs using OS/2's Web Explorer version 1.2 (comes with OS/2
   Warp 4.0). Problem does NOT occur using Netscape 2.02 for OS/2 beta 2
   (the latest beta for OS/2).
   
   Problem occurs even while accessing www.ssc.com/lg
   
   Jep Hill
   
     (Problem will always occur with versions of either Microsoft
     Explorer or Netscape before 2.0. It is caused by a bug in TABLES
     that was fixed in the 2.0 versions. I don't have access to OS/2's
     Web Explorer, so I can only guess that it's the same problem. I'd
     recommend always using the latest version of your browser.
     --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date Mon, 9 Dec 1996 10:14:04 -0800 PST
   Subject: Background 
   From: rayvd@shocking.com 
   
   
   I run at a resolution of 1152x846 (a bit odd I suppose) and although
   the Gazette pages look very nice indeed, it is a bit hard to read when
   I have my Netscape window maximized. The bindings part of the
   background seems to be optimized for a width of 1024 and thus tiles
   over again on the right side of the page. This makes reading a bit
   difficult as some of the text now overlaps the bindings on the far
   right.
   
   I'm not sure if that's a great description of the problem, but I can
   easily make you a screenshot if you want to see what I mean.
   
   Anyhow, this is only a minor annoyance--certainly one I'm willing to
   live with in order to read your great 'zine. :)
   
   Ray Van Dolson -=-=- Bludgeon Creations (Web Design) - DALnet
   #Bludgeon -- http://www.shocking.com/~rayvd/
   
     (Screen shot wont be necessary. When the web master first put the
     spiral out there, the same thing happened to me -- I use a large
     window too, but not as large as yours. He was able to expand it to
     fix it at that time. I notified him of your problem, but not sure
     if he can expand it even more or not. We'll see. Glad it's a
     problem you can live with. :-) --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Sat, 7 Dec 1996 22:16:55 +0100 (MET)
   Subject: Problem with Printing.
   From: fm@M1.whitespace.de
   
   
   Hi,
   
   This is just to let you people know, that there might be a slight
   problem. I want to point out and make it perfectly clear that this is
   NOT a complaint. I feel perfectly satisfied with the Linux Gazette as
   it is.
   
   However sometimes I prefer to have a printed copy to take with me.
   Therefore I used to print the LG. from Netscape. I'm using the new 3.1
   version now. With the last two issues I have difficulties doing so.
   All the pages with this new nice look don't print too well. The
   graphics show up at all the wrong places and only one page is printed
   on the paper. The rest is swallowed. Did you ever try to print it?
   
   I had to use an ancient copy of Mosaic, that doesn't know anything
   about tables, to print these pages. They don't look too good this way
   too, and never did. I know this old Mosaic is buggy. At least it
   doesn't swallow half of the stuff. This could as well be a bug in
   Netscape. I know next to nothing about html.
   
   Anyway, have fun.
   Regards Friedhelm
   
     (No, I don't try to print it, but will look into it. Are you
     printing out "The Whole Damn Thing" from the TOC or trying to do it
     page by page? It is out there in multi-file format and so if you
     print from say the Front Page, the front page is all you'll get.
     "The Whole Damn Thing" is one single file containing the whole
     issue, and the spiral and table stuff are removed so it should
     print out for you okay. Let me know if this is already what you are
     printing, so I'll know where to look for the problem. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Wed, 18 Dec 1996 04:02:37 +0200
   Subject: Greetings 
   From: Trucza Csaba, ctrucza@cemc.soroscj.roi
   To: fiskjm@ctrvax.Vanderbilt.Edu
   
   
   Well, Hi there!
   
   Amazing. I've just read the Linux Gazette from the first issue to this
   one, the 12th (actually I read just the first 7 issues through,
   because the others were not downloaded correctly).
   
   It's 4 in the morning and I'm enthusiastic. I knew Linux was good, I'm
   using it for a year (this is because of the lack of my english
   grammar, I mean the previous sentence, well...), so I knew it was
   good, but I didn't expect to see something so nice like this Gazette.
   
   It's good to see that there are a WHOLE LOT of people with huge will
   to share.
   
   I think we owe You a lot of thanks for starting it.
   
   Merry Christmas, a Happy New Year, and keep it up!
   
   Trucza Csaba, Romania
   
     (Thanks, I will. -- Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Mon, 23 Dec 1996 12:16:30 -0800 (PST)
   Subject: lg issue 12 via ftp?
   From: schwarz@monet.m.isar.de (Christian Schwarz)
   
   I just saw that issue #12 is out and accessible via WWW, but I can't
   find the file on your ftp server nor on any mirrors.
   
     (Sorry for the problems. We changed web servers and I went on
     vacation. Somehow in the web server change, some of the December
     files got left behind. I didn't realize until today that this had
     happened. Sorry for the inconvenience. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Fri, 20 Dec 1996 00:31:45 -0500
   Subject: Great IDEA 
   From: Pedro A Cruz, pcruz@panixc.com
   
   
   Hi:
   
   I visited your site recently and was astounded by the wealth of
   information there. I have lots of bandwidth to read your site. I
   noticed that you have issues for download. I Think it will be a great
   service to the LINUX community if you consider publishing a CDROM
   (maybe from walnut creek cdrom) as a subscription item.
   
   pedro
   
     (Yes, that is a good idea. I'll talk to my publisher about it.
     --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Sun, 22 Dec 1996 20:24:51 -0600
   Subject: Linux as router 
   From: Robert Binz, rbinz@swconnect.net
   
   
   I have found myself trying to learn how to use Linux as a usenet
   server to provide news feeds to people, and to use Linux as a IRC
   server. Information on these topics are hard to come buy. If you have
   any sources on these subjects that you can point me to I would be most
   appreciative.
   
   But any how, I have found an article in SysAdmin (Jan 96 (5.1)) that
   is titled Using Linux as a Router, by johnathon Feldman. Is it
   possible to reprint this article or get the author to write a new one
   for you?
   
   TIA
   Robert Binz
   
     (I'll look into it. In the meantime, I've forwarded your letter to a
     guy I think may be able to help you. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Fri, 13 Dec 1996 03:57:09 -0500 (EST)
   Subject: Correction for LG #12 
   From: Joe Hohertz, jhohertz@golden.net
   Organization: Golden Triangle On-Line
   
   Noticed the folowing in the News section.
   
   A couple of new Linux Resources sites:
   
     (Seems I had Joe's address wrong. Sorry. --Editor) 
     
   
   
   
     _________________________________________________________________
   
   
   
   Date: Tue, 17 Dec 1996 01:19:43 -0500
   Subject: One-shot downloads 
   From: David M. Razler, david.razler@postoffice.worldnet.att.net
   
   Folks:
   
   While I realize that the economies of the LINUX biz require that there
   be some method of making money even on the distribution of free and
   "free" software, I have a request for them of us who 1) are currently
   scraping for the cash for our Internet accounts and 2) would like to
   try LINUX.
   
   How about a one-shot download? I mean, oh, everything needed to
   establish a LINUX system in one ZIP'ed (or tar/gz'd, though zip is a
   more compatible format) file, one for each distribution?
   
   I'm currently looking to establish LINUX on my "spare" PC, a 386DX-16
   w/4 meg and a scavenged 2500MB IDE drive, etc. It will be relatively
   slow, limited, lacks a CD-rom drive, but it's free, since the machine
   is currently serving as a paperweight.
   
   I could go out and buy a used CD-rom for the beast, or run a bastard
   connection from my primary, indispensable work machine and buy the
   CDs. But I am currently disabled and spending for these things has to
   be weighed against other expenses (admittedly, I am certainly lucky
   and not destitute, it would just be better)
   
   I could get a web robot and download umpteen little files, puzzle them
   out and put them together, though the load on your server would be
   higher.
   
   Or, under my proposed system, I could download Distribution Code,
   Documents, and Major accessories in one group, then go back for the
   individual bits and pieces I need to build my system.
   
   Again, I realize that running your site costs money, and that people
   make money, admirably little money, distributing LINUX on CDs, with
   the big bucks (grin) of LINUX coming in non-free software, support and
   book sales.
   
   But if the system is to spread, providing a series of one-shot
   downloads, possibly available only to individuals (I believe one could
   copyright the *package* and require someone downloading to agree to
   use it only on a single non-commercial system and not to redistribute,
   but I am not an intellectual properties lawyer), to make life easier
   for them of us who need to learn a UNIX-style system and build one on
   the cheap.
   
   dmr
   
   
     _________________________________________________________________
   
   
   
   [ 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:
     * Another 2cent Tip for LG
     * Console Trick Follow-up
     * GIF Animations
     * How to close and reopen a new /var/adm/messages file
     * How to truncate /var/adm/messages
     * Info-ZIP encryption code
     * Kernel Compile Woes
     * Letter 1 to LJ Editor re Titlebar
     * Letter 2 to LJ Editor re Titlebar
     * PPP redialer script--A Quick Hack 
     * TABLE tags in HTML
     * Text File undelete
     * Truncating /var/adm/messages
     * 2c Host Trick
     * Use of TCSH's :e and :r Extensions
     * Various notes on 2c tips, Gazette 12
     * Viewing HOWTO Documents
     * Xaw-XPM .Xresources troubleshooting tip
     * Xterm Titlebar
       
   
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  ANOTHER 2CENT SCRIPT FOR LG
  
   Date: Wed, 11 Dec 1996 23:34:58 +0100
   From: Hans Zoebelein, zocki@goldfish.cube.net
   
   
   Hello LG people,
   
   here comes a short script which will check from time to time that
   there is enough free space available on anything which shows up in
   mount (disks, cdrom, floppy...)
   
   If space runs out, a message is printed every X seconds to the screen
   and 1 mail message per filled device is fired up.
   
   Enjoy!
   Hans

#!/bin/sh

#
# $Id: check_hdspace,v 1.18 1996/12/11 22:33:29 root Exp root $
#

#
# Since I got mysterious error messages during compile when
# tmp files filled up my disks, I wrote this to get a warning
# before disks are full.
#
# If this stuff saved your servers from exploding,
# send praising email to zocki@goldfish.cube.net.
# If your site burns down because of this, sorry but I
# warned you: no comps.
# If you really know how to handle sed, please forgive me :)
#

#
# Shoot and forget: Put 'check_hdspace &' in rc.local.
# Checks for free space on devices every $SLEEPTIME sec.
# You even might check your floppies or tape drives. :)
# If free space is below $MINFREE (kb), it will echo a warning
# and send one mail for each triggering device to $MAIL_TO_ME.
# If there is more free space than trigger limit again,
# mail action is also armed again.
#

# TODO: Different $MINFREE for each device.
# Free /*tmp dirs securely from old junk stuff if no more free space.


DEVICES='/dev/sda2 /dev/sda8 /dev/sda9'         # device; your put disks here
MINFREE=20480                                   # kb; below this do warning
SLEEPTIME=10                                    # sec; sleep between checks
MAIL_TO_ME='root@localhost'                     # fool; to whom mail warning


# ------- no changes needed below this line (hopefully :) -------

MINMB=0
ISFREE=0
MAILED=""
let MINMB=$MINFREE/1024         # yep, we are strict :)

while [ 1 ]; do
        DF="`/bin/df`"
        for DEVICE in $DEVICES ; do
                ISFREE=`echo $DF | sed s#.\*$DEVICE" "\*[0-9]\*" "\*[0-9]\*" "\
*## | sed s#" ".\*##`
                
                if [ $ISFREE -le $MINFREE ] ; then
                        let ISMB=$ISFREE/1024
                        echo  "WARNING: $DEVICE only $ISMB mb free." >&2
                        #echo "more stuff here" >&2
                        echo -e "\a\a\a\a"
                        
                        if [ -z  "`echo $MAILED | grep -w $DEVICE`" ] ; then
                                echo "WARNING: $DEVICE only $ISMB mb free.
(Trigger is set to $MINMB mb)" \
                                | mail -s "WARNING: $DEVICE only $ISMB mb free!
" $MAIL_TO_ME
                                MAILEDH="$MAILED $DEVICE"
                                MAILED=$MAILEDH
                                # put further action here like cleaning
                                # up */tmp dirs...
                        fi
                elif [ -n  "`echo $MAILED | grep -w $DEVICE`" ] ; then
                        # Remove mailed marker if enough disk space
                        # again. So we are ready for new mailing action.
                        MAILEDH="`echo $MAILED  | sed s#$DEVICE##`"
                        MAILED=$MAILEDH
                fi
        done
        sleep $SLEEPTIME

done

   
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  CONSOLE TRICK FOLLOW-UP
  
   Date: Wed, 27 Nov 1996 16:20:06 -0500 (EST)
   From: Elliot Lee, sopwith@cuc.edu 
   
   
   Just finished reading issue #12, nice work.
   
   A followup to the "Console Tricks" 2-cent tip:
   What I like to do is have a line in /etc/syslog.conf that says:

*.*                                                     /dev/tty10

   that sends all messages to VC 10, so I can know what's going on
   whether in X or text mode. Very useful IMHO.
   
   -- Elliot, http://www.redhat.com/
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  GIF ANIMATIONS
  
   Date: Thu, 28 Nov 1996 20:41:22 -0600 (CST)
   From: Greg Roelofs, newt@pobox.com 
   
   I too thought WhirlGIF (Graphics Muse, issue 12) was the greatest
   thing since sliced bread (well, aside from PNG) when I first
   discovered it, but for creating animations, it's considerably inferior
   to Andy Wardley's MultiGIF. The latter can specify tiny sprite images
   as parts of the animation, not just full images. For my PNG-balls
   animation (see http://quest.jpl.nasa.gov/PNG/), this resulted in well
   over a factor-of-two reduction in size (577k to 233k). For another
   animation with a small, horizontally oscillating (Cylon eyes) sprite,
   the savings was more than a factor of 20(!).
   
   MultiGIF is available as source code, of course. (And I had nothing to
   do with it, but I do find it darned handy.)
   
   Regards,
   Greg Roelofs, http://pobox.com/~newt/
   Newtware, Info-ZIP, PNG Group, U Chicago, Philips Research, ...
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  RE: HOW TO CLOSE AND REOPEN A NEW /VAR/ADM/MESSAGES FILE
  
   Date: Thu, 05 Dec 1996 01:09:27 -0800
   From: CyberTech, CyberTech@ns.cybertech.org
   
   
   Regarding the posting in issue #12 of your gazette, how to backup the
   current messages file & recreate, here is an alternative method...
   
   Place the lines at the end of this messages in a shell script
   (/root/cron/swaplogs in this example). Don't forget to make it +x!
   Execute it with 'sh scriptname', or by adding the following lines to
   your (root's) crontab:

# Swap logfiles every day at 1 am, local time
0 01 * * *       /root/cron/swaplogs

   The advantage to this method over renaming the logfile and creating a
   new one is that in this method, syslogd is not required to be
   restarted.

#!/bin/sh
cp /var/adm/messages /var/adm/messages.`date +%d-%m-%y_%T`
cat /dev/null >/var/adm/messages

cp /var/adm/syslog /var/adm/syslog.`date +%d-%m-%y_%T`
cat /dev/null >/var/adm/syslog

cp /var/adm/debug /var/adm/debug.`date +%d-%m-%y_%T`
cat /dev/null >/var/adm/debug

   
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  HOW TO TRUNCATE /VAR/ADM/MESSAGES
  
   Date: Mon, 02 Dec 1996 16:47:20 +0100
   From: Eje Gustafsson, gne@ffa.se 

>In answer to the question:
>
>            What is the proper way to close and reopen a new >/var/adm/message
s
>            file from a running system?
>
>       Step one: rename the file. Syslog will still be writing in it >after re
naming so you don't
>       lose messages. Step two: create a new one. After re-initializing >syslo
gd it will be used.
>just re-initialize.
>
>          1.mv /var/adm/messages /var/adm/messages.prev
>          2.touch /var/adm/messages
>          3.kill -1 pid-of-syslogd
>
>       This should work on a decent Unix(like) system, and I know Linux >is on
e of them.

   This is NOT an proper way of truncate /var/adm/messages.
   
   It is better to do:
    1. cp /var/adm/messages /var/adm/messages.prev
    2. >/var/adm/messages or cp /dev/null /var/adm/messages (both of them
       makes the file empty).
    3. No more.
       
   The problem is that when you remove the /var/adm/messages syslogd gets
   confused and unhappy and you have to give syslogd a HUPSIG but if you
   just sets the file length to zero without removing the file syslogd
   don't complain. And if you are really unlucky your system will go down
   because you didn't create /var/adm/messages quick enough or forgot it.
   
   
   Best of regards,
   Eje Gustafsson, System Administrator
   THE AERONAUTICAL RESEARCH INSTITUTE OF SWEDEN
   
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  INFO-ZIP ENCRYPTION CODE
  
   Date: Thu, 28 Nov 1996 20:58:39 -0600 (CST)
   From: Greg Roelofs, newt@pobox.com
   
   
   This is a relatively minor point, but Info-ZIP's Zip/UnZip encryption
   code is *not* DES as reported in Robert Savage's article (LG issue
   12). It's actually considerably weaker, so much so that Paul Kocher
   has pub- lished a known-plaintext attack (the existence of which is
   undoubtedly the reason PKWARE was granted an export license for the
   code). While the encryption is good enough to keep your mom and
   probably your boss from reading your files, those who desire *real*
   security should look to PGP (which is also based on Info-ZIP code, but
   only for compression).
   
   And while I'm at it, Linux users will be happy to learn that the
   upcoming releases of UnZip 5.3 and Zip 2.2 will be noticeably faster
   than the cur- rent publicly released code. In Zip's case this is due
   to a work-around for a gcc bug that prevented a key assembler routine
   from being used--Zip is now 30-40% faster on large files. In UnZip's
   case the improvement is due to a couple of things, one of which is
   simply better-optimized CRC code. UnZip 5.3 is about 10-20% faster
   than 5.2, I believe. The new ver- sions should be released in early
   January, if all goes well. And then... we start working on multi-part
   archives. :-)
   
   Greg Roelofs, http://pobox.com/~newt/
   Newtware, Info-ZIP, PNG Group, U Chicago, Philips Research, ...
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  KERNEL COMPILE WOES
  
   Date: Mon, 2 Dec 1996 21:35:29 +0400 (GMT-4)
   From: Duncan Hill, dhill@sunbeach.net
   
   
   Greetings. Having been through hell after a recompile of my kernel, I
   thought I'd pass this on.
   
   It all started with me compiling a kernel for JAVA binary support..who
   tell me do that. Somehow I think I got experimental code in..even
   worse :> Anyway, it resulted in a crash, and I couldn't recompile
   since then.
   
   Well, after several cries for help, and trying all sorts of stuff, I
   upgraded binutils to 2.7.0.3, and told the kernel to build elf support
   and in elf format, and hey presto. I'd been wrestling with the problem
   for well over a week, and every time, I'd get an error. Unfortunately,
   I had to take out sound support, so I'm going to see if it'll add back
   in.
   
   I have to say thank you to the folks on the linux-kernel mailing list
   at vger.rutgers.edu. I posted there once, and had back at least 5
   replies in an hour. (One came back in 10 minutes).
   
   As for the LG, it looks very nice seen thru Lynx 2-6 (no graphics to
   get messed up :>) I love the Weekend Mechanic, and the 2 cent tips
   mainly. Perhaps one day I'll contribute something,.
   
   Duncan Hill, Student of the Barbados Community College
   http://www.sunbeach.net/personal/dhill/dhill.htm
   http://www.sunbeach.net/personal/dhill/lynx/lynx-main.html
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  LETTER 1 TO THE LJ EDITOR RE TITLEBAR
  
   Date: Sat, 21 Dec 1996 15:18:01 -0600
   From: Roger Booth, Roger_Booth@crow.bmc.com
   To: linux@ssc.com The Jan97 Issue 33 of Linux Journal contained the
   "Linux Gazette Two Cent Tips". I was interested in the tip "X Term
   Titlebar Function". Although the text of the tip stated that the tip
   would work in ksh-based systems, I could not get it to work as shown.
   I think there are three problems. First, I think there are a few
   transcription errors in the script. Second, I believe the author is
   using embedded control characters and it was not obvious to me which
   character sequences are representations of control characters and
   which characters should be typed verbatim. Third, the author uses a
   command-line option to the echo command which is not available on all
   Unix platforms.
   
   I finally used the following script:

    if [ ${SHELL##/*/} = "ksh" ] ; then
        if [[ $TERM = x"term" ]] ; then
            HOSTNAME=`uname -n`
            label () { echo "\\033]2;$*\\007\\c"; }
            alias stripe='label $LOGNAME on $HOSTNAME - ${PWD#$HOME/}'
            cds () { "cd" $*; eval stripe; }
            alias cd=cds
            eval stripe
        fi
    fi

   I don't use vi, so I left out that functionality.
   
   The functional changes I made are all in the arguments to the echo
   command. The changes are to use \\033 rather than what was shown in
   the original tip as ^[, to use \\007 rather than ^G, and to terminate
   the string with \\c rather than use the option -n.
   
