Regex in Notepad++ 6

So, Notepad++ got updated to v6.0. One of their new features is PCRE (Perl Compatible Regular Expressions).

I tried to use this new feature to find and replace things in a file. I tried the regular expression:

{\$([a-zA-Z_]*)}

and it yelled at me, saying "Invalid regular expression".

I tested this regex in other programs (like my main IDE, Geany), and it worked fine.

Why does this not work in Notepad++ 6.0?

Solution 1:

You have to escape the {} like so:

\{\$([a-zA-Z_]*)\}

I assume Geany and rubular.com don't use PCRE (or they use it differently). Please note that {} are usually used to denote quantifiers.

Without having checked the source, I can only assume that Notepad++ tries to be too smart before passing the regular expression to the PCRE library. If I run the following code in PHP:

echo preg_match( '{\$([a-zA-Z_]*)}', '{$something}' );

It prints 1 right away. No need to escape anything.

Sorry that I can't explain it :(