Speaking of which... : Sample Code

PowerShell - Editing permissions on a file or folder

JohanS — Wed, 01 Oct 2008 15:52:49 GMT

I got the following question from a reader the other day:

I've been trying to figure out how to change permissions on a folder in PowerShell. I've looked at the Get-Acl and Set-Acl, but I can only use them to copy the settings from a pre-existing object. How do I manually configure permissions?

This is actually a quite common question, so I thought I'd write a quick post on the subject.

Get-Acl and Set-Acl

To quote the PowerShell documentation "Get-Acl gets the security descriptor for a resource, such as a file or registry key." while "Set-Acl changes the security descriptor of a specified resource, such as a file or a registry key." In other words; if you want Folder_A to have the exact same permissions as Folder_B, then you simply copy the Access Control List (ACL) of Folder_B and "paste" it onto Folder_A.

$Acl = Get-Acl "C:\Folder_B"
Set-Acl "C:\Folder_A" $Acl

So far, so good.

Changing the ACL

Okay, so you want to change the ACL. Here's some sample code for how to do that:

New-Item -type directory -path C:\MyFolder
$Acl = Get-Acl "C:\MyFolder"
$Ar = New-Object  system.security.accesscontrol.filesystemaccessrule("username","FullControl","Allow")
$Acl.SetAccessRule($Ar)
Set-Acl "C:\MyFolder" $Acl

So, first we create a new folder. We then copy the ACL of that folder. We then create a new AccessRule that gives "username" full control. We then add this AccessRule to the ACL, and finally we reapply the new, altered ACL to the folder.

If we wanted to we could also have used $Acl.RemoveAccessRule($Ar) or possibly $Acl.RemoveAccessRuleAll() as well.

/ Johan

PowerShell - Automatically organizing your mp3-collection

JohanS — Tue, 23 Sep 2008 14:53:23 GMT

Is your mp3-collection perfectly sorted? I know mine wasn't. I thought I'd address that while creating a pretty good demo-script to show some basic filtering, script structures, etc. Since I also wanted the script to extract the metadata from every file in my collection I had to use the Shell.Application Com-object as well. All in all I think it turned out pretty well.

NOTE:

This script is provided completely as is. It is not an official product in any way and I take no responsibility for any harm it may cause.

Please note that certain metadata editors that integrate directly into the Shell may cause some severe confusion in the metadata, so I'd recommend disabling them before trying. Off course I would also recommend making a backup copy of the music library before surrendering it to the mercy of PowerShell.

If you're new to PowerShell and haven't done so already I'd recommend looking at my earlier posts on the subject:
PowerShell - An introduction, Part I
PowerShell - An introduction, Part II

The script

Param([String] $Folder)
$INVALIDCHARS = [System.IO.Path]::GetInvalidPathChars() + "/", "\", "*", "?", ":"
$MUSICATTRIBS = "*.m4a", "*.m4b", "*.mp3", "*.mp4", "*.wma", "*.flc"
$PLAYLISTATTRIBS = "*.m3u", "*.zpl"
$ALLATTRIBS = $MUSICATTRIBS + $PLAYLISTATTRIBS
$PLAYLISTSFOLDER = "Playlists"
$objShell = New-Object -ComObject Shell.Application
$iTotalFiles = 0
$iCurrentFile = 0

function checkFolderName($FolderName)
{
	# Make sure the folder doesn't contain any invalid characters

	if(!$FolderName) { $FolderName = "Unknown" }
	$INVALIDCHARS | % {$FolderName = $FolderName.replace($_, "")}
	return $FolderName
}



function MoveFiles($startDir)
{
	Write-Host "Indexing playlists..."
	