   On AIX 4.1, the command "echo -n hi" echoes "-n hi"; in other words,
   -n is not a portable command-line option to the echo command. I tested
   the above script on AIX 3.2, AIX 4.1, HPUX 9.0, HPUX 10.0, Solaris 2.4
   and Solaris 2.5. I'm still trying to get Linux and my Wintel box
   mutually configured, so I haven't tested it on Linux.
   
   I have noticed a problem with this script. I use the rlogin command to
   log in to a remote box. When I exit from the remote box, the caption
   is not updated, and still shows the hostname and path that was valid
   just before I exited. I tried adding

    exits () { "exit" $*; eval stripe; }
    alias exit=exits

   and

    rlogins () { "rlogin" $*; eval stripe; }
    alias rlogin=rlogins

   Neither addition updated the caption to the host/path returned to. Any
   suggestions?
   
   Roger Booth, rbooth@bmc.com
   
   
     _________________________________________________________________
   
   
   
   
   
   
   
  LETTER 2 TO THE LJ EDITOR RE TITLEBAR
  
   Date: Fri, 13 Dec 1996 23:03:37 -0700 (MST) From: Gary Masters,
   gmasters@csn.net
   
   
   Some further clarification is needed with respect to the X Term
   Titlebar Function tip in the Linux Gazette Two Cent Tips column of the
   January 1997 issue. With regard to the -print option to find, Michael
   Hammel says, "Linux does require this." This is yet another example of
   "Your mileage may vary." Some versions of Linux do not require the
   -print option. And, although Solaris may not, SunOS 4.1.3_U1 and 4.1.4
   do require the -print option. Also, if running csh or tcsh, remember
   to escape wildcards in the file specification ( e.g. find ./ -name
   \*txt\* ) so that the shell doesn't attempt to expand them.
   
   Second, for those tcsh fans out there, here is an xterm title bar
   function for tcsh.
   
   NOTE: This works on Slackware 3.0 with tcsh version 6.04.00, under the
   tab, fv, and OpenLook window managers. Your mileage may vary.

if ( $TERM == xterm ) then
  set prompt="%h> "
  alias cwdcmd 'echo -n "^[]2;`whoami` on ${HOST} - $cwd^G^[]1;${HOST}^G"'
  alias vi 'echo -n "^[]2;${HOST} - editing file-> \!*^G" ; vim \!* ;
cwdcmd'
  alias telnet '/bin/telnet \!* ; cwdcmd'
  alias rlogin '/usr/bin/rlogin \!* ; cwdcmd'
  cwdcmd
else
  set prompt="[%m]%~% "
endif
    1. Check to see if tcsh is running in an xterm.
    2. Set the prompt to show the current history event number.
    3. Set the alias cwdcmd to display the user, host, and current path
       in the xterm title bar, and set the icon name to the host name.
       cwdcmd is a special tcsh alias, which if set holds a command that
       will be executed after changing the value of $cwd.
    4. Set a vi alias to display the user, host, and file name under edit
       in the xterm title bar. And run cwdcmd on exit to restore the
       xterm title bar and icon name.
    5. Alias telnet and rlogin to restore the xterm title bar and icon
       name upon exit. NOTE: Paths to telnet and rlogin may vary.
    6. Run the alias cwdcmd to set the initial xterm title bar and icon
       name.
    7. If this wasn't an xterm, set the prompt to show hostname and path.
       Gary Masters
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  PPP REDIALER SCRIPT--A QUICK HACK
   Date: Sun, 08 Dec 1996 13:20:25 +0200
       From: Markku J. Salama, msalama@usa.net
       
       
       This here is the way I do it, but don't use it if your area has
       some regulations about redialing the same phone numbers over and
       over:

#!/bin/sh

# A quick hack for redialing with ppp by
# Tries 2 numbers sequentially until connected
# Takes 1 cmdline parm, the interface (ppp0, ppp1...)

# You need 2 copies of the ppp-on script (here called modemon{1,2}) with
# different telephone numbers for the ISP. These scripts should be
slightly
# customized so that the passwd is _not_ written in them, but is taken
# separately from the user in the main (a.k.a. this) script.

# Here's how (from the customized ppp-on a.k.a. modemon1):
# ...
# TELEPHONE=your.isp.number1 # Then make a copy of this script ->
modemon2
                             # and change this to your.isp.number2
# ACCOUNT=your.account
# PASSWD=$1                  # This gets the passwd from the main
script.
# ...

# /sbin/ifconfig must be user-executable for this hack to work.

wd1=1                                                   # counter start
stty -echo                                              # echo off
echo -n "Password: "                                    # for the ISP
account
read wd2
stty echo                                               # back on
echo
echo "Trying..."
echo 'ATE V1 M0 &K3 &C1 ^M' > /dev/modem                # modem init,
                                                        # change as
needed

/usr/sbin/modemon1 $wd2                                 # first try
flag=1                                                  # locked

while [ 1 ]; do                                         # just keep on
going

       if [ "$flag" = 1 ]; then                         # locked?

              bar=$(ifconfig | grep -c $1)        # check for a link

              if [ "$bar" = 1 ]; then                   # connected?
                     echo "Connected!"                  # if so, then
                     exit 0                             # get outta here
              else
                     foo=$(ps ax)                       # already
running?
                     blaat=$(echo $foo | grep "/usr/sbin/pppd")

                     if [ "$blaat" = "" ]; then         # if not, then
                            flag=0                      # unset lock
                     fi
              fi

       else                                             # no lock, ready
                                                        # to continue
              wd1=$[wd1+1]
              echo "Trying again... $wd1"

              if [ $[wd1%2] = 1 ]; then                 # this modulo
test
                     /usr/sbin/modemon1 $wd2            # does the
switching
              else                                      # between the 2
numbers
                     /usr/sbin/modemon2 $wd2            # we are using
              fi

              flag=1                                    # locked again

       fi

done                                                    # All done!
   There. Customize as needed & be an excellent person. Ant DON'T break
       any laws if redialing is illegal in your area!
       
       Mark
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  TABLE TAGS IN HTML
   Date: Fri, 20 Dec 1996 11:51:22 -0500
       From: Michael O'Keefe, Michael.OKeefe@LMC.Ericsson.SE 
       Organization: Ericsson Research Canada
       
       
       G'day,
       
       Just browsing through the mailbox, and I noticed your reply to a
       user about HTML standard compliance and long download times. You
       replied that you use the spiral image (a common thing these days)
       inside a <TABLE>.
       
       I hope you are aware that a browser cannot display any contents of
       a <TABLE> until it has received the </TABLE> tag (no matter what
       version of any browser - it is a limitation of the HTML tag)
       because the browser cannot run its algorithm until it has received
       all of the <TR> and <TD> tags, and it can't be sure of that until
       the </TABLE> tag comes through. I have seen many complex sites,
       using many images (thankfully they at least used the HEIGHT and
       WIDTH tags on those images to tell the browser how big the image
       will be so it didn't have to download it to find out) but still,
       putting it in a table nullifies much of the speediness that users
       require.
       
       A solution I often offer the HTML designers under me is to use a
       <DL><DD> combination. Though this doesn't technically fit the HTML
       DTD (certain elements are not allowed in a <DL>) and I use an
       editor that will not allow illegal HTML, so I can't do it myself
       (without going via a backdoor - but that's bad quality in my
       opionion). The downside of the this is of course that you don't
       know what sized FONT the user has set on the browser, and the FONT
       size affects the indetation width of the <DD> element. But if your
       spiral image is not too wide, then that could be made a NULL
       factor. The plus to the <DL><DD> is that the page can be displayed
       instantly as it comes down (again..providing the developer uses
       the HEIGHT and WIDTH attributes on *ALL* images so that the
       browser doesn't have to pause it's display to get the image and
       work out how to lay out around the image)
       
       Michael O'Keefe
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  TEXT FILE UNDELETE
   Date: Sat, 7 Dec 1996 15:00:58 +1300 (NZDT)
       From: Michael Hamilton, michael@actrix.gen.nz 
       
       
       Here's a trick I've had to use a few times.
       
       Desperate person's text file undelete.
       
       If you accidentally remove a text file, for example, some email,
       or the results of a late night programming session, all may not be
       lost. If the file ever made it to disk, ie it was around for more
       than 30 seconds, its contents may still be in the disk partition.
       
       You can use the grep command to search the raw disk partition for
       the contents of file.
       
       For example, recently, I accidentally deleted a piece of email. So
       I immediately ceased any activity that could modify that
       partition: in this case I just refrained from saving any files or
       doing any compiles etc. On other occasions, I've actually gone to
       the trouble of bring the system down to single user mode, and
       unmounted the filesystem.
       
       I then used the egrep command on the disk partition: in my case
       the email message was in /usr/local/home/michael/, so from the
       output from df, I could see this was in /dev/hdb5

  sputnik3:~ % df
  Filesystem         1024-blocks  Used Available Capacity Mounted on
  /dev/hda3              18621    9759     7901     55%   /
  /dev/hdb3             308852  258443    34458     88%   /usr
  /dev/hdb5             466896  407062    35720     92%   /usr/local

  sputnik3:~ % su
  Password:
  [michael@sputnik3 michael]# egrep -50 'ftp.+COL' /dev/hdb5 > /tmp/x
   Now I'm ultra careful when fooling around with disk partitions, so I
       paused to make sure I understood the command syntax BEFORE
       pressing return. In this case the email contained the word 'ftp'
       followed by some text followed by the word 'COL'. The message was
       about 20 lines long, so I used -50 to get all the lines around the
       phrase. In the past I've used -3000 to make sure I got all the
       lines of some source code. I directed the output from the egrep to
       a different disk partition - this prevented it from over writing
       the message I was looking for.
       
       I then used strings to help me inspect the output

  strings /tmp/x | less
   Sure enough the email was in there.
       
       This method can't be relied on, all, or some, of the disk space
       may have already been re-used.
       
       This trick is probably only useful on single user systems. On
       multi-users systems with high disk activity, the space you free'ed
       up may have already been reused. And most of use can't just rip
       the box out from under our users when ever we need to recover a
       file.
       
       On my home system this trick has come in handy on about three
       occasions in the past few years - usually when I accidentally
       trash some of the days work. If what I'm working survives to a
       point where I feel I made significant progress, it get's backed up
       onto floppy, so I haven't needed this trick very often.
       
       Michael
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  TRUNCATING /VAR/ADM/MESSAGES
   Date: Tue, 31 Dec 1996 15:32:57 GMT+100
       From: Michel Vanaken, michel@idtech.be
       Organization: IDtech
       
       
       Hi !
       
       About the topic "How to truncate /var/adm/messages", here's the
       way to do it with a shell script :

mv /var/adm/messages /var/adm/messages.prev
touch /var/adm/messages
mv /var/adm/syslog /var/adm/syslog.prev
touch /var/adm/syslog
kill -1 `ps x | grep syslog | grep -v grep | awk '{ print $1 }'`
   Happy new year !
       Michel
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  2C HOST TRICK
   Date: Tue, 10 Dec 1996 17:27:46 +0300
       From: Paul Makeev, mac@rosprint.ru
       
       
       In order to make DHCPD by ISC/Vixie to run under Linux, you should
       have route to host 255.255.255.255. Standard "route" from
       Slackware distribution does not like the string "route add -host
       255.255.255.255 dev eth0". But you can add hostname to your
       /etc/hosts file with address 255.255.255.255, and use "route add
       hostname dev eth0" instead. It works.
       
       Paul.
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  USE OF TCSH'S :E AND :R EXTENSIONS
   Date: Mon, 02 Dec 1996 23:25:23 -0500
       From: Bill C. Riemers, bcr@feynman.com
       
       
       I'd like to congratulate Jesper Pedersen on his article on tcsh
       tricks. Tcsh has long been my favorite shell. But most of the
       features Jesper hit upon are also found in bash. Tcsh's most
       useful and unique features are its variable/history suffixes.
       
       For example, if after applying a patch one wishes to undo things,
       by moving the *.orig files to there base names, the :r extension
       which means to strip the extension comes in handy. e.g.

 foreach a ( *.orig )
    mv $a $a:r
 end
   The same loop for ksh looks like:

  for a in *.orig; do=20
    mv $a `echo $a|sed -e 's,\.orig$,,g'`
  done
   Even better, one can use the :e extension to extract the file
       extension. For example, lets say we we want to do the same thing
       on compressed files:

  foreach a ( *.orig.{gz,Z} )
    mv $a $a:r:r.$a:e
  end
   The $a:r:r is the filename without .orig.gz and .orig.Z, we tack the
       .gz or .Z back on with .$a:e.
       
       Bill
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  VARIOUS NOTES ON 2C TIPS, GAZETTE 12
   Date: Wed, 04 Dec 1996 15:30:21 -0600
       From: Justin Dossey, dossey@ou.edu 
       
       
       I noticed a few overly difficult or unnecessary procedures
       recommended in the 2c tips section of Issue 12. Since there is
       more than one, I'm sending it to you:

#!/bin/sh
         # lowerit
         # convert all file names in the current directory to lower case
         # only operates on plain files--does not change the name of
directories
         # will ask for verification before overwriting an existing file
         for x in `ls`
           do
           if [ ! -f $x ]; then
             continue
             fi
           lc=`echo $x  | tr '[A-Z]' '[a-z]'`
           if [ $lc != $x ]; then
             mv -i $x $lc
           fi
           done
   Wow. That's a long script. I wouldn't write a script to do that;
       instead, I would use this command:

for i in * ; do [ -f $i ] && mv -i $i `echo $i | tr '[A-Z]' '[a-z]'`;
done;
   on the command line.
       
       The contributor says he wrote the script how he did for
       understandability (see below).
       
       On the next tip, this one about adding and removing users, Geoff
       is doing fine until that last step. Reboot? Boy, I hope he doesn't
       reboot every time he removes a user. All you have to do is the
       first two steps. What sort of processes would that user have
       going, anyway? An irc bot? Killing the processes with a simple

kill -9 `ps -aux |grep ^ |tr -s " " |cut -d " " -f2`
   Example, username is foo

kill -9 `ps -aux |grep ^foo |tr -s " " |cut -d " " -f2`
   That taken care of, let us move to the forgotten root password.
       
       The solution given in the Gazette is the most universal one, but
       not the easiest one. With both LILO and loadlin, one may provide
       the boot parameter "single" to boot directly into the default
       shell with no login or password prompt. From there, one may change
       or remove any passwords before typing ``init 3``to start multiuser
       mode. Number of reboots: 1 The other way Number of reboots: 2
       
       That's just about it. Thanks for the great magazine and continuing
       contribution to the Linux community. The Gazette is a needed
       element for many linux users on the 'net.
       
       Justin Dossey
       
       Date: Wed, 4 Dec 1996 08:46:24 -0800 (PST)
       Subject: Re: lowerit shell script in the LG 
       From: Phil Hughes, fyl@ssc.com 
       
       
       The amazing Justin Dossey wrote:

> #!/bin/sh
> for i in * ; do [ -f $i ] && mv -i $i `echo $i | tr '[A-Z]' '[a-z]'`;
> done;
>
> may be more cryptic than
...
>
> but it is a lot nicer to the system (speed & memory-wise) too.
   Can't argue. If I had written it for what I considered a high usage
       situation I would have done it more like you suggested. The
       intent, however, was to make something that could be easily
       understood.
       
       Phil Hughes
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  VIEWING HOWTO DOCUMENTS
   Date: Sun, 22 Dec 1996 09:43:40 -0800
       From: Didier Juges, dj@destin.nfds.net
       
       
       >From a newbie to another, here is a short script that eases
       looking for and viewing howto documents. My howto's are in
       /usr/doc/faq/howto/ and are gzipped. The file names are
       XXX-HOWTO.gz, XXX being the subject. I created the following
       script called "howto" in the /usr/local/sbin directory:

#!/bin/sh
if [ "$1" = "" ]; then
    ls /usr/doc/faq/howto | less
else
    gunzip -c /usr/doc/faq/howto/$1-HOWTO.gz | less
fi
   When called without argument, it displays a directory of the available
       howto's. Then when entered with the first part of the file name
       (before the hyphen) as an argument, it unzips (keeping the
       original intact) then displays the document.
       
       For instance, to view the Serial-HOWTO.gz document, enter: $ howto
       Serial
       
       Keep up the good work.
       
       Didier
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  XAW-XPM .XRESOURCES TROUBLESHOOTING TIP.
   Date: Wed, 18 Dec 1996 17:02:07 +0100 (GMT+0100)
       From: Robin Smidsroed, dex@sysedata.no
       
       
       I'm sure a lot of you folks out there have installed the new
       Xaw-XPM and like it a lot. But I've had some trouble with it. If I
       don't install the supplied .Xresources-file, xcalc and some other
       apps (ghostview is one) segfaults whenever you try to use them.
       
       I found out that the entry which causes this, is this:

*setPixmap: /path/to/an/xpm-file
   If this entry isn't in your .Xresources, xcalc and ghostview won't
       work. Hope some of you out there need this.
       
       And while you're at ghostview, remember to upgrade ghostscript to
       the latest version to get the new and improved fonts, they
       certainly look better on paper than the old versions.
       
       Ciao!
       Robin
       
       PS: Great mag, now I'm just waiting for the arrival of my copy of
       LJ
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  XTERM TITLE BAR
   Date: Wed, 18 Dec 1996 21:21:47 -0800 (PST) From: bradshaw@nlc.com
       (Lee Bradshaw)
       
       Hi Guys,
       
       I noticed the "alias for cd xterm title bar tip" from Michael
       Hammel in the Linux Gazette and wanted to offer a possible
       improvement for your .bashrc file. A similar solution might work
       for ksh, but you may need to substitute $HOSTNAME for \h, etc:

if [ "x$TERM" = "xxterm" ]; then
   PS1='\h \w-> \[\033]0;\h \w\007\]'
else
   PS1='\h \w-> '
fi
   PS1 is an environment variable used in bash and ksh for storing the
       normal prompt. \h and \w are shorthand for hostname and working
       directory in bash. The \[ and \] strings enclose non-printing
       characters from the prompt so that command line editing will work
       correctly. The \O33]0; and \007 strings enclose a string which
       xterm will use for the title bar and icon name. Sorry, I don't
       remember the codes for setting these independently. (ksh users
       note: \033 is octal for ESC and \007 is octal for CTRL-G.) This
       example just changes the title bar and icon names to match the
       prompt before the cursor.
       
       Any program which changes the xterm title will cause
       inconsistencies if you try an alias for cd instead of PS1.
       Consider rlogin to another machine which changes the xterm title.
       When you quit rlogin, there is nothing to force the xterm title
       back to the correct value when using the cd alias (at least not
       until the next cd). This is not a problem when using PS1.
       
       You could still alias vi to change the xterm title bar, but it may
       not always be correct. If you use ":e filename" to edit a new
       file, vi will not update the xterm title. I would suggest
       upgrading to vim (VI iMproved). It has many nice new features in
       addition to displaying the current filename on the xterm title.
       
       Hopefully this tip is a good starting point for some more
       experimenting. Good luck!
       
       Lee Bradshaw, bradshaw@nlc.com
       
       
         _____________________________________________________________
       
       
       
       [ 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
   
       
       
         _____________________________________________________________
       
       
       
  SECURITY: (LINUX-ALERT) LSF UPDATE#14: VULNERABILITY OF THE LPR PROGRAM.
   
       
       Date: Sat, 26 Nov 1996
       Linux Security FAQ Update -- lpr Vulnerability
       A vulnerability exists in the lpr program version 0.06. If
       installed suid to root, the lpr program allows local users to gain
       access to a super-user account.
       
       Local users can gain root privileges. The exploits that exercise
       this vulnerability were made available.
       
       lpr utility from the lpr 0.06 suffers from the buffer overrun
       problem. Installing lpr as a suid-to-root is needed to allow print
       spooling.
       
       This LSF Update is based on the information originally posted to
       linux-security mailing list.
       
       For additional information and distribution corrections:
       Linux Security WWW:
       http://bach.cis.temple.edu/linux/linux-security linux-security &
       linux-alert mailing list archives:
       ftp://linux.nrao.edu/pub/linux/security/list-archive 
       
       
         _____________________________________________________________
       
       
       
  LINUXEXPO '97 TECHNICAL CONFERENCE
   
       
       Durham, N.C. December 31,1996-- It was announced today that the
       third annual LinuxExpo Technical Conference will be held at the
       N.C. Biotechnology Center in Research Triangle Park, NC on April
       4-5, 1997. The conference will consist of fourteen elite
       developers who will give technical talks on various topics all
       related to the development of Linux. This year the event is
       expected to draw 1,000 attendees who will be coming not only for
       the conference, but to visit the estimated 30 Linux companies and
       organizations that will be selling their own Linux products and
       giving demonstrations. The event will also include a Linux User's
       Group meeting, an install fair, and a job fair for all of the
       computer programming hopefuls. LinuxExpo '97 will be complete with
       refreshments and entertainment from the Class Action Jugglers.
       
