/*

Simple subnet calculator
By Casey Halverson
wwww.maokhian.com
Feel free to do what you please with this piece of code!
  
*/

a=arg(1)
ip=word(a,1)
subnet=word(a,2)

if a="" then do;say "subnet.rexx [ip] [subnet]";exit;end

/* convert octets into spaced out instead of .'ed out */

ip=translate(ip," ",".")
subnet=translate(subnet," ",".")

/* convert each decimal octet into a hex number then into a binary number */

ip.1=x2b(d2x(word(ip,1)))
ip.2=x2b(d2x(word(ip,2)))
ip.3=x2b(d2x(word(ip,3)))
ip.4=x2b(d2x(word(ip,4)))

sub.1=x2b(d2x(word(subnet,1)))
sub.2=x2b(d2x(word(subnet,2)))
sub.3=x2b(d2x(word(subnet,3)))
sub.4=x2b(d2x(word(subnet,4)))

/* Combined the binary sections into one big super binary number (32bits) */

do i=1 to 4
if length(sub.i)=1 then sub.i="0000000"||sub.i
if length(sub.i)=2 then sub.i="000000"||sub.i
if length(sub.i)=3 then sub.i="00000"||sub.i
if length(sub.i)=4 then sub.i="0000"||sub.i
if length(sub.i)=5 then sub.i="000"||sub.i
if length(sub.i)=6 then sub.i="00"||sub.i
if length(sub.i)=7 then sub.i="0"||sub.i
end

do i=1 to 4
if length(ip.i)=1 then ip.i="0000000"||ip.i
if length(ip.i)=2 then ip.i="000000"||ip.i
if length(ip.i)=3 then ip.i="00000"||ip.i
if length(ip.i)=4 then ip.i="0000"||ip.i
if length(ip.i)=5 then ip.i="000"||ip.i
if length(ip.i)=6 then ip.i="00"||ip.i
if length(ip.i)=7 then ip.i="0"||ip.i
end


superip=ip.1||ip.2||ip.3||ip.4
supersub=sub.1||sub.2||sub.3||sub.4
network=bitand(superip,supersub)
net.1=substr(network,1,8)
net.2=substr(network,9,8)
net.3=substr(network,17,8)
net.4=substr(network,25,8)
say "IP Address         : "ip
net.1=b2x(net.1)
net.2=b2x(net.2)
net.3=b2x(net.3)
net.4=b2x(net.4)
say "Network Address : "x2d(net.1)"."x2d(net.2)"."x2d(net.3)"."x2d(net.4)