SSH Script to cleanup folder space by removing older files. E.g. for backups

cleanup.sh

#!/bin/bash

# directory to cleanup
DIR=$1
# how much to free up in Gb
SIZE=$2
# factor to size conversion
FACTOR=1048576
MAX_FREE_SIZE=20

if [ "$DIR" = "" ]
then
    echo "ERROR: directory not specified"
    exit 1
fi

if ! cd $DIR
then
    echo "ERROR: unable to chdir to directory '$DIR'"
    exit 2
fi

if [ "$SIZE" = "" ] || [ "$SIZE" -gt "$MAX_FREE_SIZE" ]
then
    SIZE=1   # default size
fi

# convert GB to KB
SIZE=$(($SIZE * FACTOR))

actualSize() {
    # space available in Kb, take second line only
    echo $(df --output=avail --type=ext4 | tail -n 1)
    # space used
    #echo $(du -sb | cut -f1)
}

#echo "$(actualSize) - $SIZE"

if [ $(actualSize) -lt "$SIZE" ]
then
    #
    # Get list of files, oldest first.
    # Delete the oldest files until
    # free space is above the limit. Just
    # delete regular files, ignore directories.
    #
    ls -rt | while read FILE
    do
        if [ -f "$FILE" ]
        then
            if rm -f "$FILE"
            then
#                echo "Deleted $FILE"

                if [ $(actualSize) -ge "$SIZE" ]
                then
                    # we're below the limit, so stop deleting
                    exit
                fi
            fi
        fi
    done
fi