From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Sixt <j6t@kdbg.org>
Subject: Re: [PATCH] bash-completion: Print a useful error when called in a non-bash shell
Date: Fri, 6 Aug 2010 23:31:38 +0200
Message-ID: <201008062331.38279.j6t@kdbg.org>
References: <4C50B005.1030004@pileofstuff.org>
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Cc: Git Mailing List <git@vger.kernel.org>,
	"solsTiCe d'Hiver" <solstice.dhiver@gmail.com>
To: Andrew Sayers <andrew-git@pileofstuff.org>
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On Donnerstag, 29. Juli 2010, Andrew Sayers wrote:
> 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