(rds CHANNEL:io-channel, nil): io-channel expr
Rds sets in* to the value of its argument, and returns the previous value of
in*. In addition, if specialrdsaction* is non-nil, it should be a function of 2
arguments, which is called with the old channel as its first argument and the
new channel as its second argument. (rds nil) does the same as (rds stdin*).
(wrs CHANNEL:io-channel, nil): io-channel expr
Wrs sets out* to the value of its argument and returns the previous value
of out*. In addition, if specialwrsaction* is non-nil, it should be a function
of 2 arguments, which is called with the old channel as its first argument
and the new channel as its second argument. (wrs nil) does the same as (wrs
stdout*).
Global variables containing information about channels are listed below.
in* = [Initially: 0]
global
Contains the currently selected input channel. May be set or rebound by the
user. This is changed by the function rds.
out* = [Initially: 1]
global
Contains the currently selected output channel. May be set or rebound by
the user. This is changed by the function wrs.
stdin* = [Initially: 0]
global
The standard input channel (but not in the Unix sense of standard input).
Channel 0 is ordinarily the terminal and this variable is not intended to be
set or rebound.
stdout* = [Initially: 1]
global
The standard output channel. Like channel 0, channel 1 is ordinarily always
the terminal, and this variable is not intended to be set or rebound.
breakin* = [Initially: nil]
global
The channel from which the break loop gets its input. It has been set
to default to stdin*, but may have to be changed on some systems with
buffered-IO.
breakout* = [Initially: nil]
global
The channel to which the break loop sends its output. It has been set to
default to stdout*, but may have to be changed on some systems with
buffered-IO.
errout* = [Initially: 1]
global
The channel used by the errorprintf.
