Powershell -> exe -> powershell Write-Host Console Logging Failing - c#

TLDW: To support a specific process I need to go from a powershell instances/module to kick off a known safe executable for some c# magic, which then in turn needs to kick and execute a powershell script before exiting.
Powershell Entry point
{
Known Good Exe
{
Powershell Work To Do
}
}
Now ideally, this would all run from a single console instance so that all of the output is simple to look at. The exe -> powershell logging all works fine and as expected when using powershell.Streams.... The write-hosts in the powershell work all show up in the console and I get all the info I want.
powerShell.Streams.Information.DataAdded += LogMessage;
The problem comes when the outer powershell module is introduced. This one is needed because the parent process and execution environment this is running from is powershell. Once this whole stack is started from within a powershell instance, I get console logging from the outer powershell, and from the exe. BUT all of the write-hosts from the inner powershell modules disappear.
I've tried disabling the stream redirects, and a few other things, but this isn't resolving in the manner I would hope. I'm hoping someone knows if there is a way to get this to work as it solves so many problems if it just would.
PowerShell Outer:
$C#Exe = Join-Path $PSScriptRoot $C#ExePath
$C#Args = #()
Write-Host "Hello world" # will show up
& $C#Exe $C#Args
C# Exe Code:
public static void Main(string[] args)
{
Console.WriteLine("Hello world"); #Will show up
var powerShell = PowerShell.Create().AddScript("PowerShellInner.ps1");
powerShell.Streams.Information.DataAdded += LogMessage<InformationRecord>;
powerShell.Streams.Warning.DataAdded += LogMessage<WarningRecord>;
powerShell.Streams.Error.DataAdded += LogMessage<ErrorRecord>;
powerShell.Streams.Verbose.DataAdded += LogMessage<VerboseRecord>;
powerShell.Streams.Debug.DataAdded += LogMessage<DebugRecord>;
StringBuilder resultString = new StringBuilder();
foreach (dynamic item in powerShell.Invoke().ToList())
{
resultString.AppendLine(item.ToString());
}
Console.WriteLine(resultString.ToString());
}
private static void LogMessage<T>(object sender, DataAddedEventArgs e)
{
var data = (sender as PSDataCollection<T>)[e.Index];
Console.WriteLine($"[{typeof(T).Name}] {Convert.ToString(data)}");
}
PowerShell Inner:
Write-Host "Hello world" #Wont show up

UPDATE on 1/22/2020
I can't fully explain why you're experiencing what you're seeing, but the following code works.
Output from executing PowerShellOuter.ps1
Code
Notes:
Your c# program doesn't show any code manipulating input arguments,
so I didn't model any input args
You mis-used the AddScript method. It needs the text of the script, not the script name
The code below assumes that the c# exe and the two PS scripts are in the same folder
In PowerShellInner.ps1, use write-output. write-host does not output data to PowerShell Objectflow Engine but rather, as the name implies, writes directly to the host and sends nothing to the PowerShell engine to be forwarded to commands later in the pipeline. See Write-Output or Write-Host in PowerShell
PowerShellOuter.ps1
cls
$CSharpExe = Join-Path $PSScriptRoot "PowerShellExecutionSample.exe"
Write-Host "Hello from PowerShellOuter.ps1"
&$CSharpExe
pause
PowerShellInner.ps1
Write-Output "Hello from PowerShellInner.ps1"
Code for PowerShellExecutionSample.exe
using System;
using System.Collections.ObjectModel;
using System.IO;
using System.Management.Automation;
namespace PowerShellExecutionSample
{
class Program
{
static void Main(string[] args)
{
PowerShellExecutor t = new PowerShellExecutor();
t.ExecuteSynchronously();
}
}
/// <summary>
/// Provides PowerShell script execution examples
/// </summary>
class PowerShellExecutor
{
public void ExecuteSynchronously()
{
using (PowerShell PowerShellInstance = PowerShell.Create())
{
//You mis-used the AddScript method. It needs the text of the script, not the script name
string scriptText = File.ReadAllText(string.Format(#"{0}\PowerShellInner.ps1", Environment.CurrentDirectory));
PowerShellInstance.AddScript(scriptText);
Collection <PSObject> PSOutput = PowerShellInstance.Invoke();
// loop through each output object item
foreach (PSObject outputItem in PSOutput)
{
// if null object was dumped to the pipeline during the script then a null
// object may be present here. check for null to prevent potential NRE.
if (outputItem != null)
{
Console.WriteLine(outputItem.BaseObject.ToString() + "\n");
}
}
}
}
}
}
Original Answer on 1/21/2020
Updating your question to break out your code out helped - thanks.
I think you have two issues:
1) Modify your c# program to obtain the streams coming from PowerShell Inner and make your c# program re-emit the data from the PowerShell Inner output streams. Here is a Microsoft blog entry I used to crack the same nut: Executing PowerShell scripts from C#
2) Modify your PowerShell Outer to obtain the streams coming from the c# program. Here is a blog entry that seems to crack that nut: How to redirect output of console program to a file in PowerShell. The heart of this is to execute the following from your PowerShell Outer:
cmd /c XXX.exe ^>log.txt 2^>^&1
Note: The ^ are really backticks

