How to redirect ALL console output to a logfile - in an interactive script with questions prompted to the user?

[tommypoulsen]

Hi all
I'm assembling a small Powershell build-script to automate a number of script/app calls, where a lot of output is generated from scripts and app calls that are shown on the console window (which is what I want). I also, however, would like everything that is rendered on the console to be also written to a logfile.
Some of the external scripts/app calls are interactive, asking the user to confirm different actions. This particular property (interactions from the scripts prompting the user for input) is what makes this a hard problem (for me) to solve, as prompted questions does not get visualized (as they are only rendered when typing enter/return) when using e.g. Tee-Object to pipe it to the logfile.
I've been exploring using "start-transcript" to a logfile also, but basically most of the text written from app's and other scripte do not get rendered in the logfile - only on the console.
Soooooo..... any ideas on how to solve this?

(So basically I'd like exactly the same full output to the console and a logfile - and it has to work with interactive scripts/console apps)

[rhubarb-geek-nz]

This kind of thing sounds so generic that I am surprised that it does not already exist.

If I was building a solution to this it would have nothing to do with PowerShell and just be something that captured all console input/output and could be used with any console application. It should be a feature of the Windows Terminal.

In Linux/UNIX you could do this by creating a pseudo-terminal with posix_openpt to act like man in the middle between the real terminal and the command line program. With Win32 I imagine something similar could be done with CreatePseudoConsole.

I would expect this to be easier than trying to work with the PowerShell input and output mechanisms and the ReadLine module.

[tommypoulsen]

Thanks for your response. I'm not sure, however, that I'll have the time to dive into creating a pseudo-console.
I'm really puzzled about the difficulties I'm experiencing with such a rather simple and basic task ;-) - I'd assume a huge number of people are struggling with this also.

[SamErde]

I wonder if there might be an effective use case for Console.SetOut here? I was curious, and here's a quick "ask AI" example of what I mean. It's kinda neat but also feels top-heavy and disruptive with the overrides of built-in cmdlets:

# Define a C# class for writing to both console and log file
Add-Type -TypeDefinition @"
using System;
using System.IO;
using System.Text;

public class MultiTextWriter : TextWriter
{
    private TextWriter consoleOut;
    private StreamWriter fileOut;

    public MultiTextWriter(string filePath)
    {
        consoleOut = Console.Out; // Preserve original console output
        fileOut = new StreamWriter(filePath, true, Encoding.UTF8) { AutoFlush = true };
    }

    private string Timestamp => DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff");

    public override void WriteLine(string value)
    {
        string logEntry = $"[{Timestamp}] {value}";
        consoleOut.WriteLine(logEntry);
        fileOut.WriteLine(logEntry);
    }

    public override void Write(char value)
    {
        consoleOut.Write(value);
        fileOut.Write(value);
    }

    public override Encoding Encoding => consoleOut.Encoding;

    public void Close()
    {
        fileOut.Close();
    }
}
"@

# Log file path
$LogFilePath = "C:\temp\output.log"

# Create an instance of the custom writer and redirect Console output
$MultiWriter = New-Object MultiTextWriter($LogFilePath)
[Console]::SetOut($MultiWriter)

# Function to log different types of messages
function Write-Log {
    param (
        [string]$Message,
        [string]$Type = "INFO"
    )

    $Timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss.fff"
    $LogEntry = "[${Timestamp}] [$Type] $Message"

    # Output to Console and Log File
    [Console]::WriteLine($LogEntry)
}

# Override PowerShell Write-* functions to include logging
function Write-Error {
    param ([Parameter(Mandatory=$true)] [string]$Message)
    Write-Log -Message $Message -Type "ERROR"
    Microsoft.PowerShell.Utility\Write-Error -Message $Message
}

function Write-Warning {
    param ([Parameter(Mandatory=$true)] [string]$Message)
    Write-Log -Message $Message -Type "WARNING"
    Microsoft.PowerShell.Utility\Write-Warning -Message $Message
}

function Write-Information {
    param ([Parameter(Mandatory=$true)] [string]$Message)
    Write-Log -Message $Message -Type "INFO"
    Microsoft.PowerShell.Utility\Write-Information -Message $Message
}

function Write-Verbose {
    param ([Parameter(Mandatory=$true)] [string]$Message)
    Write-Log -Message $Message -Type "VERBOSE"
    Microsoft.PowerShell.Utility\Write-Verbose -Message $Message
}

# Example usage:
Write-Host "This is a regular message."
Write-Error "This is an error message."
Write-Warning "This is a warning message."
Write-Information "This is an information message."
Write-Verbose "This is a verbose message."

# Restore default console output
[Console]::SetOut([System.IO.StreamWriter]::new([Console]::OpenStandardOutput()) -replace '`$')

# Close log writer
$MultiWriter.Close()

[rhubarb-geek-nz]

Would that work with interactive sessions, keyboard input and child processes?

[rhubarb-geek-nz]

This is my solution

It is a console app that creates a pseudo terminal and writes the output to both the real console and the redirected log file.

It is not PowerShell specific, with no command line arguments it uses %COMSPEC%

Eg

C:> "c:\Program Files\rhubarb-geek-nz\Console Logger\conlog.exe" pwsh >pwsh.txt

The file captures everything, including all editing keystrokes and terminal escape codes.

You can run a console text editor within the session and it will capture all your changes.

[tommypoulsen]

Thanks a lot - although I've just done a single test-run this fix seem to do the trick.
I'm still puzzled about the complexity required to solve a rather (in my opinion) simple request, but that's about the inner workings of Windows I guess.

Once again thanks for your response - it's much appreciated.

[tommypoulsen]

I do get a number of weird characters in the logfile (see example screenshot) - but I'm in a better place anyway.

[rhubarb-geek-nz]

As requested "redirect ALL console output to a logfile". What you are seeing at the Ansi escape codes used to control the console output.

The "`e[K" clears the line to the end.

You could happily add a filter to remove these sequences, or else treat it as a post-processing step. Eg

conlog.exe pwsh | Remove-AnsiEscapeCodes > log.txt

But I don't think that is the job of conlog.exe.

It is more complicated than it would otherwise have needed to be because I wanted it to handle focus change notifications and window size changes which could only be done by using ReadConsoleInput.

I have noticed a difference between Windows-10 and Windows-11. With Windows 10 the backspace does come through as 0x08, but with Windows 11 it comes through as 0x7F.

[jman61]

How about tee-object?
It's included in the "microsoft.powershell.utility" module
https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/tee-object?view=powershell-7.4
From 'help *Tee*' :
Tee-Object Cmdlet Microsoft.PowerShell.Uti… Saves command output in a file or variable and also sends it down the pipeline.

Good luck!

[tommypoulsen]

Yeah, and I tried that also - but unfortunately it does not render input lines correctly (i.e. when prompting for user input in a batch file the line is not rendered until after the input has been entered).Regards TommySent from my Galaxy -------- Original message --------From: jman ***@***.***> Date: 06/04/2025 19:02 (GMT+01:00) To: PowerShell/PowerShell ***@***.***> Cc: tommypoulsen ***@***.***>, Author ***@***.***> Subject: Re: [PowerShell/PowerShell] How to redirect ALL console output to a logfile - in an interactive script with questions prompted to the user? (Discussion #25174) How about tee-object? It's included in the "microsoft.powershell.utility" module https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/tee-object?view=powershell-7.4 Good luck! —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***>