avg.c

#include <stdio.h>

int main()
{
    int s,n;
    scanf("%d,%d", &s, &n);
    float v = s / n;
    printf("v=%.2f \n", v);
    return 0;
}

input.c

#include <stdio.h>

int main()
{
    int flag = 1;
    int i;
    int count;
    int sum = 0;
    while(flag) {
        scanf("%d", &i);
        if(0 == i) break;
        count++;
        sum += i;
    }
    printf("%d,%d\n", sum, count);
    return 0;
}

执行

#将input.out的输出流当做avg.out的输入流
[root@VM_0_8_centos les2]# ./input.out | ./avg.out 
10
5
2
7
0
v=6.00 
[root@VM_0_8_centos les2]#