	# Do a recursive DIR in the starting directory, include everything with the attributes of a playlist.
	# Filter the result by excluding everything that is a Container (folder)
	$dirResult = get-childitem -force -path $startDir -recurse -include $PLAYLISTATTRIBS | where{! $_.PSIsContainer}
	if($dirResult)
	{
		Write-Host "Moving playlists..."

		foreach($dirItem in $dirResult)
		{
			move-item $dirItem.FullName ($PLAYLISTSFOLDER + "\" + $dirItem.Name)
		}
	}
	Write-Host "Indexing music..."

	# Do a recursive DIR in the starting directory, include everything with the attributes of a music file.
	# Again we filter the result by excluding everything that is a Container.
	$dirResult = get-childitem -force -path $startDir -recurse -include $MUSICATTRIBS | where{! $_.PSIsContainer}
	
	# Make a note of how many hits we got, so we can show the progress to the client.
	$iTotalFiles = $dirResult.Count
	if($dirResult)
	{
		foreach($dirItem in $dirResult)
		{
			# Up the counter for how many files we've processed so that we can show progress
			$iCurrentFile +=1

			# Get the metadata for the file
			$fileData = getMP3MetaData($dirItem.FullName)
			
			# Find the path where we the song should be stored
			$ArtistPath = $fileData["Album Artist"]
			if (!$ArtistPath) { $ArtistPath = $fileData["Artists"] }
			if (!$ArtistPath) { $ArtistName = "Unknown" }

			# Make shure it's a valid path
			$ArtistPath = checkFolderName($ArtistPath)
			$AlbumPath = checkFolderName($fileData.Album)
			$ArtistPath = join-path $startDir $ArtistPath 
			$AlbumPath = join-path $ArtistPath $AlbumPath

			# Check if the file should be moved
			if($dirItem.DirectoryName -ne $AlbumPath)
			{
				if(!(test-path $ArtistPath)) # If the Artist folder doesn't exist
				{
					MKDIR $ArtistPath | out-null
				}
				if(!(test-path $AlbumPath)) # If the Album folder doesn't exist
				{
					MKDIR $AlbumPath | out-null
				}
				move-item $dirItem.FullName ($AlbumPath + "\" + $dirItem.Name)
			}

			# Show progress
			$percentage = ([int](($iCurrentFile / $iTotalFiles)*100))
			cls
			Write-Host "$percentage% ($iCurrentFile files of $iTotalFiles) complete"
		}
	}
}


function removeEmptyFolders($startDir)
{
	# Get all folders and subfolders
	$dirResult = Get-childitem $startDir -recurse | where{$_.PSIsContainer}
	if($dirResult)
	{
		foreach($dirItem in $dirResult)
		{
			# If the folder is empty (Doesn't contain any music or playlists) it should be deleted
			if(isfolderempty($dirItem.FullName))
			{
				# Check if the path is still valid, we may have deleted the folder already recursively.
				if(Test-Path $dirItem.FullName)
				{
					remove-item -path $dirItem.FullName -force -recurse
				}
			}
		}
	}
}

function removeOtherFiles($startDir)
{
	# Get all non-music files (except *.jpg-files) and remove them 
	$dirResult = Get-childitem $startDir -recurse -exclude ($ALLATTRIBS + "*.jpg") | where{! $_.PSIsContainer}
	if($dirResult)
	{
		foreach($dirItem in $dirResult)
		{
			if(Test-Path $dirItem.FullName)
			{
				# Make sure the file still exists, and hasn't been deleted already
				remove-item -path $dirItem.FullName -force
			}
		}
	}
}

function isFolderEmpty($folderPath)
{
	# Search for any remaining music items in the folder.
	if(Test-Path $folderPath)
	{
		$dirChildren = get-childitem -force -path $folderPath -recurse -include $ALLATTRIBS | where{! $_.PSIsContainer}
		if($dirChildren -ne $null)
		{
			return $false
		}
		else
		{
			return $true
		}
	}
	else
	{
		# No use trying to delete the folder if it doesn't exist
		return $false
	}
}

function getMP3MetaData($path)
{
	# Get the file name, and the folder it exists in
	$file = split-path $path -leaf
	$path = split-path $path
	$objFolder = $objShell.namespace($path)
	$objFile = $objFolder.parsename($file)
	$result = @{}
	0..266 | % {
		if ($objFolder.getDetailsOf($objFile, $_))
		{
			$result[$($objFolder.getDetailsOf($objFolder.items, $_))] = $objFolder.getDetailsOf($objFile, $_)
		}
	}
	return $result
}

