Oracle Apps: Need concurrent program to run when file comes in Unix directory

[raksrules]

My requirement is to fire a concurrent program only when a file comes in a particular Unix location.

We have already built a program that is supposed to pick up files from a Unix path and process them. Now currently this program needs to be run manually by someone after putting (FTP) the files in that directory.
Another option is that we schedule this program to run at regular interval and get the job done.

But the client wants that the program should not run unnecessarily and also he wants minimum manual intervention, so he suggested that we run the program ONLY when a file is FTPed in the predefined location. How do we accomplish this requirement ???

Please suggest

[QwertyManiac]

The Unix File-Alteration-Monitor daemon may be helpful. Check it out here. (The external resource links, don't miss them. FAM provides a decent enough API and is used at many places in GNOME.)