       For addtional information: Anna Selvia, anna@linuxexpo.org 
       LinuxExpo '97 Technical Conference, www.linuxexpo.org
       3201 Yorktown Ave. Suite 113
       Durham, NC 27713
       
       
         _____________________________________________________________
       
       
       
  WWW: LINUX ARCHIVE SEARCH SITE
   
       
       Date: Thu, 21 Nov 1996
       Tired of searching sunsite or tsx-11 for some program you heard
       about on irc? Well, the Linux Archive Search (LAS) is here. It is
       a search engine that searches an updated database of the files
       contained on sunsite.unc.edu, tsx-11.mit.edu, ftp.funet.fi, and
       ftp.redhat.com. You can now quickly find out where the files are
       hiding! The LAS is living at http://torgo.ml.org/las (It may take
       a second to respond, its on a slow link). So give it a whirl, who
       knows, you may use it a lot!
       
       For additional information:
       Jeff Trout, threshar@serve.com 
       The Internet Access Company, Inc.
       
       
       
         _____________________________________________________________
       
       
       
  NETHERLANDS - LINUX BOOK ON-LINE
   
       
       Date: Thu, 05 Dec 1996
       The very first book to appear in Holland on the Linux operating
       system has gone on-line and can be found at:
       
       http://www.cv.ruu.nl/~eric/linux/boek/
       
       And of course from every (paper) copy sold, one dollar is sent to
       the Free Software Foundation. For additional information:
       Hans Paijmans, KUB-University, Tilburg, the Netherlands
       paai@kub.nl , http://purl.oclc.org/NET/PAAI/ 
       
       
         _____________________________________________________________
       
       
       
  NEW O'REILLY LINUX WWW SITE
   Date: 26 Nov 1996
       
       
       Check out the new O'Reilly & Associates, Inc. Linux web site at
       http://www.ora.com/info/linux/ 
       
       It has:
          + Free excerpt from Linux Multimedia Guide
          + Interview with Olaf Kirch
          + Recommended links to the best Linux web sites.
          + Links to our Unix & Linux book pages
   For additional information:
       O'Reilly & Associates, Inc., john@ora.com 
       
       
         _____________________________________________________________
       
       
       
  PCTV REMINDER
   
       
       The "Unix III - Linux" show will air on the Jones Computer Network
       (JCN) and the Mind Extension University Channel (MEU) the week of
       January 20, 1997.
       
       The scheduled times are:
          + Mon. 11:30 PM - 12:00 AM
          + Wed. 9:30 PM - 10:00 PM
          + Thu. 11:30 PM - 12:00 AM
          + Fri. 9:30 PM - 10:00 PM
          + Sun. 9:30 PM - 10:00 PM
   This show will also air on the NBC Superchannel (CNBC) January 25,
       1997.
       
       It is best to call your local cable operator to find the
       appropriate channel.
       
       Tom Schauer, Production Assoc. PCTV 
       
       
       
       
         _____________________________________________________________
       
       
       
  SOFTWARE ANNOUNCEMENTS
   
       
       
         _____________________________________________________________
       
       
       
  DAVINCI V2.0.2 - GRAPH VISUALIZATION SYSTEM
   
       
       November 20, 1996 (Bremen, Germany) - The University of Bremen
       announces daVinci V2.0.2, the new edition of the noted
       visualization tool for generating high-quality drawings of
       directed graphs with more than 2000 installations worldwide. Users
       in the commercial and educational domain have already integrated
       daVinci as user interface for their application programs to
       visualize hierarchies, dependency structures, networks,
       configuration diagrams, dataflows, etc. daVinci combines
       hierarchical graph layout with powerful interactive capabilities
       and an API for remote access from a connected application. In
       daVinci V2.0.2, a few extensions related to improving performance
       and usage of the previous V2.0.1 release have been made based on
       user feedback.
       
       daVinci V2.0.2 is licensed free of charge for non-profit use and
       is immediately available Linux. The daVinci system can be
       downloaded with this form:
       
       http://www.informatik.uni-bremen.de/~davinci/daVinci_get_daVinci.h
       tml 
       
       For additional information:
       Michael Froehlich, daVinci Graph Visualization Project
       Computer Science Department, University of Bremen, Germany
       http://www.informatik.uni-bremen.de/~davinci ,
       daVinci@Informatik.Uni-Bremen.DE 
       
       
         _____________________________________________________________
       
       
       
  WWW: GETWWW 1.3 - DOWNLOAD AN ENTIRE HTML SOURCE TREE
   
       
       Date: Wed, 04 Dec 1996
       Getwww is designed to download an entire HTML source tree from a
       remote URL, recursively changing image and hypertext links.
       
       From the LSM:
       Primary-site: ftp.kaist.ac.kr /incoming/www 25kB
       getwww++-1.3.tar.gz
       Alternate-site: sunsite.unc.edu
       /pub/Linux/system/Network/info-systems/www 25kB
       getwww++-1.3.tar.gz
       Platform: Linux-2.0.24
       Copying-policy: GPL
       
       
       For additional information:
       In-sung Kim, Network Tool Group, kisskiss@soback.kornet.nm.kr
       
       
         _____________________________________________________________
       
       
       
  MOTIF INTERFACE BUILDER ON UNIFIX 2.0
   
       
       Date: Sun, 01 Dec 1996
       Unifix Software GmbH is proud to announce View Designer/X, a new
       Motif interface builder available for Linux. A demo version of VDX
       is included on Unifix Linux 2.0.
       
       With object oriented and interactive application development
       tools, the software developer is able to design applications with
       better quality and in shorter times.
       
       For more information and to download the latest demo version, see:
       
       
       http://www.unifix.de/products/vdx 
       
       For additional information: Unifix Software GmbH, info@unifix.de 
       
       
         _____________________________________________________________
       
       
       
  VIEW DESIGNER/X
   Date: Fri, 13 Dec 1996
       
       
       View Designer/X, a new Motif Interface Builder for Linux has been
       released. It enables application developers to design user
       interfaces with Motif 2.0 widgets and to generate C and C++ code.
       The VDX provides an interactive Wysiwyg View and a Widget Tree
       Browser which can be used to modify the structure of the user
       interface. All resources are adjustable by Widget Resource Editor
       and by using template files the code generation of VDX is more
       flexible than those of other interface builders.
       
       Bredex GmbH, Germany is distributing the View Designer/X via Web
       service. Please see following web page for more information and
       downloading the free demo version:
       
       http://www.bredex.de/EN/vdx/
       
       Dirk Laessig, dirk@unifix.de
       
       
         _____________________________________________________________
       
       
       
  X-FILES 1.21 - GRAPHICAL FILE MANAGER IN TCL/TK
   Date: Sun, 01 Dec 1996
       
       
       X-Files is a graphical file management program for Unix/X-Window
       environment developed on Linux.
       
       For more information and packages see:
       http://pinhead.tky.hut.fi/~xf_adm/
       http://www.hut.fi/~mkivinie/xfindex.html
       java.inf.tu-dresden.de:/pub/unix/x-files
       
       For questions:
       xf_adm@pinhead.tky.hut.fi
       
       
       For additional information:
       Mikko Kiviniemi, mkivinie@cc.hut.fi , jforsten@cc.hut.fi 
       Helsinki University of Technology
       
       
         _____________________________________________________________
       
       
       
       [ 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
   
       
       
         _____________________________________________________________
       
       
       
  CONTENTS:
    8. Dialup Problem
    9. File Referencing
   10. Combining Modems for More Speed
   11. WWW Server
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  COMBINING MODEMS FOR MORE SPEED
   Date: Mon, 23 Dec 1996 23:37:00 -0800 (PST)
       From: liberty@pe.net (Keith)
       
       
       Thanks for reading this post. I have heard that it's possible to
       set up Linux to combine two analog modems into one so as to double
       the speed of a connection. Is this true, how does this work and
       where can I get more info, guidance, how-to, etc.? I have
       Slackware 96 from Infomagic. Your truly, Keith Bell
       
     I've heard of this as well. I've never used it but let's look it
     up...
     
     Ahh... that would be the EQL option in the kernel. Here's an
     excerpt from the 'make menuconfig' help pages (in the 2.0.27 kernel
     sources):
     
     Linux Kernel v2.0.27 Configuration
     
     EQL (serial line load balancing) support:
     If you have two serial connections to some other computer (this
     usually requires two modems and two telephone lines) and you use
     SLIP (= the protocol for sending internet traffic over telephone
     lines) or PPP (= a better SLIP) on them, you can make them behave
     has to be supported at the other end as well, either with a similar
     EQL Linux driver or with a Livingston Portmaster 2e. Say Yes if you
     want this and read drivers/net/README.eql.
     
     So that file is :
     EQL Driver: Serial IP Load Balancing HOWTO
     Simon "Guru Aleph-Null" Janes, simon@ncm.com
     v1.1, February 27, 1995
     
     
     (After reading this you'll know about as much on this subject as I
     do -- after using any of this you'll know *much* more). 
   
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  DIALUP PROBLEM
   Date: Tue, 31 Dec 1996 05:13:51 -0800 (PST)
       From: gekko@midusa.net
       
       
       I don't know if you can, or even are willing, help me witha
       problem i have. I'm running redhat 4.0, on a p120 w/24 megs of
       ram, kernel 2.0.18
       
     I'm willing. 
   anyway...i have this ppp connection problem and no I know knows what
       the problem is, i've looked through the FAQS, HOWTO's, tried
       #linux on irc, etc etc...no one knows what my problem is, so now
       i'm desperate.
       
       When i try to dial my isp, i get logged in fine, but its REALLY
       slow. i'm using the 'network module' ppp thing in control panel on
       X. mru=1500, asyncmap=0,speed=115000, i couldn't find a place to
       insert mtu, and when i tried putting that in /etc/ppp/options the
       script this program was using wouldn't work.
       
     Usually I see these symptoms when there is an IRQ conflict. Some of
     the data gets through -- with lots of errors and lots of
     retransmits but any activity on the rest of the machine -- or even
     just sitting there -- and you get really bad throughput and very
     unreliable connections. 
   I noticed that after i input something and then move the cursor off of
       the windows, it runs at a much faster speed, and it gets annoying
       moving the cursor back and forth. I tried dip, minicom, and this
       'network module' thing...all are slow
       
     I would do all of your troubleshooting from outside of X. Just use
     the virtual consoles until everything else works right. (Fewer
     layers of things to conflict with one another). 
   if you can shed any light on this, it would be much appreciated.
       thanks
       
     Take a really thorough look at the hardware settings for everything
     in the machine. Make a list of all the cards and interfaces -- go
     through the docs for each one and map out which ones are using
     which interfaces.
     
     I ended up going through several combinations of video cards and
     I/O cards before I got my main system all integrated. Luckily newer
     systems are getting better (this is a 386DX33 with 32Mb of RAM and
     a 2Mb video cards -- two IDE's, two floppy drives, two SCSI
     hardisks, an internal CD-ROM, and external magneto optical drive, a
     serial mouse, a modem (used for dial-in dial-out, uucp, and ppp)
     and null modem (I hook a laptop to it as a terminal for my wife)
     and an ethernet card.
     
     Another thing to check is the cabling between your serial connector
     and your modem. If you're configured for XON/XOFF you're in
     trouble. If you're configured for hardware flow control and you
     don't have the appropriate wires in your cable than you're in worse
     trouble.
     
     Troubleshooting of this sort really is best done over voice or in
     person. There are too many steps to the troubleshooting and testing
     to do effectively via e-mail. 
   
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  FILE REFERENCING
   Date: Wed, 18 Dec 1996 00:16:42 -0800 (PST)

> "A month of sundays ago L.U.S.T List wrote:"
>>      1. I do not know why on Linux some program could not run
>>      correctly.
>>              for example
>>      #include
>>      main()
>>      {
>>              printf("test\n");
>>              fflush(stdout);
>>      }
>>      They will not echo what I print.
>
> Oh yes it will. I bet you named the executable "test" ... :-)
> (this is a UNIX faq).
>

     I really suggest that people learn the tao of "./"
     
     This is easy -- any time you mean to refer to any file in the
     current directory precede it with "./" -- this forces all common
     Unix shells to refer to the file in THIS directory. It solves all
     the problems with files that start with dashes and it allows you to
     remove :.: from your path (which *all* sysadmins should do right
     NOW).
     
     That is the tao of "./" -- the two keystrokes that can save you
     many hours of grief and maybe save your whole filesystem too. 
   
       
       
         _____________________________________________________________
       
       
       
       
       
       
       
  WWW SERVER?
   Date: Tue, 31 Dec 1996 05:19:11 -0800 (PST)
       From: (Paulo Marcio Villaca Veiga) paulom@cedro.fisica.ufmg.bri
       
       
       Where can I get (or buy) a WWW server for LINUX?
       Please, help me.
       
     Web servers are included with most distributions of Linux. The most
     popular one right now is called Apache. You can look on your CD's
     (if you bought a set) or you can point a web client (browser) at
     http://www.apache.org for more information and for an opportunity
     to download a copy.
     
     There are several others available -- however Apache is the most
     well known -- so it will be the best for you to start with. It is
     also widely considered to offer the best performance and feature
     set (of course that is a matter of considerable controversy among
     "connosieurs" just as is the ongoing debate about 'vi' vs.
     'emacs'). 
   thank you
       
     You're welcome. 
   
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, James T. Dennis
      Published in Issue 13 of the Linux Gazette
   
       
       
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    "Linux Gazette...making Linux just a little more fun! "
   
       
       
         _____________________________________________________________
       
       
       
                                  COMDEX '96
                                       
    By Belinda Frazier, bel@ssc.com and Kevin Pierce, kevin@ssc.com
   
       
       
         _____________________________________________________________
       
       
       
       Comdex/Fall '96 has come and gone once again. COMDEX is the second
       largest computer trade show in the world, offering multiple
       convention floors with 2000 exhibitors plying their new computer
       products to approximately 220,000 attendees in Las Vegas, Nevada
       in November of 1996.
       
       This year's show was a great success for Linux in general. The
       first ever ``Linux Pavilion'' was organized at the Sands
       Convention Center and Linux vendors from all over the country
       participated. The Linux International (LI) booth was in the
       center, giving away literature and information for all the Linux
       Vendors. Linux International is a not-for-profit organization
       formed to promote Linux to computer users and organizations.
       Staffed by volunteers including Jon ``Maddog'' Hall and Steve
       Harrington, the LI booth was a great place for people to go to
       have their questions answered. Needless to say, the Linux
       International Booth was never empty. Surrounding LI, were Red Hat
       Software and WorkGroup Solutions.
       
       Other vendors in the pavilion included Craftwork Solutions, DCG
       Computers, Digital Equipment Corporation, Frank Kasper &
       Associates, Infomagic, Linux Hardware Solutions, SSC (publishers
       of Linux Journal), and Yggdrasil Computing. Caldera, Pacific
       HiTech, and Walnut Creek both exhibited at Comdex, but not as part
       of the Linux Pavilion.
       
       SSC gave out Linux Journals at the show and actually ran out of
       magazines early Thursday morning. Luckily, we were able to have
       some more shipped to us, but we still ran out again on Friday, the
       last day of the show. Comdex ran five full days and the Sands
       pavilion was open from 8:30 to 6 most show days which meant long
       days for all the exhibitors there.
       
       Show management put up signs, directing attendees to the Linux
       Pavilion and to "more Linux vendors". The show was so large that
       it was easy to get lost.
       
       At the LI booth and at SSC's booth, the response to Linux was
       overwhelmingly positive. Questions ranged from ``I've heard a lot
       about Linux, but I'm not sure what it is, can you enlighten me?''
       to ``I haven't checked for a few days---what is the latest
       development kernel?''
       
       For next year's Comdex in November '97, Linux vendors, coordinated
       by Linux International, are already working to put together a
       Linux pavilion at least three times as big as the one this year.
       
       Vendors interested in being part of the Linux pavilion in November
       '97 may contact Softbank who put on Comdex at mandino@comdex.com
       or to do this through Linux International, contact ``Jon Maddog''
       Hall via e-mail at maddog@zk3.dec.com.
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Belinda Frazier & Kevin Pierce
      Published in Issue 13 of the Linux Gazette
   
       
       
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             FILTERING ADVERTISEMENTS FROM WEB PAGES USING IPFWADM
                                       
    By David Rudder drig@magicweb.com
   
       
       
         _____________________________________________________________
       
       
       
       Lately, a lot of Web pages have begun selling ad space "banners."
       Wasting valuable bandwidth, these banners often hawk products I
       don't care to hear about. I'd rather not see them, and not have to
       download their contents.
       
       There are two ways of filtering out these banners. The first is to
       deny all pictures that are wider than tall and generally towards
       the top or bottom of the page. The second is to simply block all
       the accesses to and from the web sites that are the notorious
       advertisers. This second approach is the one I'm going to take.
       
       When searching around the web, you will see that many of the
       banners come from the site ad.linkexchange.com. This is the site
       we will want to ban.
       
       
         _____________________________________________________________
       
       
       
  SETTING UP YOUR FIREWALL
   
       
       Our first order of business is to set up our firewall. We won't be
       using it for security, although this doesn't prohibit also using
       the firewall for security. First, we recompile the kernel, saying
       "Yes" to CONFIG_FIREWALL. This allows us to use the built in
       kernel firewalling.
       
       Then, we need to get the IPFWADM utility. You can find it at:
       http://www.xos.nl/linux/ipfwadm . Untar, compile and install
       this utility.
       
       Since we are doing no other firewalling, this should be
       sufficient.
       
       
         _____________________________________________________________
       
       
       
  BLOCKING UNWANTED SITES
   
       
       Now, we come to the meat of the maneuver. We need now to block
       access to our machine from ad.linkexchange.com. First, block out
       access to the sight, so that our requests don't even make it
       there. ipfwadm -O -a reject -P tcp -S 0.0.0.0/0 -D
       ad.linkexchange.com 80
       
       
       This tells ipfwadm to append a rule to the Output filter. The rule
       says to reject all packets of protocol TCP from anywhere to
       ad.linkexchange.com on port 80. If you don't get this, read Chris
       Kostick's excellent article on IP firewalling at
       http://www.ssc.com/lj/issue24/1212.html.
       
       The next rule is to keep any stuff from ad.linkexchange.com from
       coming in. Technically, this shouldn't be necessary. If we haven't
       requested it, it shouldn't come. But, better safe than sorry.
       ipfwadm -I -a reject -P tcp -S ad.linkexchange.com 80 -D 0.0.0.0/0
       
       
       Now, all access to and from ad.linkexchange.com is rejected.
       
       Note: this will only work when web browsing from that machine. To
       filter for a whole network, do them same but with -F instead of -O
       and -I.
       
       
         _____________________________________________________________
       
       
       
  TESTING IT OUT
   
       
       To test, visit the site http://www.reply.net. They have a banner
       on top which should either not appear or appear as a broken icon.
       Either way, no network bandwidth will be wasted downloading the
       picture, and all requests will be rejected immediately.
       
       
         _____________________________________________________________
       
       
       
  FILLING IT OUT
   
       
       Not all banners are so easily dealt with. Many companies, like
       Netscape, host their own banners. You don't want to block access
       to Netscape, so this approach won't work. But, you will find a
       number of different advertisers set up like linkexchange. As you
       find more, add them to the list of rejected sites. Good luck, and
       happy filtering!
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, David Rudder
      Published in Issue 13 of the Linux Gazette
   
       
       
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                               FLOPPY DISK TIPS
                                       
    By Bill Duncan, VE3IED, bduncan@beachnet.org
   
       
       
         _____________________________________________________________
       
       
       
       
       
       Although more computers are becoming network connected every day,
       there are many instances where you need to transfer files by the
       ol' sneaker-net method. Here are some hints, tips and short-cuts
       for doing this, aimed at users who are new to Linux or Unix.
       (There may even be some information useful to old-timers...)
          + Formatting, Filesystems and Mounting
          + Backups, Cpio and Gzip
          + Floppy as a Raw Device for Large Files or Directories
          + Miscellaneous
   
       
       What do I use floppies for? As a consultant, I frequently do
       contract work for companies which, because of security policies,
       do not connect to the 'Net. So, FTP'ing files which I need from my
       network at home is out of the question.
       
       My current contract as an example, I am using Linux as an
       X-Windows terminal for developing software on their DEC Alphas
       running OSF. (I blew away the Windoze '95 which they had loaded on
       the computer they gave me.) I often need to bring files with me
       from my office at home, or backup my work to take back home for
       work in the evening. (Consultants sometimes work flex-hours, which
       generally means more hours...)
       
       
       
       Why use cpio(1) or tar(1) when copying files? Because it is a
       portable method of transferring files from a group of
       subdirectories with the file dates left intact. The cp(1) command
       may or may not do the job depending on Operating Systems and
       versions you are dealing with. In addition, specifying certain
       options will only copy files which are new or have changed.
       
