Go中写入临时文件后如何读取数据？

import (
    "bufio"
    "fmt"
    "io/ioutil"
    "log"
    "os"
    "path/filepath"
)

func main() {
    tmpFile, err := ioutil.TempFile("", fmt.Sprintf("%s-", filepath.Base(os.Args[0])))
    if err != nil {
        log.Fatal("Could not create temporary file", err)
    }
    defer tmpFile.Close()

    fmt.Println("Created temp file:", tmpFile.Name())

    fmt.Println("Writing some data to the temp file")
    if _, err := tmpFile.WriteString("test data"); err != nil {
        log.Fatal("Unable to write to temporary file", err)
    } else {
        fmt.Println("Data should have been written")
    }

    fmt.Println("Trying to read the temp file now")

    // Seek the pointer to the beginning
    tmpFile.Seek(0, 0)
    s := bufio.NewScanner(tmpFile)
    for s.Scan() {
        fmt.Println(s.Text())
    }
    if err := s.Err(); err != nil {
        log.Fatal("error reading temp file", err)
    }
}