Interactively grep source code. Source for
C++ JavaScript Go HTML Makefile C Other
Latest commit 5cdcd30 Apr 11, 2016 @nelhage nelhage Merge pull request #29 from livegrep/fix-lit
Fix `lit:` (regressed in previous commit)

Livegrep Build Status

Livegrep is a tool, partially inspired by Google Code Search, for interactive regex search of ~gigabyte-scale source repositories. You can see a running instance at


This respository contains three separate components: The indexing and search backend (written in C++), the web interface (server in golang, UI, obviously, in Javascript), and a CLI that talks to the web interface. These each need to be built separately.

codesearch -- the search backend

The C++ backend had a number of dependencies, including:

On a sufficiently recent Ubuntu, these are all available via apt-get:

sudo apt-get install libgflags-dev libgit2-dev libjson0-dev libboost-system-dev libboost-filesystem-dev libsparsehash-dev cmake golang

I have also made packages available in a PPA, but they are largely unmaintained since I no longer deploy livegrep on any older distributions.

Once all the dependencies are installed, a simple make should build all of the binaries into the bin/ directory.


To run livegrep, you need to invoke both the codesearch backend index/search process, and the livegrep web interface.

To run the sample web interface over livegrep itself, once you have built both codesearch and livegrep:

In one terminal, start the codesearch server like so:

bin/codesearch -listen tcp://localhost:9999 doc/examples/livegrep/index.json

In another, run livegrep:


In a browser, now visit http://localhost:8910/, and you should see a working livegrep.

Using Index Files

The codesearch binary is responsible for reading source code, maintaining an index, and handling searches. livegrep is stateless and relies only on the connection to codesearch over a TCP connection.

By default, codesearch will build an in-memory index over the repositories specified in its configuration file. You can, however, also instruct it to save the index to a file on disk. This the dual advantages of allowing indexes that are too large to fit in RAM, and of allowing an index file to be reused. You instruct codesearch to generate an index file via the -dump_index flag:

bin/codesearch -dump_index livegrep.idx doc/examples/livegrep/index.json </dev/null

Once codeseach has built the index, this index file can be used for future runs. Index files are standalone, and you no longer need access to the source code repositories, or even a configuration file, once an index has been built. You can just launch a search server like so:

bin/codesearch -load_index livegrep.idx  -listen tcp://localhost:9999


The livegrep frontend expects an optional position argument indicating a JSON configuration file; See doc/examples/livegrep/server.json for an example, and server/config/config.go for documentation of available options.

By default, livegrep will connect to a single local codesearch instance on port 9999, and listen for HTTP connections on port 8910.

github integration

livegrep includes a helper driver, livegrep-github-reindex, which can automatically update and index selected github repositories. To download and index all of my repositories (except for forks), storing the repos in repos/ and writing nelhage.idx, you might run:

bin/livegrep-github-reindex -user=nelhage -forks=false -out nelhage.idx

You can now use nelhage.idx as an argument to codesearch -load_index.

Resource Usage

livegrep builds an index file of your source code, and then works entirely out of that index, with no further access to the original git repositories.

In general, the index file will be approximately the same size as the original source code. livegrep memory-maps the index file into RAM, so it should be able to work out of index files larger than (available) RAM, but will perform much better if the file can be loaded entirely into memory.


Livegrep is open source. See COPYING for more information.