Question

I try to parse articles from wikipedia. I use the *page-articles.xml file, where they backup all their articles in a wikicode-format. To strip the format and get the raw text, I try to use Regular Expressions, but I am not very used to it. I use C# as programming language.
I tried a bit around with Expresso, a designer for Regular Expressions, but I am at the end of my wits. Here is what I want to achieve:

The text can contain the following structures:
[[TextN]] or
[[Text1|TextN]] or
[[Text1|Text2|…|TextN]]

the [[ …. ]] pattern can appear within the Texti aswell. I want to replace these structure with TextN

For identifing the structures withhin the text I tried the following RegEx:

\[\[ ( .* \|?)* \]\]

Expresso seems to run and endless loop with this one. After 5 minutes for a relative small text, I canceled the Test Run.

Then I tried something more simple, I want to capture anything between the brackets:

\[\[ .* \]\]

but when I have a line like:

[[Word1]] text inbetween [[Word2]]

the expression returns the whole line, not

[[Word1]]

[[Word2]]

Any tips from Regex-Experts here to solve the problem?

Thanks in advance,
Frank

Answer 1

\[\[(.*?\]\] would do it.

The key is the .*? which means get any characters but as few a possible.

EDIT

For nested tags one approach would be:

\[\[(?<text>(?>\[\[(?<Level>)|\]\](?<-Level>)|(?! \[\[ | \]\] ).)+(?(Level)(?!)))\]\]

This ensures that the [[ and ]] match across the text as well.