I need to create an application "dll, script or exe" which when the user upload on a folder on his server using his ftp, it will automatically run on the current folder and do some image manipulations in the folder images,
My Question is how to make something like this, which the user will not need to configure anything on his server, all what he want is upload in the right folder, and it will run automatically and keep running
Is it possible? How do it? Which Language to use?
UPDATE: I am targeting shared hosting server, which the user have no way to configure his server OS, about the OS, lets start saying its just windows.
I know that "Not possible" may be the right answer, and also "its a virus" may be another answer, i just want to know if its possible or should i think in another new way.
Everything I have read in this question screams "security vulnerability exploit". Since it's one of the main things hosting companies are making sure doesn't happen, I would say your chances are very slim to have that work.
However, if it's a web server, with something like CGI or PHP enabled, you could leverage that by uploading a CGI or PHP script in a place it can be run, and then calling it through a browser, thus doing whatever file manipulations you need... Things like safe mode, reserved or virtual directories could get in the way, but I think there is a better chance of that working.