Re: [PATCH] shell portability: Use sed instead of non-portable variable expansion

From: Johannes Sixt <j.sixt@viscovery.net>
Date: Sep 5, 2011, 07:03 UTC
Message-ID: <4E647442.9000005@viscovery.net>
In-Reply-To: <8762l73758.fsf@elisp.net>

Am 9/5/2011 7:11, schrieb Naohiro Aota:

Show 8 quoted lines

> Variable expansions like "${foo#bar}" or "${foo%bar}" doesn't work on
> shells like FreeBSD sh and they made the test to fail. This patch
> replace such variable expansions with sed.
> 
> Signed-off-by: Naohiro Aota <naota@elisp.net>
> ---
> 
> Testing on FreeBSD failed because of this "bash-ism".

These are not bashism, but features require by POSIX.

I'd rather suspect that the failures are not because FreeBSD sh does not have ${%} or ${#}, but rather that it interprets the meaning of the backslash in this case in a way different from other shells.

>  run_backend() {
>  	echo "$2" |
> -	QUERY_STRING="${1#*\?}" \
> -	PATH_TRANSLATED="$HTTPD_DOCUMENT_ROOT_PATH/${1%%\?*}" \

What happens if you write these as

	QUERY_STRING=${1#*\?} \
	PATH_TRANSLATED=$HTTPD_DOCUMENT_ROOT_PATH/${1%%\?*} \

i.e., drop the double-quotes?

-- Hannes