Canonicalize CIDR: Difference between revisions

=={{header|Phix}}==

<lang Phix>function canonicalize_cidr(string cidr)

cidr = substitute(cidr,"."," ") -- (else %d eats 0.0 etc)

if not find('/',cidr) then cidr &= "/32" end if

sequence res = scanf(cidr,"%d %d %d %d/%d")

if length(res)=1 then

integer {a,b,c,d,m} = res[1]

if a>=0 and a<=255

and b>=0 and b<=255

and c>=0 and c<=255

and d>=0 and d<=255

and m>=1 and m<=32 then

atom mask = power(2,32-m)-1,

addr = bytes_to_int({d,c,b,a})

addr -= and_bits(addr,mask)

{d,c,b,a} = int_to_bytes(addr)

return sprintf("%d.%d.%d.%d/%d",{a,b,c,d,m})

end if

end if

return "???"

end function

constant tests = {"87.70.141.1/22",

"36.18.154.103/12",

"62.62.197.11/29",

"67.137.119.181/4",

"161.214.74.21/24",

"184.232.176.184/18"}

for i=1 to length(tests) do

string ti = tests[i]

printf(1,"%-18s -> %s\n",{ti,canonicalize_cidr(ti)})

end for</lang>

{{out}}

<pre>

87.70.141.1/22 -> 87.70.140.0/22

36.18.154.103/12 -> 36.16.0.0/12

62.62.197.11/29 -> 62.62.197.8/29

67.137.119.181/4 -> 64.0.0.0/4

161.214.74.21/24 -> 161.214.74.0/24

184.232.176.184/18 -> 184.232.128.0/18

</pre>