我制作了一个简单的程序来将文本写入现有文件:
;;写入现有文件
(define write-to-a-file
(lambda (path txt)
(call-with-output-file path
(lambda (output-port)
(write txt output-port)))))
但我想修改它,以便,如果该文件不存在,则应该创建它。如果文件存在,那么它应该写入文件而不删除文件的先前内容。我正在写鸡计划。有什么想法吗?
答案 0 :(得分:5)
尝试鸡计划:
(define (write-to-a-file path txt)
(call-with-output-file path
(lambda (output-port)
(write txt output-port))
#:append))
或者对于Racket:
(define (write-to-a-file path txt)
(call-with-output-file path
(lambda (output-port)
(write txt output-port))
#:exists 'append))