[Awesome Ruby Gem] Use git gem to create, read, and manipulate Git repositories

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ruby-git

The Git Gem provides an API that can be used to create, read, and manipulate Git repositories by wrapping system calls to the git binary. The API can be used for working with Git in complex interactions including branching and merging, object inspection and manipulation, history, patch generation and more.

Installation

You can install it as a gem:

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$ gem install git

or add it into a Gemfile (Bundler):

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# Gemfile

gem 'git', '1.9.1'

Then, run bundle install.

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$ bundle install

Usages

Major Objects

Git::Base - The object returned from a Git.open or Git.clone. Most major actions are called from this object.

Git::Object - The base object for your tree, blob and commit objects, returned from @git.gtree or @git.object calls. the Git::AbstractObject will have most of the calls in common for all those objects.

Git::Diff - returns from a @git.diff command. It is an Enumerable that returns Git::Diff:DiffFile objects from which you can get per file patches and insertion/deletion statistics. You can also get total statistics from the Git::Diff object directly.

Git::Status - returns from a @git.status command. It is an Enumerable that returns Git:Status::StatusFile objects for each object in git, which includes files in the working directory, in the index and in the repository. Similar to running ‘git status’ on the command line to determine untracked and changed files.

Git::Branches - Enumerable object that holds Git::Branch objects. You can call .local or .remote on it to filter to just your local or remote branches.

Git::Remote - A reference to a remote repository that is tracked by this repository.

Git::Log - An Enumerable object that references all the Git::Object::Commit objects that encompass your log query, which can be constructed through methods on the Git::Log object, like:

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@git.log(20).object("some_file").since("2 weeks ago").between('v2.6', 'v2.7').each { |commit| [block] }

Git::Worktrees - Enumerable object that holds Git::Worktree objects.

Examples

Here are a bunch of examples of how to use the Ruby/Git package.

Require the ‘git’ gem.

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require 'git'

Git env config

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Git.configure do |config|
  # If you want to use a custom git binary
  config.binary_path = '/git/bin/path'

  # If you need to use a custom SSH script
  config.git_ssh = '/path/to/ssh/script'
end

NOTE: Another way to specify where is the git binary is through the environment variable GIT_PATH

Here are the operations that need read permission only.

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g = Git.open(working_dir, :log => Logger.new(STDOUT))

g.index
g.index.readable?
g.index.writable?
g.repo
g.dir

g.log   # returns array of Git::Commit objects
g.log.since('2 weeks ago')
g.log.between('v2.5', 'v2.6')
g.log.each {|l| puts l.sha }
g.gblob('v2.5:Makefile').log.since('2 weeks ago')

g.object('HEAD^').to_s  # git show / git rev-parse
g.object('HEAD^').contents
g.object('v2.5:Makefile').size
g.object('v2.5:Makefile').sha

g.gtree(treeish)
g.gblob(treeish)
g.gcommit(treeish)


commit = g.gcommit('1cc8667014381')

commit.gtree
commit.parent.sha
commit.parents.size
commit.author.name
commit.author.email
commit.author.date.strftime("%m-%d-%y")
commit.committer.name
commit.date.strftime("%m-%d-%y")
commit.message

tree = g.gtree("HEAD^{tree}")

tree.blobs
tree.subtrees
tree.children # blobs and subtrees

g.revparse('v2.5:Makefile')

g.branches # returns Git::Branch objects
g.branches.local
g.current_branch
g.branches.remote
g.branches[:master].gcommit
g.branches['origin/master'].gcommit

g.grep('hello')  # implies HEAD
g.blob('v2.5:Makefile').grep('hello')
g.tag('v2.5').grep('hello', 'docs/')
g.describe()
g.describe('0djf2aa')
g.describe('HEAD', {:all => true, :tags => true})

g.diff(commit1, commit2).size
g.diff(commit1, commit2).stats
g.diff(commit1, commit2).name_status
g.gtree('v2.5').diff('v2.6').insertions
g.diff('gitsearch1', 'v2.5').path('lib/')
g.diff('gitsearch1', @git.gtree('v2.5'))
g.diff('gitsearch1', 'v2.5').path('docs/').patch
g.gtree('v2.5').diff('v2.6').patch

g.gtree('v2.5').diff('v2.6').each do |file_diff|
  puts file_diff.path
  puts file_diff.patch
  puts file_diff.blob(:src).contents
end

g.worktrees # returns Git::Worktree objects
g.worktrees.count
g.worktrees.each do |worktree|
  worktree.dir
  worktree.gcommit
  worktree.to_s
end

g.config('user.name')  # returns 'Scott Chacon'
g.config # returns whole config hash

g.tags # returns array of Git::Tag objects

g.show()
g.show('HEAD')
g.show('v2.8', 'README.md')

Git.ls_remote('https://github.com/ruby-git/ruby-git.git') # returns a hash containing the available references of the repo.
Git.ls_remote('/path/to/local/repo')
Git.ls_remote() # same as Git.ls_remote('.')

