PHP使用正则表达式实现过滤非法字符串功能示例-巨人网络通讯

PHP使用正则表达式实现过滤非法字符串功能示例

本文实例讲述了PHP使用正则表达式实现过滤非法字符串功能。分享给大家供大家参考，具体如下：

一、代码

1、index.php

!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
html xmlns="http://www.w3.org/1999/xhtml">
head>
meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
title>过滤留言板中的非法字符/title>
style type="text/css">
!--
body {
  margin-left: 0px;
  margin-top: 0px;
  margin-right: 0px;
  margin-bottom: 0px;
}
-->
/style>/head>
body>
table width="1002" height="585" border="0" align="center" cellpadding="0" cellspacing="0">
 tr>
  td width="379" height="226">nbsp;/td>
  td width="445">nbsp;/td>
  td width="178">nbsp;/td>
 /tr>
   form id="form1" name="form1" method="post" action="index_ok.php">
 tr>
  td height="260">nbsp;/td>
  td align="center" valign="top">table width="430" border="1" cellpadding="1" cellspacing="1" bordercolor="#FFFFFF" bgcolor="#99CC67">
   tr>
    td width="81" height="30" align="right" bgcolor="#FFFFFF">发布主题：/td>
    td width="307" align="left" bgcolor="#FFFFFF">input name="title" type="text" id="title" size="30" />/td>
   /tr>
   tr>
    td align="right" bgcolor="#FFFFFF">发布内容：/td>
    td align="left" bgcolor="#FFFFFF">textarea name="content" cols="43" rows="13" id="content">/textarea>/td>
   /tr>
  /table>/td>
  td>nbsp;/td>
 /tr>
 tr>
  td height="99">nbsp;/td>
  td align="center" valign="top">table width="315" height="37" border="0" cellpadding="0" cellspacing="0">
   tr>
    td width="169" align="center">input type="image" name="imageField" src="images/bg1.JPG" />/td>
    td width="146" align="center">input type="image" name="imageField2" src="images/bg3.JPG" onclick="form.reset();return false;" />/td>
   /tr>
  /table>/td>
  td>nbsp;/td>
 /tr>
   /form>
/table>
/body>
/html>

2、index_ok.php

?php
$title=$_POST[title];
$content=$_POST[content];
$str="****";
$titles = preg_replace("/(黑客)|(抓包)|(监听)/",$str,$title);
$contents = preg_replace("/(黑客)|(抓包)|(监听)/",$str,$content);
?>
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
title>过滤留言板中的非法字符/title>
style type="text/css">
!--
body {
  margin-left: 0px;
  margin-top: 0px;
  margin-right: 0px;
  margin-bottom: 0px;
}
.STYLE1 {
  font-size: 12px;
  color: #855201;
}
-->
/style>/head>
body>
table width="1002" height="585" border="0" align="center" cellpadding="0" cellspacing="0">
 tr>
  td width="400" height="226">nbsp;/td>
  td width="406">nbsp;/td>
  td width="196">nbsp;/td>
 /tr>
   form id="form1" name="form1" method="post" action="index_ok.php">
 tr>
  td height="260">nbsp;/td>
  td align="left" valign="top">p class="STYLE1">发布主题：?php echo $titles;?>/p>
   p class="STYLE1">发布内容：?php echo $contents;?>/p>/td>
  td>nbsp;/td>
 /tr>
 tr>
  td>nbsp;/td>
  td align="center" valign="top">nbsp;/td>
  td>nbsp;/td>
 /tr>
 /form>
/table>
/body>
/html>

二、运行结果