Clean old files

cleaner.md

Cleaner for Backups

cleaner.sh is a script to keep a finite number of backup (files) matching a pattern. It should be scheduled on a regular basis from the outside, e.g. with cron.

Options

cleaner.sh takes a number of single or double-dashed options, possibly followed by a command to execute once the removal operations have ended. It is preferrable to separate the list of options from the command using a double-dash, to mark the definitive end of the options.

The following options are recognised.

-k or --keep

The value of this option should be the number of files to keep. It defaults to an empty string, which is understood as keeping all the files.

-f or --files

The value of this option is (usually) a glob-style pattern to point at the list of files to select from when removing the oldest ones.

-v or --verbose

When this option is given, verbosity will be increased.

Notes

This utility is tuned for maximal compatibility. It only requires a basic POSIX shell. As a result, cleaner.sh can easilty be used from containers or in embedded systems.

cleaner.sh

#!/bin/sh

# TODO:
# add a --uploads option to specify the number of latest files to uploads. Good
# in case we missed some.
# add options to wait before starting, similar to mirror.tcl
# add option to sleep and restart automatically

#set -x

# All (good?) defaults
VERBOSE=0
KEEP=
PATHS=

# Dynamic vars
cmdname=$(basename $(readlink -f $0))
appname=${cmdname%.*}

# Print usage on stderr and exit
usage() {
  exitcode="$1"
  cat << USAGE >&2
  
Description:

  $cmdname will find the latest files matching a pattern and only keep a
  finite amount of the youngest files

Usage:
  $cmdname [-option arg --long-option(=)arg] ([--] command)

  where all dash-led options are as follows (long options can be followed by
  an equal sign):
    -v | --verbose       Be more verbose
    -k | --keep          Number of files to keep, defaults to empty,
                         meaning all
    -f | --files         List of files to select from for removal
USAGE
  exit "$exitcode"
}


# Parse options
while [ $# -gt 0 ]; do
    case "$1" in
        -k | --keep)
            KEEP=$2; shift 2;;
        --keep=*)
            KEEP="${1#*=}"; shift 1;;

        -f | --files)
            PATHS=$2; shift 2;;
        --files=*)
            PATHS="${1#*=}"; shift 1;;

        -v | --verbose)
            VERBOSE=1; shift;;

        -h | --help)
            usage 0;; 
        --)
            shift; break;;
        -*)
            echo "Unknown option: $1 !" >&2 ; usage 1;;
        *)
            break;;
    esac
done

if [ -z "$PATHS" ]; then
    echo "You need to specify files to select from for removal" >& 2
    usage 1
fi

# Conditional logging
log() {
    if [ "$VERBOSE" = "1" ]; then
        echo "$1"
    fi
}

if [ -n "${KEEP}" -a "${KEEP}" -gt "0" ]; then
    log "Keeping only ${KEEP} youngest file(s) of $PATHS"
    while [ "$(ls $PATHS -1 -t | wc -l)" -gt "$KEEP" ]; do
        DELETE=$(ls $PATHS -1 -t | sort -r | tail -n 1)
        log "Removing old copy $DELETE"
        rm -rf $DELETE
    done
fi

if [ $# -ne "0" ]; then
    log "Executing $*"
    exec "$@"
fi

LICENSE

BSD 3-Clause License

Copyright (c) 2019, Emmanuel Frecon <efrecon@gmail.com>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

* Neither the name of the copyright holder nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.