Exploring Format-Hex in PowerShell

Welcome back to Wahmans PowerShell blog! Today, we’ll explore an incredibly useful cmdlet called Format-Hex. According to Microsoft, Format-Hex displays a file or other input as hexadecimal. This can be particularly useful for a variety of tasks, from debugging file formats to reverse engineering data.

Let’s look at what this cmdlet can do with a gradient of examples, from beginner to more advanced use.

Example 1: Simple Hex Dump of a File

If you have a file and you want to see its contents in hexadecimal format, just pass the file to Format-Hex.

Format-Hex -Path "C:\example\test.txt"

This will output the hexadecimal representation of the file content, which can help you examine binary files or understand file headers.

Example 2: Hex Dump of a String

You don’t always need a file. If you want to see the hex values of a string, you can convert it to bytes and pipe it into Format-Hex.

$string = "Hello, World!"
$bytes = [System.Text.Encoding]::UTF8.GetBytes($string)
$bytes | Format-Hex

This is great for understanding how strings are encoded at the byte level.

Example 3: Comparing File Binary Differences

If you’ve got two files and want to compare their binary contents visually, Format-Hex can help.

$file1 = Get-Content -Path "C:\example\file1.bin" -Encoding Byte
$file2 = Get-Content -Path "C:\example\file2.bin" -Encoding Byte

Write-Host "File 1 Hex":
$file1 | Format-Hex

Write-Host "File 2 Hex":
$file2 | Format-Hex

This won’t automate the comparison, but it gives a starting point to manually inspect differences.

Example 4: Inspecting the Byte Layout of a Custom Object

This one’s for the more advanced users. Want to inspect the byte layout of a .NET structure or object? Let’s take an example with timestamps.

$now = [DateTime]::Now.Ticks
$bytes = [BitConverter]::GetBytes($now)
$bytes | Format-Hex

This gives you the underlying byte format of a DateTime’s Tick count, which can be useful for serialization or interop debugging.

Conclusion

Format-Hex is an incredibly powerful cmdlet for working with binary data, understanding encoding, and debugging complex structures. Whether you’re just getting started or diving deep into how bytes make up the digital world, this cmdlet deserves a place in your toolbox.

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