pieces regarding powershell usage

A copy op preserving relative folder structure

$a = pwd
ls -r | 
  ? { !$_.name.Contains(".g.") }  |  
  ? { $_.Extension -eq ".cs" -or $_.Extension -eq ".csproj" }  | 
  ? { $_.lastwritetime -gt [DateTime]::Now.AddHours(-6) } | 
  % { 
    $relative = $_.fullname.Replace($a.Path + "\","")
    $Path = [System.IO.Path]::GetDirectoryName($relative)
    mkdir c:\temp\$path -erroraction SilentlyContinue
    Copy-Item -path $relative -destination c:\temp\$path 
}

logfile helper to find uncaught exceptions

function regex([string]$pattern) {
  New-Object -TypeName System.Text.RegularExpressions.Regex -ArgumentList $pattern
}

$dateMatch = regex "\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d"
Set-Variable -scope Global -name DATEMATCH -Value $dateMatch

function toDate([string]$line) {
  $m = $DATEMATCH.Matches($line)
  if ($m.Count -eq 0) { return }
  $dateString = $m[0].Value
  [DateTime]::ParseExact($dateString, "yyyy-MM-dd HH:mm:ss", [System.Globalization.CultureInfo]::InvariantCulture)
}

function runExceptionCheck {
  dir *.log | ? { $_.LastWriteTime -gt [DateTime]::Now.AddDays(-5) } | Select-String -Pattern "Uncaught exception" | 
    Add-Member -Name AsDateTime -MemberType ScriptProperty -Value { toDate $this.Line } -PassThru | 
	Sort-Object -Property AsDateTime -Descending
}