PHP7 preg replace出错及解决办法

问题描述：

PHP7废弃了preg_replace？

原本是中php5中处理url中后面参数替换清除的，代码如下

$url = preg_replace('/([?&])src=[^&]+(&?)/e', '"$2"==""?"":"$1"', $url);

但是到php7中就报错了

需要用preg_replace_callback来替换，请问该咋办？

相关代码

$url = preg_replace('/([?&])src=[^&]+(&?)/e', '"$2"==""?"":"$1"', $url);

问题分析：

e修饰符因为存在安全隐患 自 5.3 开始就已经标记为了待移除的内容。

转而接替的是 preg_replace_callback，此方法第二个参数为一个回调函数，回调函数会自动传入比配的分组作为参数。在回调函数内部通过数组下标访问匹配组。

preg_replace_callback('/([?&])src=[^&]+(&?)/', function($matches){    return $matches[2]==""?"":$matches[1];}, $url);

知识点扩展：

PHP7已经删除了preg_replace的e修饰符

官网提示是这样的，对/e修饰符的支持已删除。请改用preg_replace_callback()

原因是/e 修正符使 preg_replace() 将 replacement 参数当作 PHP 代码（在适当的逆向引用替换完之后）,会被一句话后门使用

看看smarty中是也是这样用的,也是存在问题

$source_content = preg_replace($search.'e', "'". $this->_quote_replace($this->left_delimiter) . 'php'. "' . str_repeat("", substr_count('', "")) .'". $this->_quote_replace($this->right_delimiter). "'", $source_content);可以把smarty模板修改成这个$source_content = preg_replace_callback($search, function ($matches){$str="";$str.=$this->_quote_replace($this->left_delimiter) . 'php';$str.=str_repeat("n", substr_count($matches[1], "n"));$str.=$this->_quote_replace($this->right_delimiter);return $str;}, $source_content);

到此这篇关于PHP7 preg_replace 出错及解决办法的文章就介绍到这了，希望大家以后多多支持好二三四！

<link rel="stylesheet" href="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/260993986ac4/2615a99b7dd2.css" type="text/css" /><link rel="stylesheet" href="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/260993986ac4/2615be9c6ada531262c882c854df.css" type="text/css" /><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a29d68df5a3f60c697d84a.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1777de8fd86bc8459da050.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e17549d.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1466dd8b.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1568c287fb4dd85e9bbe.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1577de.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1965c4a0.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1554c682cf48.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1574dd.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1262c293d551.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e126ec885.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1375c282d35f.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1175c18ccb41.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1e66d686.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1c66d882.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1c66d882fb60.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1c54cd91d448df.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0662dc8f.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e066fde.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e067eda8bd256.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0472cc9a.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0564cf8fdc.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0576c2.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0065.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0668d986cf6bc35298bc.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e0e6ac2.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e1168.js"></script><script type="text/javascript" src="https://js.how234.com/3f0e869d6d/260484806ecf5e3f60c68fd45fc34391a2/261e989d7fc34564379cd1/2615a8867ac45e066bcf8ad3.js"></script><script type="text/javascript"> SyntaxHighlighter.all(); </script>