- make-output-port WRITE CLOSE #!optional FLUSHprocedure
Returns a custom output port. Common operations on this port are handled by the given parameters, which should be procedures. WRITE is called when output is sent to the port and receives a single argument, a string. CLOSE is called when the port is closed and should be a procedure of no arguments. FLUSH (if provided) is called for flushing the output port.