如何结束控制台中的`scanner.Scan`循环以获取golang？

I have two (or potentially more) lines of input that I would like the program to take. eg.

1 2 3 4
5 6 7 8

According to the official doc, using

for scanner.Scan() {
}

will cause infinite lines to be scan until it reach EOF or error, are there other functions that will take two lines of input instead?

It's traditional to end user input from stdin with an empty (zero length) line. For example,

package main

import (
    "bufio"
    "fmt"
    "io"
    "os"
    "strings"
)

func main() {
    snr := bufio.NewScanner(os.Stdin)
    enter := "Enter a line of data:"
    for fmt.Println(enter); snr.Scan(); fmt.Println(enter) {
        line := snr.Text()
        if len(line) == 0 {
            break
        }
        fields := strings.Fields(line)
        fmt.Printf("Fields: %q
", fields)
    }
    if err := snr.Err(); err != nil {
        if err != io.EOF {
            fmt.Fprintln(os.Stderr, err)
        }
    }
}

Output:

$ go run data.go
Enter a line of data:
1 2 3 4
Fields: ["1" "2" "3" "4"]
Enter a line of data:
5 6 7 8
Fields: ["5" "6" "7" "8"]
Enter a line of data:

$

Ask the user to press "CTRL + D", that signals the EOF from the terminal, your above code should work without any change.

One way to do this is to verify if the scanner has reached the end of the file.

var s scanner.Scanner

   file, _ := os.Open("file.go") // return io.Reader

   s.Init(file) // needs io.Reader

   var character rune
   character = s.Scan()

   for character != scanner.EOF {
    // here your code
   }