如何使用drakma下载和保存文件:http-request和flexistreams

Question

我正在尝试下载并保存PDF,但在使用EOF-Error写入时失败.这样做的正确方法是什么？

(with-open-file (file "/home/*/test.pdf"
                      :direction :io
                      :if-does-not-exist :create
                      :if-exists :supersede
                      :element-type '(unsigned-byte 8))
  (let ((input (drakma:http-request "http://www.fractalconcept.com/ex.pdf"
                                    :want-stream t)))
    (awhile (read-byte input)
      (write-byte it file))
    (close input)))

Answer 1

解决方案是我忘了使用两个可选参数read-byte.

正确的方法是设置eof-error-p和eof-value到nil:

(with-open-file (file "/home/*/test.pdf"
                      :direction :output
                      :if-does-not-exist :create
                      :if-exists :supersede
                      :element-type '(unsigned-byte 8))
  (let ((input (drakma:http-request "http://www.fractalconcept.com/ex.pdf"
                                    :want-stream t)))
    (awhile (read-byte input nil nil)
      (write-byte it file))
    (close input)))