Richard Siddaway's Blog

Hidden Files

The last post got me thinking about hidden files and file attributes and how we can manipulate them in PowerShell.  Lets start by creating a PowerShell script.

PS> "'hello world'" > test.ps1
PS> ./test.ps1

We can see the file in a directory listing

PS> Get-ChildItem test.ps1

    Directory: C:\scripts

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-a---        30/05/2009     13:57         32 test.ps1

We can view the file attributes

PS> Get-ItemProperty -Path test.ps1 -Name Attributes

PSPath       : Microsoft.PowerShell.Core\FileSystem::C:\scripts\test.ps1
PSParentPath : Microsoft.PowerShell.Core\FileSystem::C:\scripts
PSChildName  : test.ps1
PSDrive      : C
PSProvider   : Microsoft.PowerShell.Core\FileSystem
Attributes   : Archive

We can set the attributes so the file becomes hidden using the Fileattributes enumeration

PS> Set-ItemProperty -Path test.ps1 -Name Attributes -Value ([System.IO.FileAttributes]::Hidden)

as shown previously we have to use the force to get a listing

PS> Get-ChildItem test.ps1 -Force

    Directory: C:\scripts

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
---h-        30/05/2009     13:57         32 test.ps1

But we have over written the existing attributes – oops.  Need to recreate the file and try again.  This time we will add the attribute.

PS> Set-ItemProperty -Path test.ps1 -Name Attributes -Value ((Get-ItemProperty -Path test.ps1).Attributes -bxor [System.IO.FileAttributes]::Hidden)

and we now see the existing attributes are preserved

PS> Get-ChildItem test.ps1 -Force

    Directory: C:\scripts

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-a-h-        30/05/2009     14:11         32 test.ps1

We can clear all the attributes or just rest to those we require

PS> Set-ItemProperty -Path test.ps1 -Name Attributes -Value ([System.IO.FileAttributes]::Normal) -Force
PS> Get-ChildItem test.ps1 -Force

    Directory: C:\scripts

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-----        30/05/2009     14:11         32 test.ps1

The full range of attributes can be seen

PS> [enum]::GetNames([System.IO.FileAttributes])
ReadOnly
Hidden
System
Directory
Archive
Device
Normal
Temporary
SparseFile
ReparsePoint
Compressed
Offline
NotContentIndexed
Encrypted

Normal rules still apply so we can’t compress an encrypted file

Read the complete post at http://richardsiddaway.spaces.live.com/Blog/cns!43CFA46A74CF3E96!2383.entry