parse error in one-line powershell script

Question

I am trying to create a one-line powershell script that just requests an url. The script is working fine when I run it as a ps1 file:

File "test.ps1":

$webclient=New-Object "System.Net.WebClient"
$data=$webclient.DownloadString("https://google.com")

I run this script in PS console like this:

PS C:\test.ps1 -ExecutionPolicy unrestricted

This runs without any problem, but when I try to schedule this script and make it a one-line according to these recommendations i.e. replace "" with '' and separate commands with ; so the result will be:

one-line:

powershell -ExecutionPolicy unrestricted -Command "$webclient=New-Object 'System.Net.WebClient'; $data=$webclient.DownloadString('https://google.com');"

Then I got the following problem:

Error:

The term '=New-Object' is not recognized as the name of a cmdlet, function, script file, or operable program

I tried another script that also works fine as ps1 file, but not working as one-liner:

$request = [System.Net.WebRequest]::Create("https://google.com")
$request.Method = "GET"
[System.Net.WebResponse]$response = $request.GetResponse()
echo $response

one-line:

powershell -ExecutionPolicy unrestricted -Command "$request = [System.Net.WebRequest]::Create('https://google.com'); $request.Method = 'GET'; [System.Net.WebResponse]$response = $request.GetResponse(); echo $response"

Error:

Invalid assignment expression. The left hand side of an assignment operator needs to be something that can be assigned to like a variable or a property. At line:1 char:102

According to get-host command I have powershell v 2.0. What is the problem with one-line scripts above?

Answer 1

Put the statements you want to run in a scriptblock and run that scriptblock via the call operator:

powershell.exe -Command "&{$webclient = ...}"

Note that pasting this commandline into a PowerShell console will produce a misleading error, because PowerShell (the one into which you paste the commandline) expands the (undefined) variables in the string to null values, which are then auto-converted to empty strings. If you want to test a commandline like this, run it from CMD, not PowerShell.

It might also be a good idea to have the scriptblock exit with a status code, e.g.

&{...; exit [int](-not $?)}

or

&{...; $status=$response.StatusCode.value__; if ($status -eq 200) {exit 0} else {exit $status}}