You can clone with
(defvar growlnotify-command (executable-find "growlnotify") "The path to growlnotify")
(defun growl (title message)
"Shows a message through the growl notification system using
`growlnotify-command` as the program."
(flet ((encfn (s) (encode-coding-string s (keyboard-coding-system))) )
(let* ((process (start-process "growlnotify" nil
(process-send-string process (encfn message))
(process-send-string process "\n")
(defun my-erc-hook (match-type nick message)
"Shows a growl notification, when user's nick was mentioned. If the buffer is currently not visible, makes it sticky."
(unless (posix-string-match "^\\** *Users on #" message)
(concat "ERC: name mentioned on: " (buffer-name (current-buffer)))
(add-hook 'erc-text-matched-hook 'my-erc-hook)