Re: [PATCH] tests: portability fix.

[Akim Demaille]

Le 26 août 09 à 19:56, Joel E. Denny a écrit :

> Hi Akim.
>
> On Wed, 26 Aug 2009, Akim Demaille wrote:
>
> > -echo 'start: "\T\F\0\1" ;' | tr 'TF01' '\011\014\0\1' >> input.y
> > +
> > +# It is not easy to create special characters, we can only trust tr.
> > +# Beside we cannot even expect "echo '\0'" to output two characters
> > +# (well three with \n): at least Bash 3.2 converts the two-character
> > +# sequence "\0" into a single NUL character.
> > +#
> > +# Z for 0, O for 1.
> > +echo 'start: "\T\F\Z\O" ;' | tr 'TFZO' '\011\014\0\1' >> input.y
>
> Argh!  Just a few weeks before writing that, I worked with Paolo to  
> revise
> the Autoconf documentation on echo portability.  I forget so quickly.
> Thanks for catching it.

Well, my environment did it for me :)

> According to the Autoconf documentation, we can't rely on backslash at
> all,

In a first draft I had used tr to \ -> / :)

> and we need to convert to a here document.  So, maybe we should have:
>
> cat <<EOF | tr 'TFZO' '\011\014\0\1' >> input.y
> start: "\T\F\Z\O" ;
> EOF
>
> This works for me.  But did I make it more portable?  The Autoconf
> documentation says Solaris tr can't be trusted to handle \0.
>
> Maybe we need to skip this test if od shows that input.y doesn't look
> right.

I would rather use Perl, which is widely available and it's easy to  
skip if it is not, to generate the input.