Powershell - LIKE against an array

问题

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?

回答1:

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;
}

回答2:

Here is a short version of the pattern in the accepted answer:

($your_array | %{"your_string" -like $_}) -contains $true

Applied to the case in the OP one obtains

PS C:\> ("aaa.bbb", "ccccc.*", "ddddd???.exe" | %{"ddddd000.exe" -like $_}) -contains $true
True

回答3:

I suppose you could use the Get-ChildItem -Exclude parameter:

Get-ChildItem $theFileToCheck -exclude $excludeFiles

If you have an array of files to check, Get-ChildItem accepts an array of paths:

Get-ChildItem $filesToCheck -exclude $excludeFiles

回答4:

$excludeFiles.Where{$stringToTest -like $_}

Powershell array has a Where method that can take an expression input, hence the {} instead of (). Feed in a string to test and it will iterate over the array using the standard pipe so $_ represents the element of the array.

Outputs a list of matching elements.

PS H:\> $excludeFiles = @("aaa.bbb", "ccccc.*", "ddddd???.exe")
PS H:\> $stringToTest = "ddddd000.exe"
PS H:\> $excludeFiles.Where{$stringToTest -like $_}
ddddd???.exe

来源：https://stackoverflow.com/questions/13019218/powershell-like-against-an-array

标签

arrays

powershell

sql-like