12.1.2 Managing Ports
(input-port? v) → boolean? |
v : any/c |
Returns #t if v is an input port, #f otherwise.
(output-port? v) → boolean? |
v : any/c |
Returns #t if v is an output port, #f otherwise.
v : any/c |
Returns #t if either (input-port? v) or (output-port? v) is #t, #f otherwise.
(close-input-port in) → void? |
in : input-port? |
Closes the input port in. For some kinds of ports, closing the port releases lower-level resources, such as a file handle. If the port is already closed, close-input-port has no effect.
(close-output-port out) → void? |
out : output-port? |
Closes the output port out. For some kinds of ports, closing the port releases lower-level resources, such as a file handle. Also, if the port is buffered, closing may first flush the port before closing it, and this flushing process can block. If the port is already closed, close-output-port has no effect.
(port-closed? port) → boolean? |
port : port? |
Returns #t if the input or output port port is closed, #f otherwise.
(current-input-port in) → void? |
in : input-port? |
A parameter that determines a default input port for many operations, such as read.
(current-output-port out) → void? |
out : output-port? |
A parameter that determines a default output port for many operations, such as write.
(current-error-port out) → void? |
out : output-port? |
A parameter that determines an output port that is typically used for errors and logging. For example, the default error display handler writes to this port.
(file-stream-port? port) → boolean? |
port : port? |
Returns #t if the given port is a file-stream port (see File Ports), #f otherwise.
(terminal-port? port) → boolean? |
port : port? |
Returns #t if the given port is attached to an interactive terminal, #f otherwise.
A value (distinct from all other values) that represents an end-of-file.
(eof-object? a) → boolean? |
a : any/c |
Returns #t is v is eof, #f otherwise.