This may be a easy question, but I am a bit confused. I have a script that I am using in a point-of-sale environment. 700 PCs. Each named consistently, like this – POS_A_[NUMBER] for each location. For example, POS_A_101, POS_B_101, POS_A_102, POS_B_102, etc...all the way to 700.
In my script, I am running a different process depending on if the machine is an A machine or a B machine.
I do the following:
if($env:COMPUTERNAME.ToLower() -contains "_A_")
# do some stuff
Problem is, if I run:
$env:COMPUTERNAME.ToLower() -contains "_a_"
On a machine that is named POS_A_205, I get a return of False.
However, if I run:
On a machine that is named POS_A_205, I get a return of True
What's the difference? Obviously, I know how to modify the script to function like I want, I just don't get why one is different than the other?
The PowerShell Containment operators (-Contains and -NotCOntains) are designed to work against collections like arrays not strings like $env:COMPUTERNAME. The containment operators only match exact values.
Examples from about_Comparison_Operators help:
PS C:\> "abc", "def" -Contains "def"
PS C:\> "Windows", "PowerShell" -Contains "Shell"
False #Not an exact match
The correct PowerShell operators to use in your case are -match or -like which are case-insensitive. No need to convert to lower case.