postrm is in bilibop-rules 0.4.20.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 | #!/bin/sh
set -e
# Source debconf library:
. /usr/share/debconf/confmodule
global_filter_is_supported() {
    local version="$(dpkg -l lvm2 | awk '/^ii/ {print $3}')"
    dpkg --compare-versions ${version} ge 2.02.98
}
case "${1}" in
    purge)
        # Remove custom rules:
        rm -f /etc/udev/rules.d/66-bilibop.rules
        # Restore GRUB device.map
        DEVICE_MAP="/boot/grub/device.map"
        if [ -f "${DEVICE_MAP}.bak" -o -h "${DEVICE_MAP}.bak" ]; then
            rm -f ${DEVICE_MAP}
            mv ${DEVICE_MAP}.bak ${DEVICE_MAP}
        fi
        # Comment bilibop-rules specific configuration variables in
        # the common bilibop config file:
        CONFIGFILE="/etc/bilibop/bilibop.conf"
        if grep -Eqs '^[[:blank:]]*BILIBOP_RULES(_[A-Z]+)+=' ${CONFIGFILE}; then
            sed -Ei 's,^\s*BILIBOP_RULES(_[A-Z]+)+=,#&,' ${CONFIGFILE}
        fi
        # Reset some LVM settings to what they were before the installation of
        # this package, but if, and only if lvm.conf has been modified through
        # debconf (during installation or with 'dpkg-reconfigure bilibop-rules')
        LVMCONF="/etc/lvm/lvm.conf"
        lvm_variables="obtain_device_list_from_udev filter"
        global_filter_is_supported && lvm_variables="${lvm_variables} global_filter"
        db_get bilibop-rules/physical_volumes_filter/system-only
        if [ -f "${LVMCONF}" -a "${RET}" = "true" ]; then
            for lvmvar in ${lvm_variables}; do
                db_get bilibop-rules/physical_volumes_filter/${lvmvar}
                if [ -n "${RET}" ] && grep -q "^[[:blank:]]*${lvmvar}[[:blank:]]*=" ${LVMCONF}; then
                    grep -Eq "^[[:blank:]]*${lvmvar}[[:blank:]]*=[[:blank:]]*${RET}[[:blank:]]*(#|$)" ${LVMCONF} ||
                    sed -Ei "s@^(\s*${lvmvar}\s*=).*@\1 ${RET}@" ${LVMCONF}
                fi
            done
        fi
        # And then purge the database:
        db_purge
        db_stop
        ;;
esac
case "${1}" in
    purge|remove)
        # Remove bilibop-rules script from the initramdisk:
        if [ -x /usr/sbin/update-initramfs ]; then
            update-initramfs -u
        fi
        # Trigger uevents for block devices owned by 'disk' group.
        if [ -f /etc/udev/udev.conf ]; then
            . /etc/udev/udev.conf
        fi
        udev_root="${udev_root:-/dev}"
        udev_root="${udev_root%/}"
        if [ -f /proc/partitions -a -d /sys/block -a -c ${udev_root}/null ] &&
            invoke-rc.d udev status >${udev_root}/null 2>&1; then
            cd ${udev_root}
            for dev in $(find * -type b -group disk); do
                grep -q "[[:blank:]]${dev}$" /proc/partitions &&
                opt="${opt} --sysname-match=${dev}"
            done
            udevadm trigger ${opt}
            udevadm settle
            cd ${OLDPWD}
        fi
        # Udev does not remove empty tag directories; so we do it here.
        for tag in BILIBOP INSIDEV; do
            if [ -d /run/udev/tags/${tag} ]; then
                rmdir --ignore-fail-on-non-empty /run/udev/tags/${tag}
            fi
        done
        ;;
esac
:
# vim: et ts=4 sts=4 sw=4
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