Listing 2.4.ps1

function New-FolderCreation
{
  [CmdletBinding()]
  param
  (
    [Parameter(Mandatory = $true)]
    [string]$foldername
  )
	

  $logpath  = (Get-Location).path + "\" + "$foldername" 
  $testlogpath = Test-Path -Path $logpath
  if($testlogpath -eq $false)
  {
    #Start-ProgressBar -Title "Creating $foldername folder" -Timer 10
    $null = New-Item -Path (Get-Location).path -Name $foldername -Type directory
  }
}#New-FolderCreation

function Write-Log
{
  [CmdletBinding()]
  param
  (
    [Parameter(Mandatory = $true,ParameterSetName = 'Create')]
    [array]$Name,
    [Parameter(Mandatory = $true,ParameterSetName = 'Create')]
    [string]$Ext,
    [Parameter(Mandatory = $true,ParameterSetName = 'Create')]
    [string]$folder,
    
    [Parameter(ParameterSetName = 'Create',Position = 0)][switch]$Create,
    
    [Parameter(Mandatory = $true,ParameterSetName = 'Message')]
    [String]$message,
    [Parameter(Mandatory = $true,ParameterSetName = 'Message')]
    [String]$path,
    [Parameter(Mandatory = $false,ParameterSetName = 'Message')]
    [ValidateSet('Information','Warning','Error')]
    [string]$Severity = 'Information',
    
    [Parameter(ParameterSetName = 'Message',Position = 0)][Switch]$MSG
  )
  switch ($PsCmdlet.ParameterSetName) {
    "Create"
    {
      $log = @()
      $date1 = Get-Date -Format d
      $date1 = $date1.ToString().Replace("/", "-")
      $time = Get-Date -Format t
	
      $time = $time.ToString().Replace(":", "-")
      $time = $time.ToString().Replace(" ", "")
      New-FolderCreation -foldername $folder
      foreach ($n in $Name)
      {$log += (Get-Location).Path + "\" + $folder + "\" + $n + "_" + $date1 + "_" + $time + "_.$Ext"}
      return $log
    }
    "Message"
    {
      $date = Get-Date
      $concatmessage = "|$date" + "|   |" + $message +"|  |" + "$Severity|"
      switch($Severity){
        "Information"{Write-Host -Object $concatmessage -ForegroundColor Green}
        "Warning"{Write-Host -Object $concatmessage -ForegroundColor Yellow}
        "Error"{Write-Host -Object $concatmessage -ForegroundColor Red}
      }
      
      Add-Content -Path $path -Value $concatmessage
    }
  }
} #Function Write-Log