This copies a file from your ``tahoe:`` root to a different directory, set up
earlier with "``tahoe add-alias fun DIRCAP``" or "``tahoe create-alias fun``".
+ ``tahoe cp -r ~/my_dir/ tahoe:``
+
+ This copies the folder ``~/my_dir/`` and all its children to the grid, creating
+ the new folder ``tahoe:my_dir``. Note that the trailing slash is not required:
+ all source arguments which are directories will be copied into new
+ subdirectories of the target.
+
+ The behavior of ``tahoe cp``, like the regular UNIX ``/bin/cp``, is subtly
+ different depending upon the exact form of the arguments. In particular:
+
+* Trailing slashes indicate directories, but are not required.
+* If the target object does not already exist:
+ * and if the source is a single file, it will be copied into the target;
+ * otherwise, the target will be created as a directory.
+* If there are multiple sources, the target must be a directory.
+* If the target is a pre-existing file, the source must be a single file.
+* If the target is a directory, each source must be a named file, a named
+ directory, or an unnamed directory. It is not possible to copy an unnamed
+ file (e.g. a raw filecap) into a directory, as there is no way to know what
+ the new file should be named.
+
+
``tahoe unlink uploaded.txt``
``tahoe unlink tahoe:uploaded.txt``