我正在使用preg_match_all非常长的模式.
Warning: preg_match_all(): Compilation Failed: regular expression is too large at offset 707830
搜索之后,我得到了解决方案,所以我应该在PHP.ini中增加pcre.backtrack_limit和pcre.recursion_limit的值
解决方法
增加PCRE回溯和递归限制可能会解决问题,但是当数据大小达到新限制时仍会失败. (随着更多数据不能很好地扩展)
例:
<?PHP // essential for huge PCREs ini_set("pcre.backtrack_limit","23001337"); ini_set("pcre.recursion_limit","23001337"); // imagine your PCRE here... ?>
要真正解决底层问题,必须优化表达式并(如果可能)将复杂表达式拆分为“部分”并将一些逻辑移到PHP.我希望你通过阅读这个例子得到这个想法..而不是试图用一个PCRE直接找到子结构,我展示了一种更加“迭代”的方法,使用PHP更深入地进入结构.例:
<?PHP $html = file_get_contents("huge_input.html"); // first find all tables,and work on those later $res = preg_match_all("!<table.*>(?P<content>.*)</table>!isU",$html,$table_matches); if ($res) foreach($table_matches['content'] as $table_match) { // Now find all cells in each table that was found earlier .. $res = preg_match_all("!<td.*>(?P<content>.*)</td>!isU",$table_match,$cell_matches); if ($res) foreach($cell_matches['content'] as $cell_match) { // imagine going deeper and deeper into the structure here... echo "found a table cell! content: ",$cell_match; } }