3.13.3 Switching Between Implicit and Explicit I/O

The predicates below can be used for switching between the implicit- and the explicit stream based I/O predicates.

set_input(+Stream)

Set the current input stream to become Stream. Thus, open(file, read, Stream), set_input(Stream) is equivalent to see(file).

set_output(+Stream)

Set the current output stream to become Stream.

current_input(-Stream)

Get the current input stream. Useful to get access to the status predicates associated with streams.

current_output(-Stream)

Get the current output stream.