       
       
       
         _____________________________________________________________
       
       
       
       
       
Formatting, Filesystems and Mounting

   
       
       
         _____________________________________________________________
       
       
       
       The first thing you need to do to make the floppies useful is to
       format them, and usually lay down a filesystem. There are also
       some preliminary steps which make using floppy disks much easier,
       which is the point of this article.
       
       I find it useful to make my username part of the floppy group in
       the /etc/group file. This saves you from needing to su to root
       much of the time. (You will need to log out and log back in again
       for this to take effect.) I also use the same username both on the
       client's machine and my home office which saves time. The line
       should now look like this:

floppy::11:root,username
   
       
       The following setup is assumed for the examples I present here.
       The root user must have the system directories in the PATH
       environment variable. Add the following to the .profile file in
       /root if not already there by su'ing to root.

su -   # this should ask for the root password.
cat >> .profile
PATH=/sbin:/usr/sbin:$PATH
<ctrl>-D
   You can also use your favorite editor to do this... I prefer vim(1)
       and have this symlinked to /usr/bin/vi instead of elvis(1) which
       is usually the default on many distributions. VIM has online help,
       and multiple window support which is very useful! (A symlink is
       created with a -s option to ln(1), and is actually called a
       symbolic link.)
       
       Next, add the following lines to the /etc/fstab file: (I have all
       the user mountable partitions in one place under /mnt. You may
       want a different convention, but this is useful. I also have
       /mnt/cdrom symlinked to /cd for convenience.)

/dev/fd0    /mnt/fd0  ext2    noauto,user 1 2
   
       
       Still logged in as root, make the following symlink: (If you have
       more than one floppy drive, then add the floppy number as well.)

ln  -s  /mnt/fd0  /fd

    -or-

ln  -s  /mnt/fd0  /fd0
   These two things make mounting and unmounting floppies a cinch. The
       mount(8) command follows the symlink and accesses the /etc/fstab
       file for any missing parameters, making it a useful shortcut.
       
       To make the floppy usable as an ext2fs Linux filesystem, do the
       following as root: (The username is whatever username you use on
       regularly on the system. You, of course, should not use the root
       user for normal use!)

export PATH=/sbin:/usr/sbin:$PATH   # not needed if you set environment
fdformat /dev/fd0
mke2fs /dev/fd0
mount /dev/fd0 /mnt/fd0
chown username /mnt/fd0
   You may need to specify the geometry of the floppy you are using. If
       it is the standard 3.5 inch double sided disk, you may need to
       substitute /dev/fd0H1440 for the device name (in 1.2.x kernels).
       If you have a newer 2.xx kernel and superformat(1), you may want
       to substitute this for fdformat. See the notes in the
       Miscellaneous section below, or look at the man page. You may
       now exit out of su(1) by typing:

exit
   
       
       From this point on, you may use the mount(8) and umount(8)
       commands logged in as your normal username by typing the
       following:

mount /fd
umount /fd
   
       
       
         _____________________________________________________________
       
       
       
       
       
Backups, Cpio and Gzip

   
       
       
         _____________________________________________________________
       
       
       
       
       
       For backing up my work to take home or to take back to the office
       I use cpio(1) instead of tar(1) as it is far more flexible, and
       better at handling errors etc. To use this on a regular basis,
       first create all the files you need by specifying the command
       below without the -mtime -1 switch. Then you can make daily
       backups from the base directory of your work using the following
       commands:

cd directory
mount /fd
find . -mtime -1 -print | cpio -pmdv /fd
sync
umount /fd
   
       
       When the floppy stops spinning, and the light goes out, you have
       your work backed up. The -mtime option to find(1) specifies files
       which have been modified (or created) within one day (the -1
       parameter). The options for cpio(1) specify copy-pass mode, which
       retain previous file modification times, create directories where
       needed, and do so verbosely. Without a -u (unconditional) flag, it
       will not overwrite files which are the same age or newer.
       
       This operation may also be done over a network, either from NFS
       mounted filesystems, or by using a remote shell as the next
       example shows.

mount /fd
cd /fd
rsh  remotesystem '(cd directory; find . -mtime -1 -print | cpio -oc)' |
     cpio -imdcv
sync
cd
umount /fd
   This example uses cpio(1) to send files from the remote system, and
       update the files on the floppy disk mounted on the local system.
       Note the pipe (or veritical bar) symbol at the end of the remote
       shell line. The arguments which are enclosed in quotes are
       executed remotely, with everything enclosed in braces happening in
       a subshell. The archive is sent as a stream across the network,
       and used as input to the cpio(1) command executing on the local
       machine. (If both systems are using a recent version of GNU cpio,
       then specify -Hcrc instead of c for the archive type. This will do
       error checking, and won't truncate inode numbers.)
       The remote system would have: cpio -oHcrc
       and the local side would have: cpio -imdvHcrc
       
       
       
       To restore the newer files to the other computer, change
       directories to the base directory of your work, and type the
       following:

cd directory
mount -r /fd
cd /fd
find . -mtime -1 -print | cpio -pmdv ~-
cd -
umount /fd
   
       
       If you needed to restore the files completely, you would of course
       leave out the -mtime parameter to find(1).
       
       
       
       The previous examples assume that you are using the bash(1) shell,
       and uses a few quick tricks for specifying directories. The "~-"
       parameter to cpio is translated to the previous default directory.
       In other words, where you were before cd'ing to the /fd directory.
       (Try typing: echo ~- to see the effect, after you have changed
       directories at least once.) The cd ~- or just cd - command is
       another shortcut to switch directories to the previous default.
       These shortcuts often save a lot of time and typing, as you
       frequently need to work with two directories, using this command
       to alternate between them or reference files from where you were.
       
       If the directory which you are tranferring or backing up is larger
       than a single floppy disk, you may need to resort to using a
       compressed archive. I still prefer using cpio(1) for this,
       although tar(1) will work too. Change directories to your work
       directory, and issue the following commands:

cd directory
mount /fd
find . -mtime -1 -print | cpio -ovHcrc | gzip -v > /fd/backup.cpio.gz
sync
umount /fd
   The -Hcrc option to cpio(1) is a new type of archive which older
       versions of cpio might not understand. This allows error checking,
       and inode numbers with more than 16 bits.
       
       Of course, your original archive should be created using find(1)
       without the -mtime -1 options. 
       
       
         _____________________________________________________________
       
       
       
       
       
Floppy as a Raw Device for Large Files or Directories

   
       
       
         _____________________________________________________________
       
       
       
       Sometimes it is necessary to backup or transfer a file or
       directories which are larger than a floppy disk, even when
       compressed. For this, we finally need to resort to using tar.
       
       Prepare as many floppies as you think you'll need by using the
       fdformat(8) command. You do not need to make filesystems on them
       however, as you will be using them in raw mode.
       
       If you are backing up a large set of subdirectories, switch to the
       base subdirectory and issue the following command:

cd directory
tar  -cv -L 1440 -M -f /dev/fd0  .
   This command will prompt you when to change floppies. Wait for the
       floppy drive light to go out of course!
       
       If you need to backup or transfer multiple files or directories,
       or just a single large file, then specify them instead of the
       period at the end of the tar command above.
       
       Unpacking the archive is similar to the above command:

cd directory
tar  -xv -L 1440 -M -f /dev/fd0
   
       
       
         _____________________________________________________________
       
       
       
       
       
Miscellaneous

   
       
       
         _____________________________________________________________
       
       
       
       Finally, here are some assorted tips for using floppies.
       
       The mtools(1) package is great for dealing with MS-DOG floppies,
       as we sometimes must. You can also mount(8) them as a Linux
       filesystem with either msdos or umsdos filesystem types. Add
       another entry to the /etc/fstab entry you made before, so that the
       two lines will look like this:

/dev/fd0    /mnt/fd0  ext2    noauto,user 1 2
/dev/fd0    /mnt/dos  msdos   noauto,user 1 2
   You can now mount an MS-DOS floppy using the command:

mount /mnt/dos
   You can also symlink this to another name as a further shortcut.

ln -s /mnt/dos /dos
mount /dos
   
       
       The danger of using the mount(8) commands rather than mtools(1)
       for users who are more familiar with MSDOS, is that you need to
       explicitly unmount floppies before taking them out of the drive
       using umount(8). Forgetting this step can make the floppy
       unusable! If you are in the habit of forgetting, a simple low-tech
       yellow Post-it note in a strategic place beside your floppy drive
       might save you a few headaches. If your version of Post-it notes
       has the <BLINK> tag, use it!   ;-)
       
     "umount me first!"
   
       
       Newer systems based on the 2.xx kernel are probably shipped with
       fdutils. Check to see if you have a /usr/doc/fdutils-xxx
       directory, where xxx is a version number. (Mine is 4.3). Also
       check for the superformat(1) man page. This supersedes fdformat(1)
       and gives you options for packing much more data on floppies. If
       you have an older system, check the
       ftp://ftp.imag.fr/pub/Linux/ZLIBC/fdutils/ ftp site for more
       information.
       
       The naming convention for floppies in newer 2.xx kernels has also
       changed, although the fd(4) man page has not been updated in my
       distribution. If you do not have a /dev/fd0H1440 device, then you
       probably have the newer system.
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Bill Duncan
      Published in Issue 13 of the Linux Gazette
   
       
       
         _____________________________________________________________
       
       
       
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         _____________________________________________________________
       
       
       
       
       
       
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    "Linux Gazette...making Linux just a little more fun! "
   
       
       
         _____________________________________________________________
       
       
       
       Welcom to the Graphics Muse Set your browser to the width of the
       line below for best viewing.
       &copy 1996 by mjh
         _____________________________________________________________
       
       --> Button Bar --> muse:
         1. v; to become absorbed in thought
         2. n; [ fr. Any of the nine sister goddesses of learning and the
            arts in Greek Mythology ]: a source of inspiration
   W elcome to the Graphics Muse! Why a "muse"? Well, except for the
       sisters aspect, the above definitions are pretty much the way I'd
       describe my own interest in computer graphics: it keeps me deep in
       thought and it is a daily source of inspiration.
       
       [Graphics Mews] [Musings] [Resources] indent T his column is
       dedicated to the use, creation, distribution, and dissussion of
       computer graphics tools for Linux systems.
             Last month I introduced a new format to this column. The
       response was mixed, but generally positive. I'm still getting more
       comments on the format of the column rather than the content. I
       don't know if this means I'm covering all the issues people want
       to hear about or people just aren't reading the column. Gads. I
       hope its not the latter.
             This months issue will include another book review, a
       discussion on adding fonts to your system, a Gimp user's story,
       and a review of the AC3D modeller. The holiday season is always
       busy one for me. I would have liked to do a little more, but there
       just never seems to be enough time in the day. Graphics Mews 
       
             Disclaimer: Before I get too far into this I should note
       that any of the news items I post in this section are just that -
       news. Either I happened to run across them via some mailing list I
       was on, via some Usenet newsgroup, or via email from someone. I'm
       not necessarily endorsing these products (some of which may be
       commercial), I'm just letting you know I'd heard about them in the
       past month.
             I went wondering through a local computer book store this
       month and scanned the graphics texts section. I found a few new
       tidbits that might be of interest to some of you.
       
    3D Graphic File Formats: A Programmers Reference
         Keith Rule has written a new book on 3D Graphics File Formats.
       The book, which contains over 500 pages, has been published by
       Addison-Wesley Developers Press and is listed at $39.95. It
       includes a CD-ROM with a software library for processing various
       3D file formats (both reading and writing), but the code is
       written for MS systems. Keith states there isn't any reason why
       the code shouldn't be portable to other platforms such as Linux.
       Any takers out there?
       ISBN 0-201-48835-3 indent indent
       
    OpenGL Programming for the X Window System
         I noticed a new text on the shelf of a local book store
       (Softpro, in Englewood, Colorado) this past month - Mark J.
       Kilgard's OpenGL Programming for the X Window System. This book,
       from Addison Wesley Developers Press, appears to have a very good
       coverage of how to write OpenGL applications that make use of X
       Windows API's. I haven't read it yet (or even purchased it - yet,
       but I will) so can't say how good it is. Mark is the author of the
       GLUT toolkit for OpenGL. GLUT is to OpenGL what Xt or Motif is to
       Xlib. Well, sort of. indent
       
    Fast Algorithms for 3D-Graphics
          This book, by Georg Glaeser and published by Springer, includes
       a 3.5" diskette of source for Unix systems. The diskette, however,
       is DOS formatted. All the algorithms in the text are written using
       pseudocode, so readers could convert the algorithms to the
       language of choice. indent indent
       
    ImageMagick 3.7.8 released, including a new set of image library plug-ins
         A new release of ImageMagick has been released from Alexander
       Zimmermann. This release includes a "Plug In" library containing
       the various image libraries ImageMagick needs to run. Alexander
       has uploaded this new release to Sunsite as well as ImageMagick's
       Web site. indent
       
    MpegTV Player v0.9
          A new version of the MpegTV Player has been released. This
       version now includes audio support. indent indent
       
    Imaging Technology Inc. IC-PCI frame grabber board driver
         The second public release (v 0.2.0) of a kernel module for the
       Imaging Technology Inc. IC-PCI frame grabber board (rev 1) and the
       AM-VS acquisition module has been released. This driver is
       maintained by GOM mbH (Gesellschaft fuer optische Messtechnik) TU
       Braunschweig, Institute for Experimental Mechanics. A full motion
       video test program and a read function for original camera files
       are included.
       Author: Matthias Stein
       Maintained by: Dirk Bergmann
       This software is not really free (see the LICENSE file). indent
       
    Viewmol 2.0 released
          I don't know much about this tool, but it appears to have alot
       of graphics related features, so I thought I'd mention it here.
       The LSM gives the following information:
       
       Viewmol is a program for the visualization of outputs from quantum
       chemical as well as from molecular mechanics programs. Currently
       supported are Gaussian 9x, Discover, DMol/DSolid, Gulp, Turbomole,
       and PDB files. Properties visualized include geometry (with
       various drawing modes), vibrations (animated or with arrows),
       optimization history/MD trajectories, MO energy level diagram,
       MOs, basis functions, electron density. Drawings can be saves as
       TIFF, HPGL, Postscript, input files for Rayshade.
       
       ftp://ftp.ask.uni-karlsruhe.de/pub/education/chemistry/viewmol-2.0
       .tgz indent indent indent
       
    Did You Know?
          3D Site (http://www.3dsite.com/3dsite) is a Web site devoted to
       everything 3D. There are job postings, links to free repositories
       of 3D models and lots of other valuable information.
       
             3D Cafe (http://156.46.199.2/3dcafe/) is another Web site
       with various useful 3D information. It also maintains a large
       collection of DXF and 3DS model files.
       
    An Important Survey
          I've been talking to a couple of publishers about doing a book
       aimed at Linux users. I'd like to write a User's Guide for the
       Gimp but the publisher feels a more general text on doing
       Web-based graphics might have a wider appeal (face it - the Linux
       audience just isn't the size of the MS audience - yet - but the
       publishers are considering both types of books). I told them I'd
       ask my readers which type of text they'd like to see. The Gimp
       book would include details on how to use each of the applications
       features as well as a number of tutorials for doing various types
       of effects. The book on doing graphics for Web pages would include
       discussions on using HTML, information on tools besides the Gimp
       and a few case studies (including something on animation).
       However, the Web book wouldn't go into as much detail for each of
       the tools. That information would be more general in nature.
             I don't have a server to run any CGI scripts to register
       votes, so simply mail me with your opinions. Thanks!
       
    A Call for Help
          I plan on covering more 3D tools in the future, but I have to
       learn to use them first. The next tool I'm going to look into is
       BMRT. If you use BMRT and want to help me get started drop me a
       line. I'd like to do an introduction to BMRT in the March issue
       if possible but I want to make sure I know what I'm talking about
       first. Thanks! indent indent indent
       
       Musings 
       
       
    A Gimp User's Story (or "Why I Use the Gimp")
    The following piece was posted on the Gimp User's Mailing list by
       Mike Phillips.
       
             At work, we have a "Library News Network", which is actually
       a 386 pc running a TV via a video converter in a continual
       slideshow with information about upcoming events in the law
       library and the law school. Last year, my boss did some stuff in
       Freelance Graphics which, quite frankly, was rather limited in
       effect.
             This year, it's my baby, and I'm making the slideshow
       (640x480x256 GIF files, run by a simple DOS program and looped by
       a batch file) in the GIMP. Here are some things I've done to make
       the text more readable and make the display reasonably
       eye-catching. Nothing fancy, but hopefully the tricks will give
       other people ideas to play with on their own.
             First, don't use a plain background. The blend tool is very
       nice for this, and shaded green or blue with bright text is rather
       nice looking. Start with a color and add some noise Create a blend
       image of the same size and multiply by the image with noise. This
       creates a very cool background for a slide. Better yet, if there's
       an appropriate photograph, use it! (I used a gorgeous picture of
       Yosemite Park to announce an environmental law symposium, and a
       decent photo of the U.S. Supreme Court justices to announce our
       Supreme Court Preview.)
             On the subjects of backgrounds, since I don't remember
       seeing this tip, here's a quickie for clouds: Make a plasma of the
       appropriate size, grayscale it, convert it back to color, and
       Brightness/Contrast/Gamma it into submission. I usually knock the
       brightness up about 75-100, and the blue up to around 5 and the
       green to about 2. Instant pretty sky (Obviously, skies from other
       planets could be done with reds and greens and whatnot.)
             For the text, nothing beats some good fonts. Hit a font
       archive, or buy a $10-$15 CD filled with fonts. Granted, I have
       the Caldera Network Desktop, so I can use some fonts that (I
       think) XFree can't, thanks to the font server, but it's worth a
       shot. I got a CD with 1250 fonts for $13. [Ed. Next month I'll
       cover how to add fonts to your system so you can use them with the
       Gimp. mjh]
             Here's a variation on the rounded-text tips: work out your
       text, then Duplicate it once and Offset it once (say 4x4). Edge
       Detect then Invert the duplicate and Gaussian Blur the offset
       twice. Multiply the resulting ../gx/hammel, and use the original
       as a mask to composite something else over the image resulting
       from the multiplication. Very nice, edged & floating/shadowed
       text. Shows up great on a TV monitor.
             For the text, use any appropriate single color. Bright
       colors and high contrast work very well for what I do, although
       I've played with textures, rippled blends, plasma clouds, and
       what-not.
             Of course, it can be spiced up with all sorts of clipart (I
       heartily recommend Barry's Clipart Server (www.barrysclipart.com),
       from which I shamelessly borrow, and voila, instant slideshow!
             I have left our Fall Break edition of the LNN at:
       http://www.lawlib.wm.edu/LNN-old/. if you want to see some of
       what can be done with it. You might be better off watching the
       show when the graphics aren't resized to 320x240. Also, the latest
       version of these is available at http://www.lawlib.wm.edu/LNN/.
       
       
       [Ed. Later Mike posted another message that included some
       interesting effects. I thought it might be appropriate to include
       them with his other posting.]
       
       
             Recently, while wandering through the plug-ins available, I
       found the charcoal plug-in. Compiled it, added it, used it. Rather
       nifty, actually. However, it got me thinking and experimenting,
       and I produced two potentially interesting effects:
       
       (1) Pastel sketch: Take a color (RGB) image, Edge-detect it,
       Invert, and (optionally) contrast autostretch. On many
       ../gx/hammel, this will produce a nifty pastel sketch. If the
       image is too high of detail, degrade the color or pixelize it
       first, otherwise you may end up with too many extraneous lines.
       
       (2) Watercolor sketch: Take a color (RGB) image, make a grayscale
       of it. Edge Detect the grayscale (this will give you the sketch
       lines); this can be hard to balance the way you want, so you may
       want to threshold it or pixelize the image first. Then, pixelize
       and degrade the main image to 32 colors (16 or 20 works even
       better). Eliminate the background you don't want, Gaussian blur it
       a few times, and brighten it some. Multiply the edging onto it.
       Voila; (nearly) instant watercolor, akin to the court sketches on
       news shows.
       
