Re: [PATCH 2/2] Makefile: work around ksh's failure to handle missing list argument to for loop

From: Michael J Gruber <git@drmicha.warpmail.net>
Date: Jul 5, 2010, 08:14 UTC
Message-ID: <4C319478.4070903@drmicha.warpmail.net>
In-Reply-To: <4C31796E.9050109@viscovery.net>

Johannes Sixt venit, vidit, dixit 05.07.2010 08:19:

Show 21 quoted lines

> Am 7/4/2010 20:37, schrieb Michael J Gruber:
>> Brandon Casey venit, vidit, dixit 02.07.2010 20:50:
>>> In this case, the for loop in the Makefile expands to look like this:
>>>
>>>    for p in ; do
>>>
>>> and ksh complains like this:
>>>
>>>    /bin/ksh: syntax error at line 15 : `;' unexpected
>>>
>>> The existing attempt to work around this issue, introduced by 70b89f87,
>>> tried to protect the for loop by first testing whether REMOTE_CURL_ALIASES
>>> was empty, but it does not seem to work.  So adopt Bruce Stephens's
>>
>> What does that mean? Either it works or it doesn't. I did work back
>> then. Does it (i.e.: the test for emtyness) fail to work for certain shells?
> 
> Before the test for emptyness can happen, the complete statement must be
> parsed, but ksh finds a syntax error in the statement and, therefore,
> cannot even begin to execute the statement. (ksh doesn't follow POSIX in
> this regard, where this would not be a syntax error.)

OK, thanks for clarifying. I suggest this to go into the commit message so that the "does not seem to work" is qualified.

The OP back then (before 70b89f87) used ksh on AIX 6.1, but maybe he left the thread without testing. I assume Hari's suggestion works on ksh, as well?

If we go for Brandon's version: Is there a reason for small-casing the var name? It looks as if we had two different variables with different case (which we don't).

BTW: Is the $$var gmake specific? Has anyone tested the new version on,
say, AIX, not just on Linux with ksh?

Michael