Shell Programming and Scripting

period=300 # 5 mins
threshold=3600 # 1 hour
now=`date +%Y%m%d%H%M%S`
while true
do
  for file in <your test for the presence of unprocessed files>
  do
    difference=$now - `<get $file mtime>`
    if [ $difference -ge $threshold ]
    then
      <raise an alarm for $file being $difference old>
    fi
  done
done

#!/usr/bin/ksh

function file_hours {
    perl -e 'printf "%i\n", 24*(-M shift);' -- $1
}

cd wherever

for file in *
do
    if [[ $(file_hours $file) -ge 1 ]]
    then
        echo $file is old
    else
        echo $file is new
    fi
done