rotate work history

#!/usr/bin/env bash

N=30
DRYRUN=false
WORKDIR=/home/lasse/Desktop
HISTORY=__HISTORY
HISTORY_DIR=$WORKDIR/$HISTORY/$(date +%Y%m%d)

if [ "$1" != "" ]; then N=$1; fi

mkdir -p $(dirname $HISTORY_DIR)
find $WORKDIR -maxdepth 1 -mmin +$(($N*24*60)) -not -name $HISTORY -print0 > $HISTORY_DIR.txt
#find $WORKDIR -maxdepth 1 -mmin +$(($N*24*60)) -type f -not -name $HISTORY

if [ $(cat $HISTORY_DIR.txt|tr '\0' '\n'|wc -l) -gt 0 ]; then

        if $DRYRUN; then
                cat $HISTORY_DIR.txt|xargs -0 echo mv -t $HISTORY_DIR
        else
                mkdir -p $HISTORY_DIR
                echo "Moving the following to $HISTORY_DIR:"
                cat $HISTORY_DIR.txt|tr '\0' '\n'|sed 's/^/    /'

                # Move older than N days work to history
                cat $HISTORY_DIR.txt|xargs -0 mv -t $HISTORY_DIR
        fi
fi

rm $HISTORY_DIR.txt
echo