on *:text:!ping:#: {
  if ($eval($+(%,ping-,$nick),2) == $null) {
    .ctcp $nick ping
    set %ping- $+ $nick $uptime(system)
  }
}

on *:ctcpreply:ping*: {
  if ($eval($+(%,ping-,$nick),2) != $null) {
    var %pingtime = $round($calc(($uptime(system) - $eval($+(%,ping-,$nick),2)) / 1000),3)
    .notice $nick PING response: %pingtime seconds.
    unset %ping- $+ $nick
    halt
  }
}