PHP简单的图片验证码实现

//第一段代码生成随机图片------code2.php

//开启session以用于保存生成的内容
session_start();
$table=array(
              "pic0"=>"dog",
              "pic1"=>"cat",
              "pic2"=>"fish",
              "pic3"=>"bird"
);
$index=rand(0,3);
$value=$table['pic'.$index];
$_SESSION['authcode']=$value;
//得到随机生成的图片名
$filename=dirname(__FILE__).'/pic'.$index.'.jpg';
$content=file_get_contents($filename);
header('Content-type:image/jpg');
echo $content;
?>

//第二段代码实线表单的验证

if(isset($_REQUEST['authcode'])){
session_start();
if($_REQUEST['authcode']==$_SESSION['authcode']){
echo "right";
}else{
echo "sad story";
echo  $_REQUEST['authcode'];
}
}
?>







    picture: 

     

     //通过js切换另外一张图片
     change picture

   words:


?>

/*代码的路径是linux的路径*/

验证码, PHP