Neolisk Neolisk - 3 months ago 19
PowerShell Question

Powershell - LIKE against an array

For every file being processed, its name is being checked to satisfy the condition. For example, given the following list of filters:

$excludeFiles = @"
aaa.bbb
ccccc.*
ddddd???.exe
"@ | SplitAndTrim;


It should exclude a file from processing if it matches any of the lines. Trying to avoid
match/regex
, because this script needs to be modifiable by someone who does not know it, and there are several places where it needs to implemented.

$excludedFiles
and similar are defined as a here-string on purpose. It allows the end user/operator to paste a bunch of file names right from the CMD/Powershell window.

It appears that Powershell does not accept
-like
against an array, so I cannot write like this:

"ddddd000.exe" -like @("aaa.bbb", "ccccc.*", "ddddd???.exe")


Did I miss an option? If it's not natively supported by Powershell, what's the easiest way to implement it?

Answer

You can perform a pattern match against a collection of names, but not against a list of patterns. Try this:

foreach($pattern in $excludeFiles)
{
    if($fileName -like $pattern) {break}
}

Here is how it can be wrapped into a function:

function like($str,$patterns){
    foreach($pattern in $patterns) { if($str -like $pattern) { return $true; } }
    return $false;
}