<div class="box"></div>
 .box:before{
 content: '';
 position: absolute;
 width:px;height: px;border:px red solid;
 left:-px;top:-px;
 z-index: ;
 }

@-webkit-keyframes clipMe{
%{ clip: rect(px, px, px, px); }
%{ clip: rect(px, px, px, px); }
%{ clip: rect(px, px, px, px); }
%{ clip: rect(px, px, px, px); }
%{ clip: rect(px, px, px, px); }
}

.box:after{
-webkit-animation:clipMe s linear infinite;
}

.box:before{
-webkit-animation:clipMe s -s linear infinite;
}

<div class="box">
<span>/**仅共娱乐,然并卵**/</span>
<p>Login : Jmingzi</p>
<p>password : ******</p>
<p>Access is granted</p>
<span>Welcome ymblog.net !</span>
</div>

var t = setInterval(function(){
str = con.substr(, strlen) + "_";
me.obj.html(str);
//内容打印完毕
if(strlen == con.length){
clearInterval(t);
}
strlen = strlen + ;
}, me.speed);

//初始化工作，获取几段文字内容，将它们隐藏后逐个显示即可
$(function(){
function Type(obj, speed, welcome){
this.obj = obj;
this.speed = speed;
this.welcome = welcome;
}
Type.prototype = {
init : function(){
var str = this.obj.html();
this.obj.html(this.welcome);
this.add(str);
},
add : function(con){
var me = this;
var str;
var strlen = ;
var t = setInterval(function(){
str = con.substr(, strlen) + "_";
me.obj.html(str);
//内容打印完毕
if(strlen == con.length){
clearInterval(t);
}
strlen = strlen + ;
}, me.speed);
}
}
var a = new Type($('.box'), , '正在初始化...');
a.init();
});