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Re: manunal page - uninterpretted dot
From: |
Werner LEMBERG |
Subject: |
Re: manunal page - uninterpretted dot |
Date: |
Tue, 27 Nov 2012 09:27:43 +0100 (CET) |
> I believe this is the most confusing part in groff(7):
>> \. An uninterpreted dot (period), even at start of line.
>
> AFAIK the dot character is just the default control character and
> has a special meaning only at the beginning of the line. Nowhere
> else.
Yes. However, macro expansion can make some elements vanish before
the dot.
> If the \. sequence cannot be used to suppress the meaning of
> control character at the beginning of the line, it makes no sense to
> use this sequence at all. Am I right?
No, see below.
> So what about removing this line from documentation at all?
Well, `\.' is even in the original troff documentation...
The very usage is not `\.' but `\\..' within a macro:
.de foo
. nop foo
.
. de bar
. nop bar defined within foo
\\..
..
After macro expansion, `\\..' reduces to `\..' which simply gets
interpreted as `..', and this is exactly what's needed to define `bar'
within `foo'. In other words, the necessity of having `\.' is not to
somehow extract a special meaning of `.' but rather to make `\' vanish
(which has been written as `\\' within the macro).
Werner