Answering the second part of your question, the "best" way to watch for filesystem changes is by using inotify(7). 

There is a set of utilities that can hook into the kernel interface, inotify-tools. In particular, you want inotifywait from that set of utilities:


  inotifywait efficiently waits for changes to files using Linux's inotify(7) interface. It is suitable for waiting for changes to files from shell scripts. It can either exit once an event occurs, or continually execute and output events as they occur.


You could use it like this:

#!/bin/sh
while inotifywait -e create /share/capture/*/; do
  /share/capture/per.sh
done


You script will only then be called when a new file is created. I did not test the example - I adapted it from the manual page, so please adapt as needed.

find files in a folder
I just bought a 2012 VW Jetta TDI.  The dealer asked me to do a 2,000 mile check-up to make sure everything is within tolerances.  At the check-up the service representative said my key-chain was too heavy and if I planned to keep the car for long I should reduce weight on the key-chain to keep from damaging the ignition.  I only have six other keys, a hook and two small plastic electronic computer devices on the single key ring.  It doesn't seem excessive at all compared to the usual key rings you see.

The question is, do new car ignitions still wear out due to key-ring weight?  To me this seemed like the kind of advice that might have once been true and is dispensed long after it is no longer the case.
