如何使用“匹配”cmdlet在PowerShell中过滤字符串数组（或列表）？

Question

I am trying to filter CSV files. But the following script is giving an error. How do I specify that I want to run match on each String object?

I tried various combinations, but without result.

$FileNames = [System.IO.Directory]::GetFiles("C:\Users\anagre\Desktop")

$FileNames = $FileNames | Where { -match "*.csv"}

Answer 1

Try this:

$FileNames = Get-ChildItem -Path "C:\Users\anagre\Desktop" -Filter *.csv

In your above code you didn't use the $PSItem ($_) in your where clause, and if you want to use a wildchar you have got to use the -like operator:

$FileNames|where{$_ -like "*.csv"}

or

$FileNames|where{$_ -match ".csv"}

Answer 2

The -match operator is both a comparison operator and an array operator, depending on its input object.

If it's a scalar, it returns a boolean. If it's an array, it returns all the elements of the array that match the pattern

@($Filenames) -match '*.csv'

Use the array syntax to ensure that you still get an array if there's only one filename returned by Get-ChildItem . Otherwise, you'll get back $True instead of the filename if it matches.