在golang中，我如何在一段时间后不按任何键即可获得输入

package main

import (
    "fmt"
    "os"
    "time"
)

func main() {
    var input string

    go func() {
        fmt.Print("请输入：")
        _, _ = fmt.Scanln(&input)
    }()

    select {
    case <-time.After(5 * time.Second):
        fmt.Println("时间到，没有输入")
    case <-time.After(10 * time.Second):
        fmt.Println("超时，没有输入")
    case <-time.After(15 * time.Second):
        fmt.Println("再次超时，没有输入")
    }

    fmt.Println("输入内容:", input)
}

package main

import (
    "fmt"
    "time"

    "github.com/nsf/termbox-go"
)

func main() {
    err := termbox.Init()
    if err != nil {
        panic(err)
    }
    defer termbox.Close()

    var input string
    timeout := time.After(5 * time.Second)
    finished := make(chan bool)

    go func() {
        for {
            switch ev := termbox.PollEvent(); ev.Type {
            case termbox.EventKey:
                input += string(ev.Ch)
            case termbox.EventError:
                panic(ev.Err)
            }
        }
    }()

loop:
    for {
        select {
        case <-timeout:
            break loop
        case <-finished:
            break loop
        }
    }

    fmt.Println("输入内容:", input)
}