php 字符串替换为星号或其它字符（手机号,身份证)

<?php
$str = "15832818835";
echo substr($str,0,3).'*****'.substr($str,8,strlen($str));//保留前三位和后三位
?>

或用正则

<?php
$s='www.111cn.net的王经理：13999312365 李经理：13588958741';
$s=preg_replace('#(d{3})d{5}(d{3})#', '${1}*****${2}', $s);
echo $s;
//王经理：139*****365 李经理：135*****741
?>

function half_replace($str){ 
   $len = strlen($str)/2; 
    return substr_replace($str,str_repeat('*',$len),ceil(($len)/2),$len); 
} 
 
echo half_replace('test'),"n",half_replace('tests'),"n",half_replace('exceptions');

echo strlen($idcard)==15?substr_replace($idcard,"****",8,4):(strlen($idcard)==18?substr_replace($idcard,"****",10,4):"111cn.net提示身份证位数不正常！");

<?php

$dir=dirname(__FILE__)."/../www.111cn.net /";//这里输入其它路径
//PHP遍历文件夹下所有文件
$handle=opendir($dir.".");
//定义用于存储文件名的数组
$array_file = array();
while (false !== ($file = readdir($handle)))
{
if ($file != "." && $file != "..") {
$array_file[] = $file; //输出文件名
}
}
closedir($handle);
print_r($array_file);

?>

/**
 * 删除指定目录下的所有文件
 *
 * @param String $dir  要进行操作的路径
 * 适合范围，只有用于文件夹内不存在子文件夹的情况下
 * 来源  DZ
 * 小佳(www.111cn.net)  整理 于 2006-06-26 
 */
function dir_clear($dir) {
    $directory = dir($dir);                //创建一个dir类(111cn.net的PHP手册上这么说的)，用来读取目录中的每一个文件
    while($entry = $directory->read()) {   //循环每一个文件,并取得文件名$entry
        $filename = $dir.'/'.$entry;       //取得完整的文件名，带路径的
        if(is_file($filename)) {           //如果是文件，则执行删除操作
            @unlink($filename);
        }
    }
    $directory->close();                   //关闭读取目录文件的类
    result();
}  

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript" src="jquery.js" ></script>
<script type="text/javascript">
$(function(){
 
 $("#submit").click(function(){
  //发送ajax请求
  var city = $("#city").val();
  $.post("getweather.php", {city:city}, function(data){
   if(data.weatherinfo.city){
    var city = data.weatherinfo.city;   //城市名称
    var temp1 = data.weatherinfo.temp1;  //最高气温
    var temp2 = data.weatherinfo.temp2;  //最低气温
    var weather = data.weatherinfo.weather;  //天气描述（“晴到多云”）
    alert(city+":"+weather+","+temp2+"-"+temp1); 
    return;
   }else{
    alert("没找到该城市");
   }
  },"json");
 });
 
});
</script>

<form method="post">
 请输入城市：<input type="text" name="city" id="city" value="武汉" />
 <input type="button" name="sub" id="submit" value="查看天气" />
</form>

为、<?php

 include "citycode.php";
 $city = $_POST['city'];
 $citycode = @$citycode[$city];
 //echo "shibushi";
 if(empty($citycode)){
  echo "您输入的城市不在范围内";
 }else{
  echo file_get_contents("http://www.weather.com.cn/data/cityinfo/".$citycode.".html");
 }
?>

<script type="text/javascript" src="/Public/js/jquery.min.js"></script>

<script type="text/javascript" src="finger_ajax.js"></script>

<?php

 header("Content-type:text/html;charset=utf-8");

 include "finger_ajax.php";

 $sql = "select * from finger_ajax";

 $res = mysql_query($sql,$link);

 while($row = mysql_fetch_array($res)){

  echo "<p>".$row['title']." <a href='#' onclick='finger(".$row['id'].")'><img src='finger.jpg'/>攒一下(<span class='finger".$row['id']."'>".$row['finger']."</span>)</a></p> ";

 }

?>

<?php

 /**"攒" 功能 响应ajax请求*/

 //配置

 $dbHost = "localhost";

 $dbUser = "root";

 $dbPass = "dddddd";

 $dbName = "test";

 $dbCharset = "utf8";

 $link = mysql_connect($dbHost,$dbUser,$dbPass) or die(mysql_error());

 mysql_query("set names ".$dbCharset);

 mysql_select_db($dbName);

 // End

 //接受对应的id

 if(!empty($_POST['id'])){

  $id = $_POST['id'];

  //“攒”加1

  $sql = "update finger_ajax set finger=finger+1 where id=$id;";

  if(mysql_query($sql,$link)){

   echo "ok";

  }else{

   echo "failed";

  }

 }

?>

function finger(topic_id){

 $.post("finger_ajax.php", { "id": topic_id },

   function(data){

     if(data=="ok"){

   alert("感谢您的支持！");

  }else{

   alert("对不起，失败了！");

  }

   }, "text"); 

 //获取当前“攒”的次数并加1

 var finger = parseInt($(".finger"+topic_id).html())+1;

 //更新“攒”的次数

 $(".finger"+topic_id).html(finger);

}

DROP TABLE IF EXISTS `finger_ajax`;

CREATE TABLE `finger_ajax` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `title` varchar(50) NOT NULL DEFAULT '',

  `finger` int(11) NOT NULL DEFAULT '0',

  PRIMARY KEY (`id`)

) ENGINE=MyISAM AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

-- ----------------------------

-- Records of finger_ajax

-- ----------------------------

INSERT INTO `finger_ajax` VALUES ('1', '今天天气还不错哦！去做点什么好呢？', '10');

INSERT INTO `finger_ajax` VALUES ('2', '欢迎来到 www.111cn.net，国庆将至，祝大家国庆节快乐！！', '3');

header('HTTP/1.1 301 Moved Permanently');  
header('Location: http://www.abc.com/aaa/');  
exit();

header("HTTP/1.1 404 Not Found");

header("Status: 404 Not Found");

header("HTTP/1.1 404 Not Found");
header("Status: 404 Not Found");