New-TemporaryFile

PowerShell Cmdlet: `New-TemporaryFile`

Welcome back to Wahmans PowerShell Blog! Today, we’re taking a closer look at an underrated but incredibly helpful cmdlet: New-TemporaryFile. This handy cmdlet does exactly what its name implies—it creates a temporary file for your script to use. This can be very useful for testing, intermediate data storage, or even as part of a more complex automation task.

Cmdlet Overview

New-TemporaryFile creates a zero-byte file in the temporary file path defined by the system. The path to the file is returned as a FileInfo object, allowing you to interact with it using other file-related cmdlets.

Example 1: Basic Usage (Beginner)

Let’s start with a simple example. This command creates a temporary file and displays its full path.

$tempFile = New-TemporaryFile
Write-Host "Temporary file created at: $($tempFile.FullName)"

Example 2: Writing to the Temporary File (Intermediate)

Here we create a temporary file and write some data into it.

$tempFile = New-TemporaryFile
"Hello from Wahmans PowerShell Blog!" | Out-File -FilePath $tempFile.FullName
Write-Host "Wrote text to: $($tempFile.FullName)"

Example 3: Temporary File for a Transient Log (Intermediate to Advanced)

Use a temporary file to log script activity for debugging purposes, without cluttering the file system with permanent files.

$logFile = New-TemporaryFile
for ($i = 1; $i -le 5; $i++) {
    "$((Get-Date).ToString('u')) - Iteration $i" | Out-File -FilePath $logFile.FullName -Append
}

Write-Host "Log entries saved to: $($logFile.FullName)"

Example 4: Secure Temporary File for Sensitive Data (Advanced)

Use a temporary file to store sensitive data such as a password during a script’s runtime.

$secureTempFile = New-TemporaryFile
$securePassword = "P@ssword123!"

# convert to secure string and export to temp XML file
$securePassword | ConvertTo-SecureString -AsPlainText -Force | Export-Clixml -Path $secureTempFile.FullName

Write-Host "Secure password has been written to temporary XML file: $($secureTempFile.FullName)"

# Later, you can import it
$importedPassword = Import-Clixml -Path $secureTempFile.FullName

Cleanup Tip

Remember: temporary files created using New-TemporaryFile are not auto-deleted when your script completes. Combine with Remove-Item to clean them up when no longer needed:

Remove-Item $tempFile.FullName -Force

Wrap-Up

Whether you’re a PowerShell novice or a seasoned scripter, New-TemporaryFile is a tool you should definitely keep in your toolkit. It’s incredibly useful for scenarios where temporary file creation is needed without worrying about naming conflicts or cleaning up after users.

Happy scripting, and I will see you in the next post!

PowerShell Cmdlet: New-TemporaryFile