@deffnx {C Function} scm_call_with_output_string (proc)
Calls the one-argument procedure @var{proc} with a newly created output
port. When the function returns, the string composed of the characters
-written into the port is returned.
+written into the port is returned. @var{proc} should not close the port.
@end deffn
@deffn {Scheme Procedure} call-with-input-string string proc
Given an output port created by @code{open-output-string},
return a string consisting of the characters that have been
output to the port so far.
+
+@code{get-output-string} must be used before closing @var{port}, once
+closed the string cannot be obtained.
@end deffn
A string port can be used in many procedures which accept a port