rotate.sh

#!/bin/sh
TSTAMP=`date +%Y%m%d-%H:%M:%S`
FILENAME=$1
LOGPATH=$2
Rotate=3
logfile=backup.log-`date +%Y%m%d`

echo ".............Backup Script Running on $TSTAMP............" >> $logfile
let i=$Rotate-1
if [ -f "$FILENAME.$Rotate" ];then
  echo "$FILENAME.$Rotate Found,Deleting" >> $logfile
  rm -rf $FILENAME.$Rotate
else
  echo "$FILENAME.$Rotate Not Found, Not Removing" >> $logfile
fi

while [ $i -ge 1 ]
do
  let j=$i+1;
  if [ -f "$FILENAME.$i" ];then
    echo $FILENAME.$i exists and is being moved to $FILENAME.$j >> $logfile
    mv $FILENAME.$i $FILENAME.$j
  else
    echo $FILENAME.$i not found, not moving to $FILENAME.$j >> $logfile
  fi
  let i=$i-1
done

cp $FILENAME $FILENAME.1

usage

$ bash backup.sh sample.txt