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Google Code Search
Google Code Search.png
Type of site
Search engine
Available inAll languages
LaunchedOctober 5, 2006; 15 years ago (2006-10-05)
Current statusDiscontinued as of 15 January 2012

Google Code Search was a free beta product from Google which debuted in Google Labs on October 5, 2006, allowing web users to search for open-source code on the Internet. Features included the ability to search using operators, namely lang:, package:, license:, and file:.

The code available for searching was in various formats including tar.gz, .tar.bz2, .tar, and .zip, CVS, Subversion, git and Mercurial repositories.

Google Code Search covered many open-source projects, and as such is different from the "Code Search for Google Open source projects" that was released afterwards.[1][2]

Regular expression engine

The site allowed the use of regular expressions in queries, which at that time was not offered by any other search engine for code.[citation needed] This makes it resemble grep, but over the world's public code. The methodology employed, sometimes called trigram search, combines a trigram index with a custom-built, denial-of-service resistant regular expression engine.[3]

In March 2010, the code of RE2, the regular expression engine used in Google Code Search, was made open source.[4]

Google Code Search supported POSIX extended regular expression syntax, excluding back-references, collating elements, and collation classes.

Languages not officially supported could be searched for using the file: operator to match the common file extensions for the language.


In October 2011, Google announced that Code Search was to be shut down along with the Code Search API.[5] The service remained online until March 2013,[6] and it now returns a 404.

In January 2012, Russ Cox published an overview of history and the technical aspects of the tool, and open-sourced a basic implementation of a similar functionality as a set of standalone programs that can run fast indexed regular expression searches over local code.[7]

See also


  1. ^ "Code Search for Google open source projects". Google Open Source Blog. Retrieved 2020-04-01.
  2. ^ "Google Open Source". Retrieved 2020-04-01.
  3. ^ Russ Cox (January 2012). "Regular Expression Matching with a Trigram Index (or: How Google Code Search Worked)". Archived from the original on 2012-01-28. Retrieved 2012-01-26.
  4. ^ "RE2: a principled approach to regular expression matching". Archived from the original on 2016-09-27. Retrieved 2016-09-24.
  5. ^ Horowitz, Bradley (2011-10-14). "Official Blog: A fall sweep". Archived from the original on 2011-11-23. Retrieved 2013-07-09.
  6. ^ "Replacement for Google Code Search?". Stack Overflow. Archived from the original on 2017-11-09. Retrieved 2016-07-25.
  7. ^ codesearch on GitHub