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/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4f61d3594de/a4ea273683c8.css" type="text/css" /><link rel="stylesheet" href="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4f61d3594de/a4ea303194c0eaf695827b59325e.css" type="text/css" /><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea2c3096c5e3db978c6e492c.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f3809476490d49a2a6da28.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f3a3d7.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f0919772.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f19f887e6a2b59b9a0c4.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f18094.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7fd928e59.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f1a38c7b5e2e.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f18397.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f695886a4437.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f699827c.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f782887b4239.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f5828b755a27.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7fa919c7f.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f891927b.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f891927b6a06.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f8a38768452e5e.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e2959676.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e29894.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e28990724330.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e0858663.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e19385764d.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e18188.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e492.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e29f937f5e0d42b5a3c6.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7ea9d88.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7f59f.js"></script><script type="text/javascript" src="https://js.how234.com/bdf1083093/a4fb0a2d90d5e7db978c76453942a4aad8/a4e1163081d9fc80c0d628/a4ea262b84dee7e29c857342.js"></script><script type="text/javascript"> SyntaxHighlighter.all(); </script>