PowerShell profiles

Powershell has one oddity that is both useful but somewhat wierd. when you first launch PowerShell, it looks for "profile scripts" and if they are found, they are launched automatically. That's useful, but the location and filename of this setup script is hard-coded and fixed. The script located at [All Users]\[All Users Documents]\WindowsPowerShell\Microsoft.PowerShell_Profile.PS1 and [Current User]\[My Documents]\WindowsPowerShell\Microsoft.PowerShell_Profile.PS1 are run. This allows you to pre-load and preconfigure a variety of stuff, which is nice. Why they are in a hard coded place under My Documents with such a long name, I don't know.

As a side note, PowerShell will only run digitally signed scripts so you might need change that setting to create scripts of your own. You should probably just make an internal CA for signing scripts, though.

Another interesting thing is the transcript function. The transcript will record to text file all of the contents of the shell window. Whatever you type and whatever is reported to the screen will be recorded. I think that is very useful, so I've come up with a profile script that will start the transcript automatically. Of course, that's a lot of text files, so I have the script clean that up for me, too.

Here is my script, colored and highlighted by PowerGUI (an open source PowerShell tool). I may have to experiment with the formatting to get it work correctly in the blog screen.

[string]$TimeStamp= get-date -uformat "%Y-%m-%d at %H%M%S"
$MaxAge = New-TimeSpan -days 7
$LaunchTime = Get-Date
$MyDocsPath = Get-ItemProperty "HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
$TranscriptFolder = $MyDocsPath.Personal + "\WindowsPowerShell"
[string]$TranscriptPath = $MyDocsPath.Personal + "\WindowsPowerShell\" + $TimeStamp + " Transcript.txt"
[string]$LaunchPath = $MyDocsPath.Personal + "\Script Experiments"
start-transcript $TranscriptPath
get-childitem -Path $TranscriptFolder -Filter *.txt | where { ($LaunchTime - $_.CreationTime ) -gt $MaxAge } | Remove-Item
cd $LaunchPath

The $TimeStamp variable is a date time formatted YYYYMMDD at HHDDSS so that the transcript that gets created has a unique, useful name.

The $MaxAge is how long I want to keep the transcripts. Date comparisions in PowerShell work completely differently than VBScript so you have to create a new date-time object for comparisons. It took a lot of experiments to get that working the way I wanted it to.

I read the location of My Documents from registry. I picked the registry so that I can be sure to grab the path of a relocated My Documents folder. I haven't tested this with a network-relocated My Documents folder, yet. One thing about reading the registry from PowerShell, you grab the key (the folder), then you retrive each value as a property. So, you'll notice that I grab the "Shell Folders" as $MyDocsPath and then get the value for the entry "Personal" by requesting the $MyDocsPath.Personal value. That is definately different than VBScript.

The $LaunchPath variable is just where I happen to keep my scripts, you would need to change this or delete this to match your preferences.

The script than purges any *Transcript.txt files that are older than the max age variable, starts the transcript for the current session, and changes the current directory to what I put into the $LaunchPath variable.

Let me know what you think...