TONT 31753 为什么有两份『记事本』的程序文件？

原文链接：https://devblogs.microsoft.com/oldnewthing/20060328-17/?p=31753

You may have noticed that there’s a copy of Notepad in %windir%\notepad.exe and another in %windir%\system32\notepad.exe.Why two?

可能你会注意到在 %windir%\notepad.exe 和 %windir%\system32\notepad.exe 分别各有一份记事本的程序文件，为什么会这样呢？

Compatibility, of course.

当然是为了兼容性了。

Windows 3.0 put Notepad in the Windows directory. Windows NT put it in the System32 directory. Notepad is perhaps the most commonly hardcoded program in Windows. many Setup programs use it to view the Readme file, and you can use your imagination to come up with other places where a program or batch file or printed instructions will hard-code the path to Notepad. In order to be compatible with programs designed for Windows 95, there needs to be a copy of Notepad in the Windows directory. And in order to be compatible with programs designed for Windows NT, there also needs to be a copy in the System32 directory.

Windows 3.0 在 Windows 目录下放置记事本，Windows NT 则放在 System32 目录下面。记事本大概是被硬编码到程序里最多的 Windows 组件之一了，很多安装程序都调用它来展示 Readme 文件，可想而知还有多少程序、批处理文件或印刷出来的操作说明里有硬编码的记事本的路径。为了保持与为 Windows 95 设计的应用程序的兼容性，在 Windows 目录下需要有一份记事本程序的副本，同样，为了保持与为 Windows NT 设计的程序的兼容性，System32 目录下也有一份。

And now that Notepad exists in both places, new programs have a choice of Notepads, and since there is no clear winner, half of them will choose the one in the Windows directory and half will choose the one in the System32 directory, thereby ensuring the continued existence of two copies of Notepad for years to come.

如今记事本在两个位置都有一席之地，新编写的程序就可以自由选择了。鉴于没有哪一份是明显的赢家，选择 Windows 目录下那份和选择 System32 目录下的那份的程序大概是一半一半的几率，由此保持两份副本共存的做法还要一直持续下去。