PowerShell utility to create random files

Create-RandomFiles.ps1

#Function Create-RandomFiles{
<#
.SYNOPSIS
	Generates a number of dumb files for a specific size.
 
.DESCRIPTION
	Generates a defined number of files until reaching a maximum size.
 
.PARAMETER TotalSize
	Specify the total size you would all the files combined should use on the harddrive.
	This parameter accepts the following size values (KB,MB,GB,TB).  MB is assumed if no designation is specified.
		200KB.
		5MB
		3GB
		1TB
 
.PARAMETER NumberOfFiles
	Specify a number of files that need to be created. This can be used to generate 
	a big number of small files in order to simulate User backup specefic behaviour.
 
.PARAMETER FilesTypes
    This parameter is not mandatory, but the following choices are valid to generate files with the associated extensions:
        Multimedia : ".avi",".midi",".mov",".mp3",".mp4",".mpeg",".mpeg2",".mpeg3",".mpg",".ogg",".ram",".rm",".wma",".wmv"
		Image      : ".gif",".jpg",".jpeg",".png",".tif",".tiff",".bmp",".dib",".wmf",".emf",".emz",".svg",".svgz",".dwg",".dxf",".crw",".cr2",".raw",".eps",".ico",".pcx"
        Office     : ".pdf",".doc",".docx",".xls",".xlsx",".ppt",".pptx"
				     ".rtf",".txt",".csv",".xml",".mht",".mhtml",".htm",".html",".xps",".dot",".dotx",".docm",".dotm",".odt",".wps",".xlt",".xltx",".xlsm",".xlsb",".xltm",".xla",".ods",".pot",".potx",".pptm",".potm",".pps",".ppsx",".ppsm",".odp",".pub",".mpp",".vsd",".vsdx",".vsdm",".vdx",".vssx",".vssm",".vsx",".vstx",".vst",".vstm",".vsw",".vdw"
		Junk       : ".tmp",".temp",".lock"
		Archive    : ".zip",".7z",".rar",".cab",".iso",".001",".ex_"
		Script     : ".ps1",".vbs",".vbe",".cmd",".bat",".php",".hta",".ini",".inf",".reg",".asp",".sql",".vb",".js",".css",".kix",".au3"
	If Filestypes parameter is not set, by default, the script will create all types of files.
 
.PARAMETER Path
    Specify a path where the files should be generated.
 
.PARAMETER NamePrefix
    Optional.  Allows prepending text to the beginning of the generated file names so they can be easily found and sorted.
 
.PARAMETER WhatIf
    Permits to launch this script in "draft" mode. This means it will only show the results without really making generating the files.
 
.PARAMETER Verbose
    Allow to run the script in verbose mode for debbuging purposes.
 
.EXAMPLE
   .Create-RandomFiles.ps1 -TotalSize 1GB -NumberOfFiles 123 -Path $env:Temp -FilesTypes 'Office' -NamePrefix '~'
 
   Generate in the user's temp folder 123 randomly named office files all beginning with "~" which total 1GB.
 
.EXAMPLE
   .Create-RandomFiles.ps1 -TotalSize 50 -NumberOfFiles 42 -Path C:Usersadministratordocuments

   Generate in the adminstrator's documents folder 42 randomly named files which total 50MB.
 
.NOTES
    -Author: Stéphane van Gulick
    -Email : Svangulick@gmail.com
    -Version: 1.0
    -History:
        -Creation V0.1 : SVG
        -First final draft V0.5 : SVG
        -Corrected minor bugs V0.6 : SVG
        -Functionalized the script V0.8 : SVG
        -Simplified code V1.0 : SVG

    ===== Change History =====
	based on http://powershelldistrict.com/create-files/
    -Author: Chad Simmons
    -2015/12/04: added Write-Progress, files are created with different sizes, TotalSize defaults to MB, added name prefix, added execution statistics, replaced fsutil.exe with New-Object byte[], added additional filetypes
	
.LINK
    http://www.PowerShellDistrict.com
	http://blogs.CatapultSystems.com
#>
[cmdletbinding()]
param(
    [Parameter(mandatory=$true)]$NumberOfFiles,
    [Parameter(mandatory=$true)]$path,
    [Parameter(mandatory=$true)]$TotalSize,
    [Parameter(mandatory=$false)][validateSet("Multimedia","Image","Office","Junk","Archive","Script","all","")][String]$FilesType=$all,
    [Parameter(mandatory=$false)]$NamePrefix=""
)
 
begin{
    $StartTime = (get-date)
    $TimeSpan = New-TimeSpan -Start $StartTime -end $(Get-Date) #New-TimeSpan -seconds $(($(Get-Date)-$StartTime).TotalSeconds)
    $Progress=@{Activity = "Create Random Files..."; Status="Initializing..."}
    Write-verbose "Generating files"
    $AllCreatedFilles = @()
 
