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a bidirectional stream.
implementation-dependent, but it must be an open stream that is not a generalized synonym stream to an I/O customization variables but that might be a generalized synonym stream to the value of some I/O customization variable.
The value of *terminal-io*
, called terminal I/O, is ordinarily
a bidirectional stream that connects to the user's console.
Typically, writing to this stream
would cause the output to appear
on a display screen, for example, and reading from the stream would
accept input from a keyboard. It is intended
that standard input functions such as read
and read-char
,
when used with this stream, cause echoing of the input
into the output side of the stream. The means by which this is
accomplished are implementation-dependent.
The effect of changing the value of *terminal-io*
,
either by binding or assignment,
is implementation-defined.
(progn (prin1 'foo) (prin1 'bar *terminal-io*)) ▷ FOOBAR → BAR (with-output-to-string (*standard-output*) (prin1 'foo) (prin1 'bar *terminal-io*)) ▷ BAR → "FOO"
*debug-io*, *error-output*, *query-io*, *standard-input*, *standard-output*, *trace-output*