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Re: IRC Server




- NOTE - the following letter might annoy some of you, so delete 
immidiatly when you're tired of reading on (possibly NOW).

since i read the list in chunks, this is just a set of answers to 
questions i saw on the list, opinions, etc.

if anybody bothers replying to this letter, please include ONLY the 
relevant part in your reply.

i'll discuss with myself the following LFAQ (List Frequently Answered 
Questions):
A. My opinion about this list and it's usage and purposes.
B. PORTING ircd and other software to linux.
C. automatically filtering email to various folders.
D. BOCA modems 'unquoted statement' and some general modem theory.
E. PPP on linux 'unquoted statement'

----------------------------------------------------
A. My opinion about this list and it's usage and purposes.

the list was established to allow linux users in israel to converse.
so, stick to that as much as possible. this probably includes:
  - hebrew and linux.
  - activities concerning linux in israel
  - getting help that's hard to get via phone (maybe even asking someone 
        really show you how to do something by visiting each other).
  - discussing this list.

as a rule to ANY list 
  - don't send what you didn't try yourself.
  - try to ask for 'where i can find info about....' rather then 'how do 
    i do ...'.
  - if you cannot spend time on your pet (err.. PC) - BUY assistance. 
    if you try to get it for free here - at least don't give others the 
    impression you're trying to use and abuse them.
  - be polite - even when you send hate mails.
  - nobody expects the spanish inquisition...

----------------------------------------------------------
B. PORTING ircd and other software to linux.

  i once compiled some irc server (not sure even which version) on linux. 
  the only Unnice thing was: any message sent to the server caused some 
  disk activity with a little delay. the reason for that might be swapping, 
  or some other illness. now, i'd like to share the idea with you all, 
  since it's relevant generally to ports for linux:

  1. install the sources - usually easy with gunzip filename and tar xfoS 
      filename.tar

  2. read the README files, setup things if requiered, and try to compile 
  (USUALLY 'make' for normal programs, or 'xmkmf' and then 'make' for 
  X-based programs).

  2.5 if you don't know about C programming or Makefiles - do not continue, 
  unless you're known to be a lucky guy or girl 

  3. when you get the first 
     compiler error - check the source. if some 
     function was unknown - check if you have it on your system (man 
     function - ONLY if you have a good set of man pages). 

     most of the errors occure from the usage of function calls that do not 
     exist on your system, but then you usually have something with a 
     different name (and perhaps different parameters) that does the same.

     note - linux's gcc tends to complain alot about 'not matching' 
     parameters - this may safelly be ignored if the only difference is 
     between using 'char *lemech' and haivng a 'const char *lemech' in 
     the INCLUDE file that declares that function - and yes, check the 
     headers in the include files, not just inthe man page). if 
     requiered - try to add a 
     'type cast' when calling the function - to reduce complaints.

     If you had a problem during linking - it's a matter of missing some 
     library on the link command line. here are some hints:
       - linux uses gnu lex (named flex) , so if you have a line of '-ll' in 
         the make file regarding linking, change this to '-lfl'.
       - you might try to use 'nm' to get the list of symbols out of 
         libraries which reside in /usr/lib/libXXXX.a usually - and find 
         if your missing symbol is in any of those (this is a last resort - 
         don't even try if you cannot 'grep' properly or do not have the 
         time).

     5. finally, you might have dynamic libraries that don't support some 
        options. in this case, maybe a newer version of those will help,
        or maybe giving up and asking someone who knows more about linux 
        will help.

