27 Mar
2025
27 Mar
'25
8:08 p.m.
Hi Doug,
At 2025-03-27T15:50:50-0400, Douglas McIlroy wrote:
It seems my reply to Clem went astray. POSIX Part 2,
Shell and
Utilities, is very clear:
2..2.2.181 text file: A File that contains characters organized into
one or more lines.
The lines shall not contain NUL characters ...
2.2.2.95 line: A sequence of zero or more non-<newline> characters
plus a terminating <newline> character,
Oddly--and in my opinion wrongly--the standard excludes empty files.
It would be a shock if an editor or groff refused to process an empty
file and thereby broke Kernighan's law, "Do nothing gracefully".
I think I can claim that GNU troff has long upheld that principle.
$ printf '' | ~/groff-HEAD/bin/groff | grep . || echo NO OUTPUT
NO OUTPUT
$ printf '' | ~/groff-1.23.0/bin/groff | grep . || echo NO OUTPUT
NO OUTPUT
$ printf '' | ~/groff-1.22.4/bin/groff | grep . || echo NO OUTPUT
NO OUTPUT
$ printf '' | ~/groff-1.22.3/bin/groff | grep . || echo NO OUTPUT
NO OUTPUT
That carries us back through over 10 years of groff development. I'd
bet it's been the case since 1991. Maybe earlier.
Regards,
Branden