Greasemonkey : Add copy code button in stackexchange.com (SX).

Copy code from SX v2.user.js

// ==UserScript==
// @name         Copy code from SX
// @namespace    https://gist.github.com/kpym/30d90be41ab5c248cdf7
// @version      0.3
// @description  This script use clipboard.js to add copy button for code sections on SX. When you hover a code the button "</>" appear on the top right corner. Click it and the code is copied.
// @author       kpym
// @match        *://*.stackexchange.com/*
// @match        *://*.stackoverflow.com/*
// @match        *://*.superuser.com/*
// @match        *://*.serverfault.com/*
// @match        *://*.askubuntu.com/*
// @match        *://*.stackapps.com/*
// @match        *://*.mathoverflow.net/*
// @grant        GM_addStyle
// @require https://cdn.rawgit.com/zenorocha/clipboard.js/v1.5.5/dist/clipboard.min.js
// ==/UserScript==
/* jshint -W097 */
'use strict';

// ------------------------------------------
// CSS part injected in the page
GM_addStyle(" \
.precontainer { \
    position: relative; \
} \
pre > code { \
  white-space: pre; \
} \
pre > .copy-btn { \
  background: #DDD; \
  font-family: monospace; \
  font-weight: bolder; \
  margin: 0; \
  opacity: 0; \
  padding: 4px; \
  position: absolute; \
  right: 21px; \
  top: 0px; \
  cursor: pointer; \
  -webkit-transition: opacity 0.3s ease-in-out; \
  -o-transition: opacity 0.3s ease-in-out; \
  transition: opacity 0.3s ease-in-out; \
} \
pre:hover >.copy-btn { \
    opacity: 1; \
} \
");

// ------------------------------------------
// Code part injected in the page

// add the button to any code portion
$('pre > code').before($('<span class="copy-btn">\\copy{code}</span>')).parent().wrap('<div class="precontainer"></div>');
// do the magic with clipboard.js
new Clipboard('.copy-btn', {
    text: function(trigger) {
        return $(trigger.nextElementSibling).text();
    }
})
.on('success',function (e) {$(e.trigger).html("\\done@copy")})
.on('error',function (e) {$(e.trigger).html("\\error{@*!?}")});

Copy code from SX.user.js

// ==UserScript==
// @name         Copy code from SX
// @namespace    https://gist.github.com/kpym/30d90be41ab5c248cdf7
// @version      0.1
// @description  This script use clipboard.js to add copy button for code sections on SX. When you hover a code the button "</>" appear on the top right corner. Click it and the code is copied.
// @author       kpym
// @match        http*://*.stackexchange.com/*
// @grant        GM_addStyle
// @require https://cdn.rawgit.com/zenorocha/clipboard.js/v1.5.5/dist/clipboard.min.js
// ==/UserScript==
/* jshint -W097 */
'use strict';

// ------------------------------------------
// CSS part injected in the page
GM_addStyle(" \
pre { \
    position: relative; \
} \
pre > code { \
  white-space: pre; \
} \
pre > .copy-btn { \
  background: #DDD; \
  font-family: monospace; \
  font-weight: bolder; \
  margin: 0; \
  opacity: 0; \
  padding: 4px; \
  position: absolute; \
  right: 0px; \
  top: 0px; \
  cursor: pointer; \
  -webkit-transition: opacity 0.3s ease-in-out; \
  -o-transition: opacity 0.3s ease-in-out; \
  transition: opacity 0.3s ease-in-out; \
} \
pre:hover >.copy-btn { \
    opacity: 1; \
} \
");

// ------------------------------------------
// Code part injected in the page

// add the button to any code portion
$('pre > code').before($('<span class="copy-btn">&lt;/&gt;</span>'));
// do the magic with clipboard.js
new Clipboard('.copy-btn', {
    text: function(trigger) {
        return $(trigger.nextElementSibling).text();
    }
})
.on('success',function (e) {$(e.trigger).html(":-)").css({"color":"green"})})
.on('error',function (e) {$(e.trigger).html(":-(").css({"color":"red"})});