如何判断给定字符串是否是PHP的preg_match的有效输入?

I am building an admin UI where a user can manage a list PCRE strings which get passed to PHP's preg_match at other points in my application.

我正在构建一个管理UI，用户可以在其中管理一个列表PCRE字符串，这些字符串在应用程序的其他位置传递给PHP的preg_match。

Before storing the user's input for later use by preg_match, I'd first like to validate that the user's input is a valid PCRE expression, otherwise later on passing it to preg_match throws an error.

在存储用户输入供preg_match稍后使用之前，我首先要验证用户的输入是一个有效的PCRE表达式，否则在将其传递给preg_match时将抛出一个错误。

What's the best way to validate a given string to see if it's a valid PCRE in PHP?

验证给定字符串的最佳方法是什么，看它是否是PHP中的有效PCRE ?

1 个解决方案

#1

Your best bet will be to just pass the string to preg_match, and catch any errors that happen.

最好的方法是将字符串传递给preg_match，并捕获发生的任何错误。

try{
    preg_match($in_regex, $string, $results);
    //Use $results
} catch (Exception $e) {
    echo "Sorry, bad regex (/" . $in_regex . "/)";
}

[Edit] Since that won't work, you could try:

[编辑]既然行不通，你可以试试:

function bad_regex($errno, $errstr, $errfile, $errline){
    echo "Sorry, bad regex.";
}
set_error_handler("bad_regex");
preg_match($in_regex, $string, $results);
restore_error_handler();

#1