write error: Bad file descriptor

int    pip[2];
pipe(pip);
fork();
/* parent process */
/* Close Read end of the pipe */
   close(pip[0]);

/* child process */
/* Close Write end of the pipe */
   close(pip[1]);


strace结果显示错把标准输出关掉了：
pipe([1, 11]) 
close(1)                                = 0
close(11)                               = 0