is a tool to standardize logging without the need to use new function calls in your PowerShell scripts. Just configure the log location (or don't) and start logging with your standard Write functions.

• Quick Start
• Description
• Notes
  • Bypassing Write-Log
  • Debug with Write-Information
  • Debug PSWriteLog (or Your Application)

ℹ: For more details, check out the wiki!

Quick Start

Before you do anything, install PSWriteLog. Create a new script, mine will be called foo.ps1 and will contain the following lines:

#Requires -Modules PSWriteLog
Write-Host 'Hello World!'

I love how clean and simple that is! However, the #Requires statement will terminate if you don't have PSWriteLog installed. Since we're not introducing any new functions, PSWriteLog shouldn't be required to just run the script. For more explanation about his example, check out the wiki!

To ensure there are no errors if you share your script with someone that doesn't have PSWriteLog installed, you will want to use Import-Module.

ℹ: For more details, check out the wiki!

Description

PSWriteLog has a private function called Write-Log that does all the logging for you. It's a private function because we don't want you to use it. Instead, we've created proxy functions for the Write-* functions so you don't have to learn to use a new function. These proxy functions keep the original functionality of the function intact, while also sending the outputted message to the Write-Log function. By default, Write-Log will write messages to a log file in CMTrace compatible format, but Legacy (plain-text) file format is also available. To configure PSWriteLog, what you need to do is change the default actions of the Write-Log parameters. You can specify default parameters using environment variables. Here's an example of specifying the Log file path and log type globally:

$env:PSWriteLogFilePath = "${env:SystemRoot}\Logs\MyApp.log"
$env:PSWriteLogType = 'Legacy'

ℹ: For more details, check out the wiki!

Notes

The rest of this stuff is really beyond the scope of PSWriteLog, but I hope it's useful information ...

Bypassing Write-Log

There may be instances when you are using PSWriteLog that you want to output to the screen, but not save the output to the log. Maybe you have sensitive data (e.g.: passwords, auth tokens, etc.) that you don't want saved to a log file. In those cases, you can bypass PSWriteLog's logging functionality, by telling PowerShell to use the original Microsoft function using its full path. Here's how you get the full path to Write-Host:

Get-Command Write-Host

That'll give you the source and other information:

CommandType	Name	Version	Source
Cmdlet	Write-Host	3.1.0.0	Microsoft.PowerShell.Utility

You can then call the function and provide the source path as well:

Microsoft.PowerShell.Utility\Write-Host "Password: $password"

Debug with Write-Information

I like to use Write-Information to debug because I send the messages to a variable and filter them later. Instead of scrolling through a ton of Verbose or Debug output, I can just filter down to the messages that came tagged the way I was expecting. Here's some sample code for you to play with and see what I'm talking about:

function foo {
    [CmdletBinding()]
    Param()
    Microsoft.PowerShell.Utility\Write-Information 'Test 1'
    Microsoft.PowerShell.Utility\Write-Information "[foo] Processor: $env:PROCESSOR_IDENTIFIER" -Tags 'foo','Test'
    Microsoft.PowerShell.Utility\Write-Information 'Test 2'
}
foo -InformationVariable bar
$bar | ?{ $_.Tags -eq 'foo' }

If you aren't near a PowerShell terminal, here's a quick demo:

Debug PSWriteLog (or Your Application)

In PSWriteLog every Write-Information that I use, bypasses the the log. This means that my Write-Information calls should never end up in your log file. They also have two tags:

• VertigoRay\PSWriteLog
• The Function Name (e.g.: Write-Log)

For me, when I'm working on PSWriteLog and I want to see just those messages, I'll do something like this:

$InformationPreference = 'Continue'

Write-Host 'Testing a thing' -InformationVariable 'foo'
$foo | ?{ $_.Tags -eq 'Write-Log' }

With that I'll see just want I want to see. You can use the same ideas in your scripts by always tagging your calls to Write-Information so that when you want to redirect them to a variable for easy filtering, you can.

Cheers! 🍻