PowerShell Selecting First, Last, One, Some, script.ps1

readme.md

Features

> stuff | One # returns first only
> stuff | Some # returns first 5
> stuff | Some -FromEnd # same, but in reverse

• also saves one and some's result to the variables $global:One and $global:Some
• It always returns the real, original objects
• It summarizes typenames and sizes, without breaking those objects in the output stream

Optional functions used, that are overkill

The lines CountOf | Format-ShortTypeName are optional. They are in some dotfiles

• Format-ShortTypeName @ ninmonkey.console
• OutNull and CountOf @ dotfiles
• taken from one of my personal dotfiles

Other Versions

SeeminglySciences profile, this discord thread has more context

I don't have an easily copy pasted version, and unfortunately it's quite involved, but I do have one in my profile: the actual function: https://github.com/SeeminglyScience/dotfiles/blob/bc31aaaec30343be4788d47b2c08b40d6763268d/Documents/PowerShell/Utility.psm1#L3327-L3355

required context (also the complicated part): https://github.com/SeeminglyScience/dotfiles/blob/bc31aaaec30343be4788d47b2c08b40d6763268d/Documents/PowerShell/Utility.psm1#L132-L267

a-screenshot-Select-Some-One.gif

Select-Some-Or-One.ps1

using namespace System.Collections.Generic
Import-module Pansies

function Dotfiles.Select-Some {
    <#
    .SYNOPSIS
        select 1 item, 5, or a specific count. 
    .NOTES
        - [ ] future: rewrite using steppable pipeline for an earlier exit
    .EXAMPLE
        Get-Process | One    # returns 1 item
        Get-Command | Some   # returns 5 items
        Get-Process | Some 3 # returns 3 item
        ... | Some -LastOne
    #>
    [Alias('Some', 'One')]
    param(
        [Parameter(Mandatory, ValueFromPipeline)]
        [object] $InputObject,

        [Alias('Count', 'Limit')]
        [Parameter(Position = 0)]
        [int] $FirstN = 5,
        [switch] $LastOne
    )

    begin {
        [bool]$IsUsingOne = $MyInvocation.InvocationName -eq 'One'
        [List[Object]]$Items = @()
        $selectSplat = @{}        

        if( $IsUsingOne ) { $FirstN = 1 }

        if( $LastOne ) { $selectSplat.Last = $FirstN }
        else { $selectSplat.First = $FirstN }

    }
    process {
        $Items.AddRange(@( $InputObject ))
    }
    end {
        $query = $Items | Select @SelectSplat
        if($IsUsingOne) {
            $Query
            $global:One = $Query
            'One := {0}' -f @(
                $Global:One | Format-ShortTypeName
            )   | New-Text -fg 'gray60' -bg 'gray20'
                | Write-Information -infa Continue
        } else {
            $Query
            $global:Some = $query
            'Some := {0}' -f @(
                $global:Some
                | CountOf | Format-ShortTypeName
            )   | New-Text -fg 'gray60' -bg 'gray20'
                | Write-Information -infa Continue
        }
    }
}