Search and replace options \n, \r, \t, \o, \x...

Art Kautz

What are all of these? I discovered that \t was tab, but the others remain a mystery.

PeterJones

@Art-Kautz, Welcome to the Community Forums,

Those “escape” sequences allow entering special characters in the search/replace dialog (though it’s a \0 backslash+zero, not \o backslash+letter+o)

They are documented https://www.boost.org/doc/libs/1_55_0/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html#boost_regex.syntax.perl_syntax.escapes .

They are only active when you have the search mode set to Extended or Regular Expression.

Alan Kilborn

@PeterJones

I largely ignore Extended mode. Are all of those the OP mentioned valid there? Are there any real advantages to Ext mode or should I just go back to ignoring it. If you know…

PeterJones

@Alan-Kilborn said:

Are all of those the OP mentioned valid there?

The ones the OP mentioned are the escapes listed in the dialog box for what “Extended mode” is. I never use Extended mode, but I assume if the dialog box mentions those escapes for Extended mode, they are valid for Extended mode.

Are there any real advantages to Ext mode or should I just go back to ignoring it. If you know…

From what I understand, it allows you to use characters like ^[].* without their special regex meaning. It might be nice to not have to escape those… but I rarely am searching for special characters, anyway.

guy038

Hi, @art-kautz, @Peterjones, @alan-kilborn and All,

Have a look to these two links, below. The first one is a post of mine, two years ago and the second is from the official ( and a bit out of date ! ) N++ documentation :

https://notepad-plus-plus.org/community/topic/13808/search-replace-of-multiline-text-blocs/2

http://docs.notepad-plus-plus.org/index.php/Searching_And_Replacing#Escape_sequences_supported_in_extended_mode

Best Regards,

guy038

Meta Chuh

ps to @guy038 :
omg, an old ion saliu aka parpaluck thread, what a psycho.
he even really insisted that claudia’s screenshots were all photoshopped.

Alan Kilborn

From @guy038’s posting (see EITHER hyperlink), it appears it truly is \o and not \0 (sorry, Peter). I guess I will have to remember this the next time I want to express a search in octal, as I don’t believe regex will do octal. In other words, I can promptly forget about this. :)

PeterJones

@Alan-Kilborn said:

it appears it truly is \o and not \0 (sorry, Peter)

I cannot know what the OP intended, but according to the source code, the list of characters in that string in the dialog box includes \0, not \o:

And the outdated docs #Extended Mode say,

\0
the NUL control character (ASCII 0x00). Not supported in regular expressions - use \x00 instead.

Some experiments, with a file that contains multiple 0 characters (and some others), any of the following will find the 0s:

Extended: 0
Extended: \o060
Extended: \x30
Regex: 0
Regex: \060 (no o prefix)
Regex: \x30

Similarly, if you have a file that’s got one or more NUL character

Extended: \0
Extended: \o000
Extended: \x00
Regex: \0
Regex: \000
Regex: \x00

(So I actually disagree with the docs in this regard: in regex, \0 does match the NUL character. Probably, the docs were written under the older regex engine, not the “most recent” Boost 3.5.6 engine.)

Alan Kilborn

@PeterJones

Ah, okay, so extended mode support both \0 and \o. Good to know.