Re: weird ksh eval behavior

[Ralf Wildenhues]

[ limiting to autoconf-patches ]

Hi Paul,

* Paul Eggert wrote on Thu, Dec 01, 2005 at 10:04:02PM CET:
> Ralf Wildenhues <address@hidden> writes:
> 
> > is this behavior considered "common knowledge" or should it be
> > mentioned in the Autoconf shell portability section?
> 
> The latter, I think.  I installed this:

Thanks.  I noticed a couple of nits:

> --- autoconf.texi     10 Nov 2005 18:57:58 -0000      1.933
> +++ autoconf.texi     1 Dec 2005 21:02:40 -0000       1.934
> @@ -11120,6 +11123,25 @@ $foo
>  EOF
>  @end example
>  
> +
> address@hidden @command{eval}
> address@hidden -----------------
> address@hidden @command{eval}
> +In some shell implementations (e.g., @command{ash}, OpenBSD 3.8

This is fixed in recent ash, it was just the old one shipped with Fedora
Core 3.  May or may not be relevant.

> address@hidden, @command{pdksh} v5.2.14 99/07/13.2, and @command{zsh}
> +4.2.5), the arguments of @samp{eval} are evaluated in a context where
> address@hidden is 0, so they exhibit behavior like this:
> +
> address@hidden
> +$ false; eval 'echo $?'
> +0
> address@hidden example
> +
> +The correct behavior here is to assign a nonzero value to @samp{foo},

There is no other mention of `foo' in this context.

> +but portable scripts should not rely on this.
> +
> +You should not rely on @code{LINENO} within @command{eval}.
> address@hidden Shell Variables}.
>  
>  @item @command{exit}
>  @c -----------------

Cheers,
Ralf