Get revision history of a git branch

git-rev-history.rb

#!/usr/bin/env ruby

# Usage: git-rev-history.rb [branch]
# Output:
# branch@{0} 4be30be6eb844a40ca4af301cb8b2359a5afcd30
# … up to @{9}

#!/usr/bin/env ruby

def command(*args)
  stdout = nil
  IO.popen(*args) do |io|
    stdout = io.gets
  end
  raise RuntimeError unless $?.success?
  stdout
end

def git(*args)
  command(['git', *args])
end

def git_rev_parse(rev, params = {})
  args = ['rev-parse']
  args << '--abbrev-ref' if params[:abbrev_ref]
  args << rev
  git(*args).chomp
end

def current_branch
  begin
    git_rev_parse('HEAD', abbrev_ref: true)
  rescue RuntimeError
  end
end

def history_revision(branch, i)
  "#{branch}@{#{i}}"
end

def argv
  $<.argv
end

branch = (argv[0] or current_branch)
exit(1) unless branch
(0...10).each do |i|
  hist_rev = history_revision(branch, i)
  out = [hist_rev, git_rev_parse(hist_rev)]
  puts(out.join(' '))
end