To change the source of the input stream to another device such as a disk file, the device must be opened or created to prepare it for input, and STANDARD.INPUT assigned the channel number which the OPEN command returned.

To redirect Logo's output stream, use STANDARD.OUTPUT. See also OPEN and CREATE.

Procedures which are run with the LAUNCH command or by clicking a control, bitmap, or turtle, obtain their own copy of the variable. Setting the variable affects neither the global setting nor other procedures running at the same time.

TO ECHO :FILE
    IF NOT FILE? :FILE (PR :FILE [DOES NOT EXIST]) STOP
    MAKE "CHANNEL OPEN :FILE
    MAKE "STANDARD.INPUT :CHANNEL
    ECHO.LINES
    CLOSE :CHANNEL
END

TO ECHO.LINES
    IF EOF? STOP
    MAKE "LINE RQ
    PRINT :LINE
    ECHO.LINES
END