<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
function getHost(url) {
var host = "null";
if(typeof url == "undefined"|| null == url) {
url = window.location.href;
}
var regex = /^\w+\:\/\/([^\/]*).*/;
var match = url.match(regex);
if(typeof match != "undefined" && null != match) {
host = match[1];
}
return host;
}
document.write(getHost("http://onestopweb.iteye.com/blog/2327754"));
</script>
</body>
</html>
效果图：