copies the directory dir1 to dir2.
- dir1 must already exist; dir2 must not.
- CopyDirectory copies all the files in dir1 to dir2.
- CopyDirectory sets the modification dates for dir2 and for all the files in it to be the same as those for dir1.
- CopyDirectory returns the full name of the directory it copies to, and $Failed if it cannot complete the copy.
- Directories can be specified either using "path" or File["path"].
Introduced in 1991Updated in 2016