CODEWITHSUNDEEP
powershell
FlyingFoX
FlyingFoX

Reputation: 3509

How to filter a list with a list of strings in powershell

I have a list of objects and want to filter all elements whose name is like one of the strings in a list. My current approach is to use where-object, but this results in a long chain of calls to where-object.

Get-AppxPackage |
    where-object {$_.name -notlike "*store*"} |
    where-object {$_.name -notlike "*MSPaint*"} ...

I would like to reduce the boilerplate needed here as I expect the list of strings to get quite large.
I would further like to be able to use the filter on another output, which seems I am currently only able to do by copy pasting the where-object block.

Upvotes: 4

Views: 22462

Answers (2)

ListenSoftware Louise Ai Agent
ListenSoftware Louise Ai Agent

Reputation: 4253

this code shows how to filter using -and and -or in the where-object

class cCustomField
{
[string] $Id
[string] $Name
[string] $Description
[string] $Type
[bool] $On_projects
[bool] $On_people
} 
$list = New-Object Collections.Generic.List[cCustomField]
 ... load your data ....
 filter using -and -or 
$my_object=$list | Where-Object {$_.name -EQ 'gender' -and $_.on_people -EQ $true  }

Upvotes: 0

Theo
Theo

Reputation: 61218

You can use regex notmatch instead. This will be a lot faster to execute. Something like

Get-AppxPackage | Where-Object {$_.name -notmatch 'store|MSPaint'}

Instead of typing in the literal names to not match, you can build the pattern from an array or by reading in a textfile. Lets say you have a list of names in a textfile

store
MSPaint
...

You can then read in this file as array with 

$list = Get-Content -Path "<PATH TO THE FILE>"

Next combine this list to build the pattern like

$pattern = (($list | ForEach-Object {[regex]::Escape($_)}) –join "|")

and do

Get-AppxPackage | Where-Object {$_.name -notmatch $pattern}

Hope this helps

Upvotes: 9

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