-----------------------------------------------------------------------
C. automatically filtering email to various folders.

   as i know (or knew) - slackware used to contain a filtering program named 
   'deliver'. i didn't try to mess with it, but i do mess with a program
   called 'procmail' that seems to work properly. here are a few hints:

     - mail filtering usually begins with a creation of a '.forward' file 
       in your home directory, which has some line to start the filtering
       program itself. in procmail - this is a complex line that i copied 
       from the manual pages. for those who do not know - the .forward 
       file is read by the mail server whenever it tries delivering email to 
       your mail box, and can be used to forward your email to one (or 
       several) other programs, as well as pipe it to the sdtandard input 
       of programs.
     - after that, you write a configuration file for the filter package.
       in procmail, this file contains some syntactic rules (what to 
       match in the letter's Header) and actions to be taked - erase the 
       file, put it in some folder, etc.)
     - make as many tests as you can and remove the .forward file 
       IMMEDIATLY if you spot ANY problems or even suspect them, regarind 
       your mail - people won't be able to notify you via email that you 
       have email problem.
     - Use a working package and NOT something you write on your own - 
       not using safe locking mechanisms will cause your mail box to be 
       trashed in case you get two letters simultanouaslly.
   
     if anyone needs example configuration files for procmail - send me 
     email, and i'll send you such examples. they were dag out of the 
     manual page examples, and might save you some of your precious time 
     (that you lsot if you've read this letter so far).

     note 2 - Using mail filters will cause the mail notification system
      (mistakanlly called 'biff' sometimes) to give false notifications 
     about arriving letters - you'll get a notice about each such email 
     letter - but not necessarly see the correct header printed on screen).
     when i get a solution for that - i might let you know (unless my 
     boss dissallows that).

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D. BOCA modems practice and some general modem theory.

     well - modems knowledge is one of our 'secrets' but i'd say - try to 
     keep away of these modems if you have some better (and not much more 
     expensive) alternative. some models of bocca work great, while 
     others do not.

     as for Yair Rajwan's message - this was the speed of communications 
     between the computer and the modem - NOT between the local modem and 
     the remote modem - 56700 is the theoreticall upper limit on the 
     speed of a 14,400bps modem using the v42.bis protocol for data 
     compression, and is achived RARELY on VERY sparse files. compressed 
     files will NEVER be transfered at a speed higher then 14,400bps, 
     hence defining this speed is good for WWW accesses of large pages, etc, 
     but irrelevant for FTP of compressed files from databases.
  
     furthermore - it is ALWAYS better to compress the file before 
     transferring it, then relying on the modem's compression to be 
     efficient.

     furthermore - a 14,400 bps modem still works at 2400 BAUD. even the 
     28,800 modems work at 2400 BAUD. the theoreticall limit for modems 
     that are allowed to make a delay of up to 2 bits in transmission is 
     a bit below 32,000 bps (not INCLUDING data compression done on top of 
     that), so faster modems requiere one of two:
       1. allow for a higher delay.
       2. (what is usually done) use a line with a larger bandwidth 
          (phone lines give you a range of 3.6Khz for data transmission - 
          remove this limit, and you can get to MUCH MUCH higher rates on 
          these SAME phisical lines). as far as i know, this is an 
          international standard, and not just a bezeq standard - the 3.6KHz 
          thingy. i might also be wrong, since i only assume so).

-------------------------------------------------------------
E. PPP on linux 'unquoted statement'
     
   THEORETICALLY, in order to connect your machine using PPP, you need to 
   know two things:
    1. how your software needs to be configured.
    2. the 'chat' sequence requiered by the machien that gives your the 
       PPP access (your supplier).

    the first part will be found in the software's documentation.
    the second part - should be asked for from the supplier - or from 
    other people who use THE VERY SAME SUPPLIER IN THE VERY SAME TYPE OF 
    CONNECTION - and NOT as a general question of 'how do i start up PPP 
    if my supplier uses static addresses ? as this will (initially) get 
    you nowhere. also - it's not enough to ask this from someone who 
    connects to a different system that uses the same type of router that 
    your supplier does - it might have a different configuraiton, or a 
    different version of the product, etc, which may change things. 
    and since most people know how to use the router software even less 
    then they know how to configure sendmail, or do not have permission 
    to access alot of commands on their routers , or none at all - RTFM 
    is the LAST thing to do if you want to use PPP. even if you use a 
    university which gives you PPP conenction - you'll need to ask THEM 
    about this.

that's all for now,

guy keren
choo@actcom.co.il