Powershell assistance - powershell

Question

I am currently using the below PS script to check if the currents months MS patches are installed on the system. The script is set to check the $env:COMPUTERNAME.mbsa and the Patch_NA.txt file and send the result to the $env:COMPUTERNAME.csv file.
I now need to modify this script to also pull information from other POS devices in the same location (C:\Users\Cambridge\SecurityScans) and send the results to the $env:COMPUTERNAME.csv file.
The POS devices are listed like this:
172.26.210.1.mbsa
172.26.210.2.mbsa
172.26.210.3.mbsa
and so forth.
The IP range at all our locations (last octet) is 1 - 60. Any ideas on how I can set this up?
Script:
$logname = "C:\temp\PatchVerify\$env:COMPUTERNAME.csv"
[xml]$x=type "C:\Users\Cambridge\SecurityScans\$env:COMPUTERNAME.mbsa"
#This list is created based on a text file that is provided.
$montlyPatches = type "C:\Temp\PatchVerify\Patches_NA.txt"|
foreach{if ($_ -mat"-KB(? <KB>\d+)"){$matches.KB}}
$patchesNotInstalled=$x.SecScan.check | where {$_.id -eq 500} |foreach{`
$_.detail.updatedata|where {$_.isinstalled -eq "false"}}|Select -expandProperty KBID
$patchesInstalled =$x.SecScan.check | where {$_.id -eq 500} |foreach{`
$_.detail.updatedata|where {$_.isinstalled -eq "true"}}|Select -expandProperty KBID
"Store,Patch,Present"> $logname
$store = "$env:COMPUTERNAME"
foreach ($patch in $montlyPatches)
{
$result = "Unknown"
if ( $patchesInstalled -contains $patch)
{
$result = "YES"
}
if ( $patchesNotInstalled -contains $patch)
{
$result = "NO"
}
"$store,KB$($patch),$result" >>$logname
}

Answer 1

You can find lots of information on creating functions on the web, but a simple example would be:
Function Check-Patches{
Param($FileName)
$logname = "C:\temp\PatchVerify\$FileName.csv"
[xml]$x=type "C:\Users\Cambridge\SecurityScans\$FileName.mbsa"
The rest of your existing code goes here...
}
Check-Patches "$env:ComputerName"
For($i=1;$i -le 60;$i++){
Check-Patches "172.26.210.$i"
}
If you need me to break down anything in that let me know and I'll go into further explanation, but from what you already have it looks like you have a decent grasp on PowerShell theory and just needed to know what resources are available.
Edit: I updated my example to better fit your script, having it accept a file name, and then applying that file name to the $logname and $x variables within the function.
The break down...
First we declare that we are creating a Function using the Function keyword. Following that is the name of the function that you will use later to call it, and an opening curly brace to start the scriptblock that makes up the actual function.
Next is the Param line, which in this case is very simple only declaring one variable as input. This could alternatively be done as Function Check-Patches ($FileName){ but when you start getting into more advanced functions that only gets confusing, so my recommendation is to stick with putting the parameters inside the function's scriptblock. This is the first thing you want inside of your function in most cases, excluding any Help that you would write up for the function.
Then we have updated lines for $logname and [xml]$x that use the $FileName that the function gets as input.
After that comes all of your code that parses the patch logs, and outputs to your CSV, and the closing curly brace that ends the scriptblock, and the function.
Then we call it for the ComputerName, and run a For loop. The For loop runs everything between 1 and 60, and for each loop it uses that number as the last octet of the file name to feed into the function and check those files.
A few comments on the rest of your code. $monthlypatches = could be changed to = type | ?{$_ -match "-KB(? <KB>\d+)"}|%{$matches.KB} so that the results are filtered before the ForEach loop, which could cut down on some time.
On the $patchesInstalled and $patchesNotInstalled lines you don't need the backtick at the end of that line. You can naturally have a linebreak after the beginning of the scriptblock for a ForEach loop. Having it there can be hard to see later if the script breaks, and if there is anything after it (including a space) the script can break and throw errors that are hard to track down.
Lastly, you loop through $x twice, and then $monthlyPatches once, and do a lot of individual writes to the log file. I would suggest creating an array, filling it with custom objects that have 3 properties (Store, Patch, and Present), and then outputting that at the end of the function. That changes things a little bit, but then your function outputs an object, which you could pipe to Export-CSV, or maybe later you could want it to do something else, but at least then you'd have it. To do that I'd run $x through a switch to see if things are installed, then I'd flush out the array by setting all of the monthlypatches that aren't already in that array to Unknown. That would go something like:
Function Check-Patches{
Param($FileName)
$logname = "C:\temp\PatchVerify\$FileName.csv"
[xml]$x=type "C:\Users\Cambridge\SecurityScans\$FileName.mbsa"
$PatchStatus = #()
#This list is created based on a text file that is provided.
$monthlyPatches = GC "C:\Temp\PatchVerify\Patches_NA.txt"|?{$_ -match "-KB(? <KB>\d+)"} | %{$matches.KB}
#Create objects for all the patches in the updatelog that were in the monthly list.
Switch($x.SecScan.Check|?{$_.KBID -in $monthlyPatches -and $_.id -eq 500}){
{$_.detail.updatedata.isinstalled -eq "true"}{$PatchStatus+=[PSCustomObject][Ordered]#{Store=$FileName;Patch=$_.KBID;Present="YES"};Continue}
{$_.detail.updatedata.isinstalled -eq "false"}{$PatchStatus+=[PSCustomObject][Ordered]#{Store=$FileName;Patch=$_.KBID;Present="NO"};Continue}
}
#Populate all of the monthly patches that weren't found on the machine as installed or failed
$monthlyPatches | ?{$_ -notin $PatchStatus.Patch} | %{$PatchStatus += [PSCustomObject][Ordered]#{Store=$FileName;Patch=$_;Present="Unknown"}}
#Output results
$PatchStatus
}
#Check patches on current computer
Check-Patches "$env:ComputerName"|Export-Csv "C:\temp\PatchVerify\$env:ComputerName.csv" -NoTypeInformation
#Check patches on POS Devices
For($i=1;$i -le 60;$i++){
Check-Patches "172.26.210.$i"|Export-Csv "C:\temp\PatchVerify\172.26.210.$i.csv" -NoTypeInformation
}