nodejs file 模块

File System 文件系统模块

File I/O is provided by simple wrappers around standard POSIX functions. To use this module do require('fs'). All the methods have asynchronous and synchronous forms.
文件的I/O是由标准POSIX函数封装而成。需要使用require('fs')访问这个模块。所有的方法都提供了异步和同步两种方式。
The asynchronous form always take a completion callback as its last argument. The arguments passed to the completion callback depend on the method, but the first argument is always reserved for an exception. If the operation was completed successfully, then the first argument will be null or undefined.
异步形式下，方法的最后一个参数需要传入一个执行完成时的回调函数。传给回调函数的参数取决于具体的异步方法，但第一个参数总是保留给异常对象。如果操作成功，那么该异常对象就变为null或者undefined。

若不encoding,则data输出为二进制数据

 node file.js