6 Responses to Writing CMTrace format Log files with Powershell

1. Terry Wallner says:

   January 31, 2016 at 7:53 am

   Works as Advertised! Thank you!

   Reply
2. Scott says:

   August 28, 2016 at 11:05 pm

   Thanks for the code. I’m running PS 5 on Win10:
   Name Value
   —- —-
   PSVersion 5.0.10586.494
   PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
   BuildVersion 10.0.10586.494
   CLRVersion 4.0.30319.42000
   WSManStackVersion 3.0
   PSRemotingProtocolVersion 2.3
   SerializationVersion 1.1.0.1

   OOTB, I get duplicate messages for WARNING and ERROR. I can probably track that one down.

   However, I also get an error when I run this code:

   # User defined error
   Write-CMTraceLog -Logfile C:\PowerShell\Scripts\Junk\foo.log -Message Message -Type Error -WriteBackToHost -ErrorAction continue

   # Cmdlet error (your example use case)
   Try{
   Get-Process -Name DoesnotExist -ea continue
   }
   Catch{
   Write-CMTraceLog -Logfile “C:\PowerShell\Scripts\Junk\foo.log” -Message $Error[0] -Type Error
   }

   The property ‘exception’ cannot be found on this object. Verify that the property exists.
   At C:\PowerShell\Functions\Write-CMTraceLog.ps1:173 char:16
   + if($Message.exception.Message){
   + ~~~~~~~~~~~~~~~~~~~~~~~~~~
   + CategoryInfo : NotSpecified: (:) [], PropertyNotFoundException
   + FullyQualifiedErrorId : PropertyNotFoundStrict

   Get-Process : Cannot find a process with the name “DoesnotExist”. Verify the process name and call the
   cmdlet again.
   At C:\PowerShell\Scripts\Junk\Write-CMTraceLogTest.ps1:9 char:5
   + Get-Process -Name DoesnotExist -ea continue
   + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   + CategoryInfo : ObjectNotFound: (DoesnotExist:String) [Get-Process], ProcessCommandExcepti
   on
   + FullyQualifiedErrorId : NoProcessFoundForGivenName,Microsoft.PowerShell.Commands.GetProcessCommand

   The error line is not written to the log file.

   I tried changing the line $Message.exception.Message to $Message -is [System.Exception] but that didn’t fix it.

   Reply
   • wolffhaven says:

     August 31, 2016 at 10:32 pm

     Hey Scott,

     I’ve updated the script in the article with the latest version that I’m running. That will fix the duplicate issues.

     I ran the following:

     # User defined error
     Write-CMTraceLog -Logfile C:\PowerShell\Scripts\Junk\foo.log -Message Message -Type Error -WriteBackToHost -ErrorAction continue

     And this came back ok for me, i got the expected result. Maybe try the updated function I have posted and see if it fixes your issue with this one.

     I then tried the other example you were having issues with:

     # Cmdlet error (your example use case)
     Try{
     Get-Process -Name DoesnotExist -ea continue
     }
     Catch{
     Write-CMTraceLog -Logfile “C:\PowerShell\Scripts\Junk\foo.log” -Message $Error[0] -Type Error
     }

     And I think i found the issue. When using a Try/Catch block you need a terminating error. I think this is why you need to set the erroraction to stop. If it’s set to continue, the catch block is skipped. Try for yourself by adding a Write-Host line in the catch block.

     try{
     Get-Process -Name Doesnotexist -ea Stop
     }
     catch{
     Write-CMTraceLog -Logfile “C:\temp\foo.log” -Message $Error[0] -Type Error
     Write-host ‘test’
     }

     When you run this, you’ll see that the write-host is skipped.

     If you try running:

     Try{
     Get-Process -Name DoesnotExist -ea stop
     }
     Catch{
     Write-CMTraceLog -Logfile “C:\PowerShell\Scripts\Junk\foo.log” -Message $Error[0] -Type Error
     }

     This should work for you.

     Let me know how you go!

     I have a question for you if you got time…. This function serves a purpose for me when running scripts as scheduled tasks etc, stuff where I won’t be able to view Write-Verbose or see the output to the console to see if everything has run ok. While it works, (most of the time), there’s got to be a better way. Have you stumbled on any other ways to do logging when running powershell scripts? Maybe using Start-Transcript might be a better way but then that’s a bit TOOOOO verbose?

     Reply
3. Scott says:

   September 11, 2016 at 4:34 pm

   Hey Wolffhaven,

   Thanks for the quick reply. And apologies for my very late reply. I’ve just been really really busy lately; I’m on a global committee that is taking up a lot of my free time.

   I had never used cmtrace before. After “playing” with it a bit, I thought it was “ok”, but I wished it was extensible with respect to the columns available. For example, I might want to put elapsed time for each step in the cmtrace log. Still, I might continue to use it…not sure.

   Anyway, to make a long story short, I Googled a lot more and came across NLog. Here are a few links:

   http://nlog-project.org/
   https://github.com/NLog/NLog/wiki/Extending-NLog
   http://stackoverflow.com/questions/710863/log4net-vs-nlog (long but good)
   https://www.loggly.com/blog/benchmarking-5-popular-net-logging-libraries/

   https://rafpe.ninja/2015/08/31/powershell-using-nlog-to-create-logs/
   https://gallery.technet.microsoft.com/scriptcenter/PowerShell-Logging-0c8f1c50
   https://thomasswilliams.github.io/2016/04/29/nlog-in-powershell.html

   There’s many more hits, that’s enough for now! Just Google “NLog”, “NLog vs.”, and “NLog Powershell”.

   In my case, I’d written a PS script that used the .Net SqlBulkCopy class to bulk copy SQL Server data from one database to another. I added a lot of nice console output messages, which was great for interactive use. But what about when we go production and want to run the script in batch? Start-Transcript works “ok”(ish), but didn’t have the logging I wanted.

   I don’t know the log format that cmtrace needs…but you do. So, if I were you (i.e. I had your cmtrace knowledge), I would 1) read up on NLog - it looks like a good package to have in your “kit bag”, and 2) write an extension to NLog for cmtrace output. I’m no .Net expert, but the Wiki made it look relatively easy to extend NLog to different output formats.

   Perhaps you could even submit your extension to the NLog project for inclusion in a future release?

   I will certainly read up on NLog when I get more time, and learn to incorporate it into my scripts where I need advanced logging. And if I get the chance to do some .Net programming, it’s cool that what I’ve learned with NLog is transferrable.

   I hope this helps. And thanks again for your reply. If you have further questions feel free to email directly, or obviously share here if you think it’s useful to everyone.

   Reply
   • wolffhaven says:

     September 11, 2016 at 9:06 pm

     Thanks Scott, I’ll check out Nlog it looks promising!

     Reply
4. Young Pae says:

   October 11, 2016 at 3:11 am

   I have been waiting for this script for so long! Thank you so much. One thing though, on PowerShell ISE v4.0, -WriteBackToHost:$true doesn’t write back to the host screen. Is there anything that I can do to fix? Thanks,

   Reply