Powershell: String concatenation with underscore confusion

In putting together a simple powershell script to download a file and store it on a filesystem, I came across some strangeness with the user of Underscore (_) when concatenation variables. Essentially, I wanted to create a filename based upon 2 powershell variables, separated by an underscore.

I wanted my filename to be: 

Richard_Brown.txt

And my powershell read something like:

$File = "C:\$FirstName_$LastName"

Interestingly, when run in my script the output of $File would be 

C:\Brown.txt

I was suspicious of the underscore and sure enough this was the causing the issue. I stumbled upon this thread on Stackoverflow which explains the issue as the underscore is a valid character in identifiers so its looking for a variable named $FirstName_.

There are 2 workarounds for this:

1) $File = "C:\$FirstName`_$LastName"

2) $File = "C:\${FirstName}_$LastName"

Powershell: change start location of shell

I'm starting to build up a repository of powershell scripts and I have been getting a little frustrated that every time I open up the PS shell, it defaults to my user directory:


I then have to "cd" to the location of my scripts to start working. Back a couple years ago, I remember going through some steps to personalise my PS shell (although obviously that knowledge didn't stick!) and so I thought i'd find out how to change the default dir to be my PS scripts folder.

This article suggested that I just needed to edit the Microsoft.Powershell_profile.ps1 file in the WindowsPowerShell directory in My Documents. Easy.

Off i went to that directory, only to discover it wasn't there - not hidden or protected it just didn't exist. Thinking that the location may be different on my setup, I ran the $Profile command in PS and it confirmed that it should be in C:\Documents and Settings\RichardB\My Documents\WindowsPowerShell



Then it dawned on me. Perhaps I just need to create the directory and file myself. So I navigated to My Documents and created the WindowsPowerShell folder and a Microsoft.Powershell_profile.ps1 file. The final step was to edit the file to change the behaviour I was after:

Set-Location C:\PS



A quick restart of Powershell and there we have it. A bit of time saved when using Powershell.

Powershell: use it or lose it

Powershell has been around a good few years now and I've heard so much good stuff about it but i'm still finding it difficult to "get into". As i've said before, my favoured method of learning something is to use it in anger but I find that I go through patches of using it and then just naturally drift away. Use it or lose it, is the phrase that springs to mind.

Perhaps this is because at the moment, I don't have a huge server farm to deal with and so maintenance tasks aren't onerous and so its quite tough to force yourself to use a technology if you don't need to.

In saying that, I recognise how its a powerful language and could make many tasks (eg reading error logs) much more straight forward IF you need to do those tasks on multiple servers frequently i.e Powershell helps you benefit from economies of scale.

This year, i'm going to try and make a concerted effort to "learn" powershell and add this string to my bow as I believe its going to be a must have for any database professional in the near future.