#!/bin/bash
#
#  prune_dir - prune directory by deleting files if we are low on space
#
DIR=/media/usb/ftp/data/domsod/FI9900P_00626E69B672/record
CAPACITY_LIMIT=95

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 [ "$CAPACITY_LIMIT" == "" ]
then
    CAPACITY_LIMIT=95   # default limit
fi

CAPACITY=$(df -k . | awk '{gsub("%",""); capacity=$5}; END {print capacity}')

if [ $CAPACITY -gt $CAPACITY_LIMIT ]
then
    #
    # Get list of files, oldest first.
    # Delete the oldest files until
    # we are below the limit. Just
    # delete regular files, ignore directories.
    #
    ls -rt $DIR | while read FILE
    do
        FILE="${DIR}/${FILE}"
        if [ -f $FILE ]
        then
            if rm -f $FILE
            then
                now=$(date)
                echo "${now}: Deleted $FILE" >> /var/log/ftpDeleter.log

                CAPACITY=$(df -k . | awk '{gsub("%",""); capacity=$5}; END {print capacity}')

                if [ $CAPACITY -le $CAPACITY_LIMIT ]
                then
                    # we're below the limit, so stop deleting
                    now=$(date)
                    echo "${now}: Below limit, stopped deleting. Capacity: ${CAPACITY}" >> /var/log/ftpDeleter.log
                    exit
                fi
            fi
        fi
    done
else
    now=$(date)
    echo "${now}: Don't need to delete anything, capacity: ${CAPACITY}"
fi