Here is a problem I have been banging my head at for a couple of days.I was wondering if anyone could help. I have this class of strings with this pattern: s1?=s2? s3 s4?          = always follows s1 only, and only if s1 is not empty s1 is  ({?\(?word( word)*\)?\}?)?  (it may be empty). If there is more that one ...

I am using PCRE (same with .Net) and I would have expected the following pattern to fail when i run it against the text below: (?<B><)?[^%>]+(?(B)>)% that is: look for a < , look for at least 1 char which is not % or > then, if a < was found look for a >, then look for a % in other words find expressions like ....% ...

First of all thank you for taking the time to look into this. Second, apologies for not providing more engine details. I should have known better. I am using PCRE as you guessed and I am indeed looking for the underlined part in  aaap1bbbp1cccp2ddd (I need p1 and p2 separated but that's easy). I tried  your pattern on a simple ...

Hello all, my first time posting, but I use the site often as a resource, really wonderful. First, I want to say that I realize that RegEx is not the best choice for what I need to accomplish, however, the Encryption Engine my company wrote is homegrown and only permits standard Word Lists and RegExs (. So I am using RegEx, for good or for bad. ...

I'm writing search filters using regex (PCRE flavored). My filter is this:  ((?i)((\s(529|53[01247]))\s+security).+user\sname:(?!.{1,20}(\$|caller))(?!\sdomain)) The data looks something like this: 1 <13>Mar 22 09:11:16 10.0.1.7 MSWinEventLog 0 Security 3553368 Tue Mar 22 13:11:16 2011 537 Security SYSTEM User Failure Audit ...

I'm attempting to use PCRE as part of my scripting and have hit a mental block. Regex is not a strong point for me so please bear with me. What I have is a file name such as this one: My music name (Album Name - Artist Name) 2010_12_15_14_45_55 0001.mp3 What I want to do is remove the date/time/unique number from the name which was ...

Platform: PCRE Purpose:  am trying to teach myself a little PCRE.  In particular an expression has been nagging me: <?php $text="this-that <a href=\"http://www.my-site.com/index.php\">this-that</a> ...

According to the documentation the 'u' modifer is for UTF8 not Unicode. It treats the sring as UTF8. Doc: u (PCRE_UTF8) This modifier turns on additional functionality of PCRE that is incompatible with Perl. Pattern strings are treated as UTF-8. This modifier is available from PHP 4.1.0 or greater on Unix and from PHP 4.2.3 on win32. ...

First off let me say I'm a bit over my head here. Not regex part but host the language of the regex engine. Many moons ago I posted a blog article stating why you could not write a regex that validated an e-mail address 100%. Well this is still true, however in that posted I also stated that the pattern was so massive ...

It's OK, I think I've found the answer to my own question. The # signs bracket the actual regular expression, and the e and the s are modifiers - e is equivalent to PREG_REPLACE_EVAL and  s is equivalent to PCRE_DOTALL. Maybe these are things which are so familiar to the experienced players that they almost go without saying, but ...