package main

import (
        "fmt"
        "hash/crc32"
        "strings"
        "io/ioutil"
)

// Hash - generates hash(crc32) for string
func Hash(s string) uint32 {
        crc32q := crc32.MakeTable(0xD5828281)
        return crc32.Checksum([]byte(s), crc32q)
}

func main() {
        // map to store generated data, used to detect collisions
        m := make(map[uint32]string)
        for {
                // use kernel UUIDv4 generator
                data, err := ioutil.ReadFile("/proc/sys/kernel/random/uuid")
                if err != nil {
                        continue
                }
                // convert output to string UUIDv4
                uuid := strings.TrimSpace(string(data))
                // make hash of string
                hash := Hash(uuid)
                // check if hash in map, collision
                if val, ok := m[hash]; ok {
                        if uuid != val {
                                fmt.Printf("Hash [%d] collision detected: [%s] = [%s] \n", hash, uuid, val)
                        }
                } else {
                        // add hash to map
                        m[hash] = uuid
                }
        }
}