# MAIN FUNCTION

# If no argument was passed, see if anything was piped to the function instead.
if (!$Folder)
{
	$input | % { $Folder = $_ }
}

# Check if the path is valid, if not reset it to ""
if ($Folder) { if (!(Test-Path -path $Folder)) { $Folder = "" }}

# Since no valid path was given, prompt the user for a proper path.
while (!$Folder)
{
	"Please enter the full path to the folder where you wish to rearrange your MP3's"
	$Folder = Read-Host
	if ($Folder) { if (!(Test-Path -path $Folder)) { $Folder = "" }}
}

# Make sure we have a folder to store the playlists in.
$PLAYLISTSFOLDER = join-path $Folder $PLAYLISTSFOLDER
if(!(test-path $PLAYLISTSFOLDER)) # If the Playlists folder doesn't exist
{
	MKDIR $PLAYLISTSFOLDER | out-null
}

# Now that everything is ready, begin rearranging the files.
MoveFiles($Folder)
removeEmptyFolders($Folder)
removeOtherFiles($Folder)

Running the script

So, how do you run this script?

It's quite easy. The first step would be to copy it into notepad save it with a .ps1 extension and open up PowerShell

Execution policy

If this is the first time you try to execute a script from PowerShell you will most likely have to change the execution policy for PowerShell. I'd recommend setting it to RemoteSigned. This (obviously) means that all remote scripts must be signed or PowerShell will refuse to execute them. To change the execution policy simply type:

Set-ExecutionPolicy RemoteSigned

That's it.

If you're uncertain what your execution policy setting is you simply type:

Get-ExecutionPolicy

Okay, having changed that we can now execute the script. If you saved the script in a folder that is in your system path you only need to type the filename of the .ps1 file. (The .ps1 is optional) So, if you saved it as RearrangeMP3s.ps1 you'd write RearrangeMP3s and press enter

Breakdown

Okay, so let's take a look at the separate parts of the script.

Initial variables and constants

First we declare the parameters we're going to use. In this case it's just one: $Folder.

After that we have some constants. You may want to change $MUSICATTRIBS or $PLAYLISTATTRIBS to include, or remove, extensions based on your needs. $PLAYLISTSFOLDER is a constant which indicates in which subfolder you wish to store your playlists.

Finally we have some variables. $objShell is used for file system operations, and rather than creating a new object all the time I'd rather have a global one. $iTotalFiles and $iCurrentFile are two integers used to create a progress indicator.

Functions

After the initial variables come the sub functions called by the main function. To see what each individual function does I'd recommend looking at the comments. I've prioritized readability over minimum number of keystrokes, so yes, instead of writing:

foreach($dirItem in $dirResult)
{
	move-item $dirItem.FullName ($PLAYLISTSFOLDER + "\" + $dirItem.Name)
}

I could have written

$dirResult | % { mv $_.FullName ($PLAYLISTSFOLDER + "\" + $_.Name) }

But in this case I think that would have been counterproductive.

The main function

Finally we have the main function. It is written last in the script. Why is that? Well, actually PowerShell is the most sequential language you'll ever come across. It will not bother to check the entire script for function declarations. Instead it will go through the script one line at a time. This means that the following script will not work:

SayHello

function SayHello
{
	Write-Host "Hello World"
}

When you call SayHello in the sample above the function has not yet been declared, so PowerShell will throw an exception in your face saying that SayHello is unrecognized.

