Hello @liuruiqi1993 and All,
BTW, I advice you to downgrade to the v7.5.1 version of Notepad++, because there are some encoding issues with the last two N++ versions ! See below :
https://notepad-plus-plus.org/community/topic/14936/update-to-7-5-3-file-encode-wrong/2
Now, I understand why it did,'t work with your old 5.9.4 version. Just because, since the N++ v.6.0 version, a new search engine is implemented, with the Perl Common Regular Expressions feature, of the Boost C++ regex library ! This new search engine allows you to run complicated S/R, once you’re acquainted with Regular expressions language :-))
For newby people, about regular expressions concept and syntax, begin with that article, in N++ Wiki :
http://docs.notepad-plus-plus.org/index.php/Regular_Expressions
In addition, you’ll find good documentation, about the Boost C++ Regex library, v1.55.0 ( similar to the PERL Regular Common Expressions, v5.8 ), used by Notepad++, since its 6.0 version, at the TWO addresses below :
http://www.boost.org/doc/libs/1_55_0/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html
http://www.boost.org/doc/libs/1_55_0/libs/regex/doc/html/boost_regex/format/boost_format_syntax.html
The FIRST link explains the syntax, of regular expressions, in the SEARCH part
The SECOND link explains the syntax, of regular expressions, in the REPLACEMENT part
You may, also, look for valuable informations, on the sites, below :
http://www.regular-expressions.info
http://www.rexegg.com
http://perldoc.perl.org/perlre.html
Be aware that, as any documentation, it may contain some errors ! Anyway, if you detected one, that’s good news : you’re improving ;-))