Google Code Search was a free

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product from

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

Subversion Subversion () refers to a process by which the values and principles of a system in place are contradicted or reversed in an attempt to sabotage the established social order and its structures of Power (philosophy), power, authority, tradition, h ...

git Git () is a distributed version control system that tracks versions of files. It is often used to control source code by programmers who are developing software collaboratively. Design goals of Git include speed, data integrity, and suppor ...

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.

Regular expression engine

The site allowed the use of

regular expression A regular expression (shortened as regex or regexp), sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...

s in queries, which at that time was not offered by any other search engine for code. This makes it resemble

grep grep is a command-line utility for searching plaintext datasets for lines that match a regular expression. Its name comes from the ed command g/re/p (global regular expression search and print), which has the same effect. grep was originally de ...

, but over the world's public code. The methodology employed, sometimes called trigram search, combines a trigram

index Index (: indexes or indices) may refer to: Arts, entertainment, and media Fictional entities * Index (''A Certain Magical Index''), a character in the light novel series ''A Certain Magical Index'' * The Index, an item on the Halo Array in the ...

with a custom-built, denial-of-service resistant

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

Discontinuation

In October 2011, Google announced that Code Search was to be shut down along with the Code Search API. The service remained online until March 2013, and it now returns a 404. In January 2012, Google developer 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.

References

External links

* {{Google LLC Code search engines Defunct internet search engines Code Search

Regular expression engine

Discontinuation

See also

References

External links