Re: [PATCH] printf.3: Document 'l' length modifier for a, A, e, E, f, F, g, and G

[Vincent Lefevre <vincent@vinc17.net>]

On 2022-05-20 16:44:42 +0200, Alejandro Colomar wrote:
> Hi Vincent,
> 
> On 5/20/22 16:10, Vincent Lefevre wrote:
> > Signed-off-by: Vincent Lefevre <vincent@vinc17.net>
> > ---
> >   man3/printf.3 | 12 +++++++++++-
> >   1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/man3/printf.3 b/man3/printf.3
> > index 4fa1f11f3..63ea3092f 100644
> > --- a/man3/printf.3
> > +++ b/man3/printf.3
> > @@ -502,7 +502,17 @@ argument, or a following
> >   .B s
> >   conversion corresponds to a pointer to
> >   .I wchar_t
> > -argument.
> > +argument. In C99, on a following
> 
> Why "in C99"?

According to GCC with "-Wformat -pedantic", this is new in C99:

  warning: ISO C90 does not support the ‘%le’ gnu_printf format

The printf(3) man page already mentions features that appeared in
C99. For instance: "a, A   (C99; not in SUSv2, but added in SUSv3)"
That's why I mentioned that for consistency.

I could also check that this is not in SUSv2:
  https://pubs.opengroup.org/onlinepubs/7990989775/xsh/fprintf.html

Perhaps this should be rephrased. Something like:

  On a following a, A, e, E, f, F, g, or G conversion, this
  length modifier is ignored (C99; not in SUSv2).

What do you think?

I don't know about SUSv3 (I could just see that this feature was
also supported in POSIX:2004).

> Also, see man-pages(7):
> 
>    Use semantic newlines
>        In the source of a manual page, new sentences  should  be
>        started on new lines, long sentences should be split into
>        lines  at  clause breaks (commas, semicolons, colons, and
>        so on), and long clauses should be split at phrase bound‐
>        aries.  This convention,  sometimes  known  as  "semantic
>        newlines",  makes it easier to see the effect of patches,
>        which often operate at the level of individual sentences,
>        clauses, or phrases.

Thanks for the information.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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