Golang实现类似Scan或者Scanf功能

package main

import (
        _"errors"
        "fmt"
        "io"
        "os"
        "syscall"
        "time"
        "bytes"
        _"os/exec"
        "github.com/docker/docker/pkg/term"
)

func main() {
   Stdin()
}

func Stdin() {
        var in io.Reader


        in = os.NewFile(uintptr(syscall.Stdin), "/dev/stdin")

        _,ok:= term.GetFdInfo(in)

        if ok {
                fmt.Println("Is terminal \n")
        }

        reader := bytes.NewBuffer(make([]byte, 10))

        for {
                data, _:= reader.ReadFrom(in) //很奇怪为什么一直阻塞在这里
                fmt.Printf("read from stdin %v \n", data)
                time.Sleep(2 * time.Second)
        }

}

func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error) {
	b.lastRead = opInvalid
	// If buffer is empty, reset to recover space.
	if b.off >= len(b.buf) {
		b.Truncate(0)
	}
	//因为没有读到标准输出的EOF，所以一直在读
	for {
		if free := cap(b.buf) - len(b.buf); free < MinRead {
			// not enough space at end
			newBuf := b.buf
			if b.off+free < MinRead {
				// not enough space using beginning of buffer;
				// double buffer capacity
				newBuf = makeSlice(2*cap(b.buf) + MinRead)
			}
			copy(newBuf, b.buf[b.off:])
			b.buf = newBuf[:len(b.buf)-b.off]
			b.off = 0
		}
		m, e := r.Read(b.buf[len(b.buf):cap(b.buf)])
		b.buf = b.buf[0 : len(b.buf)+m]
		n += int64(m)
		if e == io.EOF {
			break
		}
		if e != nil {
			return n, e
		}
	}
	return n, nil // err is EOF, so return nil explicitly
}