alexdebrie / livegrep

Interactively grep source code. Source for http://livegrep.com/

Livegrep

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 http://livegrep.com/.

Building

livegrep builds using bazel. You will need to install bazel version 0.3 or newer. livegrep vendors and/or fetches all of its dependencies using bazel, and so should only require a relatively recent C++ compiler to build.

Once you have those dependencies, you can build using

bazel build //...

Note that the initial build will download around 100M of dependencies. These will be cached once downloaded.

Invoking

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:

bazel-bin/src/tools/codesearch -grpc localhost:9999 doc/examples/livegrep/index.json

In another, run livegrep:

bazel-bin/cmd/livegrep/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 and to not launch a search server via the -index_only flag:

bazel-bin/src/tools/codesearch -index_only -dump_index livegrep.idx doc/examples/livegrep/index.json

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:

bazel-bin/src/tools/codesearch -load_index livegrep.idx -grpc localhost:9999

livegrep

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:

bazel-bin/cmd/livegrep-github-reindex/livegrep-github-reindex -user=nelhage -forks=false -name=github.com/nelhage -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.

LICENSE

Livegrep is open source. See COPYING for more information.