Related

Launching powershell scripts (with parameters) from c# app

I'm trying to make a simple (or so i thought) app that will make it easier to launch .ps1 scripts, so that non-powershell savvy users can use them.
Here is how its supposed to look like
Now, i managed to figure out one part about running scripts:
private string RunPowershell_1(string skripta)
{
StringBuilder stringBuilder = new StringBuilder();
foreach (string str in PowerShell.Create().AddScript(skripta).AddCommand("Out-String").Invoke<string>())
{
stringBuilder.AppendLine(str);
}
return stringBuilder.ToString();
}
But i would normally run scripts that require parameters, so i would like to be able to read list of parameters from the script i import, assign value to them and then run the scrip (output should go to either txtPreview or to a file).
Is there a way to do this?
If there is another (better) approach to this I'm all ears.
You can use this powershell command to get the list of parameters.
(get-command get-netadapter).Parameters
And this is how you can read its output in C#:
using (PowerShell ps = PowerShell.Create())
{
ps.AddScript("...");
Collection<PSObject> output = ps.Invoke();
}

Executing elevated powershell scripts from C# in .NET Core 3.0

I'm calling a self-elevating powershell script from C# code. The Script resets DNS Settings.
The script works fine when called from unelevated powershell, but takes no effect when called from C# code with no exceptions thrown.
My Execution policy is temporarily set on unrestricted and I'm running Visual Studio as Admin.
Does anyone know what's wrong?
The C#:
class Program
{
static void Main(string[] args)
{
var pathToScript = #"C:\Temp\test.ps1";
Execute(pathToScript);
Console.ReadKey();
}
public static void Execute(string command)
{
using (var ps = PowerShell.Create())
{
var results = ps.AddScript(command).Invoke();
foreach (var result in results)
{
Console.WriteLine(result.ToString());
}
}
}
}
The script:
# Get the ID and security principal of the current user account
$myWindowsID = [System.Security.Principal.WindowsIdentity]::GetCurrent();
$myWindowsPrincipal = New-Object System.Security.Principal.WindowsPrincipal($myWindowsID);
# Get the security principal for the administrator role
$adminRole = [System.Security.Principal.WindowsBuiltInRole]::Administrator;
# Check to see if we are currently running as an administrator
if ($myWindowsPrincipal.IsInRole($adminRole))
{
# We are running as an administrator, so change the title and background colour to indicate this
$Host.UI.RawUI.WindowTitle = $myInvocation.MyCommand.Definition + "(Elevated)";
$Host.UI.RawUI.BackgroundColor = "DarkBlue";
Clear-Host;
}
else {
# We are not running as an administrator, so relaunch as administrator
# Create a new process object that starts PowerShell
$newProcess = New-Object System.Diagnostics.ProcessStartInfo "PowerShell";
# Specify the current script path and name as a parameter with added scope and support for scripts with spaces in it's path
$newProcess.Arguments = "& '" + $script:MyInvocation.MyCommand.Path + "'"
# Indicate that the process should be elevated
$newProcess.Verb = "runas";
# Start the new process
[System.Diagnostics.Process]::Start($newProcess);
# Exit from the current, unelevated, process
Exit;
}
# Run your code that needs to be elevated here...
Set-DnsClientServerAddress -InterfaceIndex 9 -ResetServerAddresses
As you've just determined yourself, the primary problem was that script execution was disabled on your system, necessitating (at least) a process-level change of PowerShell's execution policy, as the following C# code demonstrates, which calls
Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass before invoking the script file (*.ps1):
For an alternative approach that uses the initial session state to set the per-process execution policy, see this answer.
The approach below can in principle be used to persistently change the execution policy for the current user, namely by replacing .AddParameter("Scope", "Process") with .AddParameter("Scope", "CurrentUser")
Caveat: When using a PowerShell (Core) 7+ SDK, persistent changes to the local machine's policy (.AddParameter("Scope", "LocalMachine")) - which require running with elevation (as admin) - are seen by that SDK project only; see this answer for details.