Footnote

There is actually a supported way of achieving the very same thing, but where's the fun in that?

Open up Windows Media Player
Go to Options -> Library and tick the checkbox for "Rearrange music in rip folder"
Go to the "Rip Music"-tab
Make sure the path is correct in the "Rip music to this location"-section
Click OK
Select all files in the library
Right-click and choose the "Advanced Tag Editor"-option
Do not change anything. Simply click Apply
Windows Media Player will now rearrange all the files using your Rip settings.

/ Johan

Implicit casting in DataRepeater not working in certain scenarios after SP1

JohanS — Wed, 30 Jan 2008 15:21:34 GMT

Problem

Using the following VB-syntax in a DataRepeater will no longer work after applying .NET Framework 2.0 Service Pack 1 in a medium-trust environment.

<asp:Repeater ID="Repeater1" runat="server">
        <ItemTemplate>
               <%#Container.DataItem("data")%><br />
        </ItemTemplate>
</asp:Repeater>

Resolution

Use Eval-method, as recommended in all Microsoft documentation. Using explicit casting would work as well, but you'd have to re-write every page if you decide to change your data layer.

Repro

Create an ASP.NET page with a repeater using a simple OleDb database as it's DataSource.

If you run this application in full trust, you should encounter no problems.

Now, set the trust level to medium. (You'll have to modify the settings and give it access to OleDbConnections.) When you run it you'll get a Security Exception:

Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file.

Exception Details: System.Security.SecurityException: Request failed.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[SecurityException: Request failed.]
   System.Security.CodeAccessSecurityEngine.ThrowSecurityException(Assembly asm, PermissionSet granted, PermissionSet refused, RuntimeMethodHandle rmh, SecurityAction action, Object demand, IPermission permThatFailed) +150
   System.Security.CodeAccessSecurityEngine.ThrowSecurityException(Object assemblyOrString, PermissionSet granted, PermissionSet refused, RuntimeMethodHandle rmh, SecurityAction action, Object demand, IPermission permThatFailed) +100
   System.Security.CodeAccessSecurityEngine.CheckSetHelper(PermissionSet grants, PermissionSet refused, PermissionSet demands, RuntimeMethodHandle rmh, Object assemblyOrString, SecurityAction action, Boolean throwException) +281
   System.Security.PermissionSetTriple.CheckSetDemand(PermissionSet demandSet, PermissionSet& alteredDemandset, RuntimeMethodHandle rmh) +67
   System.Security.PermissionListSet.CheckSetDemand(PermissionSet pset, RuntimeMethodHandle rmh) +145
   System.Security.PermissionListSet.DemandFlagsOrGrantSet(Int32 flags, PermissionSet grantSet) +43
   System.Threading.CompressedStack.DemandFlagsOrGrantSet(Int32 flags, PermissionSet grantSet) +41
   System.Security.CodeAccessSecurityEngine.ReflectionTargetDemandHelper(Int32 permission, PermissionSet targetGrant, CompressedStack securityContext) +139
   System.Security.CodeAccessSecurityEngine.ReflectionTargetDemandHelper(Int32 permission, PermissionSet targetGrant) +51

Cause and resolution

Visual Basic has always been strong on implicit casting. For example, this code is completely valid:

Dim myString As String = 10

So, in the sample at the top, Container.DataItem is merely an Object. VB then casts this to a System.Data.Common.DbDataRecord object and we're able to retrieve the "data"-property. This is no longer working after Service Pack 1.

C, in all its variations wouldn't be caught dead accepting a syntax like String = Integer, so the code at the top would never work. Instead you'd have to explicitly cast the object to the appropriate type:

<asp:Repeater ID="Repeater1" runat="server">
        <ItemTemplate>
               <%#((System.Data.Common.DbDataRecord)Container.DataItem)["data"]%><br />
        </ItemTemplate>
</asp:Repeater>

If you change the VB code so that it uses the VB equivalent: CType you will resolve the problem.

