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Re: End of file mark

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Charlie Gibbs wrote:

> Although MS-DOS text file input recognizes 0x1a as an EOF marker,
> this isn't necessary, since the file system stores the file size
> to the byte. In fact, all of my MS-DOS software took pains to
> ensure that the mark
> was never written, and removed it if present.  An early version of
> MS-DOS (3.1 IIRC) had a bug in COMMAND.COM such that if you
> redirected output to append to a file (e.g. dir >>foo), an
> existing EOF mark was not overwritten, causing all new data to be
> lost.
> 
> It's one more bit of backward compatibility that was just plain
> backward. It lives on in Windows to this day.

Old Wordstar 3.3 worked in 128 byte blocks and would always pad the 
last block with ^Z^Z^Z^Z...., Control-Z, 0x1A, or ASCII SUB, 
denoting the end-of-file.  Plenty of text editors would recognize 
this, and if saving such a file would cut that down to one ^Z.  
IIRC, they generally ended files with a ^Z.

DOS copy had a text mode which, again IIRC, you didn't usually need 
to specify, but if you did something like 'copy foo + bar foobar' 
you had to or you'd get results much like the above.  The info 
wasn't actually lost, but you had to recognize what had happened or 
use software that just didn't care and say "What is that ^Z doing in 
the middle of my file?"

-- 
Tom Hardy <rhardy702@gmail.com>

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End of file mark T <T@invalid.invalid> - 2015-08-10 10:05 -0700
  Re: End of file mark John Hasler <jhasler@newsguy.com> - 2015-08-10 12:40 -0500
    Re: End of file mark Richard Kettlewell <rjk@greenend.org.uk> - 2015-08-10 19:32 +0100
      Re: End of file mark Keith Thompson <kst-u@mib.org> - 2015-08-19 17:38 -0700
  Re: End of file mark The Natural Philosopher <tnp@invalid.invalid> - 2015-08-10 19:52 +0100
    Re: End of file mark Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-08-11 12:40 +0200
      Re: End of file mark The Natural Philosopher <tnp@invalid.invalid> - 2015-08-11 11:51 +0100
  Re: End of file mark Robert Heller <heller@deepsoft.com> - 2015-08-10 16:05 -0500
    Re: End of file mark Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-08-10 21:16 +0000
      Re: End of file mark Tom Hardy <rhardy702@gmail.com> - 2015-08-11 23:34 -0500
        Re: End of file mark Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-08-12 14:57 +0000
          Re: End of file mark Tom Hardy <rhardy702@gmail.com> - 2015-08-13 11:28 -0500
  Re: End of file mark T <T@invalid.invalid> - 2015-08-11 10:27 -0700

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