Python 3 implementation of a date-based Grandfather-father-son backup rotation scheme.
This script takes a list of dates (in the form yyyy-mm-ddThh:mm:ss, or other
parseable with the strfime(3) format) and returns the dates that should be
kept (or removed, using --remove) under the policy given by the positional
arguments passed to the script.
It is also possible to integrate gfs.py as a regular Python module.
- Python 3.6
./gfs.py daily=14 weekly=4 montly=3 yearly=2 <dates.txt
This command will read a list of dates from dates.txt, and will filter it by
the given set of policies, keeping only the latest date that fits in a maximum
number of slots (or groupings) for each cycle:
- 14 slots of daily dates
- 4 slots of weekly dates
- 3 slots of monthly dates
- 2 slots of yearly dates
The new list of dates is printed to the standard output (i.e. the terminal window, when using an interactive terminal).
$ ./gfs.py --help
usage: gfs.py [-h] [--date-format FORMAT] [--file FILENAME]
[--keep | --remove]
cycle=value [cycle=value ...]
Filter dates using the Grandfather-father-son rotation scheme.
positional arguments:
cycle=value Set one or more cycles used for rotation, e.g.,
daily=14.
optional arguments:
-h, --help show this help message and exit
--date-format FORMAT, -d FORMAT
Date format to use to parse the dates (in strftime(3)
format). Default:%Y-%m-%dT%H:%M:%S
--file FILENAME, -f FILENAME
Use filename to read a list of dates instead of the
standard input; '-' is interpreted as the standard
input.
--keep, -k Output the dates to keep in the rotation.
--remove, -r Output the dates to remove from the rotation.
Available cycles: daily, day, weekly, week, monthly, month, yearly, year
See LICENSE.