Streaming output from Invoke-WebRequest to screen - powershell

Question

I am trying to invoke a web request which will print out a stream of plain-text live. It currently works, but doesn't produce any output until the request is complete. I'm trying to find a way to see the content as soon as comes down the wire. I can currently do with with a curl command from a Linux box and it shows be each line of output as soon as it's produced. The PowerShell command I'm trying to use it something like this:
Invoke-WebRequest -Body #{id=123} -Method POST -Uri http://server/run_command/
The corresponding curl command on Linux is:
curl -d id=123 -X POST http://server/run_command/ --no-buffer
The --no-buffer option is only needed when sending the output to another command like grep. How can I accomplish this using just PowerShell?

Answer 1

I am not able to test this myself right now, but have you tried expanding the content?
(Invoke-WebRequest -Body #{id=123} -Method POST -Uri http://server/run_command/).Content

Answer 2

There are other APIs that allow reading response stream without buffering it in full.
For example https://learn.microsoft.com/en-us/dotnet/api/system.net.httpwebresponse.getresponsestream?view=net-5.0
PowerShell version of the same could look like this:
$webrequest = [System.Net.HttpWebRequest]::Create("https://en.wikipedia.org/wiki/Internet_Archive")
$responseStream = $webrequest.GetResponse().GetResponseStream()
$streamReader = [System.IO.StreamReader]::new($responseStream)
[char[]]$buffer = [char[]]::new(256)
while (($count = $streamReader.Read($buffer, 0, $buffer.Length)) -gt 0)
{
# output count characters of the buffer
}
$response.Close() > $null
$responseStream.Close() > $null