I've written myself a script to check for vm-folders in vmware vcenter that dont match the corresponding vmname. There are a few automatically deployed VMs which i need to exclude from this check. Those VMs are always similarly named, but with an incremented number at the end. I've declared an array $Vmstoginrore containing strings of them and i'm trying to match my $VmName with this array but it does not work. Ive also tried it with like but i cannot seem to get this to work.
$Vmstoignore=@( "Guest Introspection","Trend Micro Deep Security")
$VmName = "Guest Introspection (4)"
if ($Vmstoignore-match $VmName ){
Write-Output "does match"
}
else {
Write-Output "doesn't match"
}
As of v7.2.x, PowerShell offers no comparison operators that accept an array of comparison values (only the input operand - the LHS - is allowed to be an array).
However, sine the -match
operator is regex-based, you can use a single regex with an alternation (|
) to match multiple patterns.
-match
(e.g. 'foo' -match '^f'
- in your question, the operands are mistakenly reversed).The following code shows how to construct the regex programmatically from the given, literal array elements (VM name prefixes):
# VM name prefixes to match.
$Vmstoignore = @("Guest Introspection", "Trend Micro Deep Security")
# Construct a regex with alternation (|) from the array, requiring
# the elements to match at the *start* (^) of the input string.
# The resulting regex is:
# ^Guest\ Introspection|^Trend\ Micro\ Deep\ Security
$regex = $Vmstoignore.ForEach({ '^' + [regex]::Escape($_) }) -join '|'
# Sample input name.
$VmName = "Guest Introspection (4)"
# Now match the input name against the regex:
# -> $true
$VmName -match $regex
Note:
You may alternatively construct the regex directly as a string, in which case you need to manually \
-escape any regex metacharacters, such as .
(no escaping is required with your sample array):
$regex = '^Guest Introspection|^Trend Micro Deep Security'
Note that [regex]::Escape()
escapes
(spaces) as \
, even though spaces aren't metacharacters. However, if the x
(IgnorePatternWhiteSpace
) regex option is in effect (e.g. by placing (?x)
at the start of the regex), spaces that are a meaningful part of the pattern do require this escaping. In the absence of this option (it is off by default), escaping spaces is not necessary.
For a detailed explanation of the regex and the ability to interact with it, see this regex101.com page.