文件就是字序列.系统中所有的输入输出都是通过一组称为Unix I/O的系统函数调用读写文件来实现的.
The file is a sequence of bytes. All the input and output of system calls system function know as Unix I/O.
文件的概念简单精致但是非常强大,因为它向应用程序提供了一个统一的试图,来看待系统中可能含有的所有各式各样的I/O设备.同一个程序可以在使用不同磁盘技术的不同系统上运行.
The file notion is simple and elegant but it powerful, because it provides application a uniform view of all of the varied I/O devices that might be contained in the system. Same program can run on different systems that use different disk technologies.
