donglin9068 2018-05-16 06:59
浏览 186
已采纳

PHP preg_match_all不处理大数据

Why is preg_match_all not working?

$pattern = '/\{(?:[^{}]|(?R))*\}/';

$result = 161240 characters

       if (preg_match_all($pattern, $result, $matches)) {
            echo 'Success';
        } else {
            echo 'Not working';
        }

This Displays: "Not working"

  • 写回答

1条回答 默认 最新

  • dongxing2692 2018-05-16 07:50
    关注

    The pattern at play matches balanced curly brackets using regex recursion. The pattern itself looks fine and works as intended.

    <?php
    $re = '/{(?>[^{}]|(?R))*\}/m';
    $str = 'Why is preg_match_all not working?{{{{{
    $pattern = \'/\\{(?:[^{}]|(?R))*\\}/\';
    $result = 161240 characters
           if (preg_match_all($pattern, $result, $matches)){ {
                echo \'Success\';
            } else {
                echo \'Not working\';
            }
    }}}}}}{}{}{}{}{}{}{}{{{{{{}}}}}';
    
    //preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
    if (preg_match_all($re, $str, $matches)) {
    echo 'Success
    ';
    } else {
    echo 'Not working
    ';
    }
    
    // Print the entire match result
    var_dump($matches);
    

    This also works with larger input (here tested with ~5000 characters). The most likely explanation is: the pattern does not find a valid match.

    However, you are running a recursive regex on a very large input string. Many, things could go wrong. The PCRE engine reaches internal limits, your string is not properly encoded, timeouts, etc.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥50 易语言把MYSQL数据库中的数据添加至组合框
  • ¥20 求数据集和代码#有偿答复
  • ¥15 关于下拉菜单选项关联的问题
  • ¥20 java-OJ-健康体检
  • ¥15 rs485的上拉下拉,不会对a-b<-200mv有影响吗,就是接受时,对判断逻辑0有影响吗
  • ¥15 使用phpstudy在云服务器上搭建个人网站
  • ¥15 应该如何判断含间隙的曲柄摇杆机构,轴与轴承是否发生了碰撞?
  • ¥15 vue3+express部署到nginx
  • ¥20 搭建pt1000三线制高精度测温电路
  • ¥15 使用Jdk8自带的算法,和Jdk11自带的加密结果会一样吗,不一样的话有什么解决方案,Jdk不能升级的情况