簡單的C程序不打印輸出

Question

我有一個簡單的C程序

#include <stdio.h> 

int add(int, int); 
int add (int a, int b) { 
    return a+b; 
} 

int main(void) { 
    int a, b, c; 

    printf("Enter the 1st number "); 
    scanf("%d",&a); 
    printf("Enter the 2nd number "); 
    scanf("%d",&b); 
    c = add(a, b); 
    printf("The value is %d ", c); 
    return (0); 
} 

我編譯程序與cc main.c ，當我與./a.out
運行的程序，我沒有得到任何輸出在安慰。

Answer 1

出於性能原因，輸出被緩衝。更換

printf("The value is %d ", c); 

與

printf("The value is %d\n", c); 

或使用fflush(stdout);。

見Why does printf not flush after the call unless a newline is in the format string?