Mine

on $*:TEXT:/^[!@]whois?(on)?$/Si:#: {
  if ( $nick isop $chan ) || ( $nick ishop $chan ) {
    set %whois [ $+ [ $chan ] ] on
    $iif(@ isin $1,msg $chan,notice $nick) 2Whois is now 7ON 2for7 $chan $+ .
  }
}
on $*:TEXT:/^[!@](whois)?off/Si:#: {
  if ( $nick isop $chan ) || ( $nick ishop $chan ) {
    set %whois [ $+ [ $chan ] ] off
    $iif(@ isin $1,msg $chan,notice $nick) 2Whois is now 7OFF 2for7 $chan $+ .
  }
}
ON *:JOIN:#: {
  if ( %whois [ $+ [ $chan ] ] == on ) { 
    if ($nick == $me) { halt }
    set %nick $nick
    set %whoischan $chan
    whois $nick
  }
  elseif   (%whois [ $+ [ $chan ] ] == off) { halt }
}
raw 319:*:{
  if (%whoischan) {
    msg %whoischan 7 %nick 2is on 7 $gettok($3-,0,32) 2Channels: 5 $3-
    unset %whoischan
  }
}