Re: [sr #107444] constructs generated by autoconf do not work in the ash shell

[Paul Eggert]

On 08/03/10 01:30, Mark Hobley wrote:

> Some versions of the ash shell will not allow redirection to a stream number
> held in a variable:
> 
>   # This construct does not work in some versions of the ash shell
>   echo $1 >&$2

What do these shells do?  For example, if /bin/ash is where your
ash lives, what does the following command do?

        /bin/ash -c 'set 1 2; echo $1 >&$2' >/dev/null

One way to address this problem is to have Autoconf-generated
scripts test whether the shell is buggy in this way, and to reject
any such shell, using something like _AS_DETECT_REQUIRED([_AS_GT_AMP_VAR])
(where _AS_GT_AMP_VAR is a new macro that tests for the bug).
This assumes that there is some other shell on your system that does not
have the bug, and that the Autoconf-generated script will find it.