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From: David Brown <david.brown@hesbynett.no>
Newsgroups: comp.lang.c
Subject: Re: ASCII to ASCII compression.
Date: Fri, 7 Jun 2024 11:36:43 +0200
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On 06/06/2024 21:02, Malcolm McLean wrote:
> On 06/06/2024 17:55, bart wrote:
>> On 06/06/2024 17:25, Malcolm McLean wrote:
>>>
>>> Not strictly a C programming question, but smart people will see the 
>>> relavance to the topicality, which is portability.
>>>
>>> Is there a compresiion algorthim which converts human language ASCII 
>>> text to compressed ASCII, preferably only "isgraph" characters?
>>>
>>> So "Mary had a little lamb, its fleece was white as snow".
>>>
>>> Would become
>>>
>>> QWE£$543GtT£$"||x|VVBB?
>>
>> What's the problem with compressing to binary (using existing, 
>> efficient utilities), then turning that binary into ASCII (like Mime 
>> or Base64)?
>>
> Because if a single bit flips in a zip archive, it's likely the entire 
> archive will be lost. This scheme is robust. We can emed compressed text 
> in programs, and if it is corruped, only a single line will become 
> unreadable.

Ah, you want something that will work like your newsreader program that 
randomly changes letters or otherwise corrupts your spelling while 
leaving most of it readable?  :-)

Pass the data through a compressor and then add forward error checking 
mechanisms such as Reed-Solomon codes.  Then convert to ASCII base64 or 
similar.