爲什麼id變量1的輸出？

Question

#include <stdio.h> 
#include <unistd.h> 

int main() 
{ 
    int id; 
    printf("here comes the date.\n"); 
    if (id = fork() == 0) { 
     printf(「%d」, id); 
     printf ("PID is %d and ID is %d\n", getpid(),id); 
     execl ("/bin/date", "date", 0); 
    } 
    printf ("that was the date.\n"); 
} 

OUTPUT：

here comes the date. 
that was the date. 
PID is 1414 and ID is 1 
Tue Feb 10 14:03:02 PST 2015 

Answer 1

由於要設置它等於fork() == 0其結果是邏輯測試。

分叉將在分叉線程內成功（返回零）。外螺紋將具有PID。