I am creating DEB package for Ubuntu which copies binary and configuration files. When I am installing/reinstalling with a new DEB file in case of patch, upgrade or downgrade, I need information in preinst file.
I need to know the version of binary shipped with my package, and compare it with one already installed, and perform action accordingly. Binary version can be found using ./binary --version
Is there a way to get the file packaged inside DEB and run commands on it as part of preinst script. I am also ok, if I can hardcode this information in control file, and read control file in preinst script.