String Ports

      Scheme input and output can be read from or collected into a string:

•   (open-input-string string) creates an input port that reads characters from string.
•   (open-output-string) creates an output port that accumulates the output into a string.
• (get-output-string port) returns the string accumulated in a string output port. (If a non-string port is passed to get-output-string, the  exn:application:type exception is raised.)

String input and output ports do not need to be explicitly closed.

Example:

 
   (define i (open-input-string "hello world"))
   (define o (open-output-string))
   (write (read i) o)
   (get-output-string o) ; => "hello"