Re: Sed failure in contrib/sboxes on MacOS

[Andreas Kusalananda Kähäri]

On Tue, Oct 26, 2021 at 12:47:49PM +0200, Axel Kielhorn wrote:
> Hello,
> 
> I get the following error when building on MacOS 11:
> 
> sed: 17: ./contrib/sboxes/notquine.sed: unexpected EOF (pending }’s)
> 
> If I remove 
> 
> /\\##/{
>   s/\\##//
>   b}
> 
> It works:

If you insert a semicolon or a newline after the b command, you will
make it more portable.  Also, there is no need to repeat the regular
expression a second time.

        /\\##/ { s///; b; }

or even just

        s/\\##//
        t

The sed script also has another substitution further up that requries
GNU sed:

        s/.*\\##.*/&\n&/

POSIX sed can't insert a newline with its s command using \n.  However,
the following would be portable:

        s/.*\\##.*/&\
        &/

That is, escape the literal newline.

> 
> /Applications/Xcode.app/Contents/Developer/usr/bin/make  all-am
>   GEN      contrib/sboxes/msboxes.ms
>   GROFF    contrib/sboxes/msboxes.pdf
> 
> Later I get:
> 
> sed: 1: "1i .lf 1 contrib/sboxes ...": command i expects \ followed by text


This is from another GNU sed convinience feature taht allows you to
insert text with the i command on the same line as the command itself:

        1i\ .lf 1

With POSIX sed, that needs to be written

        1i\
        .lf 1

Now, looking at the Makefile or Makefile.in, at around line 4538 (search
for where DOC_SED is being used), it seems as if someone has tried to
write this properly, with a literal newline and everything.  The only
issue is that Make will remove that literal newline, which turns it into
a sed expression that only GNU sed understands.

        DOC_GROFF = $(DOC_SED) -e '1i\
        .lf 1 $<' $< | $(DOC_GROFF_ONLY)

The above is turned into something like

        LANG=C LC_ALL=C sed -e "...blah blah..." -e '1i\n .lf 1 ...etc.'

which on my OpenBSD system generates

        sed: 1: "1i\n .lf 1 doc/webpage.ms": extra characters after \ at the 
end of i command

Instead, that line in the Makefile should look like

        DOC_GROFF = $(DOC_SED) -e '1i\' -e '.lf 1 $<' $< | $(DOC_GROFF_ONLY)

That is, break the single expression string up into two.

I've only tested with OpenBSD sed.

> 
> Sed doesn’t tell me its version but the man pages says March 27, 2017.
> 
> Greetings
> 
> Axel

-- 
Andreas (Kusalananda) Kähäri
SciLifeLab, NBIS, ICM
Uppsala University, Sweden

.