code:

---

Function MOAN($a, $n, $m)
dim $i,$s,$,$!,$z

for each $! in split($a+"."+$n+"."+$m,".")
  $=256
  do $=$/2 
   if 0<=0+$!-$
    $z=$z+"1"
    $!=-$+$!
   else $z=$z+"0"
   endif
  until 1=$
 next
  $i=left($z,32)
  $s=substr($z,33,32)

 if 2<len($m)
  $m=instr(right($z,32),0)-1
 endif
select

case 0=$m
for $=instrrev($s,1) to 31
  if moan($a,$n,$)
   $m=$m+" /"+$
  endif
 next
 $=substr($m,2)

case 0=$n
 $s=0
 for $!=1 to $m
  if 2>$s $s=256 $n=$n+$+"." $=0 endif
   $s=$s/2
   if 1=substr($i,$!,1)
    $=$+$s
   endif
 next
 $=iif($m>30,"",substr($n+$,3))

case 0=$a
$!=0,128,192,224,240,248,252,254,255
$=$!
$n=split($n,".")
for $s=0 to 3
  $i=-8*$s+$m
  $i=iif($i>8,8,$i)
 $[$s]=255+$n[$s]-iif($i,$![$i],0)
next
for $s=$n[0] to $[0]
 for $!=$n[1] to $[1]
  for $m=$n[2] to $[2]
   for $i=1+$n[3] to $[3]-1
	 $a=$a+" "+$s+"."+$!+"."+$m+"."+$i
   next
  next
 next
next
$=substr($a,2)

case 1
 $=iif(left($i,$m)=left($s,$m) & $i=>$s ,1,0) ;and instr(right($i,32-$m),0),1,0) ; x.x.x.255 proper ip?
endselect
$moan=iif(instr($," "),split($),$)

EndFunction

---

this comes to 807.
added one stroke to remove a problem with special subnet-masks.
it probably still has one...
at least I feel like it does