       Mike Phillips, mike@lawlib.wm.edu indent
       
    Jim Blinn's Corner - A Trip Down the Graphics Pipeline
    indent I am not formally trained in computer graphics (1). Everything
       I know I've learned in the last year or so by reading, examining
       source code, and through the kind assistance of many members of
       the Net. So my ability to understand some of the more formal texts
       on computer graphics is limited.
             Given this limitation, I found I was still able to read and
       comprehend a good portion of Jim Blinn's book Jim Blinn's Corner -
       A Trip Down the Graphics Pipeline, which is a collection of
       articles taken from his column in the IEEE Computer Graphics and
       Applications journal. This book is the first of what may be two
       books, assuming there is sufficient interest in the first book.
       The second will cover a set of pixel arithmetic articles taken
       from the same column.
             In the preface Jim describes how he used a writing style
       that is "certainly lighter than a typical SIGGRAPH paper, both in
       depth and in attitude." I can't agree more. Computer graphics
       should be a fun subject and, despite the math, this book does
       provide a giggle here and there.
             Don't get me wrong, though. There is plenty of the technical
       details on how to compute positions in 3D space, perspective
       shadows, and subpixelic particles. Hefty stuff for the beginner.
       Nearly incomprehensible to the person who hasn't used matrix
       arithmetic in the past 8 years. Still, chapters like The Ultimate
       Design Tool (which talks about how an idea should start), and
       Farewell to Fortran (which talks about using various languages
       in computer graphics) provided enough non-mathematical discussions
       to let my brain recover while still keeping my interest peaked.
             I haven't read the book front to back yet. I'm saving whats
       left (about half the book) for my 16 days of freedom scheduled to
       start later this month. Its first on my reading list. Second will
       be my college Linear Algebra text. The first half of Jim's book
       reminded me about how much I'd forgotten in 8 years. Like the
       saying goes, one must strive for the impossible before they know
       what is possible. indent indent indent
        More Musings...
          + Review: The AC3D Modeller - An introduction to the very nifty
            3D modeller from Andy Colebourne. Warning: lots of
            ../gx/hammel on this page!
          + History of the Portable Network Graphics (PNG) format - A
            detailed look at how an Internet-based cooperative effort
            brought about this graphics file format specification.
   indent indent indent
       indent
       
    The IRTC - A raytracing competition for the fun of it
    indent F or the past few months, I've been helping to administer an
       Internet-based competition for users of raytracing software. This
       competition, the Internet Ray Tracing Competition or IRTC, is open
       to anyone interested in creating 3D ../gx/hammel using software on
       any platform as long as the software falls within a few basic
       guidelines. It is based on another competition started back in
       1994 by Matt Kruse. Matt eventually had to close down the contest
       due to the enormous amount of time it takes to run such a contest.
       At the time, he was more or less doing all the work himself.
             Earlier this year Chip Richards started to organize the
       contest once again. A group of interested individuals signed up to
       help out. In the end, most of us (myself included) provide only
       organizational input - ideas for rules or input on rulings
       regarding cheating (yes, there has been some of that), helping to
       select topics, and so forth. Most of the real work has been done
       by Chip, Bill Marrs, and Jon Peterson (although Jon has since had
       to move on to other things).
             The contest is made up independent rounds that last 2
       months. Each round has a topic which entrants must use as the
       basis for their ../gx/hammel. Entries are supposed to be new
       ../gx/hammel, created during the span of the contest, however most
       people use bits and pieces of older models that they or someone
       else has created. The tools allowed vary but raytracing tools are
       preferred and no post processing is allowed (for example, you
       can't add a lens flare after the image has been rendered). Anyone
       is allowed to vote (currently) on the ../gx/hammel and winners
       receive small prizes like CDs and prints of their ../gx/hammel.
       
       more IRTC... (same page as AC3D review)
       
       Resources 
       The following links are just starting points for finding more
       information about computer graphics and multimedia in general for
       Linux systems. If you have some application specific information
       for me, I'll add them to my other pages or you can contact the
       maintainer of some other web site. I'll consider adding other
       general references here, but application or site specific
       information needs to go into one of the following general
       references and not listed here.
       
       
       Linux Graphics mini-Howto 
       Unix Graphics Utilities 
       Linux Multimedia Page 
       
       
       
       
Future Directions

   Next month:
          + TkPOV - a POV-Ray scene file editor
          + Book Review: 3D Graphic File Formats by Keith Rule
          + Adding fonts to your system
          + Gimp Tips
          + ...and lots more!
   
       Let me know what you'd like to hear about!
       
       
         _____________________________________________________________
       
         1. Anyone having an extra, unclaimed scholarship in computer
            graphics is encouraged to contact me. I give preference to
            those who have them within commuting distance of Denver,
            where I live. 
   
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Michael J. Hammel
      Published in Issue 13 of the Linux Gazette
   
       
       
         _____________________________________________________________
       
       
       
       [ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next 
       
       
         _____________________________________________________________
       
       
       
       
       
More...

   
       Musings 
          + Review: The AC3D Modeller
          + more IRTC...
   indent
       &copy 1996 Michael J. Hammel indent
       
       
       
    Review: The AC3D Modeller
   
             There are only a few 3D modellers available for Linux: AMAPI
       (which may now only be available for the Mac, based on one report
       I've received), Midnight Modeller, SCED/SCEDA, and AC3D. Each of
       these has its advantages and disadvantages. I've tried each of
       these at least briefly. A couple, SCED and AC3D, I've used to
       actually create scenes. Lets take a quick look at one of these -
       AC3D.       AC3D comes from Andy Colebourne. It is a shareware
       modeller that comes in binary format only. It is available for
       Linux, SGI's and Sun's (both SunOS and Solaris). Once registered
       you have access to a private Web site from which you can download
       the full version of the software. Documentation is a bit sparse (a
       common problem with much of the software available for Linux, in
       this authors opinion), consisting of about 12 or 13 pages
       formatted in either HTML or Postscript. The distribution package
       contains the binary, the HTML manual with a few ../gx/hammel, and
       a set of object files that are necessary for packages which use
       the Mesa Graphics Library, which AC3D does. AC3D
       Figure 1: Example AC3D session (this is taken from the AC3D Web
       site).
             The interface consists of 4 view windows and a control
       panel. There are 3 orthographic views and a 3D view. Changes in
       one of the orthographic view windows are reflected in the other
       views. Edits are not allowed in the 3D view. The 3D view can
       provide wireframe, filled or textured surfaces. My system is not
       quite fast enough to handle anything but the wireframe surface so
       I won't be able to say much about the texturing features of the
       modeller.
             AC3D supports a number of import file formats, including DXF
       and Lightwave files. It can export POV, RIB, VRML and a couple of
       other formats. Since the modeller is a based on vertices (as
       opposed to primitives like spheres or boxes) it is quite easy to
       manipulate basic shapes into more complex ones. This can be a
       disadvantage to those used to the CSG aspects of SCED or users of
       POV-Ray, but it really doesn't take that long to get used to. Even
       though the modeller bases its shapes on vertices, there are still
       a collection of basic shapes provided: disk, line, box, sphere,
       and mesh are just some of these. These shapes are displayed with a
       given number of vertices. The number of vertices can be configured
       and its possible to add more vertices where necessary.
                   One of the nicest features is the ability to extrude a
       2D shape into 3 dimensions. Lets follow an example of this. First,
       select the "ellipse" drawing function from the control panel and
       create a stretched out ellipse in the XY orthographic view. AC3D
       Figure 2: An ellipse       Next, change the Edit type to "vertex"
       in the control panel and select all the vertices on the lower half
       of the ellipse (but not the ones on the end of the ellipse).
       Delete these with the "delete" function in the control panel. Then
       select the two lowest vertices and insert some new vertices (as
       shown in Figure 3). AC3D
       Figure 3: The ellipse has been halved and some new vertices added.
             This next part is a little tricky. What you want to do is
       select the vertices on each end of the object and move them, one
       at a time, until you get a slightly rounded effect. Then select 4
       or 5 of the vertices on the back end (the left side in Figure 4)
       and strecth them out a little, to flatten the wings trailing edge.
       Then get rid of the extra vertices along the bottom of the wings
       edge by selecting them and using the "delete" function in the
       control panel. The result should look something like Figure 4.
       AC3D
       Figure 4: The wing edge takes shape       This isn't bad, but a
       wing should be smoother around the top and edges, so change the
       Edit type to "Object" and select the wing. Then use the "Spline
       Surfaces" option from the Object pull-down menu. This adds a bunch
       of new vertices to the object and creates a smoother line around
       the wing. AC3D
       Figure 5: Smoothing the wing edge.       Now lets take this simple
       shape and extrude it. Make sure the Edit type is still "Object"
       and select the wing edge. We need to change to the XZ orthographic
       view window. Up to this point we've been using the XY viewport.
       Click on "Extrude" under the Mouse options in the control panel.
       Grab the object in the XZ viewport and drag up. The original
       points stay put and a new set of points is moved to where ever you
       drag to. Once you let go of the mouse button you'll see the new
       points get connected to their corresponding points on the original
       object. Notice how the connecting lines aren't quite straight.
       This would be bad for a real wing, so we'll straighten them out.
       AC3D
       Figure 6: The wing edge gets extruded.       In this next figure,
       the control panel was used to change the Edit mode to "vertices"
       and the vertices on the new side of the extruded object have been
       selected. Once selected, the "move" option under the Mouse
       features allows the selected vertices to be moved as a group. When
       these vertices are moved the lines connecting them to the opposite
       end are redrawn. You can play with this a bit in order to get the
       connecting lines to become straight. Note that its not absolutely
       necessary to correctly align the two ends of the extruded object,
       but this is one way to do so if you feel it necessary. AC3D
       Figure 7: The ends of the extruded object are aligned.       Now
       switch back to the "object" Edit mode and select the object. The
       bounding box (in green) has handles that can be grabbed to drag
       the bounding box to resize the object. Use the middle top and
       bottom handles to make the object wider in the XZ view. AC3D
       Figure 8: Stretch the object a bit.       Next, switch back to
       "vertices" Edit mode and select the vertices on one end of the
       object. Click on "Create Surface" under Functions in the control
       panel. If the surface (as viewed in the 3D view) does not appear
       solid you can select "Poly" under Surface to create a solid
       surface to close the end of the object. Repeat this process for
       the other end.
       
             Viola! You've got a solid surfaced wing, just like the one
       in Figure 9. (The grid is an option for the 3D view window and not
       part of the image.) Of course, this is a pretty simplistic
       example, but you should get the idea of how easy it is to create
       shapes using AC3D. You'll need to export the file to POV or RIB
       format and add some real textures to finish up the project, of
       course. AC3D
       Figure 9: The solid surfaced wing.
             When I first started examining modellers I got my hands on
       SCED, a nifty modeller from Stephen Chenney. One of the nice
       features of SCED is that it is constraint based - you can join
       objects using CSG and then constrain them to certain points. This
       allows you to create an arm, for example, that can bend only at
       the elbow. AC3D works similarly in that you can rotate any set of
       points around a single point within one of the orthographic views.
       For example, if I created an arm I could select "Rotate" from the
       control panel and then use the mouse to rotate the arm around a
       single point, such as the elbow, in one of the 2D view windows. If
       I need it to move in 3D I need to do this type of rotation in 2 or
       more of the 2D view windows. This process is a little different
       than SCED, which can move objects in 3 dimensions, but the result
       is the same. In fact, at times it can be a little easier to keep
       your bearings using multiple rotations in 2D.
             Since I've never used any of the modellers available for
       other systems (such as high end modellers on SGI's or any of the
       modellers available for Microsoft or Mac systems) I can't say how
       well AC3D compares to them. I do know that I found the modeller
       fairly easy to learn, but I tend to be more motivated than some
       folks. AC3D could use some online help (whats the difference
       between a "Poly" and a "Polyline", for example) and more detailed
       documentation in general. It would also be nice to be able to
       unhide selected objects instead of all hidden objects. Andy has
       told me that a new version coming soon will include the ability to
       specify the exact dimensions of a selected object or set of
       vertices. This is a very important feature in my eyes. I tend to
       like to use modellers to create individual objets and then use the
       conditional constructs of POV-Ray to position multiple copies of
       them, such as trees or rocks or houses. By constraining an object
       to a unit size it makes it easier to position and resize objects
       using POV-Ray.
             Of all the modellers I've tried AC3D is probably the easiest
       to use. Its ability to import formats like DXF gives it a step up
       on SCED, although I really like the latter too. I don't
       particularly mind that you don't get the source to AC3D since I'm
       mostly interested in just using the modeller and not in developing
       new features for it. It would be nice if there were a plug-in
       interface, but I'm not such a power user yet that I need that
       feature. Aside from a lack of detailed documentation, and a few
       keystrokes that are already used by fvwm, I find the AC3D modeller
       worth the registration price.
       
       indent
       
       
       
    more IRTC...
   
             The contest started in earnest in May/June of 1996. The
       topic then was Time and there were some stunning entries. In
       July/August we had fewer entries, but the topic - Summer - was a
       little tougher to nail down. In September/October we hit the
       jackpot with Science Fiction. Well over 200 entries were submitted
       for this round. Thats quite a difference from the 20-30 submitted
       during Matt's original contests. Fortunately much of the work for
       viewing, voting, and tabulating information has been automated.
       The contest has been great fun and has been accompanied with
       lively discussions on the associated irtc-l mailing list.
             Unfortunately, there are always those that have to try to
       ruin things for everyone else. We had some people submit
       ../gx/hammel that were fair but not likely winners. They then
       submitted multiple votes. A vote consists of ratings of all the
       ../gx/hammel with values between 1-20 for each in 3 categories -
       needless to say this takes awhile to accomplish. Any vote that
       does not include ratings for all ../gx/hammel is not counted in
       the final tally. The multiple votes were done offline (which is
       permissable) and submitted from different email accounts. The
       artists ../gx/hammel received very high marks while all the rest
       received very low (within a very small range) ratings. Then they
       got some of their friends to do the same thing. Beyond this,
       others have submitted numerous entries that they had made in the
       past (prior to the contest) that just happen to fit the category
       (how many 3D artists, for fun or profit, have *never* made a space
       scene?) in order to turn the contest into their own private
       gallery. The spirit of the competition is lost on some people, I'm
       afraid.
             I haven't done any of the automation nor have I worked on
       the very nice web site for the contest. But I've watched Chip and
       Bill do so. Its very frustrating knowing how much effort they put
       into this, trying very hard not to give themselves or anyone else
       unfair advantages and still make the contest fun for everyone only
       to see someone still try to cheat the system. Why? For a couple of
       CDs? Remember when the Internet was a friendly, honest place?
             Still, the contest continues and the Admin Team is working
       on ways of keeping the contest fun, open to participation, and
       fair. The guys could use a new host for their contest. Walnut
       Creek, the current host, appears to be limiting ftp connections
       and the amount of disk space required for 200+ ../gx/hammel can
       get rather large.
             If you are into 3D rendering for the fun of it you owe it to
       yourself to take a shot at the IRTC. Its fun to see how your
       ../gx/hammel stack up against others. Many of the voters offer
       comments on the ../gx/hammel which can very useful in any future
       ../gx/hammel you render. Check our the IRTC Web Site to get more
       details and join in!
       
       indent &copy 1996 by Michael J. Hammel 
       
More...

   
       Musings 
       
       
       
       
    History of the Portable Network Graphics (PNG) format
   by Greg Roelofs 
       
       Prehistory
             The Story of PNG actually begins way back in 1977 and 1978
       when two Israeli researchers, Jacob Ziv and Abraham Lempel, first
       published a pair of papers on a new class of lossless
       data-compression algorithms, now collectively referred to as
       ``LZ77'' and ``LZ78.'' Some years later, in 1983, Terry Welch of
       Sperry (which later merged with Burroughs to form Unisys)
       developed a very fast variant of LZ78 called LZW. Welch also filed
       for a patent on LZW, as did two IBM researchers, Victor Miller and
       Mark Wegman. The result was...you guessed it...the USPTO granted
       both patents (in December 1985 and March 1989, respectively).
             Meanwhile CompuServe--specifically, Bob Berry--was busily
       designing a new, portable, compressed image format in 1987. Its
       name was GIF, for ``Graphics Interchange Format,'' and Berry et
       al. blithely settled on LZW as the compression method. Tim Oren,
       Vice President of Future Technology at CompuServe (now with
       Electric Communities), wrote: ``The LZW algorithm was incorporated
       from an open publication, and without knowledge that Unisys was
       pursuing a patent. The patent was brought to our attention, much
       to our displeasure, after the GIF spec had been published and
       passed into wide use.'' There are claims [1] that Unisys was made
       aware of this as early as 1989 and chose to ignore the use in
       ``pure software''; the documents to substantiate this claim have
       apparently been lost. In any case, Unisys for years limited itself
       to pursuit of hardware vendors--particularly modem manufacturers
       implementing V.42bis in silicon.
             All of that changed at the end of 1994. Whether due to
       ongoing financial difficulties or as part of the industry-wide
       bonk on the head provided by the World Wide Web, Unisys in 1993
       began aggressively pursuing commercial vendors of software-only
       LZW implementations. CompuServe seems to have been its primary
       target at first, culminating in an agreement--quietly announced on
       28 December 1994, right in the middle of the Christmas
       holidays--to begin collecting royalties from authors of
       GIF-supporting software. The spit hit the fan on the Internet the
       following week; what was then the comp.graphics newsgroup went
       nuts, to use a technical term. As is the way of Usenet, much ire
       was directed at CompuServe for making the announcement, and then
       at Unisys once the details became a little clearer; but mixed in
       with the noise was the genesis of an informal Internet working
       group led by Thomas Boutell [2]. Its purpose was not only to
       design a replacement for the GIF format, but a successor to it:
       better, smaller, more extensible, and FREE.
       
       The Early Days (All Seven of 'Em)
             The very first PNG draft--then called ``PBF,'' for Portable
       Bitmap Format-- was posted by Tom to comp.graphics,
       comp.compression and comp.infosystems.www.providers on Wednesday,
       4 January 1995. It had a three-byte signature, chunk numbers
       rather than chunk names, maximum pixel depth of 8 bits and no
       specified compression method, but even at that stage it had more
       in common with today's PNG than with any other existing format.
             Within one week, most of the major features of PNG had been
       proposed, if not yet accepted: delta-filtering for improved
       compression (Scott Elliott); deflate compression (Tom Lane, the
       Info-ZIP gang and many others); 24-bit support (many folks); the
       PNG name itself (Oliver Fromme); internal CRCs (myself); gamma
       chunk (Paul Haeberli) and 48- and 64-bit support (Jonathan
       Shekter). The first proto-PNG mailing list was also set up that
       week; Tom released the second draft of the specification; and I
       posted some test results that showed a 10% improvement in
       compression if GIF's LZW method was simply replaced with the
       deflate (LZ77) algorithm. Figure 1 is a timeline listing many of
       the major events in PNG's history.
       
       indent 4 Jan 95 PBF draft 1 (Thomas Boutell) 4 Jan 95
       delta-filtering (Scott Elliott) 4 Jan 95 deflate compression (Tom
       Lane et al.) 4 Jan 95 24-bit support (many) 5 Jan 95 TeleGrafix
       LZHUF proposal (same or slightly larger) 6 Jan 95 PNG name (Oliver
       Fromme) 7 Jan 95 PBF draft 2 (Thomas Boutell) 7 Jan 95 ZIF early
       results (Greg Roelofs) 7 Jan 95 internal CRC(s) (Greg Roelofs) 8
       Jan 95 gamma chunk (Paul Haeberli) 8 Jan 95 48-, 64-bit support
       (Jonathan Shekter) 9 Jan 95 FGF proposal, implementation (Jeremy
       Wohl) 10 Jan 95 first NGF/PBF/proto-PNG mailing list (Jeremy Wohl)
       15 Jan 95 PBF draft 3 (Thomas Boutell) 16 Jan 95 CompuServe
       announces GIF24 development (Tim Oren) 16 Jan 95 spec available on
       WWW (Thomas Boutell) 16 Jan 95 PBF draft 4 (Thomas Boutell) 23 Jan
       95 PNG draft 5 (Thomas Boutell) 24 Jan 95 PNG draft 6 (Thomas
       Boutell) 26 Jan 95 final 8-byte signature (Tom Lane) 1 Feb 95 PNG
       draft 7 (Thomas Boutell) 2 Feb 95 Adam7 interlacing scheme (Adam
       Costello) 7 Feb 95 CompuServe announces PNG == GIF24 (Tim Oren) 13
       Feb 95 PNG draft 8 (Thomas Boutell) 7 Mar 95 PNG draft 9 (Thomas
       Boutell) 11 Mar 95 first working PNG viewer (Oliver Fromme) 13 Mar
       95 first valid PNG ../gx/hammel posted (Glenn Randers-Pehrson) 1
       May 95 pnglib 0.6 released (Guy Eric Schalnat) 1 May 95 zlib 0.9
       released (Jean-loup Gailly, Mark Adler) 5 May 95 PNG draft 10
       (Thomas Boutell) 13 Jun 95 PNG home page (Greg Roelofs) 8 Dec 95
       PNG spec 0.92 released as W3C Working Draft 23 Feb 96 PNG spec
       0.95 released as IETF Internet Draft 28 Mar 96 deflate and zlib
       approved as Informational RFCs (IESG) 22 May 96 deflate and zlib
       released as Informational RFCs (IETF) 1 Jul 96 PNG spec 1.0
       released as W3C Proposed Recommendation 11 Jul 96 PNG spec 1.0
       approved as Informational RFC (IESG) 4 Aug 96 VRML 2.0 spec
       released with PNG as requirement (VAG) 1 Oct 96 PNG spec 1.0
       approved as W3C Recommendation 14 Oct 96 image/png approved (IANA)
       indent Figure 1: a PNG timeline
             Perhaps equally interesting are some of the proposed
       features and design suggestions that ultimately were not accepted:
       the Amiga IFF format; uncompressed bitmaps either gzip'd or stored
       inside zipfiles; thumbnail ../gx/hammel and/or generic multi-image
       support; little-endian byte order; Unicode UTF-8 character set for
       text; YUV and other lossy image-encoding schemes; and so forth.
       Many of these topics produced an amazing amount of discussion--in
       fact, the main proponent of the zipfile idea is still making noise
       two years later.
       
