Back to Basics: Use PowerShell to Search Servers for Specific Software

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An old acquaintance, Mr. Rupert Torquil-Smythe Esq. (yes, it is he), recently wanted to know whether a certain piece of software was installed on a particular list of servers in his test lab.

I asked him for the list of servers (servers.txt) and the name of the software (Python). I then wrote and ran this:

$Servers = Get-Content -Path .\servers.txt

foreach ($Server in $Servers) {

$Found = (Get-WmiObject -ComputerName $Server -Query {select name from win32_product where name like '%Python%'} -ErrorAction SilentlyContinue).Name

if ($Found) {

Add-Content -Path .\output.txt -Value "================"

Add-Content -Path .\output.txt -Value "$Server"

Add-Content -Path .\output.txt -Value "================"

foreach ($Entry in $Found) {

Add-Content -Path .\output.txt -Value $Entry

}

Add-Content -Path .\output.txt -Value " "

}

}

 

We end up with a text file (output.txt) containing details of each server that has Python installed.

Things to note:

  • servers.txt is read and stored as a variable ( $Servers)
  • we use WMI to query each of the remote servers, from  $Servers, in a foreach loop
  • the query string is WQL
    • we only ask for the name property to be returned (select name is more efficient than select * )
    • % allows for a wildcard search, e.g. any number of characters before and after Python
  • Win32reg_AddRemovePrograms rather than Win32_Product should be used in production environments