glm_cidr

This is a simple library to assist with answering these basic questions:

• Is a given ip address in a given subnet?
• What is the next usable address in a given subnet, after a given address?
• How many usable addresses are in a given subnet?

I’m sure there are other interesting questions related to cidr.

Feel free to fork and/or submit PR’s for additional functionality.

gleam add glm_cidr
use subnet <- result.try(cidr.subnet_from_string("10.0.0.0/24"))
use metadata <- result.try(cidr.metadata(subnet))

// returns metadata like this:
//
// -> cidr.SubnetMetadata(
//      network: cidr.Ipv4(10, 0, 0, 0),
//      broadcast: cidr.Ipv4(10, 0, 0, 255),
//      first_host: cidr.Ipv4(10, 0, 0, 1),
//      last_host: cidr.Ipv4(10, 0, 0, 254),
//      usable_hosts: 254,
//      prefix: 24,
//      hex_netmask: "0xFFFFFF00",
//    ),

use next <- result.try(cidr.next_usable(subnet, cidr.Ipv4(10,0,0,0)))

// returns the next usable ip address:
//
// -> cidr.Ipv4(10, 0, 0, 1)

See tests and docs for further details on how to use.

Documentation can be found at https://hexdocs.pm/glm_cidr.

Development

make