Syntax
where either
The OCHANNEL: command specifies the channel that should be used
for output until a further OCHANNEL: command is issued. The
output
channel is reset to zero (interactive screen) whenever a
RESTART: command is issued, but not when a
CLEAR: command is issued.
As an example, consider the fragment of code shown in
Figure 2.3. The commands in this fragment (1) link an output
channel to an external file (which will be created if it does not
already exist); (2) redirect output to this file; (3) print
a message which will appear as text at the head of this file; and (4)
redirect output back to the screen.
, representing the interactive screen, or 
is an integer representing an output channel number.
Figure 2.3: Redirecting output
