PowerShellでdirname/basename

DirnameAndBasename.ps1

function dirname 
{
    Param
    (
        [Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, Position=1,
        HelpMessage="Files or directories for which you want to get the parent directory name")]
        [String[]] $Path
    )

    foreach ($item in (Get-Item $Path)) {
        if ($item.PSIsContainer) {
            $item.FullName
        } else {
            [IO.Path]::GetDirectoryName($item.FullName)
        }
    }
}

function basename 
{
    Param
    (
        [Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, Position=1,
        HelpMessage="Files or directories for which you want to get basename")]
        [String[]] $Path,

        [Parameter(Mandatory=$false, ValueFromPipeline=$false, ValueFromPipelineByPropertyName=$false)]
        [Switch] $WithinExtension
    )

    foreach ($item in (Get-Item $Path)) {
        if ($item.PSIsContainer) {
            Write-Output ""
        } else {
            if ($WithinExtension) {
                [IO.Path]::GetFileName($item.FullName)
            } else {
                [IO.Path]::GetFileNameWithoutExtension($item.FullName)
            }
        }
    }
}