But.. It doesn't work well. (Because the sequence of line is not arranged.)  It is better way to use ' redmine_access_logger'  plugin than this    #!/bin/bash  # Setting LOG_FILE=/redmine-3.3.3/log/production.log #LOG_FILE=mylog.log PIDFILE=/var/run/redmine_info_log.pid  # Program Variables OUTPUT_LOGDIR=`dirname ${LOG_FILE}`  OPT_DEBUG=0 URI_FILTER_REGEX="(^\"/people/avatar)|(^/attachments/thumbnail/)|(^\"/issues/.*\.xml)"  function echo_log() {   if [ "$2" != "" ]; then     echo "$1" >> $2   else     echo "$1"   fi }   if [ -f $PIDFILE ] then   PID=$(cat $PIDFILE)   ps -p $PID > /dev/null 2>&1   if [ $? -eq 0 ]   then     echo "Process already running"     exit 1   else     ## Process not found assume not running     echo $$ > $PIDFILE     if [ $? -ne 0 ]     then       echo "Could not create PID file"       exit 1     fi   fi else   echo $$ > $PIDFILE   if [ $? -ne 0 ]  ...