例 2.1. helloworld.user.js
// Hello World! example user script
// version 0.1 BETA!
// 2005-04-22
// Copyright (c) 2005, Mark Pilgrim
// Released under the GPL license
// http://www.gnu.org/copyleft/gpl.html
//
// --------------------------------------------------------------------
//
// This is a Greasemonkey user script.
//
// To install, you need Greasemonkey: http://greasemonkey.mozdev.org/
// Then restart Firefox and revisit this script.
// Under Tools, there will be a new menu item to "Install User Script".
// Accept the default configuration and install.
//
// To uninstall, go to Tools/Manage User Scripts,
// select "Hello World", and click Uninstall.
//
// --------------------------------------------------------------------
//
// ==UserScript==
// @name Hello World
// @namespace http://diveintogreasemonkey.org/download/
// @description example script to alert "Hello world!" on every page
// @include *
// @exclude http://diveintogreasemonkey.org/*
// @exclude http://www.diveintogreasemonkey.org/*
// ==/UserScript==
alert('Hello world!');正如您所见到的,这个Hello World脚本的大部分都是注释。有些注释,比如如何安装,没什么特殊含义;那只是对初学者的一些指导。但是,有一节注释确实有特殊含义,下一节会有详细的解释。
要看到脚本的效果,您首先要安装,然后访问一个不在diveintogreasemonkey.org域名下的网站(例如,Google)。这个页面将会像平时一样显示出来,还会弹出一个对话框:“Hello world!”