Select-Nth.psm1
|
function Select-Nth { <# .SYNOPSIS Retrieves or skips every Nth object from the input collection. .DESCRIPTION This function filters the input collection and returns, or skips, every Nth object. .PARAMETER InputObject The collection of objects to filter. .PARAMETER Nth The interval for selecting objects (e.g., return every 5th object). .PARAMETER SkipNth The interval for skipping objects (e.g., skip every 5th object). .EXAMPLE Select-Nth -InputObject $myObjects -Nth 3 .EXAMPLE 1..10 | Select-Nth -Nth 2 .EXAMPLE 1..10 | Select-Nth -SkipNth 3 #> [CmdletBinding()] param ( [Parameter(ValueFromPipeline, Mandatory, ParameterSetName = 'nth')] [Parameter(ValueFromPipeline, Mandatory, ParameterSetName = 'skip_nth')] [Object[]] $InputObject, [Parameter(Mandatory, ParameterSetName = 'nth')] [int]$Nth, [Parameter(Mandatory, ParameterSetName = 'skip_nth')] [int]$SkipNth ) begin { $object_counter = 0; } process { $InputObject | ForEach-Object { $object_counter++; if ($PSCmdlet.ParameterSetName -eq 'skip_nth') { if ($object_counter -ge $SkipNth) { $object_counter = 0; } else { Write-Output $InputObject } } if ($PSCmdlet.ParameterSetName -eq 'nth') { if ($object_counter -ge $Nth) { Write-Output $InputObject $object_counter = 0; } } } } } |