Tom Lane wrote:
> Bruce Momjian <[EMAIL PROTECTED]> writes:
> > One other idea would be to set CFLAGS to "" before including template,
> > and just test to see if it is still "" after --- that might be cleaner
> > than saving the original value and comparing.
>
> Yeah, that bothered me a bit too --- what if the template tries to set
> CFLAGS to its already-existing value? I was thinking that unsetting
> CFLAGS before running the template would be the best answer.
I assume he did it that way so if you do:
CFLAGS=
in the template file that it would be honored. I see lots of this in
configure:
ac_env_CFLAGS_set=${CFLAGS+set}
but that uses 'set' if the variable is null or unset:
${parameter:+word}
Use Alternate Value. If parameter is null or
unset, nothing is substituted, otherwise the expan-
sion of word is substituted.
However, I thought null meant "", but I now think null basically means
the same as unset in this manual page. Notice that '+' tests only for
unset, and knows when you have done VAR= and VAR="":
$ echo ${Y+no}
$ Y=
$ echo ${Y+no}
no
$ Y=""
$ echo ${Y+no}
no
$ unset Y
$ echo ${Y+no}
$
so the proper test would be to unset the variable, then use ${var+val}
to test CFLAGS after the template file is included.
--
Bruce Momjian | http://candle.pha.pa.us
[EMAIL PROTECTED] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
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