standardized error messages

[John Quarterman]

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Date: Sun, 11 Aug 85 23:20:34 edt
From: Ian! D. Allen <ihnp4!watmath!idallen>
To: ut-sally!std-unix
Subject: On interspersing options in command lines.

At Waterloo, we've used full-word options on our Honeywell/GCOS system
for years.  Gosh it makes reading the "man" pages easier!  We're bringing
an automated full-word-options parser to our UNIX systems now, and our
parser will have the "+help" self-documentation feature.  (At Waterloo
we use "+" and "-" for ON and OFF, rather than '-opt' and '-noopt'.)

Consider how the following syntax might be interpreted:

   $ commandname +optimize file1 -optimize file2 file3

1) Options are only recognized at the beginning of a command line.
   - file1 is optimized; file named '-optimize' is not found
2) Options are recognized where they are found, and apply to all
   following objects.
   - file1 is optimized; file2 and file3 are not optimized
3) Options apply to the entire command line, no matter where they are found.
   - option '+optimize' conflicts with '-optimize' and nothing is done

Waterloo is currently using the Type 3 interpretation.  If options
apply to the entire command line, no matter where they are typed, I can
enter the words on my command lines in the order I think of them.  I
find the most common way I enter command lines is to type in all the
file names first, then follow them with the modifying options I want.
In the rare (very rare) cases where I want to apply the same command
with different options to some files, I use separate command lines.

I claim that the convenience of letting users type in the words in the
order they want more than compensates for the resulting need to use
multiple commands every now and then.  (I'd love to have some survey data
to back this claim up.)

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