Directory.GetFiles查找不存在的文件 [英] Directory.GetFiles finds nonexisting files

问题描述

我只是偶然发现 System.IO.Directory 中 GetFiles 方法的未记录行为.

I just stumbled upon an undocumented behavior of the GetFiles methods in System.IO.Directory.

只要传递给该方法的 searchPattern 参数包含保留的Windows设备名称，例如"nul.*" 或"aux.bmp" ，该方法返回一个包含不存在文件名的数组，例如 C:\ Users \ ft1 \ nul 或 D:\ aux 等.

Whenever the searchPattern parameter passed to the method contains a reserved Windows device name, such as "nul.*" or "aux.bmp", the method returns an array containing the name of a nonexisting file, like C:\Users\ft1\nul or D:\aux, etc.

我想知道那些设备名称在上下文中是否具有特殊含义，例如".或".."，或者这仅仅是一种错误.无论如何，那似乎仍然很奇怪.例如，此代码段在C#中:

I wonder if those device names have a special meaning it that context, like "." or "..", or if this is just a sort of bug. Anyway, that still seems pretty weird. For example, this code snippet in C#:

string[] fileNames = Directory.GetFiles(@"C:\D:\..\..\...\", "con.txt");
foreach (string fileName in fileNames) Console.WriteLine(fileName);

打印

C:\D:\..\..\...\con

有任何线索吗?

推荐答案

这是已知的.这是关于命名的操作系统设计文件，路径和命名空间(Windows)

This is known. It is an operating system design regarding Naming Files, Paths, and Namespaces (Windows)

节选:

请勿将以下保留名称用作文件名:CON，PRN，AUX，NUL，COM1，COM2，COM3，COM4，COM5，COM6，COM7，COM8，COM9，LPT1，LPT2，LPT3，LPT4，LPT5，LPT6，LPT7，LPT8和LPT9.也要避免在这些名称后面加上扩展名；例如，不建议使用NUL.txt.有关更多信息，请参见命名空间.

Do not use the following reserved names for the name of a file: CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9. Also avoid these names followed immediately by an extension; for example, NUL.txt is not recommended. For more information, see Namespaces.

这些基本上是文件名别名(命名空间)，因此它们始终全局存在(在每个文件夹中).如果您尝试枚举它们，则会将它们取回，因为它们确实存在.

These are basically filename aliases (namespaces), so they always exist globally (in every folder). If you attempt to enumerate them, you'll get them back because they do exist.

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