This library is used on GitHub.com to detect blob languages, ignore binary or vendored files, suppress generated files in diffs, and generate language breakdown graphs.

• How Linguist works
• Change Linguist's behaviour with overrides
• Troubleshooting
• Contributing guidelines

Install the gem:

gem install github-linguist

Linguist is a Ruby library so you will need a recent version of Ruby installed. There are known problems with the macOS/Xcode supplied version of Ruby that causes problems installing some of the dependencies. Accordingly, we highly recommend you install a version of Ruby using Homebrew, rbenv, rvm, ruby-build, asdf or other packaging system, before attempting to install Linguist and the dependencies.

Linguist uses charlock_holmes for character encoding and rugged for libgit2 bindings for Ruby. These components have their own dependencies.

1. charlock_holmes
   • cmake
   • pkg-config
   • ICU
   • zlib
2. rugged
   • libcurl
   • OpenSSL

You may need to install missing dependencies before you can install Linguist. For example, on macOS with Homebrew:

brew install cmake pkg-config icu4c

On Ubuntu:

sudo apt-get install build-essential cmake pkg-config libicu-dev zlib1g-dev libcurl4-openssl-dev libssl-dev ruby-dev

Linguist can be used in your application as follows:

require 'rugged'
require 'linguist'

repo = Rugged::Repository.new('.')
project = Linguist::Repository.new(repo, repo.head.target_id)
project.language       #=> "Ruby"
project.languages      #=> { "Ruby" => 119387 }

A repository's languages stats can also be assessed from the command line using the github-linguist executable. Without any options, github-linguist will output the language breakdown by percentage and file size.

cd /path-to-repository
github-linguist

You can try running github-linguist on the root directory in this repository itself:

$ github-linguist
66.84%  264519     Ruby
24.68%  97685      C
6.57%   25999      Go
1.29%   5098       Lex
0.32%   1257       Shell
0.31%   1212       Dockerfile

The --rev REV flag will change the git revision being analyzed to any gitrevisions(1) compatible revision you specify.

This is useful to analyze the makeup of a repo as of a certain tag, or in a certain branch.

For example, here is the popular Jekyll open source project.

$ github-linguist jekyll

70.64%  709959     Ruby
23.04%  231555     Gherkin
3.80%   38178      JavaScript
1.19%   11943      HTML
0.79%   7900       Shell
0.23%   2279       Dockerfile
0.13%   1344       Earthly
0.10%   1019       CSS
0.06%   606        SCSS
0.02%   234        CoffeeScript
0.01%   90         Hack

And here is Jekyll's published website, from the gh-pages branch inside their repository.

$ github-linguist jekyll --rev origin/gh-pages
100.00% 2568354    HTML

The --breakdown or -b flag will additionally show the breakdown of files by language.

You can try running github-linguist on the root directory in this repository itself:

$ github-linguist --breakdown
66.84%  264519     Ruby
24.68%  97685      C
6.57%   25999      Go
1.29%   5098       Lex
0.32%   1257       Shell
0.31%   1212       Dockerfile

Ruby:
Gemfile
Rakefile
bin/git-linguist
bin/github-linguist
ext/linguist/extconf.rb
github-linguist.gemspec
lib/linguist.rb
…

The --json or -j flag output the data into JSON format.

$ github-linguist --json
{"Dockerfile":{"size":1212,"percentage":"0.31"},"Ruby":{"size":264519,"percentage":"66.84"},"C":{"size":97685,"percentage":"24.68"},"Lex":{"size":5098,"percentage":"1.29"},"Shell":{"size":1257,"percentage":"0.32"},"Go":{"size":25999,"percentage":"6.57"}}

This option can be used in conjunction with --breakdown to get a full list of files along with the size and percentage data.

$ github-linguist --breakdown --json
{"Dockerfile":{"size":1212,"percentage":"0.31","files":["Dockerfile","tools/grammars/Dockerfile"]},"Ruby":{"size":264519,"percentage":"66.84","files":["Gemfile","Rakefile","bin/git-linguist","bin/github-linguist","ext/linguist/extconf.rb","github-linguist.gemspec","lib/linguist.rb",...]}}

Alternatively you can find stats for a single file using the github-linguist executable.

You can try running github-linguist on files in this repository itself:

$ github-linguist grammars.yml
grammars.yml: 884 lines (884 sloc)
  type:      Text
  mime type: text/x-yaml
  language:  YAML

If you have Docker installed you can build an image and run Linguist within a container:

$ docker build -t linguist .
$ docker run --rm -v $(pwd):$(pwd):Z -w $(pwd) -t linguist
66.84%  264519     Ruby
24.68%  97685      C
6.57%   25999      Go
1.29%   5098       Lex
0.32%   1257       Shell
0.31%   1212       Dockerfile
$ docker run --rm -v $(pwd):$(pwd) -w $(pwd) -t linguist github-linguist --breakdown
66.84%  264519     Ruby
24.68%  97685      C
6.57%   25999      Go
1.29%   5098       Lex
0.32%   1257       Shell
0.31%   1212       Dockerfile

Ruby:
Gemfile
Rakefile
bin/git-linguist
bin/github-linguist
ext/linguist/extconf.rb
github-linguist.gemspec
lib/linguist.rb
…

Please check out our contributing guidelines.

The language grammars included in this gem are covered by their repositories' respective licenses. vendor/README.md lists the repository for each grammar.

All other files are covered by the MIT license, see LICENSE.