# google/codesearch

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3,980 stars · 398 forks · Go · BSD-3-Clause

## Links

- GitHub: https://github.com/google/codesearch
- Homepage: http://swtch.com/~rsc/regexp/regexp4.html
- awesome-repositories: https://awesome-repositories.com/repository/google-codesearch.md

## Description

Codesearch is an indexed code search engine and large-scale source indexer designed to execute regular expressions across extensive source code trees. It functions as a tool for finding specific text patterns in large codebases by analyzing and indexing massive volumes of source files for rapid retrieval.

The system utilizes a specialized trigram-based search index to accelerate complex regular expression queries. This indexing approach filters candidate documents via three-character sequences before applying full regular expression scans to ensure high performance on large datasets.

The engine handles Unicode text processing for UTF-8 and Latin-1 encoded content, ensuring consistent character matching and casing across different languages. Its capabilities cover source code indexing, pattern matching, and high-performance regular expression search.

## Tags

### Development Tools & Productivity

- [Code Pattern Searches](https://awesome-repositories.com/f/development-tools-productivity/regular-expression-search-and-replace/code-pattern-searches.md) — Finds specific text patterns across large codebases by applying regular expressions to a source index. ([source](https://cdn.jsdelivr.net/gh/google/codesearch@master/README.md))
- [Regex Search Engines](https://awesome-repositories.com/f/development-tools-productivity/regex-search-engines.md) — Executes complex regular expression queries over large datasets with high performance via trigram filtering.
- [Text Pattern Search](https://awesome-repositories.com/f/development-tools-productivity/text-pattern-search.md) — Matches regular expressions against strings to identify the exact positions and boundaries of the found text. ([source](http://swtch.com/~rsc/regexp/regexp3.html))

### Data & Databases

- [Trigram Indexes](https://awesome-repositories.com/f/data-databases/index-construction/full-text-inverted-indexes/trigram-indexes.md) — Utilizes a trigram-based inverted index to filter candidate documents before applying full regular expression scans.
- [Source Code Indexing](https://awesome-repositories.com/f/data-databases/repository-indexing-pipelines/source-code-indexing.md) — Analyzes large volumes of source code to create a searchable index for rapid retrieval of code segments. ([source](https://cdn.jsdelivr.net/gh/google/codesearch@master/README.md))
- [Regexp Code Search Engines](https://awesome-repositories.com/f/data-databases/search-indexing-technologies/search-indexing/search-and-indexing/regexp-code-search-engines.md) — Provides a high-performance search engine using an inverted trigram index to execute regular expressions across code trees.
- [Trigram-Based Indexing](https://awesome-repositories.com/f/data-databases/search-indexing-technologies/search-indexing/search-and-indexing/trigram-based-indexing.md) — Uses a specialized trigram-based index to filter candidate files and accelerate complex regular expression queries.
- [Multi-Repository Code Searches](https://awesome-repositories.com/f/data-databases/semantic-search/code-search/multi-repository-code-searches.md) — Enables finding specific text patterns or code segments across massive repositories using fast indexing.
- [Document Filtering](https://awesome-repositories.com/f/data-databases/document-filtering.md) — Identifies potential matches by executing regular expression queries against an optimized index to narrow document sets.
- [Full-Text Inverted Indexes](https://awesome-repositories.com/f/data-databases/index-construction/full-text-inverted-indexes.md) — Implements an inverted index that maps text fragments to file locations for rapid code retrieval.

### Software Engineering & Architecture

- [Filter-and-Scan Pipelines](https://awesome-repositories.com/f/software-engineering-architecture/string-matching-algorithms/multi-pattern-matching-algorithms/filter-and-scan-pipelines.md) — Uses a fast initial index filter followed by a precise regular expression pass to locate exact boundaries.

### Part of an Awesome List

- [Code Analysis and Quality](https://awesome-repositories.com/f/awesome-lists/devtools/code-analysis-and-quality.md) — Fast code search tool.