File I/O operations - scheme

Question

Can someone point me to basic file I/O operations examples in Scheme?

I just want to try basic read/write/update operations on a file.

Finding it difficult a

Answer 1

Please see the following post if you are working with a R5RS compliant Scheme:

R5RS Scheme input-output: How to write/append text to an output file?

The solution presented there is as follows:

; This call opens a file in the append mode (it will create a file if it doesn't exist)
(define my-file (open-file "my-file-name.txt" "a"))

; You save text to a variable
(define my-text-var1 "This is some text I want in a file")
(define my-text-var2 "This is some more text I want in a file")

; You can output these variables or just text to the file above specified
; You use string-append to tie that text and a new line character together.
(display (string-append my-text-var1 "\r\n" my-file))
(display (string-append my-text-var2 "\r\n" my-file))
(display (string-append "This is some other text I want in the file" "\r\n" my-file))

; Be sure to close the file, or your file will not be updated.
(close-output-port my-file)