One of my favorite powershell commands when cleaning up:

$RootFolder = 'C:\tfs'
Get-ChildItem $RootFolder bin -Recurse | Remove-Item -Recurse
Get-ChildItem $RootFolder obj -Recurse | Remove-Item -Recurse

Last couple of weeks I have been generating a lot of files (and restricting their ACLs) and today I decided to remove all those files. The problem is that my user account did not have permissions on those files. Here is a small script that will first take ownership of the file, then grants FullControl permissions, and finally removes the file

function RemoveFile
{
	param($FileName)
	
	&takeown /F $FileName
	
	$User = [System.Security.Principal.WindowsIdentity]::GetCurrent().User
	
	$Acl = Get-Acl $FileName
	$Acl.SetOwner($User)
	$AccessRule = New-Object System.Security.AccessControl.FileSystemAccessRule($User, "FullControl", "Allow")
	$Acl.SetAccessRule($AccessRule)
	Set-Acl $FileName $Acl

	Remove-Item $FileName
}

Get-ChildItem *.txt -R | % { RemoveFile $_.FullName; }

Edit on 2011-10-19

Resetting the permissions with icacls c:\output /reset /t and then calling Remove-Item c:\output -R does the trick.

function RemoveFiles
{
 param($Directory)
 icacls $Directory /reset /t
 Remove-Item $Directory -R
}

RemoveFiles c:\output;

Earlier this week i tried to run a command on a remote computer but it did not seem to work:

$name = 'tim';
$computer = 'localhost';
Invoke-Command -ComputerName $computer -ScriptBlock { Write-Host "Hello $name" }

Because powershell serialises the { Write-Host “Hello $name” } as a string this ends up at the remote computer as { Write-Host “Hello $null” }. In order to send our ‘dynamic’ command string over the wire we have to make sure it is serialised correctly:

$scriptBlock = $executioncontext.InvokeCommand.NewScriptBlock("Write-Host `"Hello $name`"");
Invoke-Command -ComputerName $computer -ScriptBlock $scriptBlock;

Sometimes you run into a situations where a given task spawns a separate thread and completes it’s work on that separate thread. Eg: sending a bit XMLA to SQL Server Analysis Services with Microsoft.AnalysisServices.Deployment.exe and then waiting for the processing to be completed. Anyway, here is a simple function that will wait untill a given file exists:

function WaitForFile($File) {
 while(!(Test-Path $File)) {
  Start-Sleep -s 10;
 }
}

A while ago i wrote a small script to take care of deployment. Configuring the source folders went as following:

param(
	$BaseDir = (Get-Location).Path,
	$WebDir = (Resolve-Path "$BaseDir\web"),
	$DatabaseDir = (Resolve-Path "$BaseDir\database")
)

The problem with this code is that it only works when your current working directory is set to the location of this script. An administrator (or build system) invokes the script as following:

PS C:\Users\Admin>& 'D:\Deployments\20110124\Deploy.ps1';

Because we don’t want to annoy the consumer of our script with the burden of making sure he is in the correct directory we modified our code as following:

param(
	$BaseDir = (Split-Path $MyInvocation.MyCommand.Definition),
	$WebDir = (Resolve-Path "$BaseDir\web"),
	$DatabaseDir = (Resolve-Path "$BaseDir\database")
)

A quick win