C编程:仅从fgets打印int [英] C programming: print only int from fgets

问题描述

查看此main:

int main(void)
{
    int i;
    int ch;
    char str[512];
    fgets(str, sizeof str, stdin);

    for (i = 0; i <= (strlen(str)); i++)
    {
        if (str[i] != '\0' && str[i] != '\n')
        {
            int num = atoi(&str[i]);
            printf("%d\n", num);
        }
    }

    return 0;
}

我希望与用户的数字保持一致，并获取所有没有任何spaces或tabs的数字​​.

I want to get line with numbers from user and get all the numbers without any spaces or tabs.

例如:

输入1 2 3. 但是在这种情况下，输出为:

The input 1 2 3. But in this case this the output:

1
2
2
3
3

那为什么我两次收到2和3?

So why i received 2 and 3 twice?

推荐答案

这是我的处理方式:

char line[256];
if (fgets(line, sizeof line, stdin) != NULL)
{
    const char *ptr = line;
    while (*ptr != '\0')
    {
        char *eptr = NULL;
        const long value = strtol(ptr, &eptr, 10);
        if (eptr != ptr)
            printf("%ld\n", value);
        else
            break;
        ptr = eptr;
    }
}

这使用 strtol() ，因此它还将处理负数；如果这是不正确的，您当然可以添加检查以将其过滤掉.我认为这比使用strtok()的任何方法都要好.

This uses strtol() so it will also handle negative numbers; if this is incorrect you can of course add checks to filter them out. I think this is way better than anything using strtok().

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