Do something depending on previous version installed ?

[Jan-Frode Myklebust <janfrode tanso net>]

I need to stop the service and delete some files before starting the
same service when upgrading a package, depending on which version I'm
upgrading from. I assume I should do this in %postun, where we
normally restart the service, but how can I check the version of the
previously installed package ?



  -jf