java hscompiler watcher

#!/bin/bash
PID="$1"
PATTERN="$2"
LOG_PATH="$3"
if [ -z "$PATTERN" ]
then
    PATTERN="com.db"
fi
SLEEP_PERIOD=2
echo "" > /tmp/hscompile"$PID".last
echo "" > $LOG_PATH/compiletimes.log
# watches a compile log and reports approximately when db code is compiled
while [ 1 -eq 1 ]
do
    cp $LOG_PATH/console.log /tmp/hscompile"$PID".next
#    diff --unchanged-line-format='' --old-line-format='' --new-line-format='%L' /tmp/hscompile.last /tmp/hscompile.next > /tmp/hscompile.new
    OLD_COUNT=$( wc -l < /tmp/hscompile"$PID".last )
    NEW_COUNT=$( wc -l < /tmp/hscompile"$PID".next )
    NEW_LINES=$(( NEW_COUNT-OLD_COUNT ))
    if [ $NEW_LINES -gt 0 ]
    then
        tail -"$NEW_LINES" /tmp/hscompile"$PID".next | grep $PATTERN > /tmp/hscompile"$PID".new
        COMPILED_COUNT=$( wc -l < /tmp/hscompile"$PID".new )
        echo "found $COMPILED_COUNT new entries"
        if [ $COMPILED_COUNT -gt 0 ]
        then
            LOG_MESSAGE=$(date '+%d-%b-%Y %T')" - $COMPILED_COUNT new entries"
            echo $LOG_MESSAGE >> $LOG_PATH/compiletimes.log
            cat /tmp/hscompile"$PID".new >> $LOG_PATH/compiletimes.log
        fi
    else
        echo "No new entries in console.log"
    fi
    mv /tmp/hscompile"$PID".next /tmp/hscompile"$PID".last
    if [ -e /tmp/hscompile"$PID".new ]
    then
        rm /tmp/hscompile"$PID".new
    fi
    sleep $SLEEP_PERIOD
done