This has never been the recommended approach

So, is the resolution to use explicit casting? Well, not really. If you look at the C# example above you might notice a potential problem. If we change our data layer we would have to go through every single page and change the explicit casting. This is one of the reasons why we've always recommended using the Databinder.Eval method for VB and C# alike, so if you've followed the design guidelines your code should look like this:

<asp:Repeater ID="Repeater1" runat="server">
        <ItemTemplate>
               <%#DataBinder.Eval(Container.DataItem, "data")%><br />
        </ItemTemplate>
</asp:Repeater>

Actually, as of Framework 2.0 it's enough to write Eval("data").

So, if you review the documentation on msdn for Framework 1.1, Framework 2.0, knowledge base articles, etc. you'll see that we consistently recommend using the Eval method.

/ Johan

My language of choice can't decode an URIEncoded string

JohanS — Fri, 16 Mar 2007 11:25:00 GMT

Problem:

Some time ago I was asked to help in decoding an URI Encoded string from VB6. URL Decoding is simple enough, but when you're working with Greek, Hebrew, etc. that just isn't enough.

Resolution:

A quick search revealed a truckload of samples on how to do URL Decoding, but URI Decoding is a bit harder. I decided to stand on the shoulders of geniuses and ran Reflector on the Microsoft.JScript.dll. The code was fairly easy to convert, but I thought I'd share it in case you don't want to do it yourself. :)

I've commented out (but otherwise left intact) all the spots where .NET would throw an exception, since this would be a good spot to implement your own error handler.

Anyway, bring on the code!

/ Johan

Private Function Encode2(ByVal Text1 As String) As String
      Dim builder1 As String
      builder1 = ""
      Dim num1 As Integer
      num1 = 0
      Do While (num1 < Len(Text1))
            Dim ch1 As String
            ch1 = Mid(Text1, num1 + 1, 1)
            If InURISet(ch1, 2) Then
                  builder1 = builder1 & (ch1)
            Else
                  Dim num2 As Integer
                  num2 = AscW(ch1)
                  If ((num2 >= 0) And (num2 <= 127)) Then
                        Call AppendInHex(builder1, num2)
                  ElseIf ((num2 >= 128) And (num2 <= 2047)) Then
                        Call AppendInHex(builder1, (RShiftWord(num2, 6) Or 192))
                        Call AppendInHex(builder1, ((num2 And 63) Or 128))
                  ElseIf ((num2 < 55296) Or (num2 > 57343)) Then
                        Call AppendInHex(builder1, (RShiftWord(num2, 12) Or 224))
                        Call AppendInHex(builder1, ((RShiftWord(num2, 6) And 63) Or 128))
                        Call AppendInHex(builder1, ((num2 And 63) Or 128))
                  Else
                        If ((num2 >= 56320) And (num2 <= 57343)) Then
'                              Throw New JScriptException(JSError.URIEncodeError)
                        End If
                        If (num1 >= Len(Text1)) Then
'                              Throw New JScriptException(JSError.URIEncodeError)
                        End If
                        Dim num3 As Integer
                        num3 = Mid(Text1, num1 + 1, 1)
                        If ((num3 < 56320) Or (num3 > 57343)) Then
'                              Throw New JScriptException(JSError.URIEncodeError)
                        End If
                        num2 = ((LShiftWord((num2 - 55296), 10) + num3) + 9216)
                        Call AppendInHex(builder1, (RShiftWord(num2, 18) Or 240))
                        Call AppendInHex(builder1, ((RShiftWord(num2, 12) And 63) Or 128))
                        Call AppendInHex(builder1, ((RShiftWord(num2, 6) And 63) Or 128))
                        Call AppendInHex(builder1, ((num2 And 63) Or 128))
                  End If
            End If
            num1 = num1 + 1
      Loop
      Encode2 = builder1
End Function

