I have an array with Strings, let´s say
$data = @(
"Haus",
"Maus",
"Laus",
"Schnitzel",
"Elefant"
)
I want to check it against multiple Regex from an array.
$regexChecks = @(
".*aus.*",
".*fant.*"
)
I tried something like this
$test = $data |? {$regexChecks -notmatch $_}
Write-Host $test
I expect only the String "Schnitzel" as output.
you can put the regex as a string. This would only return Schnitzel
$data = @(
"Haus",
"Maus",
"Laus",
"Schnitzel",
"Elefant"
)
$Regex = '.*Schnitzel.*'
$test = $data | ? { $_ -match $Regex }
Write-Host $test
if you want to check more than one regex, use | to seperate them
This would output Schnitzel and Maus
$Regex = '.*Schnitzel.*|.*Maus.*'
This would return Schnitzel, Maus, Laus and Haus
$Regex = '.*Schnitzel.*|.*aus.*'
EDIT:
You can also have a regex array, and join them with |:
$RegexArray = @(
'.*Schnitzel.*',
'.*Maus.*'
)
$Regex = $RegexArray -join '|'
$test = $data | ? { $_ -match $Regex }
Regular expression matches are much slower operations that literal comparisons (-eq) or even wildcard matches (-like), so you should reduce the number of comparisons as much as possible. Since you have an array of regular expressions you can simply merge them into a single one like this:
$regexChecks = '.*aus.*', '.*fant.*'
$re = $regexChecks -join '|'
If you want multiple literal strings matched you can tell PowerShell to escape them first (just in case they contain special characters like dots, square brackets, etc.):
$re = ($regexChecks | ForEach-Object {[regex]::Escape($_)}) -join '|'
Also, you don't need to add leading and trailing .* to your expressions, because regular expressions aren't anchored by default. Just leave them out.
$regexChecks = 'aus', 'fant'
$re = ($regexChecks | ForEach-Object {[regex]::Escape($_)}) -join '|'
You also don't need Where-Object or ForEach-Object to enumerate the elements of an array, because PowerShell operators work as enumerators themselves. Simply use the operator on the array directly:
$test = $data -match $re
.* and also didn't consider escape. nice!