Caveat: If the current user's / machine's execution policy is controlled by a GPO (Group Policy Object), it can NOT be overridden programmatically - neither per process, nor persistently (except via GPO changes).
class Program
{
static void Main(string[] args)
{
var pathToScript = #"C:\Temp\test.ps1";
Execute(pathToScript);
Console.ReadKey();
}
public static void Execute(string command)
{
using (var ps = PowerShell.Create())
{
// Make sure that script execution is enabled at least for
// the current process.
// For extra safety, you could try to save and restore
// the policy previously in effect after executing your script.
ps.AddCommand("Set-ExecutionPolicy")
.AddParameter("Scope", "Process")
.AddParameter("ExecutionPolicy", "Bypass")
.Invoke();
// Now invoke the script and print its success output.
// Note: Use .AddCommand() (rather than .AddScript()) even
// for script *files*.
// .AddScript() is meant for *strings
// containing PowerShell statements*.
var results = ps.AddCommand(command).Invoke();
foreach (var result in results)
{
Console.WriteLine(result.ToString());
}
// Also report non-terminating errors, if any.
foreach (var error in ps.Streams.Error)
{
Console.Error.WriteLine("ERROR: " + error.ToString());
}
}
}
}
Note that the code also reports any non-terminating errors that the script may have reported, via stderr (the standard error output stream).
Without the Set-ExecutionPolicy call, if the execution policy didn't permit (unsigned) script execution, PowerShell would report a non-terminating error via its error stream (.Streams.Error) rather than throw an exception.
If you had checked .Streams.Error to begin with, you would have discovered the specific cause of your problem sooner.
Therefore:
When using the PowerShell SDK, in addition to relying on / catching exceptions, you must examine .Streams.Error to determine if (at least formally less severe) errors occurred.
Potential issues with your PowerShell script:
You're not waiting for the elevated process to terminate before returning from your PowerShell script.
You're not capturing the elevated process' output, which you'd have to via the .RedirectStandardInput and .RedirectStandardError properties of the System.Diagnostics.ProcessStartInfo instance, and then make your script output the results.
See this answer for how to do that.
The following, streamlined version of your code addresses the first point, and invokes the powershell.exe CLI via -ExecutionPolicy Bypass too.
If you're using the Windows PowerShell SDK, this shouldn't be necessary (because the execution policy was already changed in the C# code), but it could be if you're using the PowerShell [Core] SDK, given that the two PowerShell editions have separate execution-policy settings.
# Check to see if we are currently running as an administrator
$isElevated = & { net session *>$null; $LASTEXITCODE -eq 0 }
if ($isElevated)
{
# We are running as an administrator, so change the title and background color to indicate this
$Host.UI.RawUI.WindowTitle = $myInvocation.MyCommand.Definition + "(Elevated)"
$Host.UI.RawUI.BackgroundColor = "DarkBlue"
Clear-Host
}
else {
# We are not running as an administrator, so relaunch as administrator
# Create a new process object that starts PowerShell
$psi = New-Object System.Diagnostics.ProcessStartInfo 'powershell.exe'
# Specify the current script path and name as a parameter with and support for scripts with spaces in its path
$psi.Arguments = '-ExecutionPolicy Bypass -File "{0}"' -f
$script:MyInvocation.MyCommand.Path
# Indicate that the process should be elevated.
$psi.Verb = 'RunAs'
# !! For .Verb to be honored, .UseShellExecute must be $true
# !! In .NET Framework, .UseShellExecute *defaults* to $true,
# !! but no longer in .NET Core.
$psi.UseShellExecute = $true
# Start the new process, wait for it to terminate, then
# exit from the current, unelevated process, passing the exit code through.
exit $(
try { ([System.Diagnostics.Process]::Start($psi).WaitForExit()) } catch { Throw }
)
}
# Run your code that needs to be elevated here...
Set-DnsClientServerAddress -InterfaceIndex 9 -ResetServerAddresses

How do I set $ConfirmPreference = "None" for a PowerShell instance?

