The former will accept any UNIX file name, but the FileName must be instantiated. The latter will only accept simple file names with no directory component, and insists that the file must already exist, but in return will generate FileName . The main use for this routine is to select files with a particular extension. There is another set of three predicates finding exactly the same solutions, but returning them as a set of FileName - FullName pairs. Once you have obtained a file or directory name, you can ask about the properties of that file or directory.
Properties fall into several classes.
The arguments are this way round so you can use them for sorting. The arguments are in this order so you can use them for sorting. The times given are local times, not GMT times.