Maximizing Productivity with PowerShell’s Copy-Item, Download, and Script Invocation

I’m sure you had situations where you have file explorer windows open, and you drag a file or folder from one window to the other. You can certainly use drag and drop method in many scenarios, but if you have a terminal open you also have many options.

Copy-Item on Local Machine

Copy File to a Different Folder and Compare Hashes

Here is an example of copying a file, comparing the MD5 hash using Get-FileHash cmdlet, then retrieving the file size using a computed property.

$fileName = "npp.8.6.4.Installer.x64.exe"
$sourcePath = Join-Path $env:USERPROFILE "Downloads\$fileName"
$destinationPath = (Get-Location).Path

copy-item -path $sourcePath -Destination $destinationPath -Force

if(test-path (join-path $destinationPath $fileName) ){
    $compareHash = (Get-FileHash -Algorithm MD5 (join-path $destinationPath $fileName)).Hash -eq (Get-FileHash -Algorithm MD5 $sourcePath).Hash
    $size = Get-Item (Join-Path $destinationPath $fileName) | Select-Object @{Name="sizeInMB"; Expression={$_.Length / 1MB}}
    Write-Output("File hashes for $fileName Match: {0} - $fileName size: {1} MB" -f $compareHash, $size.sizeInMB)
}

The source path directly points to the file we want to copy. The destination is a folder the file will be copied to. We test the destination file path, if it exists, we compare the file hashes. We also use the computed property sizeInMB and output this in a formatted output stream.

Copy All Items in Folder to Destination Folder

You can also use the Copy-Item Cmdlet to recursively copy items at all depths to the destination directory. This can be useful for images if I want to copy the contents of my pictures folder when working on a blog post from a remote machine, then uploading them all to the destination. Just a note, we will be using the * wildcard – If the path contains a wildcard character (*), all files and directories within the specified directory, including those within subdirectories, will be copied to the destination directory. This is the desired outcome

$sourcePath = Join-Path $env:USERPROFILE "Downloads\pictures"
$destinationPath = Join-Path (Get-Location).Path "Content"

Get-ChildItem $sourcePath -Recurse -Directory -Name
# level2
# level2\level3
if( -not (Test-Path $destinationPath)){ new-item -ItemType Directory -path $destinationPath -Force }

copy-item -path $sourcePath\* -Destination $destinationPath -Recurse -Force

I wanted to show you the item structure is maintained between the source and destination folders when using this method.

Copying Items from an SMB share

If you configured a Domain Controller documented in this blog post, you can easily configure SMB. SMB, or Server Message Block, is a network protocol for file and printer sharing in Windows environments, facilitating resource access. This protocol uses port TCP 445. You can certainly configure SMB between two Windows workstations using a workgroup.

Configure SMB using WorkGroup

1. Set Workgroup Name:
   • On both workstations, ensure they are part of the same workgroup. By default, Windows workstations are often set to the “WORKGROUP” workgroup. You can verify or change this by right-clicking on “This PC” or “My Computer,” selecting “Properties,” and then clicking on “Advanced system settings” or “Change settings” under “Computer name, domain, and workgroup settings.”
2. Enable Network Discovery:
   • Open “Control Panel” > “Network and Sharing Center.”
   • Click on “Change advanced sharing settings” on the left panel.
   • Ensure that network discovery, file and printer sharing, and public folder sharing are turned on for the appropriate network profile (private or public).
3. Share Folders:
   • Right-click on the folder you want to share, select “Properties,” and then go to the “Sharing” tab.
   • Click on “Advanced sharing.”
   • Check the box that says “Share this folder,” and then click “Permissions” to set the desired permissions for the shared folder.
4. Allow SMB Through Windows Firewall:
   • Open “Control Panel” > “System and Security” > “Windows Defender Firewall.”
   • Click on “Allow an app or feature through Windows Defender Firewall” on the left panel.
   • Ensure that “File and Printer Sharing” is allowed for the network profile you are using.
5. Access Shared Folders:
   • Open File Explorer and navigate to “Network” or type \\computer_name or \\computer_ip_address in the address bar to access shared folders on the other workstation.

