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(librep.info)Output Streams

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Enter node , (file) or (file)node

Output Streams
--------------

   These are the different types of output stream, for the functions
which use them see Note: Output Functions.

`FILE'
     Writes to the file object FILE. Note: Files.

`FUNCTION'
     The function FUNCTION is called with one argument, either a string
     or a character. This should be used as the circumstances dictate.
     If the function returns a number it is the number of characters
     actually used, otherwise it is assumed that all the characters
     were successful.

`PROCESS'
     Writes to the standard input of the process object PROCESS. If
     PROCESS isn't running an error is signalled. Note: Processes.

`t'
     Appends the character(s) to the end of the status line message.

`()'
     Write to the stream stored in the variable `standard-output'.

   It is also possible to store the characters sent to an output stream
in a string.

 - Function: make-string-output-stream
     Returns an output stream. It accumulates the text sent to it for
     the benefit of the `get-output-stream-string' function.

 - Function: get-output-stream-string string-output-stream
     Returns a string consisting of the text sent to the
     STRING-OUTPUT-STREAM since the last call to
     GET-OUTPUT-STREAM-STRING (or since this stream was created by
     `make-string-output-stream').

          (setq stream (make-string-output-stream))
              => ("" . 0)
          (prin1 keymap-path stream)
              => ("(lisp-mode-keymap global-keymap)" . 64)
          (get-output-stream-string stream)
              => "(lisp-mode-keymap global-keymap)"

 - Variable: standard-output
     This variable contains the output stream which is used when no
     other is specified (or when the given output stream is false).

 - Variable: standard-error
     This variable contains the output stream which is used when an
     error message is being reported.

   Applications that embed `librep', or dynamically loaded extensions,
may provide further output stream types.