struct data {     u_short sin_port;     struct  in_addr sin_addr;     unsigned char id; };  struct data Data[141];  char *buf,*buf1, buf1 = (char *)malloc(10000); memset(buf1, 0, 10000);  for (i =0;i< 141;i++)  {         memcpy(buf1, &Data[i].id,20);         printf("buf11: %x
", buf1);         buf1+=20;         memcpy(buf1, &Data[i].sin_addr, 4);         buf1+=4;         memcpy(buf1, &Data[i].sin_port, 2);         buf1+=2;         size1 += 26;  }  buf1 -= size1;     write(fd2, buf1, size1+1); close(fd2); free(buf1); 

我发现这样写入的数据总是不对/？请教哪里有问题啊？一般都是先写入buffer,再写入文件？