Now that we have SMB configured, lets copy content using Copy-Item and SMB protocol

$remoteShare= '\\TEST-DC-01\General'
$destination = (Get-Location).Path

Copy-Item -Path $remoteShare\* -Include *.txt -Destination $destination

Downloading and Invoking a File or Script

A useful way to retrieve and launch files us by using the Net.WebClient class. I recently learned this method and think of it as simply copying the file from the remote server to the destination folder. We specify the url and we can download it to our local machine.

Just as a reference here are some Net.WebClient methods for downloading data. Similarly, there are methods for uploading data in the docs.

Download the File using Net. WebClient

In this example, we specify the URL of the file we want to download $url and the destination where we want to save it locally.

$fileName = "npp.8.6.4.Installer.x64.exe"
$destinationPath = Join-Path (Get-Location).Path $fileName
$url = "https://github.com/notepad-plus-plus/notepad-plus-plus/releases/download/v8.6.4/npp.8.6.4.Installer.x64.exe"

$webClient = (New-Object Net.WebClient)
$webClient.DownloadFile($url, $destinationPath)

Here we specify the destination file name and the URL. We create a new Net.WebClient object and use the DownloadFile() method to download the file to the destination

Executing the File and Installing the Software

We downloaded Notepad++ but it would be nice if we could automatically run the downloaded file and install the package. Let’s add a bit of logic to achieve this.

if(test-path $destinationPath){
    $p = Start-Process $destinationPath -ArgumentList "/S" -PassThru -Wait
    $p.WaitForExit()
    if($p.HasExited -and ($p.ExitCode -eq 0)){
        Write-Output "Successfully installed $fileName"
    }
}

We test for the existence of the file, then we use Start-Process to run the executable and install the program. When the process exits with zero, we can write an output stream to the terminal.

Copy the File and Change the File Extension

Here we will use Copy-Item cmdlet to copy a .ps1 file to our network share using SMB. the .ps1 file is named createDirectory.ps1 and the contents are one line, create a folder in the script root.

# createDirectory.ps1
New-Item -Path (join-path $PSScriptRoot "TestDirectory") -ItemType Directory -Force

Copying the file to the destination and changing the extension.

$fileName = 'createDirectory.ps1'
$destinationPath = "\\test-dc-01\General\"
copy-item -Path $fileName -Destination (Join-Path $destinationPath "$fileName.txt") -Force          

Follow the SMB TCP stream in WireShark

I was curious if I could see the SMB transfer happening using a network protocol analyzer, and it’s straightforward to filter and follow the stream using WireShark. There were a few posts about this, but I just selected the interface to capture packets, ran my script to copy the file, and stopped the capture. I used one filter SMB2, then since this was the only SMB stream in the capture, I right clicked the first SMB2 packet > Follow > TCP Stream. Wildly, using SMB2 protocol, we were able to get the contents of the text file being transferred and the file name just by following the TCP stream. Might be time to upgrade to SMB3.

When you copy an item over SMB, the data is usually transferred as a series of packets between the client and the server. These packets contain the information needed to recreate the file or folder on the destination location.

Download the File, Remove the Extension, and Run it

Now that we have our lab setup, lets download the createDirectory.ps1.txt file using Net.WebClient object from the SMB share to our local machine, remove the txt extension, and invoke the PowerShell script.

$webClient = New-Object Net.WebClient
$source = "\\TEST-DC-01\General\createDirectory.ps1.txt"
$fileName = "createDirectory.ps1"

if((test-path $source) -and ($source -like "*ps1.txt")){
    $webClient.DownloadFile($source, (Join-Path $PSScriptRoot $fileName))
    Invoke-Expression (Join-Path $PSScriptRoot $fileName) >$null
}

That was really cool. As I write this, I am gaining a better understanding of the cmdlet and the SMB protocol, and more importantly I hope you are too.

Conclusion

This blog can assist you with the downloading and copying items using the Copy-Item cmdlet and the Net.WebClient .NET class. There are other cool methods to explore like DownloadString() so you can save space on the host and invoke the command. I thought this topic was useful for fellow tech-minded people for all the reasons listed and because it can increase your efficiency at work. If you have suggestions for improvements, or just want to share some knowledge, drop some knowledge in the comment section or Contact Me.