Use -Notlike to Filter out Multiple Strings in Powershell
I'm Trying to Read the Event Log for a Security Audit for All Users Except Two, but Is It Possible to Do That with the -Notlike Operator? It's Something Like...
I'm trying to read the event log for a security audit for all users except two, but is it possible to do that with the -notlike operator?
It's something like that:
Get-EventLog -LogName Security | where {$_.UserName -notlike @("*user1","*user2")}
I have it working for a single user, like:
Get-EventLog -LogName Security | where {$_.UserName -notlike "*user1"}
8 Answers
V2 at least contains the -username parameter that takes a string[], and supports globbing.
V1 you want to expand your test like so:
Get-EventLog Security | ?{$_.UserName -notlike "user1" -and $_.UserName -notlike "*user2"}
Or you could use "-notcontains" on the inline array but this would only work if you can do exact matching on the usernames.
... | ?{@("user1","user2") -notcontains $_.username}
I think Peter has the right idea. I would use a regular expression for this along with the -notmatch operator.
Get-EventLog Security | ?{$_.Username -notmatch '^user1$|^.*user$'}
In order to support "matches any of ..." scenarios, I created a function that is pretty easy to read. My version has a lot more to it because its a PowerShell 2.0 cmdlet but the version I'm pasting below should work in 1.0 and has no frills.
You call it like so:
Get-Process | Where-Match Company -Like '*VMWare*','*Microsoft*'
Get-Process | Where-Match Company -Regex '^Microsoft.*'
filter Where-Match($Selector,[String[]]$Like,[String[]]$Regex) {
if ($Selector -is [String]) { $Value = $_.$Selector }
elseif ($Selector -is [ScriptBlock]) { $Value = &$Selector }
else { throw 'Selector must be a ScriptBlock or property name' }
if ($Like.Length) {
foreach ($Pattern in $Like) {
if ($Value -like $Pattern) { return $_ }
}
}
if ($Regex.Length) {
foreach ($Pattern in $Regex) {
if ($Value -match $Pattern) { return $_ }
}
}
}
filter Where-NotMatch($Selector,[String[]]$Like,[String[]]$Regex) {
if ($Selector -is [String]) { $Value = $_.$Selector }
elseif ($Selector -is [ScriptBlock]) { $Value = &$Selector }
else { throw 'Selector must be a ScriptBlock or property name' }
if ($Like.Length) {
foreach ($Pattern in $Like) {
if ($Value -like $Pattern) { return }
}
}
if ($Regex.Length) {
foreach ($Pattern in $Regex) {
if ($Value -match $Pattern) { return }
}
}
return $_
}
don't use -notLike, -notMatch with Regular-Expression works in one line:
Get-MailBoxPermission -id newsletter | ? {$_.User -NotMatch "NT-AUTORIT.*|.*-Admins|.*Administrators|.*Manage.*"}
Easiest way I find for multiple searches is to pipe them all (probably heavier CPU use) but for your example user:
Get-EventLog -LogName Security | where {$_.UserName -notlike "*user1"} | where {$_.UserName -notlike "*user2"}
Scenario: List all computers beginning with XX1 but not names where 4th character is L or P
Get-ADComputer -Filter {(name -like "XX1*")} | Select Name | Where {($_.name -notlike "XX1L*" -and $_.name -notlike "XX1P*")}
You can also count them by enclosing the above script in parens and adding a .count method like so:
(Get-ADComputer -Filter {(name -like "XX1*")} | Select Name | Where {($_.name -notlike "XX1L*" -and $_.name -notlike "XX1P*")}).count
$listOfUsernames = @("user1", "user2", "etc", "and so on")
Get-EventLog -LogName Security |
where { $_.Username -notmatch (
'(' + [string]::Join(')|(', $listOfUsernames) + ')') }
It's a little crazy I'll grant you, and it fails to escape the usernames (in the unprobable case a username uses a Regex escape character like '\' or '(' ), but it works.
As "slipsec" mentioned above, use -notcontains if possible.
Using select-string:
Get-EventLog Security | where {$_.UserName | select-string -notmatch user1,user2}
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