c - 无法在 c 中使用 fscanf 读取整数

Question

FILE *fin = fopen("figura.in", "r");
if(fscanf(fin, "%d %d %d %d", &int[0], &int[1], &int[2], &int[3]) == 1)     {
        printf("%d\t%d\t%d\t%d\n", int[0], int[1], int[2], int[3]);
    } else {
        printf("failed to read integer.\n");
    }

我无法读取整数。该文件没问题，它包含 4 个整数。怎么了？

Answer 1

您应该检查 fscanf 是否返回 4，即格式字符串中的输入数:

if(fscanf(fin, "%d %d %d %d", &arr[0], &arr[1], &arr[2], &arr[3]) == 4) 

来自man page :

return the number of input items successfully matched and assigned, which can be fewer than provided for, or even zero in the event of an early matching failure.