Return a subset of a file

<#
.Synopsis
   Given a file, return a subset of that file.
.Description
   Restriction is by line number. At least 2 arguments are required:
   - the file name, including path, and
   - the last line to be returned. So if the file contains 1000 lines, and the second
     argument is 500 (and there is no 3rd argument), then lines 1-500 will be returned
   If the argument count is 3, then for simplicity, this last argument is taken to be
   the FIRST line to include. The example below shows how this plays.
   Generate a test file for the examples below thus:
   1..1000 > d:\scratch\1000_line_file.txt
.Example
   This will return lines 1-500 from the original
   "d:\scratch\1000_line_file.txt" | Reduce-File 500
.Example
   This will return lines 3-500 from the original
   "d:\scratch\1000_line_file.txt" | Reduce-File 500 3
.Example
   This will return lines 3-1000 from the original, because 1000 is the maximum: no exception is thrown:
   "d:\scratch\1000_line_file.txt" | Reduce-File 1500 3
.Example
    This will write the output to a further file. Note that it is not possible in this function to write back to the same file - a separate function should manage that.
   "d:\scratch\1000_line_file.txt" | Reduce-File 1500 3 | Out-File .\x.txt
#>
function Reduce-File
{
    Param
    (
        [Parameter(Mandatory=$true, ValueFromPipeline=$true)]
        [string]
        $FileNameWithPath,
        [Parameter(Mandatory=$true, Position=1)]
        [int]
        $LastLineNumberToInclude,
        [Parameter(Mandatory=$false, Position=2)]
        [int]
        $FirstLineNumberToInclude
    )

    Process {
        $lines = get-content $FileNameWithPath
        if ($LastLineNumberToInclude -gt $lines.Count) {
            $LastLineNumberToInclude = $lines.Count
        }

        $restrictedFile = $lines |
            select -First $LastLineNumberToInclude |
                select -Last $($LastLineNumberToInclude - ($FirstLineNumberToInclude - 1))
        $restrictedFile
    }
}