I am looking for a file sharing script (PHP or Ruby on Rails) that:
- has user management
- admin can set a hierarchy of directories/folders
- user can upload file to directory
- user can see other files and download them
Someting similar to iDocScript.
I think you should check out ownCloud, I've been using it for quite some time now and it's great. It meets your requirements of,
ownCloud gives you web services under your control. It is a self-hosted open source platform with file sync & sharing at its core and available clients for desktop and mobile. The web frontend has apps for Pictures, Calendar, Contacts, News/RSS, Bookmarks, Notes, Music and much more via an open app platform! ownCloud Server can be installed on Windows and Linux operating systems, and is available via packages, sources, or a one file php installer.