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 ANSI Common Lisp    21 Streams    21.2 Dictionary of Streams
 
| 21.2.54  *terminal-io* | 
Variable | 
  
 - Value Type:
 - 
a bidirectional stream.
  - Initial Value:
 - 
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.
  - Description:
 - 
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.
 
  - Examples:
 - 
 (progn (prin1 'foo) (prin1 'bar *terminal-io*))
  FOOBAR
   BAR
 (with-output-to-string (*standard-output*)
   (prin1 'foo) 
   (prin1 'bar *terminal-io*))
  BAR
  "FOO"
 
  - See Also:
 - 
*debug-io*,
*error-output*,
*query-io*,
*standard-input*,
*standard-output*,
*trace-output*
  - Allegro CL Implementation Details:
 - 
 None.
  
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