       Onward, Frigidity
             One of the real strengths of the PNG group was its ability
       to weigh the pros and cons of various issues in a rational manner
       (well, most of the time, anyway), reach some sort of consensus and
       then move on to the next issue without prolonging discussion on
       ``dead'' topics indefinitely. In part this was probably due to the
       fact that the group was relatively small, yet possessed of a
       sufficiently broad range of graphics and compression expertise
       that no one felt unduly ``shut out'' when a decision went against
       him. (All of the PNG authors were male. Most of them still are.
       I'm sure there's a dissertation in there somewhere...) But equally
       important was Tom Boutell, who, as the initiating force behind the
       PNG project, held the role of benevolent dictator--much the way
       Linus Torvalds does with Linux kernel development. When consensus
       was impossible, Tom would make a decision, and that would settle
       the matter. (On one or two rare occasions he might later have been
       persuaded to reverse the decision, but this generally only
       happened if new information came to light.)
             In any case, the development model worked: by the beginning
       of February 1995, seven drafts had been produced, and the PNG
       format was settling down. (The PNG name was adopted in Draft 5.)
       The next month was mainly spent working out the details:
       chunk-naming conventions, CRC size and placement, choice of filter
       types, palette-ordering, specific flavors of transparency and
       alpha-channel support, interlace method, etc. CompuServe was
       impressed enough by the design that on the 7th of February they
       announced support for PNG as the designated successor to GIF,
       supplanting what they had initially referred to as the GIF24
       development project. [3] By the beginning of March, PNG Draft 9
       was released and the specification was officially frozen--just
       over two months from its inception. Although further drafts
       followed, they merely added clarifications, some recommended
       behaviors for encoders and decoders, and a tutorial or two.
       Indeed, Glenn Randers-Pehrson has kept some so-called ``paleo
       PNGs'' that were created at the time of Draft 9; they are still
       readable by any PNG decoder today. [4]
       
       Oy, My Head Hurts
             But specifying a format is one thing; implementing it is
       quite another. Although the original intent was to create a
       "lightweight" format--and, compared to TIFF or even JPEG, PNG is
       fairly lightweight--even a completely orthogonal feature set can
       introduce substantial complications. For example, consider
       progressive display of an image in a web browser. First comes
       straight decoding of the compressed data; no problems there. Then
       any line-filtering must be inverted to get the actual image data.
       Oops, it's an interlaced image: now pixels are appearing here and
       there within each 8x8 block, so they must be rendered
       appropriately (and possibly buffered). The image also has
       transparency and is being overlaid on a background image, adding a
       bit more complexity. So far we're not much worse off than we would
       be with an interlaced, transparent GIF; the line filters and 2D
       interlacing scheme are pretty straightforward extensions to what
       programmers have already dealt with. Even adding gamma correction
       to the foreground image isn't too much trouble.
             But wait, it's not just simple transparency; we have an
       alpha channel! And we don't want sparse display--we really like
       the replicating progressive method Netscape Navigator uses. Now
       things are tricky: each replicated pixel-block has some percentage
       of the fat foreground pixel mixed in with complementary amounts of
       the background pixels in the block. And just because the current
       fat pixel is 65% transparent (or, even worse, completely opaque)
       doesn't mean later ones in the same block will be, too: thus we
       have to remember all of the original background pixel-values until
       their final foreground pixels are composited and overlaid. Toss in
       the ability to render all of this nicely on an 8-bit, colormapped
       display, and most programmers' heads will explode.
       
       Make It So!
             Of course, some of these things are application
       (presentation or front-end) issues, not general PNG-decoding
       (back-end) issues. Nevertheless, a good PNG library should allow
       for the possibility of such applications--which is another way of
       saying that it should be general enough not to place undue
       restrictions on any programmer who wants to implement such things.
       
             Once Draft 9 was released, many people set about writing PNG
       encoders and/or decoders. The true glory is really reserved for
       three people, however: Info-ZIP's Jean-loup Gailly and Mark Adler
       (both also of gzip fame), who originally wrote Zip's deflate() and
       UnZip's inflate() routines and then, for PNG, rewrote them as a
       portable library called zlib [5]; and Guy Eric Schalnat of Group
       42, who almost single-handedly wrote the libpng reference
       implementation (originally ``pnglib'') from scratch. [6] The first
       truly usable versions of the libraries were released two months
       after Draft 9, on the first of May, 1995. Although both libraries
       were missing some features required for full implementation, they
       were sufficiently complete to be used in various freeware
       applications. (Draft 10 of the specification was released at the
       same time, with clarifications resulting from these first
       implementations.)
       
       Fast-Forward to the Present
             The pace of subsequent developments slowed at that point.
       This was partly due to the fact that, after four months of intense
       development and dozens of e-mail messages every day, everyone was
       burned out; partly because Guy controlled libpng's development and
       became busy with other things at work; and partly because of the
       perception that PNG was basically ``done.'' The latter point was
       emphasized by a CompuServe press release to that effect in
       mid-June (and one, I might add, in which their PR guys claimed
       much of the credit for PNG's development, sigh).
             Nevertheless, progress continued. In June of 1995 I set up
       the PNG home page, now grown to roughly a dozen pages [7]; Kevin
       Mitchell officially registered the ``PNGf'' Macintosh file ID with
       Apple Computer. In August Alexander Lehmann and Willem van Schaik
       released a fine pair of additions to the NetPBM image-manipulation
       suite, particularly handy under Linux: pnmtopng and pngtopnm
       version 2.0. And in December at the Fourth International World
       Wide Web Conference, the World Wide Web Consortium (W3C) released
       the PNG Specification version 0.92 as an official standards-track
       Working Draft.
             1996 saw the February release of version 0.95 as an Internet
       Draft by the Internet Engineering Task Force (IETF), followed in
       July by the Internet Engineering Steering Group's (IESG) approval
       of version 1.0 as an official Informational RFC. (However, the
       IETF secretary still hasn't issued the actual RFC number at the
       time of this writing, five months later. Sigh.) The Virtual
       Reality Modeling Language (VRML) Architecture Group in early
       August adopted PNG as one of the two required image formats for
       minimal VRML 2.0 conformance. [8] Meanwhile the W3C promoted the
       spec to Proposed Recommendation status in July and then to full
       Recommendation status on the first of October. [9] Finally, in
       mid-October the Internet Assigned Numbers Authority (IANA)
       formally approved ``image/png'' as an official Internet Media
       Type, joining image/gif and image/jpeg as non-experimental image
       formats for the Web. Much of this standardization would not have
       happened nearly as quickly without the tireless efforts of Tom
       Lane and Glenn Randers-Pehrson, who took over editing duties of
       the spec from Thomas Boutell.
       
       Current Status
             So where are we today? The future is definitely bright for
       PNG, and the present isn't looking too bad, either. I now have
       over 125 applications listed [10] with PNG support either current
       or planned (mostly current); among the ones available for Linux
       are:
          + XV (image viewer/converter)
          + ImageMagick (image viewer/converter)
          + GRAV (image viewer)
          + Zgv (image viewer)
          + xli (image viewer)
          + XPaint (image editor)
          + The GIMP (image editor)
          + Image Alchemy (image converter)
          + pnmtopng/pngtopnm (image converters)
          + XEmacs (editor/web browser/operating system/etc.)
          + gforge (fractal terrain generator)
          + Fractint (fractal generator)
          + Ghostscript (PostScript viewer/converter)
          + GNUplot (plotting program)
          + PV-WAVE (scientific visualization program)
          + POV-Ray (ray-tracer)
          + VRweb (VRML browser)
          + X Mosaic (web browser)
          + Arena (web browser)
          + Chimera (web browser)
          + Grail (web browser)
          + Amaya (web browser/editor)
          + Mapedit (image-map editor)
          + WWWis (HTML IMG sizer)
          + file(1) (Unix file-type identifier)
   
             Discerning readers will note the conspicuous absence of
       Netscape Navigator. Despite the fact that Netscape was aware of
       the PNG project from the beginning and unofficially indicated
       ``probable support''; despite the nice benefits gamma correction,
       alpha support and 2D interlacing bring to WWW applications;
       despite the fact that the WWW Consortium, of which Netscape is a
       member, released the PNG spec as its first official
       Recommendation; despite the requirement to support PNG in VRML 2.0
       viewers like Netscape's own Live3D plug-in; and despite
       considerable pestering by members of the PNG group and the
       Internet community at large, Netscape is still only
       ``considering'' future support of PNG. Until Netscape either
       supports PNG natively or gets swept away by Microsoft or someone
       else, PNG's usefulness as an image format for the Web is
       considerably diminished.
             On the other hand, our buds at Microsoft recognized the
       benefits of PNG and apparently embraced it wholeheartedly. They
       have not only made it the native image format of the Office97
       application suite but have also repeatedly promised to put it into
       Internet Explorer (theoretically by the time of the 4.0
       betas--we'll see about that). Assuming they do, Netscape is almost
       certain to follow suit. (See? Microsoft is good for something!) At
       that point PNG should enjoy a real burst of WWW interest and
       usage.
             In the meantime, PNG viewing actually is possible with Linux
       Netscape; it's just not very useful. Rasca Gmelch is working on a
       Unix plug-in with (among other things) PNG support. Although it's
       still an alpha version and requires ImageMagick's convert utility
       to function, that's not the problem; Netscape's brain-damaged
       plug-in architecture is. Plug-ins have no effect on HTML's IMG
       tag: if there's no native support for the image format and no
       helper app defined, the image is ignored regardless of whether an
       installed plug-in supports it. Instead you must use Netscape's
       EMBED extension. That means anyone who wants universally viewable
       web pages loses either way: PNG with IMG doesn't work under
       Netscape, and PNG with EMBED doesn't work under much of anything
       except Netscape and MSIE (and those only if the user has installed
       a working PNG plug-in).
             But support by five or six other Linux web browsers ain't
       bad, and even mainstream applications like Adobe's Photoshop now
       do PNG natively. More are showing up every week, too. Life is
       good.
       
       The Future
             As VRML takes off--which it almost certainly will,
       especially with the advent of truly cheap, high-performance 3D
       accelerators--PNG will go along for the ride. (JPEG, which is the
       other required VRML 2.0 image format, doesn't support
       transparency.) Graphic artists will use PNG as an intermediate
       format because of its lossless 24-bit (and up) compression and as
       a final format because of its ability to store gamma and
       chromaticity information for platform-independence. Once the
       ``big-name'' browsers support PNG natively, users will adopt it as
       well--for the 2D interlacing method, the cross-platform gamma
       correction, and the ability to make anti-aliased balls, buttons,
       text and other graphic elements that look good on *any* color
       background (no more ``ghosting,'' thanks to the alpha-channel
       support).
             Indeed, the only open issue is support for animations and
       other multi-image applications. In retrospect, the principal
       failure of the PNG group was its delay in extending PNG to MNG,
       the "Multi-image Network Graphics" format. As noted earlier,
       everyone was pretty burned out by May 1995; in fact, it was a full
       year before serious discussion of MNG resumed. As (bad) luck would
       have it, October 1995 is when the first Netscape 2.0 betas arrived
       with animation support, giving the (dying?) GIF format a huge
       resurgence in popularity.
             At the time of this writing (mid-December 1996), the MNG
       specification has undergone some 27 drafts--almost entirely
       written by Glenn Randers-Pehrson--and is close to being frozen. A
       couple of special-purpose MNG implementations have been written,
       as well. But MNG is too late for the VRML 2.0 spec, and despite
       some very compelling features, it may never be perceived as
       anything more than PNG's response to GIF animations. Time will
       tell.
       
       At Last...
             It's always difficult for an insider to render judgment on a
       project like PNG; that old forest-versus-trees thing tends to get
       in the way of objectivity. But it seems to me that the PNG story,
       like that of Linux, represents the best of the Internet:
       international cooperation, rapid development and the production of
       a Good Thing that is not only useful but also freely available for
       everyone to enjoy.
             Then again, maybe I'm just a shameless egotist (nyuk nyuk
       nyuk). You decide....
       
       Acknowledgments
             I'd like to thank Jean-loup Gailly for his excellent
       comp.compression FAQ, which was the source for much of the patent
       information given above. [11] Thanks also to Mark Adler and JPL,
       who have been the fine and generous hosts for the PNG home pages,
       zlib home pages, Info-ZIP home pages and my own, personal home
       pages. (Through no fault of Mark's, that will all come to an end
       as of the new year; oddly enough, JPL has decided that none of it
       is particularly relevant to planetary research. Go figure.)
       
       References [1] Raymond Gardner, rgardner@teal.csn.org, 8 Jan 1995
       23:11:58 GMT, comp.graphics/comp.compression, Message-ID . See
       also Michael Battilana's article discussing the legal history of
       the GIF/LZW controversy:
             http://www.cloanto.com/users/mcb/19950127giflzw.html [2]
       http://www.boutell.com/boutell/ [3]
       http://www.w3.org/pub/WWW/Graphics/PNG/CS-950214.html [4]
       http://www.rpi.edu/~randeg/paleo_pngs.html [5]
       http://quest.jpl.nasa.gov/zlib/ [6]
       ftp://swrinde.nde.swri.edu/pub/png/src/ [7]
       http://quest.jpl.nasa.gov/PNG/ (but probably moved to
       http://www.wco.com/~png/ by 1 January 1997) [8]
       http://vag.vrml.org/VRML2.0/FINAL/spec/part1/conformance.html
       [9] http://www.w3.org/pub/WWW/TR/REC-png.html [10]
       http://quest.jpl.nasa.gov/PNG/pngapps.html [11]
       http://www.cis.ohio-state.edu/hypertext/faq/usenet/compression-f
       aq/top.html indent &copy 1996 by Michael J. Hammel
       
       
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    "Linux Gazette...making Linux just a little more fun! "
   
       
       
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                           INDEXING TEXTS WITH SMART
                                       
    By Hans Paijmans paai@kub.nl
   
       
       
         _____________________________________________________________
       
       
       
1. The uses of Linux and MS-DOS

   
       
       Although my colleagues here on Tilburg University may think that I
       spend my time fiddling with Linux on a PC that could be put to
       better uses, they are wrong. The 'fiddling with Linux' I do at
       home; at my work I only do the bare minimum necessary to keep
       Linux fed and happy. As most readers of this journal know, this
       involves making the occasional backup and for the rest: nothing.
       
       When I sit in front of my PC, I work (well, mostly). Linux makes
       it possible to do my work with a minimum of fuss and a big part of
       the credit for this goes to Jacques Gelinas, the man who wrote
       Umsdos: a layer between the Unix operating system and the vanilla
       MS-DOS 8+3 FAT system. This makes it possible to access the
       DOS-partition of my hard disk from either operating system. This
       is good news, because I am totally dependent from two programs:
       SMART, an indexing and retrieval system and SPSS for Windows to
       twiddle the data I obtain form SMART. SMART only runs under Unix
       (and not all Unixes for that matter) and SPSS4Windows, obviously,
       runs under MS-Windows and whatever the virtues of this operating
       system may be, you emphatically do not want to use it in any kind
       of experimental environment.
       
       I suppose that SPSS (Statistical Package for the Social Sciences)
       will be familiar to most Linux users. If not: SPSS is just what it
       says, a statistical package but not only for the 'social sciences'
       but for about everyone who needs statistical analysis of his data.
       SMART, however, is an indexing and retrieval program for text.
       What is more: it does not just index the words, it also adds
       weights to them. It also allows the user to compare the indexed
       documents in the so-called Vector Space Model and to compute the
       distances between the documents, or between documents and queries.
       To understand why this is special we must delve a bit in the
       typical problems of Information Retrieval, i.e. the storage of
       books, articles etcetera and the retrieval of those on content.
       
1.1 Why indexing is not enough

   
       
       When at the end of the sixties automatic indexing of texts became
       a viable option many people thought that the problems of
       information retrieval were solved. Programs like STAIRS (IBM,1972)
       enabled the users to file and rapidly retrieve documents on any
       word in the text or on boolean combinations (AND, OR, NOT) of
       those words and who could ask for more? Then, in 1985 a famous
       article was published by two researchers in the field [1]. In this
       article they reported on the performance of STAIRS in real life
       and they showed that the efficiency of STAIRS and similar systems
       was, in fact, much lower than assumed. Even experienced users
       could not obtain a recall of more than 20-40% of the relevant
       documents in a database of 100,000 documents, and worse, they were
       not aware of the fact.
       
       
       The problem with all retrieval systems of this type is that human
       language is so fuzzy. There may be as much as a dozen different
       terms and words pointing to one and the same object, whereas one
       word may have widely different meanings. In Information Retrieval
       this will lead to one of two situations. Either you try to obtain
       a high precision, when almost all the retrieved documents are
       relevant (but an unknown number of other relevant documents are
       not included) or you go for high recall, but then a lot of
       irrelevant documents will be included in the result. When in a
       retrieved set of documents the proportion of irrelevant documents
       is high, the user will probably stop looking at the documents
       before he or she has found all the relevant ones: in fact his
       futility-point has been reached. In such a case the net result
       is equal to the situation in which those relevant records that
       would be presented after the user reached that futility-point were
       not retrieved. Therefore the concept of ranking, i.e. the ordering
       of retrieved documents on relevance, is very important in
       Information Retrieval.
       
2. SMART

   
       
       Modern (and not so modern) research has offered a number of
       possible solutions to this dilemma. Some of those solutions use
       the concept of weighted keywords. This means that every
       keyword-document combination has a weight attached that
       (hopefully) is an indication of the relevance of that particular
       keyword for that particular document. SMART does just that: it
       creates indexes for a database of documents and attaches weights
       to them. The way that happens may be expressed intuitively as 'the
       more a word occurs in the less documents, the higher the weight'.
       Or, if the word 'dog' occurs twenty times in a given document, but
       in no other documents, you may be relatively certain that this
       document is about dogs. Information Retrieval addicts like me talk
       about the tf.idf weight.
       
       Smart offers several options as to how that weight should be
       arrived at: I generally prefer the so-called atc-variation,
       because it adjusts for the length of the individual documents.
       
       It calculates the tf.idf in three steps. The first step creates
       the value tex2html_wrap_inline96 for the term-frequency (tf) as
       
       
       
       displaymath86
       
       
       
       where tex2html_wrap_inline100 is the term with the highest
       frequency in the document. This adjusts for the document-length
       and the number of terms. Then the weight tex2html_wrap_inline102
       is calculated as
       
       
       
       displaymath87
       
       
       
       where N is as before the number of documents and F the document
       frequency of term t (the number of documents in which term t
       occurs). Finally the cosine normalization is applied by
       
       
       
       displaymath88
       
       
       
       where T is the number of terms in the document vector. Now we have
       a number between zero and one that hopefully correlates with the
       importance of the word as a keyword for that document. For a
       detailed discussion of these and similar techniques see e.g.
       Salton and McGill ([2]). You will love it!
       
       This is not all. When SMART has constructed the index in one of
       the various ways available, it also can retrieve the documents for
       you. This is done according to something called ``the Vector Space
       Model''. This model is best explained using a three-dimensional
       example of a vector-space; you can add another few thousand
       dimensions in your own imagination.
       
       Imagine you want to index your documents according to three
       keywords 'cat', 'dog' and 'horse'; keywords that may or may not
       occur in your documents. So you draw three axes to get a normal
       three-dimensional coordinate system. One dimension can be used to
       indicate the ``cat-ness'' of every document, the other its
       ``dog-ness'' and the third the ``lion-ness''. To make things easy
       we only use binary values 0 and 1, although SMART can cope with
       floats (the 'weights' mentioned before. So if a document is about
       cats, it scores a one on the corresponding axis, otherwise it
       scores a zero. Any document may now be drawn in that space
       according to the occurrence of one or more of the keywords and now
       we have a relatively easy way to compute the difference between
       those document. Moreover a query consisting of one or more of the
       keywords can be drawn in the same space and the documents can be
       ranked according to the distance to that query. Of course a
       typical document database has thousands of keywords and
       accordingly thousands of dimensions, but the arithmetics involved
       in multi-dimensional distances do not matter much to modern
       computers, and if they bother you, you just have to smoke
       something illegal and matters will rapidly become clear. If only
       till the next morning.
       
       So SMART accepts queries, ranks the documents according to the
       ``nearness'' to that query and return them to you in that order.
       Therefore it is still one of the best retrieval systems that are
       ever written although it lacks the bells and whistles of its more
       expensive counterparts in some operating systems I could mention.
       And although it is not really optimized for speed, it runs
       typically 10-30 times faster than the fastest indexing program I
       ever saw under MS-Windows.
       
