PowerShell ProcessStartInfo stdout stderr

ProcessStartInfo.ps1

Set-StrictMode -Version 'latest'
$ErrorActionPreference = 'stop'

$ProcessStartInfo = [System.Diagnostics.ProcessStartInfo]::new()
$ProcessStartInfo.FileName               = 'C:\Windows\System32\cmd.exe'
$ProcessStartInfo.Arguments              = '/c echo normal boring standard out && echo this is the error message 1>&2'
$ProcessStartInfo.CreateNoWindow         = $true
$ProcessStartInfo.UseShellExecute        = $false
$ProcessStartInfo.RedirectStandardOutput = $true
$ProcessStartInfo.RedirectStandardError  = $true

$Process = [System.Diagnostics.Process]::new()
$Process.StartInfo = $ProcessStartInfo
[void]$Process.Start()
$Process.WaitForExit()

Write-Host
'stdout:' | Write-Host -ForegroundColor Cyan
$Process.StandardOutput.ReadToEnd() | Write-Host

Write-Host
'stderr:' | Write-Host -ForegroundColor Red
$Process.StandardError.ReadToEnd() | Write-Host


<# this works, but the above produces cleaner output
$sbSomeError = [scriptblock]::Create({
    "some normal boring stdout" | Write-Output
    "some error message" | Write-Error
})

$ProcessStartInfo.FileName  = 'C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe'
$ProcessStartInfo.Arguments = "-NonInteractive -EncodedCommand `"$([System.Convert]::ToBase64String( [System.Text.Encoding]::Unicode.GetBytes($sbSomeError.ToString()) ))`""
#>