mkbackupwin

$filename=$args[0]


$dateStr=Get-Date -format yyMMdd

if([System.IO.File]::Exists($filename)){
    if([System.IO.File]::Exists("${filename}.${dateStr}.bak")){
        Move-Item "${filename}.${dateStr}.bak" "${filename}.prev_${dateStr}.bak"
    }
    Copy-Item "$filename" "${filename}.${dateStr}.bak"
}