General :: Move Files In A Folder If It Is Not In Use?

In my bash script I need to move files in a folder if it is not in use.

Code:
for entry in `ls /root/shared_storage/input`; do
echo $entry
run=`lsof /root/shared_storage/input/$entry`
ru=${run:0:5}
echo $entry
if [ "$ru" == "" ]; then
........
It worked fine sometimes but sometimes it just get stuck at lsof. Is there any other way that I can use here to check if the $entry is using some other process?