Re: Command Substitution in AC_ARG_WITH Help Strings

[Keith Marshall]

On Sunday 31 July 2005 10:49 pm, Andreas Schwab wrote:
> > MY_LANGUAGE_SET([`cd lang; echo ?? | tr " " ,`])
> >
> > and have the result of the command substitution
> >
> >    `cd lang; echo ?? | tr " " ,`
> >
> > appear in the `configure --help' output.
>
> This won't do the right thing if configure is executed outside the source
> directory (for buiding in a separate directory).

I realise this;  perhaps I oversimplified the example,  which was intended 
only to illustrate the concept.  The real code would obviously need to refer 
back to ${srcdir}, to circumvent this limitation.

> > Given these limitations, can anyone suggest a better mechanism for
> > achieving this objective?
>
> Use esyscmd to interpolate the output of the command at configure creation
> time.

But does that really offer any advantage over using a shell script to do the 
same thing?  It still performs the substitution at the time when configure is 
generated, rather than when it is run.

Regards,
Keith.