Encode a uint32 into a byte slice, write it to disk, and read it from disk.

encodeuint.go

package main

import (
	"encoding/binary"
	"io/ioutil"
	"log"
	"fmt"
)

const (
	max_uint8  uint8  = 255                  // 1 byte min
	max_uint16 uint16 = 65535                // 2 byte min
	max_uint32 uint32 = 4294967295           // 4 byte min
	max_uint64 uint64 = 18446744073709551615 // 8 byte min
)

func main() {
	fmt.Printf("Writing to disk, "); test32()
	if err := ioutil.WriteFile("test", v, 0666); err != nil {
		log.Println(err)
	}
	if b, err := ioutil.ReadFile("test"); err != nil {
		log.Println(err)
	} else {
		fmt.Println("Read from disk,", b)
	}
	
	test16()
	test32()
	test64()
	
}

func test16() {
	bs := make([]byte, 2)
	binary.LittleEndian.PutUint16(bs, max_uint16)
	fmt.Println(bs)
}

func decUint16(b []byte) uint16 {
	return uint16(b[0]) | uint16(b[1]) << 8	
}

func test32() {
	bs := make([]byte, 4)
	binary.LittleEndian.PutUint32(bs, max_uint32)
	fmt.Println(bs)
}

func test64() {
	bs := make([]byte, 8)
	binary.LittleEndian.PutUint64(bs, max_uint64)
	fmt.Println(bs)
}