Filter a list of dates according to a filter spec
For example, suppose you make hourly backups, but you don't want to keep older backups. Then a command like this:
cd /backups && ls | datefilter -print0 | xargs -0 rm
will make a decent selection of files to remove.
Note that datefilter will try to extract a date (in iso8601-like format) from the input strings; it doesn't actually look at the file dates or anything like that.
By default, it will use the following filter specification:
- keep a file every hour for the past 2 weeks
- keep a file every day for the past 4 weeks
- keep a file every week for the past 3 months
- keep a file every 2 weeks for the past year