Simple Bash Log Rotate Function

Here's a simple function that you can add to your Bash script to rotate a log. This function will rotate the log everytime the script runs, up to 5 logs.

You can modify it to meet your needs.

# Log rotation
LOG_DIR=${HOME}/bin/log
LOG="${LOG_DIR}/my_script.log"

LogRotate () {
# Deletes old log file
if [ -f $LOG ] ; then
  CNT=5
  let P_CNT=CNT-1
  if [ -f ${LOG}.5 ] ; then
    rm ${LOG}.5
  fi
  
  # Renames logs .1 trough .4
  while [[ $CNT -ne 1 ]] ; do
    if [ -f ${LOG}.${P_CNT} ] ; then
      mv ${LOG}.${P_CNT} ${LOG}.${CNT}
      let CNT=CNT-1
      let P_CNT=P_CNT-1
    fi
  done

  # Renames current log to .1
  mv $LOG ${LOG}.1
  echo "" > $LOG
fi
}