Extracting matches with gaps

Question

I'm not sure if this is possible, but can't hurt to ask.

I want to search through files for either one or two strings. Let me make an example.

<span class="postername"><a href="mailto:[e-mail]">ExampleUser</a></span><span class="postertrip">!ExampleTripcode</span>

I'd like to extract the name and tripcode of the user in a single string - right now I'm using <span class="postername">.*?\n to get the entire line and then making a second pass replacing <.*?> with an empty string, but I'm wondering if it's possible to do the whole thing in one step.

Also, a thing to note would be that the "ExampleUser" element is the only one that is guaranteed to appear - email and tripcode usually don't.

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C# newbie, learning on the go. I will probably ask a lot of followup questions about any answers already given, so fair warning and all.

Answer 1

On Fri, 10 Aug 2012 07:06:13 +0000, TheQuinch wrote:

 

>

>

>I'm not sure if this is possible, but can't hurt to ask.

>

>

>

>I want to search through files for either one or two strings. Let me make an example.

>

><span class="postername"><a href="mailto:[e-mail]">ExampleUser</a></span><span class="postertrip">!ExampleTripcode</span>

>

>

>

>I'd like to extract the name and tripcode of the user in a single string - right now I'm using <span class="postername">.*?\n to get the entire line and then making a second pass replacing <.*?> with an empty string, but I'm wondering if it's possible to do the whole thing in one step.

>

>

>

>Also, a thing to note would be that the "ExampleUser" element is the only one that is guaranteed to appear - email and tripcode usually don't.

>

>

>C# newbie, learning on the go. I will probably ask a lot of followup questions about any answers already given, so fair warning and all.

 

You can use capturing groups and, to deal with the absence of an element, non-capturing groups.  Something like:

 

<span class="postername">.*(?:a href=[^>]+>)(?<UserName>[^<]+)(?:.*(?:class="postertrip">)(?<TripCode>[^<]+))?

 

might work, although from your description I'm not sure of the definitive identifier for UserName.  I did assume that the ExampleUser would always be first, but if the order could be reversed, a different regex, perhaps using alternation, could be devised.

 

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Ron

Answer 2

http://social.msdn.microsoft.com/Forums/en-US/regexp/thread/d8dcb6a7-4bf3-4ec0-9252-2424c141c5ca

You can Test your regular expression without compiling/executing .net applicaiton

Answer 3

Hi TheQuinch,

Welcome to the MSDN Forum.

Please try this code:

string finalString = Regex.Replace("YourtargetString", @"<span class=""postername"">(.*?)\n", @"<span class=""postername"">");

I hope this will be helpful.

Best regards,

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Mike Feng
MSDN Community Support | Feedback to us
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