module System

  def add_env_var(variable, path)
    envfile = "/etc/profile.d/99generic.sh"
    foundvar = false
    arr = IO.readlines( envfile ) if File::exists?( envfile )
    length = arr.length - 1

    for i in 0..length
      if arr[i][variable] then
        line = arr[i].chomp.split( '=' )
        paths = line[1].split( ':' ) << path
        arr[i] = line[0] + "=" + paths.uniq.join( ':' ) + "\n"
        foundvar = true
        break
      end
    end

    if !foundvar then
      arr << "export #{variable}=#{path}"
    end

    aFile = File.new( envfile, "w" )
    aFile.syswrite( "#{arr.flatten}" )
  end
end