Bug#747320: Mandate "type" in /bin/sh

[Bill Allombert <ballombe@debian.org>]

On Wed, May 07, 2014 at 02:32:39PM +0100, Ian Jackson wrote:
> Package: debian-policy
> Version: 3.9.5.0
> 
> I came across this in /etc/init.d/exim4:
> 
>   OLDIFS="$IFS"
>   IFS=:
>   for p in $PATH; do
>     if [ -x "$p/$UPEX4CONF" ]; then
>       IFS="$OLDIFS"
>       $p/$UPEX4CONF $UPEX4OPTS
>       return 0
>     fi
>   done
>   IFS="$OLDIFS"
> 
> I imagine that this kind of thing is found in many other places.
> 
> It seems to me that given that dash and bash both provide `type', and
> the underlying functionality necessarily exists in the shell, it would
> be better to mandate that the shell expose it.
> 
> I therefore propose that the following should be added to the list of
> additional features listed in policy 10.4:
> 
>   * The XSI extension `type' must be supported .  It must exit
>     zero iff the command is found.  The output format is not
>     specified and scripts must not rely on it; scripts should
>     rely only on the exit code using a construct such as
>        if type foo >/dev/null 2>&1; then ...

Could you do a survey of current valid /bin/sh shells and see which of them
suport XSI type already ?

Cheers,
-- 
Bill. <ballombe@debian.org>

Imagine a large red swirl here.