Xref: utzoo comp.sources.d:2009 comp.binaries.ibm.pc.d:72
Path: utzoo!mnetor!uunet!steinmetz!davidsen
From: davidsen@steinmetz.ge.com (William E. Davidsen Jr)
Newsgroups: comp.sources.d,comp.binaries.ibm.pc.d
Subject: Re: Standard for file transmission
Message-ID: <10711@steinmetz.ge.com>
Date: 4 May 88 13:08:38 GMT
References: <292@cullsj.UUCP> <55@psuhcx.psu.edu> <537@csccat.UUCP> <I> <would> <like> <to> <clear> <up> <a> <couple> <of> <notions> <that> <have> <been> <expressed> <over> <296@cullsj.UUCP>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: General Electric CRD, Schenectady, NY
Lines: 68
Keywords: protocol compression source

In article <296@cullsj.UUCP> jeff@cullsj.UUCP (Jeffrey C. Fried) writes:
| 
|   1) COMPRESS is a text only compression routine.  It will not now, or ever,
|      help in the compression of binary files.

[ compress gives about 30% compression on binaries, depending on
  content. Whoever told you that it was for text only was completely
  wrong. ]
| 
|   2) ARITH is a more general compression routine using adaptive arithmetic 
|      coding.  It will compress binary files where there is redundancy, but
|      when it fails (on an extremely random file) the result increases very
|      little (under 1% in my experience).  It compresses better than HUFFMAN,
|      but it is NOT faster than SQ/UNSQ which are written in assembler whereas
|      ARITH is written in C.
|      (Once again, i will post it if there is sufficient interest.)

[ once again, do it, in source, so that others can test it themselves
  rather than relying on your opinion. ]
| 
|   3) The source for ZOO, PKARC, and the others is NOT available.  Therefore
|      we are at the whims of whomever is currently supporting (or not supporting)
|      them.

[ the sources for zoo and arc have been posted several times to the net,
  and are available on a number of sites via ftp, uucp, and simple BBS
  download. ]

|   5) On the weak side, there is as yet, no CRC or checksum for any of these,
|      but adding it would be someithing i am willing to take responsibility
|      for should enough people decide they would like to take the approach
|      which i'm currently suggesting.

[ zoo and arc both have CRC. ]

|      Also, there no directory support provided with these tools.  They work
|      on only one file at a time.  This is also correctable since the source
|      is available.

[ arc works on multiple files in multiple directories, but doesn't
  preserve subdirectory information. zoo preserves the information unless
  told not to do it (an option). ]
| 
|   5) LASTLY: I am not trying to criticize the ARC routines, rather i am trying
|      [ deleted for brevity ]
|      Remember, for those of us who are NOT using the NET at the expense of a
|      university, the cost of communication, and therefore the time required
|      to transmit a file, are VERY important.

[ everyone would like faster transmissions, but not at the expense of
  using a non-standard format which people can't use. Sending info which
  is not useful is a *real* waste of bandwidth. ]
| 
|    If this sounds like a flame, then please assign my apparent bad attitude to
| poor methodology rather than a desire to upset people.  This is provided in the
| spirit of adding to what i hope will become a meaningful dialog with a very
| practicle result.  

The most charitable assumption I can make is that you are woefully
misinformed about the matters on which you speak. Please post this
"ARITH" routine to let others evaluate it, and read the responses to
your posting, many of which will probably not be even a polite as this
one.

-- 
	bill davidsen		(wedu@ge-crd.arpa)
  {uunet | philabs | seismo}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me