package main
import (
  "fmt"
  "os"
  "io"
)
func main() {
  fileName := "C:\\Robert\\日志分析\\tools_go\\vdn_sqlInterface\\a.txt"
  file, err := os.OpenFile(fileName, os.O_RDWR, 0666)
  if err != nil {
    fmt.Println("Open file error!", err)
    return
  }
  defer file.Close()
  stat, err := file.Stat()
  if err != nil {
    panic(err)
  }
  var size = stat.Size()
  fmt.Println("file size=", size)
  // define read block size = 2
  buf := make([]byte, 2)
  for {
    length, err := file.Read(buf)
    if err != nil {
      if err == io.EOF {
        break
      } else {
        fmt.Println("Read file error!", err)
        return
      }
    }
    fmt.Println(length, string(buf))
  }
  fmt.Println("File read ok!")
}

file size= 23
2 AB
2 CD
2 EF
2 GH
2 I
2
H
2 EL
2 LO
2 G
2 OL
2 AN
1 GN
File read ok!

func main() {
 res := make([]int, 0)
 res = append(res, 1) //同函数内append前后地址不变
 for i, v := range res {
 println(i,v)
 }
}

func solve(res []int) {
 res = append(res, 1) //不在同一函数内append前后地址变
}
 
func main() {
 res := make([]int, 0)
 for i, v := range res {
 println(i,v)
 }
}

func solve(res []int) []int {
 return append(res, 1)
}
 
func main() {
 res := make([]int, 0)
 for i, v := range solve(res) {
 println(i,v)
 }
}