And here are the operations that will need to write to your git repository.

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g = Git.init
  Git.init('project')
  Git.init('/home/schacon/proj',
  { :repository => '/opt/git/proj.git',
      :index => '/tmp/index'} )

g = Git.clone(URI, NAME, :path => '/tmp/checkout')
g.config('user.name', 'Scott Chacon')
g.config('user.email', '[email protected]')

# Clone can take an optional logger
logger = Logger.new
g = Git.clone(URI, NAME, :log => logger)

g.add                                   # git add -- "."
g.add(:all=>true)                       # git add --all -- "."
g.add('file_path')                      # git add -- "file_path"
g.add(['file_path_1', 'file_path_2'])   # git add -- "file_path_1" "file_path_2"

g.remove()									# git rm -f -- "."
g.remove('file.txt')						# git rm -f -- "file.txt"
g.remove(['file.txt', 'file2.txt'])		# git rm -f -- "file.txt" "file2.txt"
g.remove('file.txt', :recursive => true) 	# git rm -f -r -- "file.txt"
g.remove('file.txt', :cached => true)		# git rm -f --cached -- "file.txt"

g.commit('message')
g.commit_all('message')

# Sign a commit using the gpg key configured in the user.signingkey config setting
g.config('user.signingkey', '0A46826A')
g.commit('message', gpg_sign: true)

# Sign a commit using a specified gpg key
key_id = '0A46826A'
g.commit('message', gpg_sign: key_id)

g = Git.clone(repo, 'myrepo')
g.chdir do
new_file('test-file', 'blahblahblah')
g.status.changed.each do |file|
  puts file.blob(:index).contents
end
end

g.reset # defaults to HEAD
g.reset_hard(Git::Commit)

g.branch('new_branch') # creates new or fetches existing
g.branch('new_branch').checkout
g.branch('new_branch').delete
g.branch('existing_branch').checkout
g.branch('master').contains?('existing_branch')

g.checkout('new_branch')
g.checkout(g.branch('new_branch'))

g.branch(name).merge(branch2)
g.branch(branch2).merge  # merges HEAD with branch2

g.branch(name).in_branch(message) { # add files }  # auto-commits
g.merge('new_branch')
g.merge('new_branch', 'merge commit message', no_ff: true)
g.merge('origin/remote_branch')
g.merge(g.branch('master'))
g.merge([branch1, branch2])

g.merge_base('branch1', 'branch2')

r = g.add_remote(name, uri)  # Git::Remote
r = g.add_remote(name, Git::Base)  # Git::Remote

g.remotes  # array of Git::Remotes
g.remote(name).fetch
g.remote(name).remove
g.remote(name).merge
g.remote(name).merge(branch)

g.fetch
g.fetch(g.remotes.first)
g.fetch('origin', {:ref => 'some/ref/head'} )

g.pull
g.pull(Git::Repo, Git::Branch) # fetch and a merge

g.add_tag('tag_name') # returns Git::Tag
g.add_tag('tag_name', 'object_reference')
g.add_tag('tag_name', 'object_reference', {:options => 'here'})
g.add_tag('tag_name', {:options => 'here'})

Options:
  :a | :annotate
  :d
  :f
  :m | :message
  :s

g.delete_tag('tag_name')

g.repack

g.push
g.push(g.remote('name'))

g.worktree('/tmp/new_worktree').add
g.worktree('/tmp/new_worktree', 'branch1').add
g.worktree('/tmp/new_worktree').remove
g.worktrees.prune

Some examples of more low-level index and tree operations

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g.with_temp_index do

  g.read_tree(tree3) # calls self.index.read_tree
  g.read_tree(tree1, :prefix => 'hi/')

  c = g.commit_tree('message')
  # or #
  t = g.write_tree
  c = g.commit_tree(t, :message => 'message', :parents => [sha1, sha2])

  g.branch('branch_name').update_ref(c)
  g.update_ref(branch, c)

  g.with_temp_working do # new blank working directory
    g.checkout
    g.checkout(another_index)
    g.commit # commits to temp_index
  end
end

g.set_index('/path/to/index')


g.with_index(path) do
  # calls set_index, then switches back after
end

g.with_working(dir) do
# calls set_working, then switches back after
end

g.with_temp_working(dir) do
  g.checkout_index(:prefix => dir, :path_limiter => path)
  # do file work
  g.commit # commits to index
end

References

[1] ruby-git/ruby-git: Ruby/Git is a Ruby library that can be used to create, read and manipulate Git repositories by wrapping system calls to the git binary. - https://github.com/ruby-git/ruby-git

[2] git | RubyGems.org | your community gem host - https://rubygems.org/gems/git/