Forums Scripts & Popups $regex help (detect repeating characters)

Let's say I want to look for the word "barf" and forms of different spellings like "barph"...

I know that /(bar)(f|ph)/g will get both of those...

How do I detect "baaarrrrfff" though, as an example?

Specifically, I'm trying to make a swear kicker that will use RE's to be a bit wiser for the detection, and the one thing that can evade are repeated letters (or if they type out the word in the form of b-a-r-f or "b a r f").. Any assistance would be appreciated.

/b+a+r+(?:f+|p+h+)/g

a+ will get aaaaaaaaaa or a, so that version will catch bbbaaarrrphhhhh.

If you don't need to capture (for later use in \1 or $regml(N)), use the above just to match. If you require the match to be returnable, surround the whole thing with ( ).

/(b+a+r+(?:f+|p+h+))/g

what does the ?: do out of curiousity? And would ya happen to know any sites that don't babble excessively and then give 1 or two examples and claim to be a tutorial on RE's?

and thanks dude.. I had actually thought of asking you directly (I've noticed your expertise in other posts) but thought that this could help others too if they can make use of any of it.

?: makes a non-capturing subpattern. Try http://www.regular-expressions.info/ and http://www.pcre.org/man.txt

Additionally, using (?: to make it not capture also means that the regex engine doesn't need to set up a memory structure to hold results, which speeds up the regex somewhat, especially for nested subpatterns - $regml(29).

ie, $regml wouldn't hold any of it (the section with ?: in it) or it would be in $regml but not by itself?

...hey, this is useful stuff, I ain't gonna knock what I can learn from it.. And I am still looking over those two sites (Thanks Online).. Getting some nice information from there too.

Hey,

if you are looking for some regex tutorials, then these might interest you (no particular order):

http://www.pcre.org/

http://www.pcre.org/man.txt

http://www.perldoc.com/perl5.8.0/pod/perlre.html

http://us4.php.net/manual/en/pcre.pattern.syntax.php

http://www.regular-expressions.info/

http://tlc.perlarchive.com/articles/perl/pm0001_perlretut.shtml

http://www.mircscripts.org/download.php?id=2393&type=1

http://www.mircscripts.org/showdoc.php?type=tutorial&id=989

http://perl.plover.com/Regex/

http://gnosis.cx/publish/programming/regular_expressions.html


Man I hate my current studies! I wanna go and learn all the stuff mentioned in the above sites, but unfortunately I have to start studying for the upcoming exams

Oh well, enjoy the tutorials!


Greetz

Wolfie: If you do not capture anything with ( ) then $regml will hold nothing at all. This includes those (?: ) sections, they won't be in $regml either. That means that if you DO want $regml to hold something, you have to capture what you DO want with ( ).

FiberOPtics: Be aware that some of those sites might refer to a slightly incompatible version of Regular Expressions. PCRE means Perl-Compatible Regular Expressions. The version that Perl uses is slightly different and so may need some translation or may not work at all in PCRE.

Hello,

I'm well aware of this

It is even mentioned in some sites like the PHP one that there are differences.

I gave all those sites as they might be useful.


Greetz