Subject: Re: make(1) question; purpose of ${ :? : }
To: Luke Mewburn <lukem@NetBSD.org>
From: Simon Gerraty <sjg@juniper.net>
List: tech-toolchain
Date: 01/08/2004 18:17:13
On Fri, 9 Jan 2004 11:23:23 +1100, Luke Mewburn writes:
>what limitations are there on the expression before the ':?'  ?
>can we do stuff like
>	${defined(FOO)||${BAR}!=3D"" :?true:false}

The expression is passed to Cond_EvalExpression() so pretty much
anything that it can swallow is ok.  So

A=defined(PATH) && defined(USER)

x:
	@echo "The answer for '$A' is ${$A:?yes:no}"

works, but

A=defined(USER) && ${USER} == "sjg"

does not.  It would be nice if the expression could be arbitrarily
complex.


--sjg