验证scanf函数输入 [英] Validate input of scanf

问题描述

我需要阅读时间：在这个确切的格式分钟。我使用的：

I need to read hours:minutes in this exact format. I use:

    int hours, minutes;

    if (scanf("%d:%d", &hours, &minutes)!= 2)
    {
        printf("Wrong input.\n");
        return 1;
    }
else if (minutes>60 || minutes<0 || hours<0)
    {
        printf("Wrong input.\n");
        return 1;
    }

    time = hours*60 + minutes;

    /*read another time interval */
     if (scanf("%d:%d", &hours, &minutes)!= 2)
    {
        printf("Wrong input 2.\n");
        return 1;
    }
else if (minutes>60 || minutes<0 || hours<0)
    {
        printf("Wrong input 2.\n");
        return 1;
    }
   ...

工作正常，但我需要得到输入错误还的情况下，有人进入如5：38abc

works fine, but I need to get "wrong input" also in situations that someone enters e.g. 5:38abc

推荐答案

运营商加入格式字符串相匹配的新行：

Add an operator to the format string to match the newline:

int hours, minutes;
char str[2];

if (scanf("%d:%d%1[\n]", &hours, &minutes, str)!= 3)

％[\\ N] 匹配换行字符，字段宽度 1 使其停止正好1日后匹配性格。

%[\n] matches newline characters, and the field width 1 makes it stop matching after exactly 1 character.

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