Private Function Decode2(ByVal Text1 As String) As String
      Dim builder1 As String
      Dim num1 As Integer
      num1 = 0
      Do While (num1 < Len(Text1))
            Dim ch1 As String
            ch1 = Mid(Text1, (num1) + 1, 1)
            If (ch1 <> "%") Then
                  builder1 = builder1 & (ch1)
            Else
                  Dim ch2 As String
                  Dim num2 As Integer
                num2 = num1
                  If ((num1 + 2) >= Len(Text1)) Then
'                        Throw New JScriptException(JSError.URIDecodeError)
                  End If
                  Dim num3 As Byte
                  num3 = HexValue(Mid(Text1, (num1 + 2), 1), Mid(Text1, (num1 + 3), 1))
                  num1 = (num1 + 2)
                  If ((num3 And 128) = 0) Then
                        ch2 = Chr(num3)
                  Else
                        Dim num4 As Integer
                        num4 = 1
                        Do While ((LShiftWord(num3, (num4 And 31)) And 128) <> 0)
                              num4 = num4 + 1
                        Loop
                        If (((num4 = 1) Or (num4 > 4)) Or ((num1 + ((num4 - 1) * 3)) >= Len(Text1))) Then
'                              Throw New JScriptException(JSError.URIDecodeError)
                        End If
                        Dim num5 As Integer
                        num5 = (num3 And RShiftWord(255, ((num4 + 1) And 31)))
                        Do While (num4 > 1)
                              If (Mid(Text1, (num1 + 2), 1) <> "%") Then
'                                    Throw New JScriptException(JSError.URIDecodeError)
                              End If
                              num3 = HexValue(Mid(Text1, (num1 + 3), 1), Mid(Text1, (num1 + 4), 1))
                              num1 = (num1 + 3)
                              If ((num3 And 192) <> 128) Then
'                                    Throw New JScriptException(JSError.URIDecodeError)
                              End If
                              num5 = ((LShiftWord(num5, 6)) Or (num3 And 63))
                              num4 = num4 - 1
                        Loop
                        If ((num5 >= 55296) And (num5 < 57344)) Then
'                              Throw New JScriptException(JSError.URIDecodeError)
                        End If
                        If (num5 < 65536) Then
                              ch2 = (ChrW(num5))
                        Else
                              If (num5 > 1114111) Then
'                                    Throw New JScriptException(JSError.URIDecodeError)
                              End If
                              builder1 = builder1 & (Chr(((RShiftWord((num5 - 65536), 10) And 1023) + 55296)))
                              builder1 = builder1 & (Chr((((num5 - 65536) And 1023) + 56320)))
                              GoTo Label_01D4
                        End If
                  End If
                  If InURISet(ch2, 0) Then ' This can probably be omitted. It looks like it'll never be True.
                        builder1 = builder1 & Mid(Text1, num2 + 1, ((num1 - num2) + 1))
                  Else
                        builder1 = builder1 & ch2
                  End If
Label_01D4:
            End If
            num1 = num1 + 1
      Loop
      Decode2 = builder1
End Function

Private Function HexValue(ByVal ch1 As String, ByVal ch2 As String) As Byte
      Dim num1 As Integer
      Dim num2 As Integer
      num1 = HexDigit(ch1)
      num2 = HexDigit(ch2)
      If ((num1 < 0) Or (num2 < 0)) Then
'            Throw New JScriptException(JSError.URIDecodeError)
      End If
      HexValue = CByte((LShiftWord(num1, 4) Or num2))
End Function

Private Function HexDigit(ByVal c As String) As Integer
    Dim retVal As Integer
    retVal = -1
    If ((c >= "0") And (c <= "9")) Then
          retVal = (Asc(c) - Asc("0"))
    End If
    If ((c >= "A") And (c <= "F")) Then
          retVal = (((10) + Asc(c)) - Asc("A"))
    End If
    If ((c >= "a") And (c <= "f")) Then
          retVal = (((10) + Asc(c)) - Asc("a"))
    End If
    HexDigit = retVal
End Function

