学步园

二进制文件的内容：

Offset      0  1  2  3  4  5  6  7   8  9  A  B  C  D  E  F

00000000   12 31 23 12 31 22 31 23  12 31 22 22 22 22 22 22    1# 1"1# 1""""""
00000010   22 22 22 12 23 12 23 00  00 00 00 00 00 00 00 00   """ # #         
00000020   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000030   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000040   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000050   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000060   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000070   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000080   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
00000090   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
000000A0   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
000000B0   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
000000C0   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   
000000D0   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00                   

代码：

package main

import (
	"bytes"
	"fmt"
	"io"
	"os"
)

func main() {
	file, err := os.OpenFile("test", os.O_RDONLY, os.ModePerm)
	if err != nil {
		defer file.Close()
		os.Exit(0)
	}
	file.Seek(8, 0)
	fmt.Println("Success Open File")
	var buffer bytes.Buffer
	io.CopyN(&buffer, file, 8)
	_bytes := buffer.Bytes()
	var magic []byte = []byte{0x12, 0x31, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22}
	for _, byte := range _bytes {
		fmt.Printf("%02X ", byte)
	}
	fmt.Println()
	if bytes.Compare(magic, _bytes) == 0 {
		fmt.Println("Equal")
	}
}

结果：

	Success Open File
	12 31 22 22 22 22 22 22 
	Equal