# File lib/unicorn/worker.rb, line 73
  def user(user, group = nil)
    # we do not protect the caller, checking Process.euid == 0 is
    # insufficient because modern systems have fine-grained
    # capabilities.  Let the caller handle any and all errors.
    uid = Etc.getpwnam(user).uid
    gid = Etc.getgrnam(group).gid if group
    Unicorn::Util.chown_logs(uid, gid)
    @tmp.chown(uid, gid) if @tmp
    if gid && Process.egid != gid
      Process.initgroups(user, gid)
      Process::GID.change_privilege(gid)
    end
    Process.euid != uid and Process::UID.change_privilege(uid)
    @switched = true
  end