小问题背后的故事-64位系统的system32重定向

laiwatch

在这个帖子http://club.excelhome.net/thread-1517617-1-2.html 提到一个非常有趣的问题
shell 居然无法打开system32下的的截图程序, snippingtool.exe
还有这等事, 赶紧试试,.........................................额,真的打开不开
这是神马情况, 这等这么奇葩的事, 反复试了一下,还是不行

1. C:\Windows\Sysnative\SnippingTool.exe

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使用CMD/Powershell,都可以直接打开, 为什么shell就不行
打开snipp的属性, 居然发现奇怪的东东, snipp的位置居然不是指向system32

1. C:\Windows\WinSxS\amd64_microsoft-windows-snippingtool-app_31bf3856ad364e35_6.3.9600.17415_none_8acefd165d6066de\SnippingTool.exe

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这是.............????
直接shell, 还是不行, 使用cmd打开, 直接出错
又试了在shell 通过cmd 和 Powershell,间接打开, 还是没用
赶紧开虚拟机,搞起, 服了................., 虚拟机为Windows7 x86(主机Windows8.1, x64)
在虚拟机中, shell 直接就打开了, 看了一下文件对应的位置, 指向system32, 没问题
这不是妥妥歧视x64么...............
老规矩, StackOverflow翻一下有无类似的问题, 尽管有人提到类似的问题, 但是没人解答.......拿来主义是不行了
终于还是要去翻Microsoft docs, 天书
终于找到问题的症结所在了
https://docs.microsoft.com/en-us/windows/win32/winprog64/file-system-redirector?redirectedfrom=MSDN

1. <b>The %windir%\System32 directory is reserved for 64-bit applications on 64-bit Windows</b>. Most DLL file names were not changed when 64-bit versions of the DLLs were created, so 32-bit versions of the DLLs are stored in a different directory. WOW64 hides this difference by using a file system redirector.

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简单的说就是: system32目录是为64位专门准备的, 32位的去其他地方待着额...........为什么还是叫system32呢?而不是system64呢?
下面揭晓答案...........

laiwatch

在这里 https://www.samlogic.net/articles/32-64-bit-windows-folder-x86-syswow64.htm详细提到了Windows x64 下的system32/SysWOW64, Program Files/Program Files(86) 之间的关系

Folder name	Folder path	Description
System32	C:\Windows\System32	Windows System folder (system directory) for 64-bit files
SysWOW64	C:\Windows\SysWOW64	Windows System folder (system directory) for 32-bit files
Program Files	C:\Program Files	Folder for 64-bit program files
Program Files (x86)	C:\Program Files (x86)	Folder for 32-bit program files

换言之就是: The 'System32' folder is for 64-bit files and the 'SysWOW64' folder is for 32-bit files
微软怎么起名字这么鬼的
https://www.samlogic.net/articles/sysnative-folder-64-bit-windows.htm

具体就是: As explained above, accessing the 64-bit System32 folder from a 32-bit application by simply inserting "\System32" in the folder path is not possible.
直接访问 system32下的文件是不可能, 为此微软搞了重定向(Redirect)来实现
出现了一个作为中转的虚拟文件夹: C:\Windows\Sysnative(无法直接用资源管理器访问)

也就是之前的: C:\Windows\Sysnative\SnippingTool.exe改成: C:\Windows\Sysnative\SnippingTool.exe, 就能通过shell打开这个进程了
继续翻, 在这里又发现了好东西
https://docs.microsoft.com/en-us/windows/win32/api/wow64apiset/nf-wow64apiset-wow64revertwow64fsredirection

1. Option Explicit
   
2. Private Declare Function LoadLibrary Lib "kernel32.dll" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
   
3. Private Declare Function FreeLibrary Lib "kernel32.dll" (ByVal hLibModule As Long) As Long
   
4. Private Declare Function GetProcAddress Lib "kernel32.dll" (ByVal hModule As Long, ByVal lpProcName As String) As Long
   
5. Private Declare Function Wow64DisableWow64FsRedirection Lib "Kernel32" (ByRef oldvalue As Long) As Boolean
   
6. Private Declare Function Wow64RevertWow64FsRedirection Lib "Kernel32" (ByVal oldvalue As Long) As Boolean
   
7. 
   
8. 'https://www.samlogic.net/articles/sysnative-folder-64-bit-windows.html
   
9. 'https://docs.microsoft.com/en-us/windows/win32/api/wow64apiset/nf-wow64apiset-wow64revertwow64fsredirection
   
10. 'https://docs.microsoft.com/en-us/windows/win32/winprog64/file-system-redirector?redirectedfrom=MSDN
    
11. 'http://blog.sina.com.cn/s/blog_792da39c01013bzh.html
    
12. 'https://www.cnblogs.com/lhglihuagang/p/3930874.html
    
13. 
    
14. Private Function IsSupport(ByVal strDLL As String, strFunctionName As String) As Boolean
    
15.     Dim hMod As Long, lPA As Long
    
16.     hMod = LoadLibrary(strDLL)
    
17.     If hMod Then
    
18.         lPA = GetProcAddress(hMod, strFunctionName)
    
19.         FreeLibrary hMod
    
20.         If lPA Then
    
21.             IsSupport = True
    
22.         End If
    
23.     End If
    
24. End Function
    
25. 
    
26. Sub OpenSnipp()
    
27.     If IsSupport("Kernel32", "Wow64DisableWow64FsRedirection") And IsSupport("Kernel32", "Wow64RevertWow64FsRedirection") Then
    
28.     Else
    
29.         Exit Sub
    
30.     End If
    
31.     Dim fsRedirect As Long
    
32.     fsRedirect = Wow64DisableWow64FsRedirection(fsRedirect)
    
33.     If fsRedirect Then
    
34.         Shell "c:\windows\system32\SnippingTool.exe", vbNormalFocus
    
35.         Wow64RevertWow64FsRedirection fsRedirect
    
36.         Exit Sub
    
37.     End If
    
38.     Shell "c:\windows\system32\SnippingTool.exe"
    
39. End Sub
    

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终于从翻到好东西了
更多的细节,大家可以参考链接的内容
http://blog.sina.com.cn/s/blog_792da39c01013bzh.html
https://www.cnblogs.com/lhglihuagang/p/3930874.html

zpy2

https://zhidao.baidu.com/question/327578317.html
syswow64?

zpy2

laiwatch 发表于 2020-1-12 16:03
在这里 https://www.samlogic.net/articles/32-64-bit-windows-folder-x86-syswow64.htm详细提到了Windows  ...

  
But if a 32-bit application really needs access to the 64-bit System32 folder in a 64-bit Windows; is it possible? The answer is yes, it is possible, and in this article we will show you how this can be done.

从这句话看，如果是 64位 的 office应该不会重定向了，上面的问题也可以通过安装64位office解决的

laiwatch

zpy2 发表于 2020-1-12 19:40
But if a 32-bit application really needs access to the 64-bit System32 folder in a 64-bit Wind ...

是的, 虚拟机 win8.1 x64 , office 2016 x64, shell +snip可以直接打开