Using "net.ParseIP" and "net.IPString" to convert between IP address representations | CUE

Jonathan Matthews

commented cue

This Commented CUE demonstrates how to use the built-in functions net.ParseIP and net.IPString to convert IPv4 and IPv6 addresses between their canonical string and list-of-bytes representations.

package example

import "net"

v4String: "198.51.100.14"
v6String: "2001:db8:85a3::8a2e:370:7334"

// Use net.ParseIP to convert IP addresses from strings to lists of bytes.
v4Bytes: net.ParseIP(v4String)
v6Bytes: net.ParseIP(v6String)

// Use net.IPString to convert IP addresses from lists of bytes to strings.
// Notice that we're assigning net.IPString's output to the same field names we
// started with, above. By performing this cross-check we confirm that
// net.IPString and net.ParseIP both act as the inverse function of the other.
v4String: net.IPString(v4Bytes)
v6String: net.IPString(v6Bytes)

$ cue eval
v4String: "198.51.100.14"
v6String: "2001:db8:85a3::8a2e:370:7334"
v4Bytes: [198, 51, 100, 14]
v6Bytes: [32, 1, 13, 184, 133, 163, 0, 0, 0, 0, 138, 46, 3, 112, 115, 52]

The net built-in package

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