修改Emacs-W3M的默认Search

如,修改Emacs-W3M的默认Search为DuckDuck Go ==> http://www.duckduckgo.com/?q=%s

(setq w3m-search-default-engine "DuckDuck Go")

(add-to-list 'w3m-search-engine-alist
    '("DuckDuck Go" "http://www.duckduckgo.com/?q=%s"))

(defadvice w3m-search (after change-default activate)
      (let ((engine (nth 1 minibuffer-history)))
  (when (assoc engine w3m-search-engine-alist)
    (setq w3m-search-default-engine engine))))