When creating an rpm package, the spec file can specify a number of scripts to be run before and after package install and uninstall. For the simple cases of a new install or an uninstall it is obvious which script runs when. However, the documentation didn’t seem very clear on the behavior during a package upgrade (rpm -U).

Documenting this as a note to my future self, for the next time I need it… The table shows which script runs when (and in what order) and what integer parameter it is given:

With this, the scripts can do something like:

%pre

case "$*" in
  1)
    echo package is about to be installed for first time
    ;;
  2)
    echo package is about to be upgraded, prepare component
    echo for upgrade (e.g. stop daemons, etc)
    ;;
esac
exit 0