Re: [PATCH] bash-completion: Print a useful error when called in a non-bash shell

From: Johannes Sixt <j6t@kdbg.org>
Date: Aug 6, 2010, 21:31 UTC
Message-ID: <201008062331.38279.j6t@kdbg.org>
In-Reply-To: <4C50B005.1030004@pileofstuff.org>

On Donnerstag, 29. Juli 2010, Andrew Sayers wrote:

Show 5 quoted lines

> Detect whether the shell supports process substitution with <()
> Shells that fail the test will not be able to load git-completion.bash
>
> If a bad shell is found, print a warning which gives the user as much
> debugging information as possible.

This cannot work the way you implemented it:

> +$( 
> +	exec 2>/dev/null
> +	$(exec < <( ))
> + )

Any shell that does not support the <() syntax will have exited at this time with a syntax error and never get to print something.

This could work:

  (eval : '$(exec < <( ) )' 2>/dev/null)

> +if [[ 0 -ne $? ]]

Of course, you must not use unportable [[ ]] syntax here, either.

> +then
> +	cat <<EOF
> ...

-- Hannes