[TUHS] non-Posix input files

[Clem Cole]

Chet  - as I said, we tried so hard to keep that kind of crap out. Dennis
was right. FWIW: with UNIX (POSIX), input will end if an EOF  and the ANSI
C untilies will obey it or a newline, so you can write the code to work
fine either way. But that's a choice of implementation/what subroutines -
how you think about the data.

I'll accept that that is what the words say in the >>awk<< specification
document, but as one of the original authors of the first UNIX standard and
the later POSIX standard I can say we tried hard to mak sure we got it
right and follow the idea: A regular file has no structure and never to
allow the standard to impose it.  I think the core standard still says
that, and the basic idea is unchanged. The actual structure of the input
file is an application idea, not a UNIX/POSIX defined idea.

The issue here is the term POSIX.   Do you mean it to be the kernel (.1)
and if a >>specific<< application with .2  (the C compiler itself, awk, ed)
which might put structure onto the file and that's fine.  The  >>OS<< does
not set the structure — it is done by something else.

I understand having the application do it; I wish it did not. Many
applications (even text editors) can (and have) been written without
needing one specific structure, which is my point.  I also accept that the
folks who took over the standard in the name of "progress" changed
(relaxed) much of what we worked so hard to avoid, knowing there were
dragons - particularly WRT to textual information. We really did not want
to repeat the errors of the 1960s.  *i.e.*, as George Santayana originally
wrote, *“Those who cannot remember the past are condemned to repeat it.” *
ᐧ

On Thu, Mar 27, 2025 at 3:05 PM Chet Ramey <chet.ramey at case.edu> wrote:

> On 3/27/25 3:00 PM, Clem Cole wrote:
> > Argh -- I standard corrected.  We worked hard at the beginning to keep
> that
> > crap out -- sigh.
> >
> > But  at least is does says: POSIX.1-2024 /_does not _//_distinguish
> between
> > text files and binary files_/ (see the ISO C standard)
>
> It also says "The standard utilities that have such restrictions always
> specify "text files" in their STDIN or INPUT FILES sections," so you can't
> avoid it.
>
> awk is one such utility (sh is not). This is an application requirement, so
> awk is required to add a newline at the end of a file that does not have
> one.
>
> --
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                  ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, UTech, CWRU    chet at case.edu    http://tiswww.cwru.edu/~chet/
>
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