3. The DOS connection

   
       
       But I am not using SMART for bread-and-butter retrieval, but for
       the weights it computes and the indexes it creates. At this point
       I want to do some other manipulations of these data and again I
       have to offer my thanks to the developers of unix in general and
       to Linux in particular. A whole string of ever more complicated
       and sophisticated shell scripts, the standard unix tools and a few
       of My Very Own utilities suffice to process the SMART output to a
       file that is ready for importing in SPSS.
       
       Nevertheless now I have to quit Linux and boot MS-DOS, start
       MS-Windows and finally enter SPSS to do the statistics and create
       some graphs. I am a newcomer to Unix (indeed it was the fact that
       Linux offered a way to use SMART that pulled me over the line two
       years ago), but already I am wondering how people can live in the
       stifling atmosphere of MS-Windows. The fact that you can't really
       run two applications at the same time is not even the worst thing.
       But who is responsible for the idea that Icons and Popups were
       better and more efficient than the plain old command line? And
       what happened to pipes and filters? And a sensible command
       language? Be that as it may, SPSS gets the job done and when the
       output is written to disk I immediately escape back to Linux to
       write the final article, report or whatever with LaTeX.
       
       
4. The bad news

   
       
       On this point I have two messages: one is good, the other bad.
       I'll start with the good news. SMART is obtainable by anonymous
       ftp from Cornell University and may be used for free for
       scientific and experimental purposes. Better yet: it compiles
       under Linux without much tweaking and twiddling. Also there exists
       a fairly active mailing list for people who use SMART
       (smart-peoplecs.cornell.edu).
       
       
       
       The bad news: the manual. What manual? SMART is not for the faint
       of heart; after unpacking and compilation you'll find some
       extremely obscure notes and examples and that is it. Nevertheless,
       if you have more than just a few megabytes of text to manage AND
       the stamina to learn SMART, it certainly is the best solution for
       your information retrieval needs. But don't I wish somebody would
       write a comprehensive manual! In the meantime you may perhaps be
       helped by my ``tutorial for newbees'', to be found at
       http://pi0959.kub.nl:2080/Paai/Onderw/Smart/hands.html.
       
       
       
       
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  BIBLIOGRAPHY
   1
       Blair, D.C.; Maron, M.E.,An evaluation of retrieval effectiveness
       for a full-text document retrieval system,Communications of the
       ACM V28:3, 1985, pp. 289-299.
       
   2
       G. Salton and M.J. McGill,Introduction to Modern Information
       Retrieval New York [etc.] : McGraw-Hill, 1983.
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Hans Paijmans
      Published in Issue 13 of the Linux Gazette
   
       
       
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About Linux text editors / product announcement

    By Oleg L. Machulskiy machulsk@shade.msu.ru
   
       
       
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          + Generally about Linux text editors
          + What I'd like to have in text editor
          + Some program examples
   
       
       
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       Generally about UNIX text editors
       
       All of my friends who use Linux always told me that text editors
       is very important problem under this OS (I mean text-mode editors
       with 100K executable for writing programs). As I understand, this
       problem is not a problem of Linux itself, but it's a problem of
       every UNIX. What's more I know which reasons cause this trouble.
       There is two reasons: putc output to screen and getc input from
       keyboard. In other OS-es user (programmer) can catch Alt+<letter>
       or Shift+<letter> keystrokes and use it as a commands of editor.
       In UNIX user has only 256 ASCII-codes avialable (really, much less
       than 256) and because of it every UNIX editor uses either very
       long sequences of keystrokes as editing commands (as emacs or joe)
       or it has two editing modes (command mode and typing mode in VI
       for example). On X-s everything is better, because here we can get
       scan code (not real scan, but this code is anough for all my
       needs) of the key pressed and status of Shift-keys (Alt, Caps,
       Shift, Ctrl and mouse buttons), so we can use functional keys,
       arrow-keys and everything else You can find on Your keyboard
       (everybody knows how to do that).
       
       But even with text mode editors under Linux everything is not so
       bad: You can switch keyboard to RAW mode and do with it all You
       want (don't forget to get another console from which You will
       execute shutdown -r now command during beta-testing Your program).
       But it's very important to understand that RAW-keyboard programs
       will not work through telnet. Also is very important to set
       SIGSEGV and SIGKILL signal handlers so that they'll switch
       keyboard back to normal mode from RAW when something happens. Once
       I heard about kernel patching so that You can use ScrollLock key
       to switch between raw and normal mode, but I don't know how to
       apply this patch.
       
       
         _____________________________________________________________
       
       
       
       What I'd like to have in text editor
       
       Caution : This section is very private. Maybe someone will find
       something useful for him(here) here, but probably not. This
       section is mostly about my own text editor, so, if You got used to
       Turbo-Vision-like editors and You're satisfied, then probably You
       will find the follwing not interesting. So don't read it, don't
       waste Your time.
        
        Editor must be the same on every operating system
            (multi-platform).
            
            
        Editor must handle advanced search feature: I need not only case
            sensetive/insensetive search, but as a minimum a wildcard
            searh or regular expressions search (this type of search
            includes wildcards).
            
            
        Editor must support projects: user must be able to create a list
            of files (sources of some program) and walk through these
            files freely (enter into file, quit from file, switch to
            another file, ...). The possible solution is to assign some
            keystroke as an "enter-into-file" command, and then, when
            user invokes "enter-into-file", open a file with a name
            similar to the word under cursor (For example, you can enter
            in h-file from the text of c-program; just move cursor to the
            #include "..." statement and press the "enter-into-file"
            key).
            
            
        Editor must handle many files opened at the same time so that
            user can freely move from one text to another (very often I
            need to read declarations of functions in .h files)
            
            
        Editor must support compiling, make etc. from within text editor
            (generally: execution OS command from within editor)
            
            
        Commands must be rather simultaneous pressings of a few keys
            than sequences of keystrokes. It seems to me, it isn't
            comfortable to type (F10, 'F', 'O' , filename) every time You
            need to open a new file. Besides, with such a keyboard layout
            it's impossible to work fast. This requirement causes a
            problem: text editor cannot work through telnet, because
            telnet protocol transfers only ASCII-codes, but not
            scan-codes.
            
            
        Text editor must consider a text not as a sequence of chars but
            as a sequence of lines, where each line is a sequence of
            chars. There is a lot of text editors in which text is a
            vector (For example ME (MSDOS MultiEdit) , Turbo Editor
            (Borland Programming Environments), JOE (linux), etc.), But I
            don't know how to work with tables in these editors or how to
            set // (C++ comment) at the beginning of 10 lines of program
            on the screen.
            
            
        Editor must support macrocommands as a recordable sequences of
            keystrokes.
            
            
        If editor supports programming language, so that I can write my
            own commands, it would be fine.
            
            
        I think programs-structurizing is very useful feature. I'll
            explain: I'd like to have text of my program in pre-hypertext
            form so that I see a list of functions on the screen, I put
            cursor on the name of desired function, press "open"-key and
            now I can edit source of that function, but besides that I
            must be able to edit this file with usual text editor and I
            must be able to compile that file without errors, hence all
            additional info about hypertext structure of program must be
            placed into comments (comments are specific for each file
            type, but in most cases it depends on file extension).
            
            
        Keyboard layout must be as much tunable as possible (if my End
            key is broken, I can use F11 key instead). Besides I often
            need keyboard layout for second language (cyrillic).
            
            
        I don't like when editor wastes screen space on frames of
            windows or any other unuseful things (80 * 25 isn't very
            roomy)
            
            
        Font on the screen must be fixed (I hate proportional fonts).
   
       
       If You're interested in all that, You can try our example of such
       a text editor. I think it isn't the best editor, but I got used to
       it. May It will be useful for someone. To get it, go to
       http://shade.msu.ru/~machulsk and download 330K zip file, which
       contains sources and 5 executables for Linux console, Linux X11,
       OS/2, DOS and Win32 (95/nt). Docs are also included in HTML /
       plainTeX format.
       
       
         _____________________________________________________________
       
       
       
       Example of switching to RAW keyboard mode (C++ syntax)


   #include <stdio.h >   #include <stdlib.h >   #include <unistd.h >   #include
 <errno.h >   #include <linux/kd.h >   #include <signal.h >   #include <sys/ioc
tl.h >   /*.................*/
   void Terminate(int a) {
       if( ioctl(con_fd,KDSKBMODE,om)<0 ) {puts("Press RESET?");exit(-1);}
                  /*trying to set old keydoard mode*/
       }
   /*.................*/
  class TKeyboard{
     int om; /* old keyboard mode descriptor */
     int con_fd; /* console descriptor */
     TKeyboard(){
         signal(SIGKILL, Terminate ); /*setting SIGKILL signal handler*/
         signal(SIGQUIT, Terminate ); /*setting SIGQUIT signal handler*/
         signal(SIGSEGV, Terminate ); /*setting SIGSEGV signal handler*/
         if( 0==(con_fd=open("/dev/tty",O_RDWR)) ) {puts("error");exit(-1);}
                           /*getting console descriptor*/
         if( ioctl(con_fd,KDGKBMODE,&om)<0 ) {puts("error");exit(-1);}
                           /*getting old keydoard mode*/
         if( ioctl(con_fd,KDSKBMODE,K_RAW)<0 ) {puts("error");exit(-1);}
                           /*setting RAW keydoard mode*/
         }
     ~TKeyboard(){
         Terminate(0);
         }
     int GetScanCode(){
         int c;
         ioctl(con_fd,TIOCINQ,&cd); /*query*/
         if(cd==0) /*keyboard buffer is empty*/
         read(con_fd,&c,1); /*get next scancode from console*/
         }
     } KBD;
   /*.................*/
   void main() {
       /*.................*/
       /*................. program body */
       /*.................*/
       }
   
         _____________________________________________________________
       
       
       
       Thank You!
    My addresses: machulsk@shade.msu.ru
   homepage on(in?) Shade
         _____________________________________________________________
       
       
       
       scuze me for bad english, but my native language is Russian 
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Oleg L. Machulskiy
      Published in Issue 13 of the Linux Gazette
   
       
       
         _____________________________________________________________
       
       
       
       [ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next 
       
       
         _____________________________________________________________
       
       
       
       
       
       
         _____________________________________________________________
       
       
       
    "Linux Gazette...making Linux just a little more fun! "
   
       
       
         _____________________________________________________________
       
       
       
                        TWO NEW X-WINDOWS MAIL CLIENTS
                                       
    by Larry Ayers
   Copyright (c) 1996
       
      Published in Issue 13 of the Linux Gazette
   
         _____________________________________________________________
       
  INTRODUCTION
   
       
       There are several full-featured text-mode mail clients available
       for Linux, and these programs (such as Pine and Elm) are probably
       the most commonly used mailers in the Linux/unix world. One reason
       for this tendency is that they run equally well in both console
       and X sessions (in an xterm). They also have a longer development
       history than their X-windows counterparts which results in the
       accretion of more features and options. There has been ample time
       for the developers to deal with bugs as well.
       
       Many of the X-windows mailers I've tried have either been too
       basic, too beta, or awkward to use. I've always returned to Pine,
       my standby. Recently two X-based mailers have been released (in
       late beta versions), both of which are stable and well-provided
       with features and options. When I say stable I mean that they have
       functioned well for me, I haven't lost any mail, and they both
       have been through several releases in which the most egregious
       bugs seem to have been ironed out.
       
       Mail programs are a rather personal sort of software. I've found
       it to be prudent to copy any existing mailbox files or directories
       to a safe location before installing any new mail client. You
       never know until you try just what a new mailer will do with your
       existing mail messages the first time it is run. As an example,
       mbox-style mail "folders" (which are just single files with
       messages concatenated) might be willy-nilly transformed into
       MH-style directories, with each message becoming an individual
       numbered file. I suppose there may exist a technique to reverse
       this metamorphosis, but I don't know what it might be, aside from
       manually using an editor.
         _____________________________________________________________
       
  TKMAIL
   
       
       Paul Raines has been working on a Tcl/Tk mail client for some time
       now. I'll let him describe its origin:


   I began the project at the beginning of '92 while a physics
  grad student at the Univ. of Penn.  I had been put in charge
  of several SGI workstations and was disappointed in the X
  window mail readers I had found. I had recently got into
  Tcl/Tk programming and played around with putting Tk
  interfaces on top of command line programs for physics
  simulation.  I figured it would be easy to do one to sit on
  top of the mailx command and did. That produced tkmail 1.x.
  Eventually I decided I was too limited by the mailx command
  and wrote a Perl backend to serve as an extensible
  equivalent. That produced tkmail 2.x.  Perl was used because
  its text processing features were much faster than Tcl but I
  wanted to keep the whole program as scripts for portability.
  This proved a lost cause as Perl proved as hard to port as C
  code.  For my update to work with Tk4.0, I decided to drop
  Perl in favor of writing my own C code as a module extension
  to Tcl. The past year was the last of my graduate career and
  mostly devoted to finishing my thesis leaving little time
  for work on tkmail. It is sort of behind in some of the
  features out there today (MIME, POP, IMAP, etc) but I hope
  to rectify that soon.

            The most important future plans are:

                   * better MIME support

                   * better key binding customization

                   * an "auto-filing" feature

                   * better search support 
   
       
       
       TkMail is very customizable; Paul Raines includes with the
       distribution an alternate Tk text-manipulation library which
       allows the use of emacs-style key-bindings in the compose window.
       This library can be used with other Tk programs as well. Colors
       and fonts can be independently selected for the folder-view and
       compose window. Much of the configuration can be done from
       menu-selections.
       
       Here is a screenshot of the main folder-view window:
       
       
       Tkmail Main Window
       
       And here is one of the composition window:
       
       
       the Composition Window
       
       TkMail, like many other Linux mailers, in effect acts as a
       front-end to sendmail. Luckily most recent Linux distributions
       come with sendmail preconfigured. If your inbox is on a POP server
       you will need to use popclient, fetchmail, or fetchpop to retrieve
       your messages and leave them in a mailbox file on your local disk,
       where mail clients can find them.
       
       Among the many features of this beta release are:
          + easy inclusion of files into message compositions with
            automatic uuencoding and compression, if desired
          + ability to access an alternate editor from the composition
            window
          + spell check compositions using an X windows interface (using
            ispell)
          + reads aliases from either standard .mailrc or elm aliases.txt
          + sorting of messages on any field and the ability to write out
            the folder physically in that order
          + simple MIME reading and composition tool
          + built in 'biff' icon for notification of new mail on multiple
            folders
          + dynamic (at startup) menus for quick access to mail folders
            for reading, copying, and moving messages
   
       
       
       TkMail is set up initially to open a small debugging window from
       which the main program can be started. Once it becomes evident
       that the program is working to your satisfaction this can be
       disabled by editing the main tkmail4 script and changing the line
       set mfp(debug) 1 to set mfp(debug) 0, or just start it with the
       -nodebug option.
       
       I have found TkMail 4.0b8 to be easy to learn and use, and its
       interface is nice-looking. With a little more work on the MIME
       abilities it will be as effective an X mail client as any
       available.
       
       Paul Raines maintains a home page for TkMail; the source for the
       4.0b8 version is available here.
         _____________________________________________________________
       
  XFMAIL
   
       
       Some months ago John Fisk wrote about the XFmail program in the
       Gazette. His account inspired me to try it out, but I had quite a
       few problems with the message editing window, so much so that when
       I tried to mail the developers a comment on their program, the
       message was corrupted and I doubt that it was legible to them. I
       gave up and deleted it soon after, making a mental note to check
       it out later when perhaps it had become more usable.
       
       Recently I did just that, and found that a new editing module had
       been contributed which really makes a difference in usage of the
       mailer. No longer is there a limit to the amount of the text in
       the editing window. This change, I believe, makes XFMail a
       credible choice as a Linux mail client.
       
       XFMail requires the XForms library. This is available from the
       XForms web-site, which will always have the latest version and
       news. If you obtain the archive be aware that the package includes
       a GUI designer as well as many samples. All you need to keep if
       you're not a programmer is the XForms shared and static libraries
       (libforms.so.81 and libforms.a) and the header file (forms.h).
       These three files will enable you to compile XForms applications,
       such as XFMail from source.
       
       In order to try the current beta (which I recommend) you'll need
       to obtain the source archive from the XFMail home FTP site. As
       long as you have the XForms library files installed it should
       compile for you, notwithstanding the warning message at the FTP
       site. If your current mailbox is in the common mailx format (a
       single file), you might want to copy the file (INBOX or whatever)
       to another location before installing XFMail. The default
       behaviour is for XFMail to transform your messages into the
       multiple-file MH format; after installation you can disable this
       and move your mailbox back. If you already store your mail in the
       MH manner the program will load your messages without moving them.
       
       
       Even though XFMail reads and stores messages in MH format, it
       doesn't require that you have the MH system installed.
       
       This mail client can handle all mail fetching and delivery needs
       for a single-user machine. The user is given the option of using
       sendmail for delivery (either on- or off-line), or using XFMail to
       directly contact the SMPT server and deliver outgoing mail.
       Fetching new mail can be done externally,(popclient et al), or via
       XFMail directly. These features could be helpful for new users who
       would rather not deal with sendmail; all functions can be handled
       by the mailer.
       
       XFMail has the recognizable XForms look, familiar to users of the
       Lyx front-end program for TeX/Latex. The XForms library gives
       programs a unique look, unlike standard X or Motif. The user
       interface is perhaps not quite as fancy as some, but it's not hard
       to become accustomed to it. There are some limitations in choice
       of colors; the selection available is greater than that of
       console-ANSI programs, but less than the amount available to
       standard X clients.
       
       Here are some screenshots of the various XFMail windows:
       
       
       The Main Window
       The Composition Window
       
       
       And here is the logging window:
       
       
       [IMAGE]
       
       
       Among the other features of this mailer are an internal address
       book, full MIME support, and support for faces and picons. Support
       is planned for compatibility with mailx-style mail-folders.
       
       XFMail is quite an ambitious programming project; if you do try
       out the beta version I'm sure the authors would appreciate hearing
       any comments you may have. There also exists an XFMail mailing
       list; send a message to: majordomo@Burka.NetVision.net.il with
       "subscribe xfmail" in the message body.
       
       Visit the XFMail homepage for the latest news; by the time you
       read this, beta 0.5 may well have been released.
       
       XFMail is being developed by Gennady B. Sorokopud and Ugen J.S.
       Antsilevich.
         _____________________________________________________________
       
    Larry Ayers<layers@vax2.rainis.net>
   Last modified: Tue Dec 17 19:05:43 CST 1996
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Larry Ayers
      Published in Issue 13 of the Linux Gazette
   
       
       
         _____________________________________________________________
       
       
       
       [ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next 
       
       
         _____________________________________________________________
       
       
       
       
       
       
         _____________________________________________________________
       
       
       
    "Linux Gazette...making Linux just a little more fun! "
   
       
       
         _____________________________________________________________
       
       
       
                              MISCELLANEOUS NOTES
                                       
    by Larry Ayers
   Copyright (c) 1996
       
      Published in Issue 13 of the Linux Gazette
   
         _____________________________________________________________
       
  FUN WITH LITTLE SHELL-SCRIPTS
   
       
       After typing the same command or editing the same rc-file for the
       dozenth time the idea of a short executable shell-script will
       gradually rise to the surface of my mind. As an example, last year
       after much trial-and error I figured out how to start my S3
       X-server in 16-bit mode. This was great, but I found that there
       were a few programs which preferred to be run in 8-bit mode.
       Typing startx -- -bpp 16 and startx -- -bpp 8 began to become
       tiresome; then it dawned on me that I could write a shell script
       for each color-depth which would do the typing for me. One of them
       looks like this:


        #!/bin/sh
        # x16: starts x in 16-bit mode
        startx -- -bpp 16
   
       
       Just a simple little script (made executable with chmod +x x16)
       but so handy!
       
       Encouraged by this, it occurred to me that changing
       window-managers could be done in a similar way. I normally use
       fvwm2, but lately I've been fooling around with one of fvwm's
       hacked offspring, the Afterstep window-manager. Since I didn't
       have Afterstep's configuration quite as usefully customised as my
       mainstay fvwm2's, I didn't want to use it the majority of the
       time. Rather than editing ~/.xinitrc each time I wanted to switch
       to Afterstep, then again to switch back, I copied ~/.xinitrc
       twice. The first copy is .xinitrc-f and it's just my normal copy.
       The second, .xinitrc-a starts Afterstep instead. The scripts which
       control this are as follows:


        #!/bin/sh
        # xa: starts x with afterstep
        cp ~/.xinitrc-a ~/.xinitrc ; startx
   
       
       and


        #!/bin/sh
        # xf: starts x with fvwm2
        cp ~/.xinitrc-f ~/.xinitrc ; startx
   
       
       Of course, while in an X-session another window-manager can be
       easily started from a menu. I spend a fair amount of time working
       in a console session without X running, in which case the above
       scripts are useful.
       
       It just occurred to me as I write this that these tasks could be
       as easily done using aliases or functions in ~/.bashrc. The only
       difference I suppose would be that shell-functions are
       memory-resident whereas the scripts aren't.
       
