+** url-download
+To download file in =elisp=, best is =url-copy-file=, here refer [[http://stackoverflow.com/questions/4448055/download-a-file-with-emacs-lisp][download-a-file-with-emacs-lisp]] using =url-retrieve-synchronously= wrapping
+as a http download client tool
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ (defun sd/download-file (&optional url download-dir download-name)
+ (interactive)
+ (let ((url (or url
+ (read-string "Enter download URL: ")))
+ (download-dir (read-directory-name "Save to (~/Downloads): " "~/Downloads" "~/Downloads" 'confirm' nil)))
+ (let ((download-buffer (url-retrieve-synchronously url)))
+ (save-excursion
+ (set-buffer download-buffer)
+ ;; we may have to trim the http response
+ (goto-char (point-min))
+ (re-search-forward "^$" nil 'move)
+ (forward-char)
+ (delete-region (point-min) (point))
+ (write-file (concat (or download-dir
+ "~/Downloads/")
+ (or download-name
+ (car (last (split-string url "/" t))))))))))
+#+END_SRC
+