Question

当我运行以下内容时：

$MATH_REGEX = '/(?=(?<!\\)\$).(.+?)(?<!\\)\$/';
preg_replace_callback($MATH_REGEX, function ($match) {
        $latex_code = $match[0];
        return lx($latex_code); //lx is defined elsewhere
    }, "Test string $a=b$ .");

我明白了：

$ php test.php
PHP Warning:  preg_replace_callback(): Compilation failed: missing ) at offset 26 in /home/sbird/public_html/faith/lib/view.php on line 26

我的正则表达式出了什么问题？

编辑：

$ php --version
PHP 5.3.2-1ubuntu4.15 with Suhosin-Patch (cli) (built: May  4 2012 00:38:52) 
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies

Answer 1

您正在逃避(：

/(?=(?<!\\)\$).(.+?)(?<!\\)\$/
                 here:  ^^^

传递给preg_replace_callback的结果字符串如下所示：

php > $MATH_REGEX = '/(?=(?<!\\)\$).(.+?)(?<!\\)\$/';
php > echo $MATH_REGEX;
/(?=(?<!\)\$).(.+?)(?<!\)\$/
                       ^^ !!!

php-regex没有编译

1 个答案: