未经许可复制文件

Question

I have a powershell script that copies some files for later use by a Python script. The copy operation is this:

ls $env:MINGW_32 -r -ea silentlycontinue -fo -inc "*.dll" | % { cp $_.fullname "build\lib.win32-2.7" }

Nothing particularly interesting or unusual. The interesting (frustrating) part is what happens later:

error: [Error 5] Access is denied: 'build\\bdist.win32\\4758ccaeay32.dll'

CPython in fact has logic in distutils that explicitly resets the file permissions after it copies the DLLs to avoid this exact issue. I have attempted to replicate this in powershell but have not been successful:

$location = ".\build";
#Search recursivly through location defined;
get-childitem -r $location | foreach{
     $tempLocation = $_.FullName;
     #Get ACL for tempLocation;
     $acl = get-acl $tempLocation;
     #Get SID of explicit ACL;
     $acl.Access | where{
          $_.isinherited -like $false} | foreach{
          #Foreach SID purge the SID from the ACL;
          $acl.purgeaccessrules($_.IdentityReference); 
          #Reapply ACL to file or folder without SID;
          Set-Acl -AclObject $acl -path $tempLocation;
     }
}

Are there any suggestions to reset or preferably avoid copying the file permissions in the first place so that the Python script does not fail?

Answer 1

Try a slightly different approach. Instead of rebuilding each file's ACLs build one ACL and apply it to all files. Also, I believe that your call to .PurgeAccessRules(<IdentityReference>) should instead be calls to .RemoveAccessRule(<AccessRule>)

$location = ".\build"

#Get ACLs for first file in the folder
$ACL = GCI $location -File | Select -First 1 | Get-Acl
#Remove all non-inherited access rules, piped to Out-Null to avoid 'True' spam as it removes rules
$ACL.Access | ?{!$_.IsInherited} | %{$ACL.RemoveAccessRule($_) | Out-Null}

#Search recursivly through location defined;
GCI -r $location | Set-Acl -AclObject $ACL

Aliases used (truncated results):

PS C:\Users\TMTech> Get-Alias GCI,?
CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Alias           GCI -> Get-ChildItem
Alias           % -> ForEach-Object
Alias           ? -> Where-Object