Takes an unsorted list of backup names and returns a list of backups for deletion. The backup rotation rules are given via command line args. The backup names need to contain the time and a date(1) like format specifier is required to parse those.
The following example will make prunef keep 7 daily, 4 weekly and 6 monthly backups.
prunef --keep-daily 7 \ --keep-weekly 4 \ --keep-monthly 6 \ "example.org_%Y-%m-%d_%H-%M-%S.tar.gz"
By default it will parse the dates using the local timezone. The algorithm uses
UTC internaly. If the entries are created in UTC use the
To list backups that should be kept use the
The algorithm works by creating timestamp slots according to the rules given. The first slot is always now. A slot ends where the next timestamp begins. The slots are filled with entries, that are between a slot timestamp and the following timestamp. If an entry exists, it will be replaced if another matches the slot and is more recent.
Slots may not be filled, if there is no entry matching the timestamps.
That means you will only fill all slots, if the backups are created
with lower intervals than the lowest slot interval. If for example
a backup is created every 2 hours and
--keep-hourly 4 is provided,
only 2 backups will be kept.
If no arguments are given, only one slot with now as timestamp will be created. Hence the latest backup will never be returned to be pruned.
Compile with make:
$ make install
For Arch Linux there's also an AUR package available.