#!/bin/bash 
set -e
#  $HeadURL$ $LastChangedRevision$

TRIES=2
INTERVAL=15

case "$1" in
    upgrade|remove) for ((I=0; I<$TRIES; I++)); do
                        ((I==0)) || {
                            echo "prerm/$1: udi appears to be running; waiting $((INTERVAL*(TRIES-I)))s more before giving up ..." >&2
                            sleep 15
                        }
                        lockfile-create -p -r 0 -l -q /tmp/udi.lock && exit 0
                    done
                    exit 1 ;;
    deconfigure)    : ;;
    failed-upgrade) #  failed-upgrade called after the old verion of the package's prerm failed (as a sort
                    #  of "maybe the new one will work" approach). Since that only fails when udi is locking
                    #  out an upgrade, we want to abort in this situation. Which means that also the 
                    #  new version of the prerm script should fail. See https://www.debian.org/doc/debian-policy/ch-maintainerscripts.html
                    #  specifically section 6.6, for more details.
                    exit 1 ;;
    *)              echo "prerm called with unknown argument \`$1'" >&2
	            exit 1 ;;
esac

exit 0