If the delimiter needs to be matched inside the pattern it must be escaped using a backslash. If the delimiter appears often inside the pattern, it is a good idea to choose another delimiter in order to increase readability.
So escape it:
'/\[attachment=.*?].*\[\/attachment]/'
^
By the way: Currently the quantifier in .* is greedy, that means it will match as much as possible. You might want to change it to an ungreedy variant using ? like you did before.
You need a delimeter, and you need to escape it if you're actually using it in your expression (i.e.: [/attachment] has a / in it). Escape it or change your delimiter (# for example).
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您需要转义模式内每一次出现的分隔符：
所以逃避它：
顺便说一句：目前
.*中的 量词是贪婪的，这意味着它将尽可能匹配。您可能想像以前一样使用?将其更改为非贪婪变体。You need to escape every occurrence of the delimiter inside the pattern:
So escape it:
By the way: Currently the quantifier in
.*is greedy, that means it will match as much as possible. You might want to change it to an ungreedy variant using?like you did before.您需要一个分隔符，如果您实际上在表达式中使用它，则需要转义它（即：
[/attachment]有一个/ 中）。转义它或更改分隔符（例如#）。You need a delimeter, and you need to escape it if you're actually using it in your expression (i.e.:
[/attachment]has a/in it). Escape it or change your delimiter (#for example).我想我解决了这个问题。我在示例中的测试数据很糟糕，因此我尝试匹配无效的模式。
I think I solve this. My test data in the example was bad, so I was trying to match an invalid pattern.