function filesize ([string]$filepath)
{
if($filepath -eq $null){
throw "null path"
}
dir -Path $filepath | ForEach-Object -Process{
if($_.psiscontainer -eq $true){
$length=0
dir -Path $_.fullname -Recurse | ForEach-Object{
$length+=$_.length
}
$l=$length/1GB
$_.name+" size is : {0:n3} GB" -f $l
}
}
}
filesize -filepath "C:\"