[Oberon] RE: Unix line delimiters (was: Refine *Mail*.Mod)

Chris Burrows chris at cfbsoftware.com
Mon Oct 30 00:12:53 MET 2006


> 
> Just a pedantic point, Ken and Dennis used KSR-33 to invent 
> Unix, along with some model 37's and a lot of glass ttys 
> shortly after.
> Here's a link to an image of the first pdp-11 model 20 they 
> shared with the patent department at Murray Hill.  I don't 
> know why they used just newlines as line deliminters, but I 
> don't think it wasn't because of the output devices.
> 

I agree. Just the opposite in fact - they deliberately designed text files
in a way that was independent of any particular input / output device. Why
use a pair of characters to denote a line delimiter when one was sufficient?
The following extract from 'A Retrospective' by Dennis Richie, The Bell
System Technical Journal, July / August 1978, Vol 57, No 6 Part 2. 

"A text file, for example, is stored as a sequence of characters with
new-line characters to delimit lines.  This form of storage is not only
efficient in space when compared with fixed-length records, or even records
described by character counts, but is also the most convenient form of
storage for the vast majority of text-processing programs, which almost
invariably deal with character streams. Most important of all, however, is
the fact that there is only one representation of text files. One of the
most valuable characteristics of UNIX is the degree to which separate
programs interact in useful ways; this interaction would be seriously
impaired if there were a variety of representations on the same
information."

Although this might seem obvious today, it was quite a departure from common
practice at the time. On other systems the applications (not systems)
programmer had to meticulously format text in different ways, depending on
where it was coming from or going to. 

--
Chris Burrows
CFB Software
http://www.cfbsoftware.com/gpcp



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