Occasionally, PowerShell scripts are made available via direct download. Let’s find the most efficient way to download text-based files via PowerShell. We’ll use the famous “Dancing Rick ASCII” script published by PowerShell Team member Lee Holmes for our examples. It is located here:
http://bit.ly/e0Mw9w
When opened in a browser, you’ll see the PowerShell source code as plain text, and the original URL is shown in the browser bar:
http://www.leeholmes.com/projects/ps_html5/Invoke-PSHtml5.ps1
Many users resort to .NET methods to download text files like this:
# download code $url = "http://bit.ly/e0Mw9w" $webclient = New-Object Net.WebClient $code = $webclient.DownloadString($url) # output code $code
There is no need for this, though, because Invoke-WebRequest is a convenient wrapper around that object:
# download code $url = "http://bit.ly/e0Mw9w" $page = Invoke-WebRequest -Uri $url -UseBasicParsing $code = $page.Content
Via its parameters, it includes proxy support and support for credentials right out of the box.
There’s an even more convenient cmdlet calling Invoke-RestMethod. It basically does the same but returns the data as text, JSON, or XML:
# download code $url = "http://bit.ly/e0Mw9w" $code = Invoke-RestMethod -Uri $url -UseBasicParsing
Provided you are confident that the code is legit and won’t harm your system, you can now invoke it:
# invoke the code Invoke-Expression -Command $code
Or, you can save it to disk and run it as a regular PowerShell script:
# download code $url = "http://bit.ly/e0Mw9w" $code = Invoke-RestMethod -Uri $url -UseBasicParsing # save to file and run $outPath = "$home\Desktop\dancingRick.ps1" $code | Set-Content -Path $outPath -Encoding UTF8 Start-Process -FilePath powershell -ArgumentList "-noprofile -noexit -executionpolicy bypass -file ""$outPath"""
If you plan to download the content to a file in the first place, then Invoke-WebRequest is the better choice because it can save contents directly to file:
# download code $url = "http://bit.ly/e0Mw9w" $outPath = "$home\Desktop\dancingRick.ps1" $code = Invoke-WebRequest -Uri $url -UseBasicParsing -OutFile $outPath & $outPath
You can run the downloaded file directly in your own PowerShell session by using the call operator (&), rather than using Start-Process. If this fails, most likely your execution policy does not allow PowerShell scripts to be run. Change the setting like so, then try again:
PS> Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned
