Find the first commit of all committers in a git log file

gitlog.rb

require 'date'

class Commit
  attr_accessor :sha_id, :author, :date, :comment
end


commits = Hash.new
commits_number = Hash.new { |k,v| k[v] = 0 }

comment = nil
current_commit = nil
File.open("/tmp/gitlog") do |file|
  file.each_line do |line| 
    # Example of SHA-1 id
    # 27517033c286c78f3d4ed9d9b15b3ad834e1b6d2
    if line =~ /^commit ([a-f0-9]{40})$/
      if current_commit != nil
        current_commit.comment = comment.strip
        commits[current_commit.author] = current_commit
        commits_number[current_commit.author] += 1
      end
      comment = nil
      current_commit = Commit.new
      current_commit.sha_id = $1
    elsif line =~ /^Author: (.*)$/
      current_commit.author = $1
    elsif line =~ /^Date:   (.*)$/
      current_commit.date = Date.parse($1)
    else 
      if comment != nil
        comment += line
      else
        comment = line
      end
    end
  end
end

Hash[commits.sort_by { |k,v| v.date }].each_pair do |k,v|
  puts "#{k}\t#{v.date}\t#{commits_number[k]}\n#{v.comment}"
  puts "-" * 50
end