[plt-scheme] Writing Bytes into a file

For writing, you can encode an 8-bit integer into a char, and then
write that char to a file. Reading is similar. So for example, you
could use these functions:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define read-byte
  (lambda (port)
    (char->integer (read-char port))))

(define write-byte
  (lambda (byte port)
    (write-char (integer->char byte) port)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

MzScheme also provides the "integer->integer-byte-string" and
"integer-byte-string->integer" functions which help when converting
values larger than 8-bits into low-level representations.

"Djos" <djos06 at wanadoo.fr> writes:

>   For list-related administrative tasks:
>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> 
> are there any fonctions like these , to write bytes into a file , with plt
> scheme ?
> 
> (write-byte byte binary-output-port) ; writes an exact 8-bit integer and
> returns an unspecified value
> (read-byte binary-input-port)  ; returns an exact integer, or an end-of-file
> object
> 
> (I found these functions here :
> http://www.cs.hmc.edu/~fleck/envision/user-manual/binary-files.html )