livegrep

Livegrep is an interactive tool designed for performing regex searches on large-scale source code repositories, inspired by Google Code Search. It allows users to search through gigabyte-scale repositories efficiently. The tool is built using Bazel, requiring a recent C++ compiler and downloads dependencies automatically. Livegrep operates with a codesearch backend that handles indexing and search processes, while the livegrep frontend provides a web interface for users to interact with the search results.

The backend, codesearch, builds an in-memory index from the source repositories specified in its configuration file, which can also be saved to disk for reuse. This enables handling of indexes too large to fit in RAM. The frontend connects to the codesearch instance and presents the search results through a web interface, typically available at http://localhost:8910.

Livegrep supports integration with GitHub through a dedicated driver, livegrep-github-reindex, which can automatically update and index selected repositories. Additionally, livegrep offers a local repository browser, allowing users to view source files directly within the tool.

The tool is available as Docker images, facilitating easy deployment and usage. Livegrep's CI builds Docker images into the livegrep organization repository on every merge to the main branch. The tool memory-maps the index file into RAM, optimizing performance when the index fits entirely in memory, though it can also work with larger files stored on fast SSDs.

Livegrep uses Google's re2 regular expression engine, providing mostly PCRE-compatible regex support. The tool is open-source, licensed under the 2-clause BSD license, with its source code and documentation available on GitHub.