I am trying to run PowerShell scripts using C# using this link as a reference.
So far I have got:
try
{
using (PowerShell PowerShellInstance = PowerShell.Create())
{
PowerShellInstance.AddCommand(scriptPath);
var PSOutput = PowerShellInstance.Invoke();
if (PowerShellInstance.Streams.Error.Count > 0)
{
foreach (var line in PowerShellInstance.Streams.Error)
{
Console.WriteLine(line);
}
return false;
}
else
{
return true;
}
}
}
catch (Exception ex)
{
return false;
}
Which keeps throwing an exception:
"AuthorizationManager check failed."
Inner Exception: A command that prompts the user failed because the
host program or the command
type does not support user interaction. The host was attempting to
request confirmation with the following message: Run only scripts that
you trust. While scripts from the internet can be useful, this script
can potentially harm your computer. If you trust this script, use the
Unblock-File cmdlet to allow the script to run without this warning
message. Do you want to run C:\PowerShellScripts\MyScript.ps1?
So looking at the Exception I can see it's asking me to confirm the script but there is no window for the user to interact, hence the exception.
So I started looking at how to stop the confirmation text and found Powershell New-Item: How to Accept Confirmation Automatically
But even adding:
PowerShellInstance.AddScript("$ConfirmPreference = \"None\"");
PowerShellInstance.Invoke();
Before executing my script didn't work. So is there a way of setting $ConfirmPreference = "None" for my PowerShell instance using C#?
While the accepted answer solved this specific problem, the correct way of setting $ConfirmImpact preference variable is via session state:
var sessionState = InitialSessionState.CreateDefault();
sessionState.Variables.Add(new SessionStateVariableEntry("ConfirmPreference", ConfirmImpact.None, ""));
using (PowerShell shell = PowerShell.Create(sessionState))
{
// execute commands, etc
}
(This is for visitors who came here from Google search results)
I think it has something to do with the Execution Policy. You can query the execution policy with the Cmdlet Get-ExecutionPolicy. You can:
change the Execution Policy to (for example): "Unrestricted" by
using Set-ExecutionPolicy Unrestricted or
run your script by running powershell.exe -ExecutionPolicy Bypass C:\PowerShellScripts\MyScript.ps1 or
unblock the script by using the Cmdlet Unblock-File C:\PowerShellScripts\MyScript.ps1

The term 'New-CsOnlineSession' is not recognized as the name of a cmdlet

I am trying to run a power shell script from the c#.
When running the power shell script only, it runs successfully. But , while trying to run the same script from the c# . I get the error "The term 'New-CsOnlineSession' is not recognized as the name of a cmdlet"
Here is the code:
public static void GetLyncUsers(string userName, string password)
{
using (PowerShell powerShellInstance = PowerShell.Create())
{
var script = string.Format("$Username =\"{0}\"\n" +
"$Password =\"{1}\"\n" +
"$secpasswd = ConvertTo-SecureString $Password -AsPlainText -Force\n" +
"$cred = new-Object System.Management.Automation.PSCredential ($Username , $secpasswd)\n" +
"$CSSession = New-CsOnlineSession -Credential $cred\n" +
"Import-PSSession $CSSession -AllowClobber\n" +
"Get-CsOnlineUser", userName, password);
// use "AddScript" to add the contents of a script file to the end of the execution pipeline.
// use "AddCommand" to add individual commands/cmdlets to the end of the execution pipeline.
powerShellInstance.AddScript(script);
// use "AddParameter" to add a single parameter to the last command/script on the pipeline.
// invoke execution on the pipeline (collecting output)
Collection<PSObject> psOutput = powerShellInstance.Invoke();
// check the other output streams (for example, the error stream)
if (powerShellInstance.Streams.Error.Count > 0)
{
// I am getting this error
//The term 'New-CsOnlineSession' is not recognized as the name of a cmdlet
}
}
Is there anything i am missing? I am new to powershell in general.
Solution:
using (PowerShell powerShellInstance = PowerShell.Create())
{
// Import-Module lynconlineconnector
powershellInstance.Commands
.AddCommand("Import-Module")
.AddArgument("lynconlineconnector");
// rest of your code ....
Why?
When running an interactive session in powershell v3 and higher, the host traps CommandNotFound, and searches every module in all the known locations. If it finds the command, it automatically loads the module, and proceeds normally.
When running same script in C#, the CommandNotFound exception isn't trapped, and hence you get the error.
Related Question(s):
PowerShell - How to Import-Module in a Runspace
#PSTip Cmdlet Discovery and Module auto-loading
I ran into the same problem. You have to install the Lync/Skype For Business Online Connector as described on Technet
The setup program copies the Skype for Business Online Connector
module (and the New-CsOnlineSession cmdlet) to your local computer.

