fmt.Scanf不会占用字符串末尾的所有字符 [英] fmt.Scanf does not consume all the characters through the end of the string

问题描述

package main
import "fmt"

func main(){
    var i int
    fmt.Print("input integer: ")
    fmt.Scanf("%d", &i)

}

当我从终端运行这个小程序并输入为

when I run this small program from terminal and give input as

input integer: 3.ls

它还执行 ls 命令或当我输入

it also executes ls command or when i give input

input integer: 665.cd someDir

它执行 cd someDir .这是Scanf在go中的正常行为吗?这在C语言中不会发生.有人可以解释发生了什么事.

it executes cd someDir. Is this normal behavior with Scanf in go.This does not happen in C. Can someone explain what's happening.

推荐答案

您的 fmt.Scanf(％d"，& i)调用仅从输入中解析一个整数，它直到行尾才使用.

Your fmt.Scanf("%d", &i) call only parses an integer from the input, it does not consume input until the end of line.

如果输入 3.ls ，则将 3 解析为十进制数字，并使用.并将停止扫描.您的应用程序到此结束，因此其余部分( ls 和换行符)将由您的shell执行.

If you input 3.ls, then 3 is parsed as the decimal number, and . is consumed and will stop the scanning. Your app ends here, so the rest (ls and the newline) will be executed by your shell.

使用 bufio.Scanner 来阅读行，例如:

fmt.Print("input string: ")
scanner := bufio.NewScanner(os.Stdin)
if !scanner.Scan() {
    return // no input
}
var i int
fmt.Sscanf(scanner.Text(), "%d", &i)
fmt.Println("Entered:", i)

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