Shell Programming and Scripting

I have a directory that has files going into it and moving out on a regular basis. The normal state of the directory would be to be empty. I need to write a script that will check to see if files are Not moving out of the directory. Any help would be most welcome.

And what have you done to solve this...

maybe a script like:

Code:

#!/bin/sh

dir_name="some_directory_name"
wtime=10

while :
do
   d=$(find $dir_name -maxdepth 1 -name $dir_name ! -cmin -$wtime)
   if [ -n "$d" ]
   then
      echo $dir_has not been updated in more than $wtime minutes.
      #echo $dir_has not been updated in more than $wtime minutes. | mail to_somebody
      exit
   fi
   (( w = wtime * 60 ))
   sleep $w
done

What would be an acceptable files' residence time in that directory?

Thank-you for the suggestions. I have written a script that tracks the oldest time that a file is in the directory. if there are no files in the directory when the script runs the oldest time becomes the script execution time. When it runs next if there are files the oldest time becomes the mtime of the oldest file. If the oldest time matches the mtime of a file on the next run it errors and sends a message to our monitoring system .
Again Thanks for your help.