Write XML Files with Powershell - The Easy Way

 I needed to create a custom XML file using powershell as part of a script I was developing. I found it difficult to understand and use the in-built XML functionality with powershell so I attempted to simply use write-output commands to write the XML file. It worked - mostly, but the application I was submitting the XML file wasn't recognizing it. As it turns out there's some hidden properties within a properly formed XML file which requires a little trick to get right when forming it this way - so here's how I did it..

            $xmlfile = "C:\temp\test.xml"
            write-output '<?xml version="1.0"?>' | out-file "$xmlfile"

            write-output '<test>' | out-file "$xmlfile" -append

            write-output "  <version>1.0</version>" | out-file "$xmlfile" -append

            write-output '</test>' | out-file "$xmlfile" -append

            $xml = [xml](Get-Content $xmlfile)

            $xml.Save($xmlfile)

The first part of the script is fairly straightforward - declare the path to your XML file in the $xmlfile variable.

Then, use write-output commands to enter the text data into your XML file - make sure you include the -append argument after the first line to ensure the lines are appended onto the end of the file - you can open the file in a text editor such as NotePad++ to make sure it appears as you expect. Make sure you close off all your tags so that formatting is valid.

The last 2 lines is the trick I previously mentioned - use the [xml] class with get-content to import the XML file into the $xml variable. Once the data is in the $xml variable, it is then re-saved - these 2 lines are what puts the hidden formatting into the XML file to make it valid.

Creating Custom Tables in Powershell

When working with scripts, it is often necessary to collect, store and present information in a table format. An example of this could be to export a number of properties from a users mailbox in Exchange into a table format.

For my example, I will run the following command to export all the properties of a mailbox (mine) to a variable called $UserList

$UserList = get-mailbox -ResultSize Unlimited | Where-Object {$_.DisplayName -eq "Morrissey, Peter"}

The next thing to do is to declare/create the table. It can be called anything you like, but I tend to use $report. The following line of code creates the table;

$report = @()

Next, you need to populate each row of your table with whatever fields you require. This would usually be done with a ForEach statement where you cycle through a list of objects, with numerous properties for each object.

In my example, the object list is stored in $UserList. I can run the command $UserList | fl to display the list of all the properties available for each object in my variable.

This ForEach command will cycle through each entry in $UserList (in my example it is only a single entry for my mailbox) and add whatever properties of that object I declare into the table (I have used DisplayName and Database) but you can use as many as you like - they just need to be separated by a semi colon (;)

ForEach ($User in $UserList)
             {
             $report += New-Object psobject -Property @{DisplayName=$($User.DisplayName);Database=$($User.Database)}

             }

This is a simple example and will create a table with two values for each row; DisplayName and Database.

Once you have populated all the rows you require in your table, you can then export it to a CSV file using the following command;

$report | select DisplayName, Database | Export-CSV -path "C:\ReportOutput.csv"

Once again, you will need to replace $report with whatever variable you used to declare your table. You also need to use the Select component to select all the table fields you wish to export into the CSV file - in my case it was the DisplayName and Database fields.

Finally, once the CSV file is exported, you can then attach it to an email and send it to yourself (or someone else) as outlined in my previous blog post.