simplePowershellLsGrep.ps1

function Get-LsGrep {
    [Alias("lgrep")]
    [CmdletBinding()]
    param (
        [Parameter(ValueFromPipeline)]
        [System.Array]
        $lsOutput,
        # Parameter help description
        [Parameter(Position=1)]
        [System.String]
        $greppable
    )

    begin {
        [System.Collections.ArrayList]$dataArray = @()
    }

    process {
        $dataArray.Add($lsOutput) >> $null
    }

    end {
        $stringResult = ($dataArray | Out-String)
        return $stringResult | %{$_.Split([System.Environment]::NewLine)} | sls $greppable
    }
}