add new packaging feature debian/<package>.purge
"debian/postrm" scripts currently contain a lot of calls to 'rm' or 'rmdir'; running these two commands will give you a quick overview:
grep "rmdir --ignore-fail-on-non-empty" /var/lib/dpkg/info/*.postrm grep "rm -f" /var/lib/dpkg/info/*.postrm
Here is a (very small) sample (grep "rm -f" /var/lib/dpkg/info/*.postrm | grep -v \* | wc -l gives me 187):
/var/lib/dpkg/info/adduser.postrm: rm -f /etc/adduser.conf /var/lib/dpkg/info/console-setup.postrm: rm -f /etc/default/console-setup /var/lib/dpkg/info/debian-archive-keyring.postrm: rm -f /etc/apt/trusted.gpg.d/debian-archive-keyring.gpg /var/lib/dpkg/info/grub-pc.postrm: rm -f /etc/default/grub /var/lib/dpkg/info/locales.postrm: rm -f /etc/locale.gen /var/lib/dpkg/info/locales.postrm: rm -f /etc/default/locale /var/lib/dpkg/info/lsb-release.postrm: rm -f /etc/lsb-release /var/lib/dpkg/info/readline-common.postrm: rm -f /etc/inputrc /var/lib/dpkg/info/util-linux.postrm: rm -f /etc/adjtime
this could be moved to "debian/<package>.purge" files only containing the path:
# comment # the files are processed in the order specified in this file # so: first files & the eventually volatile folders # holding those files /path/to/folder/file # this is the same as calling "rmdir --ignore-fail-on-non-empty" # folders must end with a '/' to be recognized as such /path/to/folder/
If postrm exists, theses files would be proceeded after it and only it exited successfully.
- this information would be machine-parsable (postrm is not), this could benefit 'cruft', but other packages too
1. dpkg --search could help users known where some loose file in /etc comes from; it would work like locate -e and only match existing files.
2. dpkg --listfiles could show those, but we must check if it is backward compatible
- this would trim postrm scripts
- if the postrm only included something like
if [ "$1" = purge ]; then rm -rf /somefile fi
it would completely go away. dpkg would avoid starting a shell, making the removal faster. A simple unlink() is much more lightweight.
Some packages will need runtime registration of files to purge on package removal, how can we accommodate those?