How to break from the scanner.scan() for-loop?

Question

When I use "bufio" package, the standard code is just like:

input := bufio.NewScanner(os.Stdin)
for input.Scan() {
    // xxxxx
}

When I run the program, the for-loop can't stop whatever I input. I have tried newline, space, ctrl-d, ctrl-z. According to the document, a blank newline should be able to stop the program.

The program is running under Windows 7 CMD environment, or mingw-bash.

Thanks.

the scan() stops either by reaching the end of the input or an error — simon_xia, Apr 11 '16 at 13:10
Agree with @icza it's a duplicate. By the way just curious according to what document it is supposed to stop for a blank newline? — Alexander Trakhimenok, Apr 11 '16 at 13:43
@AlexanderTrakhimenok I misunderstand the document. I've got the answer from the duplicate question. Thanks. — Hewei Liu, Apr 12 '16 at 06:03

score 3 · Accepted Answer · answered Apr 11 '16 at 14:47

3

You may input some specific string as a signal to stop the loop. In the below example, whenever "quit" is entered, the loop breaks.

package main

import (
    "bufio"
    "os"
)

func main() {
    input := bufio.NewScanner(os.Stdin)
    for input.Scan() {
        indata := input.Text()
        if indata == "quit" {
            break
        }
    }
}

answered Apr 11 '16 at 14:47

Nipun Talukdar

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1

Thanks for the answer. – Hewei Liu Apr 12 '16 at 06:00
You can simulate `EOF` in terminal. On **Linux** is `CTRL + D`, on **Windows** `CTRL + Z`: [source](https://stackoverflow.com/questions/1118957/c-how-to-simulate-an-eof) – rgb Aug 19 '19 at 18:22

How to break from the scanner.scan() for-loop?

1 Answers1