sets the current directory. If Dir is free variable than the directory of the running program is set, i.e. the directory of the PRO or SPJ file.
retrieves the current directory.
creates a new directory.
removes a directory.
deletes a file.
Moves the file File1 into the file File2
File1 string representing
the path to a real file that will be moved
File2 string representing the path to the new file name