PowerShell and Excel: Yes, They Work Together

Adam Bertram

Adam Bertram

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Microsoft Excel is one of those ubiquitous tools most of us can’t escape even if we tried. Many IT professionals use Excel as a little database storing tons of data in various automation routines. What’s the best scenario of automation and Excel? PowerShell!

Excel spreadsheets have always been notoriously hard to script and automate. Unlike it’s less-featured (and simpler) CSV file counterpart, Excel workbooks aren’t just simple text files. Excel workbooks required PowerShell to manipulate complicated Component Object Model (COM) objects thus you had to have Excel installed. Not anymore.

Thankfully, an astute PowerShell community member, Doug Finke, created a PowerShell module called ImportExcel for us mere mortals. The ImportExcel module abstracts away all of that complexity. It makes it possible to easily manage Excel workbooks and get down to PowerShell scripting!

In this article, let’s explore what you can do with PowerShell and Excel using the ImportExcel module and a few popular use cases.

Prerequisites

When running the ImportExcel module on a Windows system, no separate dependencies are necessary. However, if you’re working on macOS, you will need to install the mono-libgdiplus package using brew install mono-libgdiplus. All examples in this article will be built using macOS but all examples should work cross-platform.

If you’re using macOS, be sure to restart your PowerShell session before continuing.

Installing the ImportExcel Module

Start by download and installing the module via the PowerShell Gallery by running Install-Module ImportExcel -Scope CurrentUser. After a few moments, you’ll be good to go.

Using PowerShell to Export to an Excel Worksheet

You may be familiar with the standard PowerShell cmdlets Export-Csv and Import-Csv. These cmdlets allow you to read and export PowerShell objects to CSV files. Unfortunately, there’s no Export-Excel and Import-Excel cmdlets. But using the ImportExcel module, you can build your own functionality.

One of the most common requests a sysadmin has is exporting PowerShell objects to an Excel worksheet. Using the Export-Excel cmdlet in the ImportExcel module, you can easily make it happen.

For example, perhaps you need to find some processes running on your local computer and get them into an Excel workbook.

The Export-Excel cmdlet accepts any object exactly the way Export-Csv does. You can pipe any kind of object to this cmdlet.

To find processes running on a system with PowerShell, use the Get-Process cmdlet which returns each running process and various information about each process. To export that information to Excel, use the Export-Excel cmdlet providing the file path to the Excel workbook that will be created. You can see an example of the command and screenshot of the Excel file generated below.

Get-Process | Export-Excel -Path './processes.xlsx'
Output of Export-Excel cmdlet
Output of Export-Excel cmdlet

Congrats! You’ve now exported all the information just like Export-Csv but, unlike Export-Csv, we can make this data a lot fancier. Let’s make sure the worksheet name is called Processes, the data is in a table and rows are auto-sized.

By using the AutoSize switch parameter to autosize all rows, TableName to specify the name of the table that will include all the data and the WorksheetName parameter name of Processes, you can see in the screenshot below what can be built.

Get-Process | Export-Excel -Path './processes.xlsx' -AutoSize -TableName Processes -WorksheetName Proccesses
Autosize Switch Parameter Result
Autosize Switch Parameter Result

The Export-Excel cmdlet has a ton of parameters you can use to create Excel workbooks of all kinds. For a full rundown on everything Export-Excel can do, run Get-Help Export-Excel.

Using PowerShell to Import to Excel

So you’ve exported some information to a file called processes.xlsx in the previous section. Perhaps now you need to move this file to another computer and import/read this information. No problem. You have Import-Excel at your disposal.

At its most basic usage, you only need to provide the path to the Excel document/workbook using the Path parameter as shown below. You’ll see that it reads the first worksheet, in this case, the Processes worksheet, and returns PowerShell objects.

Import-Excel -Path './processes.xlsx'
Path Parameter
Path Parameter

Maybe you have multiple worksheets in an Excel workbook? You can read a particular worksheet using the WorksheetName parameter.

Import-Excel -Path './processes.xlsx' -WorkSheetname SecondWorksheet

Do you need to only read certain columns from the Excel worksheet? Use the HeaderName parameter to specify only those parameters you’d like to read.

Import-Excel -Path './processes.xlsx' -WorkSheetname Processes -HeaderName 'CPU','Handle'

The Import-Excel cmdlet has other parameters you can use to read Excel workbooks of all kinds. For a full rundown on everything Import-Excel can do, run Get-Help Import-Excel.

Using PowerShell to Get (and Set) Excel Cell Values

You now know how to read an entire Excel worksheet with PowerShell but what if you only need a single cell value? You technically could use Import-Excel and filter out the value you need with Where-Object but that wouldn’t be too efficient.

Instead, using the Open-ExcelPackage cmdlet, you can “convert” an Excel workbook into a PowerShell object which can then be read and manipulated. To find a cell value, first, open up the Excel workbook to bring it into memory.

$excel = Open-ExcelPackage -Path './processes.xlsx'

The Open-ExcelPackage is similar to using New-Object -comobject excel.application if working directly with COM objects.

Next, pick the worksheet inside of the workbook.

$worksheet = $excel.Workbook.Worksheets['Processes']

This process is similar to the COM object way of opening workbooks with excel.workbooks.open.

Once you have the worksheet assigned to a variable, you can now drill down to individual rows, columns, and cells. Perhaps you need to find all cell values in the A1 row. You simply need to reference the Cells property providing an index of A1 as shown below.

$worksheet.Cells['A1'].Value

You can also change the value of cells in a worksheet by assigning a different value eg. $worksheet.Cells['A1'] = 'differentvalue'

Once in memory, it’s important to release the Excel package using the Close-ExcelPackage cmdlet.

Close-ExcelPackage $excel

Converting Excel to CSV Files with PowerShell

Once you have the contents of an Excel worksheet represented via PowerShell objects, “converting” Excel worksheets to CSV simply requires sending those objects to the Export-Csv cmdlet.

Using the processes.xlsx workbook created earlier, read the first worksheet which gets all of the data into PowerShell objects and then export those objects to CSV using the command below.

Import-Excel './processes.xlsx' | Export-Csv -Path './processes.csv' -NoTypeInformation

If you now open up the resulting CSV file, you’ll see the same data inside of the Processes worksheet (in this example).

Converting Multiple Worksheets

If you have an Excel workbook with multiple worksheets, you can also create a CSV file for each worksheet. To do so, you can find all the sheets in a workbook using the Get-ExcelSheetInfo cmdlet. Once you have the worksheet names, you can then pass those names to the WorksheetName parameter and also use the sheet name as the name of the CSV file.

Below you can the example code needed.

## find each sheet in the workbook
$sheets = (Get-ExcelSheetInfo -Path './processes.xlsx').Name
## read each sheet and create a CSV file with the same name
foreach ($sheet in $sheets) {
	Import-Excel -WorksheetName $sheet -Path './processes.xlsx' | Export-Csv "./$sheet.csv" -NoTypeInformation
}

Conclusion

Using the ImportExcel PowerShell module, you can import, export and manage data in Excel workbooks exactly like you would CSVs without having to install Excel!

In this article, you learned the basics of reading and writing data to an Excel workbook but this just scratches the surface. Using PowerShell and the ImportExcel module, you can create charts, pivot tables and leverage other powerful features of Excel!

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