       These examples may seem self-evident or trivial to the unix-gurus
       out there, but they were part of the learning process for me.
       Perhaps this piece will encourage the beginners out there to try
       some similar scripting.
         _____________________________________________________________
       
  KEYBOARDS AND RXVT
   
       
        Here's a discovery I made recently concerning rxvt, the
       memory-saving alternative to xterm. I received an email message
       recently in response to my article last month concerning S-lang
       applications, in which I opinionated about rxvt vs. xterm. The
       poster of the message wondered whether there is any way to use
       shift-page-up and shift-page-down to scroll the rxvt window,
       similar to the way console screens (and xterms) scroll. I had
       tried to get this to work without success, and some usenet
       messages had led me to believe that without patching the source
       rxvt just wouldn't scroll from the keyboard.
       
       Recently I installed the S.u.S.E. distribution, but didn't install
       the supplied rxvt package. I recompiled rxvt version 2.19 in this
       new environment, and to my surprise the above-mentioned scrolling
       keys worked! This piqued my curiosity, so I began prowling through
       the directory hierarchy searching for the difference in config
       files which made this behaviour possible. I came up with two
       differences: first, there was a new entry in the ~/.Xmodmap file.
       The lines


           keycode 64 = Meta_L
           keycode 0x6D = Multi_key
   
       
       had been added to the "keycode 22 = BackSpace" line which I had in
       my previous installation. Second, the /etc/termcap file was
       different than the ones I'd seen before; a new rxvt stanza had
       been included which looks like this:


rxvt|rxvt terminal emulator:\
        :am:km:mi:ms:xn:xo:\
        :co#80:it#8:li#65:\
        :AL=\E[%dL:DC=\E[%dP:DL=\E[%dM:DO=\E[%dB:IC=\E[%d@:\
        :LE=\E[%dD:RI=\E[%dC:UP=\E[%dA:ae=^O:al=\E[L:as=^N:bl=^G:\
        :cd=\E[J:ce=\E[K:cl=\E[H\E[2J:cm=\E[%i%d;%dH:cr=^M:\
        :cs=\E[%i%d;%dr:ct=\E[3k:dc=\E[P:dl=\E[M:do=^J:ei=\E[4l:\
        :ho=\E[H:ic=\E[@:im=\E[4h:\
        :is=\E[r\E[m\E[2J\E[H\E[?7h\E[?1;3;4;6l\E[4l:\
        :k1=\E[11~:k2=\E[12~:k3=\E[13~:k4=\E[14~:k5=\E[15~:\
        :k6=\E[17~:k7=\E[18~:k8=\E[19~:k9=\E[20~:kI=\E[2~:\
        :kN=\E[6~:kP=\E[5~:kb=\177:kd=\EOB:ke=\E[?1l\E>:kh=\E[H:\
        :kl=\EOD:kr=\EOC:ks=\E[?1h\E=:ku=\EOA:le=^H:md=\E[1m:\
        :me=\E[m:mr=\E[7m:nd=\E[C:rc=\E8:sc=\E7:se=\E[m:sf=^J:\
        :so=\E[7m:sr=\EM:ta=^I:te=\E[2J\E[?47l\E8:ti=\E7\E[?47h:\
        :ue=\E[m:up=\E[A:us=\E[4m:
   
       
       I have noticed, though, that if I type the command echo $TERM in
       an rxvt window the result is xterm-color, so perhaps the above
       rxvt termcap entry isn't being used at all.
       
       I'd love to know if anyone else has any luck transplanting either
       or both of these two changes into their system. The rxvt termcap
       entry can be pasted right into your /etc/termcap file; in mine it
       is right after the xterm stanzas. I don't believe the order of
       stanzas is important, though.
         _____________________________________________________________
       
  PARTITIONS AND DIRECTORIES
   
       
       After using linux for a while you tend to take for granted the
       supple flexibility inherent in the Linux manner of dealing with
       files, partitions, and mount-points. Recently I began to feel
       constrained by a relatively small /usr partition, so I thought I'd
       do some experimenting.
       
       I happened to have an unused 100 mb. partition on my disk, so I
       created an ext-2 filesystem on it and mounted it on an empty
       directory, /new, created for this purpose. Then I ran this
       command: cp -a /usr/X11R6 /new. Using cp with the -a switch is
       really handy, as it copies all subdirectories, links, and files,
       and also saves permissions.
       
       The next step was modifying the /etc/fstab file, inserting the
       following entry which causes /usr/X11R6 to be mounted on the new
       partition:


         /dev/hda11     /usr/X11R6   ext2     defaults   1   2
   
       
       Before rebooting I dropped back to a console and deleted the
       entire contents of the /usr/X11R6 directory.
       
       I was reasonably certain this would work, but I must confess I was
       surprised when (after rebooting) X started up without comment, as
       if nothing had changed.
       
       Linux doesn't really care, after all, where files are located, as
       long as there is a congruence between the partition table and the
       contents of the /etc/fstab file. One benefit of this laxity is
       that repartitioning (with all of the attendant backing up,
       restoring, etc.) should seldom be necessary.
         _____________________________________________________________
       
       
       
    Larry Ayers<layers@vax2.rainis.net>
   Last modified: Tue Dec 17 21:31:27 CST 1996
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, Larry Ayers
      Published in Issue 13 of the Linux Gazette
   
       
       
         _____________________________________________________________
       
       
       
       [ TABLE OF CONTENTS ] [ FRONT PAGE ] Back Next 
       
       
         _____________________________________________________________
       
       
       
       
       
       
         _____________________________________________________________
       
       
       
    "Linux Gazette...making Linux just a little more fun! "
   
       
       
         _____________________________________________________________
       
       
       
Petition to Cancel Filed Against Linux Trademark

   
       
       Members of the LINUX community have been up in arms during the
       past six months over the efforts of an individual named William R.
       Della Croce, Jr. from the Boston area to collect 10% royalties on
       sales from businesses marketing Linux products. He bases his
       written demands on a US trademark which he claims to hold on the
       name "LINUX" for a computer operating system. He, in fact, holds
       such a registered trademark, based on his claim made under penalty
       of perjury that he is the owner and first user of the mark for
       operating systems, and that he was not aware in 1994 or 1995 of
       any other person who might claim or be using this name and mark
       for an operating system. This claim is absurd on its face.
       
       WorkGroup Solutions, Yggdrasil Computing, Linux International,
       SSC/Linux Journal, and Linus Torvalds have retained an
       internationally known software industry attorney, G. Gervaise
       Davis III, of the Davis & Schroeder law firm in Monterey, CA to
       seek cancelation of this registration on the grounds that it is
       fraudulent and obtained under false pretenses. Mr. Davis and his
       firm are handling the case on a vastly reduced fee basis, because
       of their long standing relationship with the U.S. software
       industry. Davis was the original attorney for Gary Kildall and
       Digital Research of CP/M fame in the 1980s.
       
       A Petition to Cancel was in fact filed with the Trademark Trial
       and Appeals Board in Washington, DC. on November 27, 1996,
       detailing the improper actions of Della Croce and setting out the
       true facts with a number of exhibits and attachments. Mr. Davis
       advises us that we can expect to have further steps taken by TTAB,
       under their complex procedural rules over the next few months.
       TTAB will first notify Della Croce of the filing and permit him
       time to respond, then evidence can be collected and depositions
       taken, and then the parties can file briefs and other responses.
       Often these cases take more than a year to be resolved by a TTAB
       decision.
       
       All of our industry is fully aware that Linus Torvalds developed
       Linux and that it has become one of the world's most popular
       operating systems during the past six years. The participants in
       this proceeding expect the TTAB to cancel the registration, after
       hearing and seeing the massive evidence demonstrating that Della
       Croce had no conceivable legal basis for his claim to the mark.
       
       The petition itself is available here and on the websites of each
       of the petitioners and Mr. Davis' law firm at www.iplawyers.com.
       We urge that interested persons read it, and distribute it and
       this message to all members of the LINUX community so that they
       will be aware of what is being done about this outrageous
       trademark claim. We will try to keep everyone posted on
       developments in the case through user groups and webpages.
       
       We will continue to keep you updated on the happenings in this
       action. Check the Linux Hot News Button for the latest updates.
       
       
         _____________________________________________________________
       
       
       
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    "Linux Gazette...making Linux just a little more fun! "
   
       
       
         _____________________________________________________________
       
       
       
SLEW: Space Low Early Warning

    By James T. Dennis jim@starshine.org
   
       
       
         _____________________________________________________________
       
       
       
       
       
       One of the worst things you can do to your linux or other
       Unix-like system is to allow any of the filesystems to get full.
       
       System performance and stability will suffer noticeable
       degradation when you pass about 95% and programs will begin
       failing and dying at %100 percent. Processes that are run as
       'root' (like sendmail and syslog) will actually fill their
       filesystem past 100% since the kernel will allocate some of the
       reserved space for them.
       
       (Yes, you read that right -- when you format a file system a bit
       of space is reserved for root's exclusive use -- read the mke2fs,
       e2fsck, tune2fs for more on that).
       
       Considering the importance of this issue you might think that our
       sophisticated distributions would come with a pre-configured way
       to warn you long before there was a real problem.
       
       Sadly this is one of those things that is "too easy" to bother
       with. Any professional Unix developer, system administrator or
       consultant would estimate a total time for writing, installing and
       testing such an application at about 15 minutes (I took my time
       and spent an hour on it).
       
       Here's the script:


        #! /bin/bash
                ## SLEW: Space Low Early Warning
                ##      by James T. Dennis,
                ##      Starshine Technical Services
                ##
                ## Warns if any filesystem in df's output
                ## is over a certain percentage full --
                ## mails a short report -- listing just
                ## "full" filesystem.
                ## Additions can be made to specify
                ## *which* host is affected for
                ## admins that manage multiple hosts

        adminmail="root"
                ## who to mail the report to


        threshold=${1:?"Specify a numeric argument"}
                ## a percentage -- *just the digits*

        # first catch the output in a variable
        fsstat=`/bin/df`

        echo "$fsstat" \
                | gawk '$5 + 0 > '$threshold' {exit 1}'  \
           || echo "$fsstat" \
                | { echo -e "\n\n\t Warning: some of your" \
                        "filesystems are almost full \n\n" ;
                        gawk  '$5 + 0 > '${threshold}' + 0 { print $NF, $5, $4
}' } \
                | /bin/mail -s "SLEW Alert" $adminmail

        exit


   That's twelve lines of code and a mess of comments (counting each of
       the "continued" lines as a separate line).
       
       Here's my crontab entry:

        ## jtd: antares /etc/crontab
        ## SLEW: Space Low Early Warning
        ##      Warn me of any filesystems that fill past 90%
        30 1 * * * nobody /root/bin/slew 90
   
       
       Note that the only parameter is a 1 to 3 digit percentage. slew
       will silently fail (ignore without error) any parameter(s) that
       don't "look like" numbers to gawk.
       
       Here's some typical output from the 'df' command:

Filesystem         1024-blocks  Used Available Capacity Mounted on
/dev/sda5              96136   25684    65488     28%   /
/dev/sda6              32695      93    30914      0%   /tmp
/dev/sda10            485747  353709   106951     77%   /usr
/dev/sda7              48563   39150     6905     85%   /var
/dev/sda8              96152    1886    89301      2%   /var/log
/dev/sda9             254736  218333    23246     90%   /var/spool
/dev/sdb5             510443  229519   254557     47%   /usr/local
   
       
       Note that I will be getting a message from slew tomorrow if my
       news expire doesn't clean off some space on /var/spool. The rest
       of my filesystems are fine.
       
       Obviously you can set the cron job to run more or less often and
       at any time you like -- this script takes almost no time memory or
       resources.
       
       The message generated can be easily modified -- just add more
       "continuation" lines after the 'echo -e' command like:


           || echo "$fsstat" \
                | { echo -e "\n\n\t Warning: some of your" \
                        "filesystems are almost full \n\n" \
                        "You should add your custom text here.\n"\
                        "Don't forget to move the ';' semicolon "\
                        "and don't put whitespace\n" \
                        "after the backslash at the ends of these lines\n\n";

   Note how the first echo feeds into the grouping (enclosed by the
       braces) so that the contents of $fsstat are appended after the
       message. This is a trick that might not work under other shells.
       
       Also, if you plan on writing similar shell scripts, note that the
       double quotes around the variable names (like "$fsstat") preserve
       the linefeeds in their values. If you leave the quotes out your
       text will look ugly.
       
       The obvious limitation to this script is that you can only specify
       one threshold value for all of the file systems. While it would be
       possible (and probably quite easy) to do this some other way -- it
       doesn't matter to 90% of us. I suspect that almost anyone who does
       install this script will set the threshold to 85, 90 or 95 and
       forget about it.
       
       One could also extend this script to do some groping (using
       various complex find commands) to list things like:
          + Who is the biggest disk hog (which user is taking up all the
            space and what are his or her largest files)?
            
          + What are the oldest, least accessed files on that filesystem?
            
            
            This last question could be answered using something like

        
                'find -xdev -printf "%A@" | sort -n | head' --

        which reads something like "find all the links on this filesystem
            and print time that they were last access (expressed as
            seconds since 1970) and their filenames; sort that and just
            give me a few of the ones from the top of the sorted list."
            As you can see, find commands can get very complex very
            quickly.
   
       
       I chose to keep this script very simple and will develope specific
       scripts to suggest file migrations and deletions as needed.
       
       As you can see it is possible to do quite a bit in Linux/Unix
       using high level tools and very terse commands. Certainly the
       hardest part of writing a script like this is figuring out minor
       details about quoting and syntax (when to enclose blocks in braces
       or parentheses) and in determining how to massage the text that's
       flowing through your pipes.
       
       The first time I wrote slew was while standing in a bookstore a
       couple of years ago. A woman near me was perusing Unix books in my
       favorite section of the store and I asked if I could help her find
       something in particular. She described the problem as it was
       presented to her in a job interview. I suggested a 'df | grep &&
       df | mail' type of approach and later, at home, fleshed it in and
       got it working.
       
       Over the years I lost the original (which was a one-liner) and
       eventually had one of the systems I was working with hiccup. That
       made me re-write this. I've left it on all of my systems ever
       since.
       
       I'd like to encourage anyone who developes or maintains a
       distribution (Linux, FreeBSD, or whatever) to add this or
       something like it to the default configuration on your systems.
       Naturally it is free for any use (it's too trivial to copyright in
       my personal opinion; so, that there is no doubt, I hereby place
       SLEW (comments and code) into the public domain).
       
       
         _____________________________________________________________
       
       
       
      Copyright 1997, James T. Dennis, Starshine Technical Services
      Published in Issue 13 of the Linux Gazette
   
       
       
         _____________________________________________________________
       
       
       
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                            LINUX GAZETTE BACK PAGE
                                       
      Copyright 1997 Specialized Systems Consultants, Inc.
      For information regarding copying and distribution of this material see
      the Copying License.
   
       
       
         _____________________________________________________________
       
       
       
  CONTENTS:
          + About This Month's Authors
          + Not Linux
   
       
       
       
       
         _____________________________________________________________
       
       
       
  ABOUT THIS MONTH'S AUTHORS
   
       
       
         _____________________________________________________________
       
       
       
       
       
    Larry Ayers
   Larry Ayers lives on a small farm in northern Missouri, where he is
       currently engaged in building a timber-frame house for his family.
       He operates a portable band-saw mill, does general woodworking,
       plays the fiddle and searches for rare prairie plants, as well as
       growing shiitake mushrooms. He is also struggling with configuring
       a Usenet news server for his local ISP.
       
    James T. Dennis
   Jim Dennis is the proprietor of Starshine Technical Services. His
       professional experience includes work in the technical support,
       quality assurance, and information services (MIS) departments of
       software companies like Quarterdeck, Symantec/ Peter Norton Group,
       and McAfee Associates -- as well as positions (field service rep)
       with smaller VAR's. He's been using Linux since version 0.99p10
       and is an active participant on an ever-changing list of mailing
       lists and newsgroups. He's just started collaborating on the 2nd
       Edition for a book on Unix systems administration. Jim is an avid
       science fiction fan -- and recently got married at the World
       Science Fiction Convention in Anaheim.
       
    Bill Duncan
   Bill has worked with Unix systems since the early Version 7 days on
       PDP-11's. He worked with Xenix throughout most of the eighties and
       has also worked with many other flavors of Unix over the years,
       but his operating system of choice is now Linux. When not working
       or fiddling with his four Linux systems at home (which is rare),
       he might have some time left over for his other hobbies; his dog
       (Daisy), photography and Amateur Radio.
       
    Michael J. Hammel
   Michael J. Hammel, is a transient software engineer with a background
       in everything from data communications to GUI development to
       Interactive Cable systems--all based in Unix. His interests
       outside of computers include 5K/10K races, skiing, Thai food and
       gardening. He suggests if you have any serious interest in finding
       out more about him, you visit his home pages at
       http://www.csn.net/~mjhammel. You'll find out more there than you
       really wanted to know.
       
    Oleg Machulski
   Oleg Machulski is a student of Laboratory of Computing methods at the
       Faculty of Mechanics and Mathematics, Moscow State University.
       He has been a Linux enthusiast since Sept.1996 as well as an OS/2
       enthusiast. After receiving the source of a very unusual DOS text
       editor, where the program was structurized in a hypertext manner
       from his scientific advisor Andrey V. Astreling, he wrote and
       ported the following functions: search, macrocommands, multiple
       pages and so on. Brief history of that freeware project could be
       found at http://shade.msu.ru/~machulsk/mmm/mmm.html Also, I like
       to play guitar and listen to jazz music. Additional info can be
       found at my homepage http://shade.msu.ru/~machulsk
       
    Hans Paijmans
   
       
        Hans "Paai" Paijmans is University lecturer & researcher at
       Tilburg University and a regular contributor to several Dutch
       journals. Together with E. Maryniak he wrote the first dutch book
       on Linux--already two years ago. My, doesn't the time fly. His
       homepage is at http://pi0959.kub.nl:2080/paai.html.
       
    Greg Roelofs
   Greg Roelofs, aka Cave Newt, is best described as a phenomenon, as in,
       ``Captain, we're picking up strange readings from that unexplained
       phenomenon over there.'' Greg's job description is appropriately
       schizoid, given his interest in far too many things for his own
       good. He's a full-time researcher in
       multimedia/image-compression/WWW stuff at Philips Research at Palo
       Alto, having made the switch from Unix system administrator in
       August 1995. He likes to fancy himself a software developer; among
       other things, he has been a member of the Info-ZIP team for six
       years and the principal author of UnZip for most of that time.
       (He's also a member of the Portable Network Graphics Development
       Group and the maintainer of the PNG and zlib home pages.) As for
       recreational interests, he likes to amuse himself by cycling
       (often to work); skiing--any flavor, although snow preferred,
       especially if it means he can drive in it; scuba diving--for 18
       years now, from the shores of Lake Superior to the coast of
       Venezuela to the kelp beds of Monterey; and hiking/backpacking,
       particularly in the Sierra Nevada range; and amateur photographer.
       
       
    James Shelburne
   
       
        James Shelburne currently lives in Waco, Texas where he spends
       most of his free time working on various Linux networking
       projects. Some of his interests include Perl + CGI, Russian,
       herbal medicine and the Ramones (yes, you heard right, the
       Ramones). He is also a staunch Linux advocate and tries to convert
       every MacOS/MS Windows/AMIGA user he comes into contact with.
       Needless to say, only other Linux users can stand him. 
       
       
       
       
         _____________________________________________________________
       
       
       
  NOT LINUX
   
       
       
         _____________________________________________________________
       
       
       
       
       
       Thanks to all our authors, not just the ones above, but also those
       who wrote giving us their tips and tricks and making suggestions.
       Thanks also to our new mirror sites.
       
       I'd like to apologize for being later than usual getting LG
       posted. The weather in Seattle has been a more than a little
       bizarre lately. My neighborhood got about 20 inches of snow from
       December 26 to December 29. Since the normal yearly snowfall is
       about 4 inches, everything stopped, including the buses for the
       first time in Metro history. SSC had a portion of the roof give
       way under the weight of snow and water (the rains started December
       29 and haven't quit yet). As a result of the flooding, things are
       in quite a mess around the office. Yearly rainfall in Seattle is
       usually 31 inches; this year we had 55 inches. I thought I was
       back in Houston!
       
       Actually, I was back in Houston during my vacation week before
       Christmas. The weather wasn't great there either -- rainy and
       cold, and I was counting on sunshine. However, I still had a good
       time visiting with family and friends. My grandchildren, Sarah and
       Rebecca, are a delight to be with -- I miss them a lot.
       
       Have fun!
       
       
         _____________________________________________________________
       
       
       
       Marjorie L. Richardson
       Editor, Linux Gazette gazette@ssc.com
       
       
         _____________________________________________________________
       
       
       
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       Linux Gazette, http://www.ssc.com/lg/
       This page written and maintained by the Editor of Linux Gazette,
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