Calling PowerShell cmdlet from C# throws CommandNotFoundException

I'm trying to call the Add-AppxPackage cmdlet from C#. I found the MSDN article on running PowerShell from C# code. I have referenced the System.Management.Automation assembly and have tried the following code snippets, all of which result in the same exception when trying to call powerShell.Invoke():
System.Management.Automation.CommandNotFoundException was unhandled
The term 'Add-AppxPackage' is not recognized as the name of a cmdlet,
function, script file, or operable program. Check the spelling of the
name, or if a path was included, verify that the path is correct and
try again.
Snippet 1:
var powerShell = PowerShell.Create();
powerShell.AddCommand(string.Format("Add-AppxPackage '{0}'", appxFilePath));
foreach (PSObject result in powerShell.Invoke())
{
Console.WriteLine(result);
}
I understand why this doesn't work, since I shouldn't be providing parameters in the AddCommand() function.
Snippet 2:
var powerShell = PowerShell.Create();
powerShell.AddCommand("Add-AppxPackage");
powerShell.AddParameter("Path", appxFilePath);
foreach (PSObject result in powerShell.Invoke())
{
Console.WriteLine(result);
}
Snippet 3:
var powerShell = PowerShell.Create();
powerShell.AddCommand("Add-AppxPackage");
powerShell.AddArgument(appxFilePath);
foreach (PSObject result in powerShell.Invoke())
{
Console.WriteLine(result);
}
My C# project targets .Net 4.5, and if I do powerShell.AddCommand("Get-Host") it works and the Version it returns back is 4.0. Add-AppxPackage was added in v3.0 of PowerShell, so the command should definitely exist, and it works fine if I manually run this command from the Windows PowerShell command prompt.
Any ideas what I am doing wrong here? Any suggestions are appreciated.
-- Update --
I found this post and this one, and realized there is a AddScript() function, so I tried this:
Snippet 4:
var powerShell = PowerShell.Create();
powerShell.AddScript(string.Format("Add-AppxPackage '{0}'", appxFilePath));
var results = powerShell.Invoke();
foreach (PSObject result in results)
{
Console.WriteLine(result);
}
And it does not throw an exception, but it also doesn't install the metro app, and the "results" returned from powerShell.Invoke() are empty, so I'm still at a loss...
-- Update 2 --
So I decided that I would try just creating a new PowerShell process to run my command, so I tried this:
Process.Start(new ProcessStartInfo("PowerShell", string.Format("-Command Add-AppxPackage '{0}'; $key = $Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyUp')", appxFilePath)));
but it still throws the same error that Add-AppxPackage is not a recognized cmdlet.
ANSWER
If you follow the long comment thread on robert.westerlund's answer, you will see that for some reason when running/launched from Visual Studio, PowerShell was not including all of the PSModulePaths that it does when running straight from a PowerShell command prompt, so many modules are not present. The solution was to find the absolute path of the module that I needed (the appx module in my case) using:
(Get-Module appx -ListAvailable).Path
And then import that module before trying to call one of its cmdlets. So this is the C# code that worked for me:
var powerShell = PowerShell.Create();
powerShell.AddScript(string.Format(#"Import-Module 'C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\Appx\Appx.psd1'; Add-AppxPackage '{0}'", appxFilePath));
var results = powerShell.Invoke();
UPDATED ANSWER
You can see from this other post I opened, that the problem was with a bug in a Visual Studio extension (in my case StudioShell) causing not all of the PSModulePaths to be loaded. After uninstalling that extension all of the modules were loaded correctly and I no longer needed to manually import the module.
In PowerShell there is a difference between terminating errors (which stops the execution) and non-terminating errors (which are just written to the error stream).
If you want to create a non-terminating error in a function of your own, just use the Write-Error cmdlet. If you want to create a terminating error, use the Throw keyword. You can read more about these concepts if you run Get-Help Write-Error, Get-Help about_Throw and Get-Help about_Try_Catch_Finally.
Using the Add-AppxPackage with a non existing package is a non terminating error and will thus be written to the error stream, but no execution halting exception will be thrown. The following code tries to add a non existing package and then writes the error to the console.
var powerShell = PowerShell.Create();
powerShell.AddScript("Add-AppxPackage NonExistingPackageName");
// Terminating errors will be thrown as exceptions when calling the Invoke method.
// If we want to handle terminating errors, we should place the Invoke call inside a try-catch block.
var results = powerShell.Invoke();
// To check if a non terminating error has occurred, test the HadErrors property
if (powerShell.HadErrors)
{
// The documentation for the Error property states that "The command invoked by the PowerShell
// object writes information to this stream whenever a nonterminating error occurs."
foreach (var error in powerShell.Streams.Error)
{
Console.WriteLine("Error: " + error);
}
}
else
{
foreach(var package in results)
{
Console.WriteLine(package);
}
}

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