Message when file is dropped

Hi there,

I'm from germany and I have to do a very specific task with our new ejabberd environment. Our users are connected to some network folders. Now, if someone puts a file in specific folder, another user should be automatically informed via jabber. Something like this: "The File doc.pdf has been placed in your folder...". Any suggestions how to do that?

Maybe an ejabberd module is not the right way. My Ideas: First of all I have to build a tool or service which listen to the folders. After a file has been placed my programm calls commandline tool which sends the message. Is the such a commandline tool? Similar to the handling of ejabberdctl?