Return the port to which errors and warnings should be sent (the standard error in Unix and C terminology).

Reads a line of input from port. The handle-newline parameter determines what is done with terminating end-of-line delimiter. The default, 'trim, ignores the delimiter; 'peek leaves the delimiter in the input stream; 'concat appends the delimiter to the returned value; and 'split returns the delimiter as a second value. You can use the last three options to tell if the string was terminated by end-or-line or by end-of-file.

Takes a string and returns an input port that delivers characters from the string. The port can be closed by close-input-port, though its storage will be reclaimed by the garbage collector if it becomes inaccessible.

(define p
  (open-input-string "(a . (b c . ())) 34"))

(input-port? p)                 ⇒  #t
(read p)                        ⇒  (a b c)
(read p)                        ⇒  34
(eof-object? (peek-char p))     ⇒  #t

Returns an output port that will accumulate characters for retrieval by get-output-string. The port can be closed by the procedure close-output-port, though its storage will be reclaimed by the garbage collector if it becomes inaccessible.

(let ((q (open-output-string))
  (x '(a b c)))
    (write (car x) q)
    (write (cdr x) q)
    (get-output-string q))        ⇒  "a(b c)"

Given an output port created by open-output-string, returns a string consisting of the characters that have been output to the port so far.

Create an input port that gets its data from string, call proc with that port as its one argument, and return the result from the call of proc

Create an output port that writes its data to a string, and call proc with that port as its one argument. Return a string consisting of the data written to the port.

Forces any pending output on port to be delivered to the output device and returns an unspecified value. If the port argument is omitted it defaults to the value returned by (current-output-port).

Get the prompt procedure associated with port.

Set the prompt procedure associated with port to prompter, which must be a one-argument procedure taking an input port, and returning a string.

The default prompt procedure. It returns "#|kawa:L|# ", where L is the current line number of port. When reading a continuation line, the result is "#|C---:L|# ", where C is the character returned by (input-port-read-state port). The prompt has the form of a comment to make it easier to cut-and-paste.

Return the current column number or line number of input-port, using the current input port if none is specified. If the number is unknown, the result is #f. Otherwise, the result is a 0-origin integer - i.e. the first character of the first line is line 0, column 0. (However, when you display a file position, for example in an error message, we recommend you add 1 to get 1-origin integers. This is because lines and column numbers traditionally start with 1, and that is what non-programmers will find most natural.)

Set (0-origin) line number of the current line of port to num.

Get the line number of the current line of port, which must be a (non-binary) input port. The initial line is line 1. Deprecated; replaced by (+ 1 (port-line port)).

Set line number of the current line of port to num. Deprecated; replaced by (set-port-line! port (- num 1)).

Get the column number of the current line of port, which must be a (non-binary) input port. The initial column is column 1. Deprecated; replaced by (+ 1 (port-column port)).

Returns a character indicating the current read state of the port. Returns #\Return if not current doing a read, #\" if reading a string; #\| if reading a comment; #\( if inside a list; and #\Space when otherwise in a read. The result is intended for use by prompt prcedures, and is not necessarily correct except when reading a new-line.

A symbol that controls how read handles letters when reading a symbol. If the first letter is ‘U’, then letters in symbols are upper-cased. If the first letter is ‘D’ or ‘L’, then letters in symbols are down-cased. If the first letter is ‘I’, then the case of letters in symbols is inverted. Otherwise (the default), the letter is not changed. (Letters following a ‘\’ are always unchanged.)

Controls how bytes in external files are converted to/from internal Unicode characters. Can be either a symbol or a boolean. If port-char-encoding is #f, the file is assumed to be a binary file and no conversion is done. Otherwise, the file is a text file. The default is #t, which uses a locale-dependent conversion. If port-char-encoding is a symbol, it must be the name of a character encoding known to Java. For all text files (that is if port-char-encoding is not #f), on input a #\Return character or a #\Return followed by #\Newline are converted into plain #\Newline.

This variable is checked when the file is opened; not when actually reading or writing. Here is an example of how you can safely change the encoding temporarily:

(define (open-binary-input-file name)
  (fluid-let ((port-char-encoding #f)) (open-input-file name)))

The number base (radix) to use by default when printing rational numbers. Must be an integer between 2 and 36, and the default is of course 10. For example setting *print-base* to 16 produces hexadecimal output.

If true, prints an indicator of the radix used when printing rational numbers. If *print-base* is respectively 2, 8, or 16, then #b, #o or #x is written before the number; otherwise #Nr is written, where N is the base. An exception is when *print-base* is 10, in which case a period is written after the number, to match Common Lisp; this may be inappropriate for Scheme, so is likely to change.

The right margin (or line width) to use when pretty-printing.

If this an integer, and the available width is less or equal to this value, then the pretty printer switch to the more miser compact style.