Function LShiftWord(ByVal w As Integer, ByVal c As Integer) As Integer
LShiftWord = w * (2 ^ c)
End Function

Function RShiftWord(w As Integer, c As Integer) As Integer
RShiftWord = w \ (2 ^ c)
End Function

Private Function InURISet(ByVal ch As String, ByVal flags As Integer) As Boolean
    Dim bRetval As Boolean
    bRetval = False
    If (flags = 2) Then
        If ((((ch >= "0") And (ch <= "9")) Or ((ch >= "A") And (ch <= "Z"))) Or ((ch >= "a") And (ch <= "z"))) Then
            bRetval = True
        End If
        Select Case ch
              Case "_", "~", "'", "(", ")", "*", "-", ".", "!"
                    bRetval = True
        End Select
    End If
    If (flags = 1) Then
        Select Case ch
              Case "#", "$", "&", "+", ",", "/", ":", ";", "=", "?", "@"
                    bRetval = True
        End Select
    End If
    InURISet = bRetval
End Function

Private Sub AppendInHex(ByRef bs As String, ByVal value As Integer)
      bs = bs & "%"
      Dim num1 As Integer
      num1 = (RShiftWord(value, 4) And 15)
      bs = bs & (IIf((num1 >= 10), Chr((num1 - 10) + 65), Chr(num1 + 48)))
      num1 = (value And 15)
      bs = bs & (IIf((num1 >= 10), Chr((num1 - 10) + 65), Chr(num1 + 48)))
End Sub

Stress-O-Matic

JohanS — Mon, 27 Nov 2006 13:41:00 GMT

A very simple stress-test

The other day I was asked by a customer if I a small application that could be used to stress a web application. I didn't feel like responding "Sure I do! Visual Studio 2005 Team Edition For Software Testers" and I also didn't feel like saying "Why don't you make one yourself using the webbrowser control?" So instead I wrote a small script. It's all very basic and simple, but I still thought it might be of use to someone. Just copy the code below into a .vbs-file and you're good to go.

Please note, however that the script relies heavily on WScript.Echo to tracks it's progress, so you should use CScript as the host rather than WScript. If you're unfamiliar with CScript & WScript I recommend taking a look at this article: MSDN: Running Scripts from Windows

CONST NUMBEROFLOOPS = 3 '****** How many times do you want the script to loop?
CONST DELAYTIME = 3 '****** How many seconds do you want to wait?
CONST URL = "http://www.microsoft.com"
Dim Http
Set Http = CreateObject("MSXML2.XMLHTTP")

Main

Function SendHTTPRequest()
   Http.Open "GET", URL , False
   Http.setRequestHeader "If-None-Match","qwerty"
   Http.setRequestHeader "Cache-Control","no-cache,max-age=0"
   Http.setRequestHeader "Pragma","no-cache"
   Http.send
   '****** Uncomment this in case you want to see the response for some reason...
   'WScript.Echo(Http.responseText)
End Function

Sub Main()
   Wscript.Echo("Test started at: " & Now())
   WScript.Echo("Will access """ & URL & """ " & NUMBEROFLOOPS & " times in " & DELAYTIME & " second intervals.")
   For I = 1 to NUMBEROFLOOPS
      WScript.Echo( I & ": Accessing """ & URL & """")
      SendHTTPRequest()
      Wscript.Echo("Waiting " & DELAYTIME & " seconds:")
      For J = DELAYTIME To 1 Step -1
         WScript.Sleep 1000
         Wscript.Echo("Waiting " & J-1 & " seconds:")
      Next
      WScript.Echo( I & ": Complete")
   Next
   Wscript.Echo("Test completed at: " & Now())
End Sub

That's all for now.

/ Johan