MediaWiki Regex Search – How to Search MediaWiki Sites Using Regular Expressions

mediawikiregexwikipedia

I'd like to search for phrases using regular expressions on sites such as Wikipedia and Wikimedia Commons. Is it possible to do this?

Example regex search query: (facebook|google) (corporate history|websites)

It's already possible to do the same on Google (as demonstrated here), so I want to know whether it's possible for Wikipedia as well.

Best Answer

It's available and powered by the CirrusSearch (based on ElasticSearch) which is the used search engine in the MediaWiki sites, and the Wikimedia platform.

Some usage examples:

Note: Full guide reference, and source - on Wikipedia: Help:Searching#Search_string_syntax.

As for your question:

Logical operators

The search engine supports boolean logic in searches. The logical operators include the "-" (minus sign) character for "logical not", the AND, the OR, and the grouping parentheses brackets: (_).

Logical OR must be spelled in capital letters; the AND operator is assumed for all terms (separated by spaces), but capital AND is equivalent.

More examples:

Simple AND, OR: "credit card" OR "payment card", "credit card" AND "payment card" - will work as expected.
Suffixed tilde character for fuzzy search ("sounds like") - For example, searching for charlie~ parker~ returns Charlie Parker, Charles Palmer, Charley Parks (up to two character difference, not including the first one).
Wildcard search - searching face*e - starts with face and ends with an e with anything in the middle.

Extra reading

Read more about the search engine and this extension to unveil their full functionality and features.

Related Solutions

Google Search – How to Search Using Regular Expressions

This feature is not available in classic Google Search and it's not in Google's roadmap. You can learn more about this topic watching the Google video Will Google implement the ability to search with regular expressions?

However, there's one exception. Google Code Search supports regular expressions. Of course, the search target for this topic search engine is reduced to source code only.

It is worth to mention that some Google search keywords can partially replace regular expressions. For example, if you want to search any two-word variation of "search TERM", you can use the wildcard operator.

search *

will find results for search and any other (one) word. I often use it to check basic English grammar rules or synonyms (e.g., "as easy as *").

MediaWiki – Search Within a Category

This is possible on Wikimedia Commons.

Can I specify categories when searching?

[...] To do this, just add +incategory:"CategoryName" to the search string. [...]

For example, if you wanted to look for the purple things in the "Flowers" category, you'd use this:

purple +incategory:"Flowers"

Be warned that if you're trying this on a default or fresh install of a MediaWiki site, it may not work since it's a Lucene search specific function that needs setting up.