auto-detecting krb versions for build

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Jim McDonough <jmcd at us.ibm.com> writes:

> As some of you may have noticed, the UL builds on the farm don't work.  The
> culprit is the pre- 0.5 heimdal that is installed, as it doesn't have
> AP_OPTS_USE_SUBKEY, which is needed to do password changes.  Unless someone
> knows how to accomplish password changes to a win KDC without it, we need
> to be able to detect the package and release of kerberos installed.
> Heimdal before 0.5 doesn't have it.  I'm not sure how far you have to go
> back in MIT to not find it.

Heimdal before 0.5 didn't have AP_OPTS_USE_SUBKEY, however I think it
allways generated and used a subkey anyway, so defining it to 0 should make
it work.

> krb5-config takes a --version option and prints something like:
> heimdal 0.4d
> $Id: krb5-config.in,v 1.8 2001/01/29 06:56:51 assar Exp $
>
> or in the case of MIT:
> Kerberos 5 release 0.0.0
>
> Yes, 0.0.0, but I'm using a dev version.   In any case, I'd like to take
> that output, and if it has "heimdal", make a decision based on the
> number...since I'm not a wiz (more like a whiz) at these sorts of string
> cutting/comparing in shells...anyone want to tell me how to do it?

`expr expr1 : expr2` or case statement is usully what I use.

Love