使用示例
## 使用示例
```int fd = 0;
char temp[30];
fd = FDI_fopen("test_file", "wb");
if (fd != 0){
printf("debug> open file for write OK\n");
memset(temp, 0, 30);
sprintf(temp,"Hello world! _%d",count);
FDI_fwrite(temp, 20, 1, fd);
FDI_fclose(fd);
} else {
printf("debug> open file for write error\n");
}
```