Get path of currently marked file

Im running OS X and I'm wondering if there is a way to get the path of the currently marked file in Finder. Like, can UNIX determine what file i have clicked on? Reasons for this would be for example, I could make a service that runs a shell script, so that when I right click a file, I can choose, "Create Symlink" or something similar. ln -s path/to/currently/marked/file path/to/currently/marked/file_symlink And there could be loads of other stuff that you could do with this.