Get cumulated traffic usage from webalizer stats, send email if over limit

check_traffic.sh

#!/bin/bash
LIMIT=45000000
USAGE=0

for dir in /path/to/stats/*/
do
  LOCAL_USAGE=`head -n 2 $dir/webalizer.hist | tail -n 1 | cut -d" " -f6`
  USAGE=$(($USAGE + $LOCAL_USAGE))
done

if [ $USAGE -gt $LIMIT ]
then
  echo "Traffic limit of $LIMIT reached"  | mail -s "Traffic limit of $LIMIT reached" email@host.tld
fi