Re: [PATCH 6/8] fortran: use grep -F instead of fgrep

[Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>]

On 24 June 2022 14:35:20 CEST, Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> wrote:
>Hi Xi,
>
>> On Fri, 2022-06-24 at 13:13 +0200, Bernhard Reutner-Fischer wrote:
>>
>>> > -       if $(SHELL) -c 'install-info --version | sed 1q | fgrep -s -v
>>> > -i debian' >/dev/null 2>&1; then \
>>> > +       if $(SHELL) -c 'install-info --version | sed 1q | grep -F -s -v
>>> > -i debian' >/dev/null 2>&1; then \
>>> >           echo " install-info --delete --info-dir=$(DESTDIR)$(infodir)
>>> > $(DESTDIR)$(infodir)/gfortran.info"; \
>>> >           install-info --delete --info-dir=$(DESTDIR)$(infodir)
>>> > $(DESTDIR)$(infodir)/gfortran.info || : ; \
>>> >         else : ; fi; \
>>> 
>>> I'd replace -s >/dev/null 2>&1 with -q while at it.
>>> 
>>> But why is -F used here in the first place?
>>> I do not see much in debian that can be interpreted as a regex?
>>
>> I'm not sure.  It was there since 2004.  Perhaps the author thinks fgrep
>> may save several CPU cycles :).  I'll just use a plain grep in PATCH v2.
>>
>> Rainer: do you have some idea about the availability of "-q" on
>> different hosts?  If you agree I'll use it instead of -s > /dev/null
>> too.
>
>again, the autoconf manual warns agains it, even more so against -s.
>That's the first reference for portability issues and shouldn't be
>ignored without good reason.
>
>In the GCC and Solaris context, /bin/grep supports both -q and -s in
>Solaris 11.3 and 11.4.  It doesn't support -q on Solaris 10, though
>(again, no longer relevant for GCC).

The good reason I would bring forward is that the systems mentioned in the autoconf docs are all not supported anymore (IRIX, ancient or old Solaris etc).
Furthermore, grep(1) is required by POSIX to support -q since at least 1997; see https://pubs.opengroup.org/onlinepubs/007908799/xcu/grep.html

That's about 25 years now, so everybody had plenty of time to implement this specific part, which is even trivial to implement for this particular case of grep -q.

All in all i think that we should not be held hostage by such systems any longer, at least for such cases that are trivial to fix to conformance. Of course that may be just /me.

Iff fixing egrep or fgrep occurrences though,  we should use plain grep where applicable, like in this case, IMO.

thanks,