    function Create-FileName {
        [CmdletBinding(SupportsShouldProcess=$true)]
        param(
            [Parameter(mandatory=$false)][validateSet("Multimedia","Image","Office","Junk","Archive","Script","all","")][String]$FilesType=$all,
		    [Parameter(mandatory=$false)]$NamePrefix=""
		)
        begin {
			$AllExtensions = @()
			$MultimediaExtensions = ".avi",".midi",".mov",".mp3",".mp4",".mpeg",".mpeg2",".mpeg3",".mpg",".ogg",".ram",".rm",".wma",".wmv"
			$ImageExtensions      = ".gif",".jpg",".jpeg",".png",".tif",".tiff",".bmp",".dib",".wmf",".emf",".emz",".svg",".svgz",".dwg",".dxf",".crw",".cr2",".raw",".eps",".ico",".pcx"
			$OfficeExtensions     = ".pdf",".doc",".docx",".xls",".xlsx",".ppt",".pptx"
			$OfficeExtensions2    = ".rtf",".txt",".csv",".xml",".mht",".mhtml",".htm",".html",".xps", `
									".dot",".dotx",".docm",".dotm",".odt",".wps", `
									".xlt",".xltx",".xlsm",".xlsb",".xltm",".xla",".ods",`
									".pot",".potx",".pptm",".potm",".pps",".ppsx",".ppsm",".odp", `
									".pub",".mpp",".vsd",".vsdx",".vsdm",".vdx",".vssx",".vssm",".vsx",".vstx",".vst",".vstm",".vsw",".vdw"
			$OfficeExtensions    += $OfficeExtensions2
			$JunkExtensions       = ".tmp",".temp",".lock"
			$ArchiveExtensions    = ".zip",".7z",".rar",".cab",".iso",".001",".ex_"
			$ScriptExtensions     = ".ps1",".vbs",".vbe",".cmd",".bat",".php",".hta",".ini",".inf",".reg",".asp",".sql",".vb",".js",".css",".kix",".au3"
			$AllExtensions        = $MultimediaExtensions + $ImageExtensions + $OfficeExtensions + $JunkExtensions + $ArchiveExtensions + $ScriptExtensions
			$extension = $null
		}
        process{
			Write-Verbose "Creating file Name"
	 
			switch ($filesType) {
				"Multimedia" {$extension = $MultimediaExtensions | Get-Random}
				"Image"      {$extension = $ImageExtensions | Get-Random}
				"Office"     {$extension = $OfficeExtensions | Get-Random }
				"Junk"       {$extension = $JunkExtensions | Get-Random}
				"Archive"    {$extension = $ArchiveExtensions | Get-Random}
				"Script"     {$extension = $ScriptExtensions | Get-Random}
				default      {$extension = $AllExtensions | Get-Random }
			}
			Get-Verb | Select-Object verb | Get-Random -Count 2 | %{$Name+= $_.verb}
			$FullName = $NamePrefix + $name + $extension
			Write-Verbose "File name created : $FullName"
			Write-Progress @Progress -CurrentOperation "Created file Name : $FullName"
        }
        end {
			return $FullName
        }
    }
}
#----------------Process-----------------------------------------------
 
process {
	If ($TotalSize -match '^d+$') { [string]$TotalSize += "MB" } #if TotalSize isNumeric (did not contain a byte designation, assume MB
    $Progress.Status="Creating $NumberOfFiles files totalling $TotalSize"
    Write-Progress @Progress
 
    Write-Verbose "Total Size is $TotalSize"
    $FileSize = $TotalSize / $NumberOfFiles
    $FileSize = [Math]::Round($FileSize, 0)
    Write-Verbose "Average file size of $FileSize"
    $FileSizeOffset = [Math]::Round($FileSize/$NumberOfFiles, 0)
    Write-Verbose "file size offset of $FileSizeOffset"
    $FileSize = $FileSizeOffset*$NumberOfFiles/2
    Write-Verbose "Beginning file size of $FileSize"
 
    while ($FileNumber -lt $NumberOfFiles) {
        $FileNumber++
        If ($FileNumber -eq $NumberOfFiles) { 
            $FileSize = $TotalSize - $TotalFileSize
            Write-Verbose "Setting last file to size $FileSize"
        }
        $TotalFileSize = $TotalFileSize + $FileSize
        $FileName = Create-FileName -filesType $filesType
        Write-Verbose "Creating : $FileName of $FileSize"
        $Progress.Status="Creating $NumberOfFiles files totalling $TotalSize.  Run time $(New-TimeSpan -Start $StartTime -end $(Get-Date))"
        Write-Progress @Progress -CurrentOperation "Creating file $FileNumber of $NumberOfFiles : $FileName is $FileSize bytes." -PercentComplete ($FileNumber/$NumberOfFiles*100)

        $FullPath = Join-Path $path -ChildPath $FileName
#        Write-Verbose "Generating file : $FullPath of $Filesize"
        try{
            #fsutil.exe file createnew $FullPath $FileSize | Out-Null
            $buffer=New-Object byte[] $FileSize  #http://blogs.technet.com/b/heyscriptingguy/archive/2010/06/09/hey-scripting-guy-how-can-i-use-windows-powershell-2-0-to-create-a-text-file-of-a-specific-size.aspx
            $fi=[io.file]::Create($FullPath)
            $fi.Write($buffer,0,$buffer.length)
            $fi.Close()
		}
        catch{
            $_
        }
 
        $FileCreated = ""
        $Properties = @{'FullPath'=$FullPath;'Size'=$FileSize}
		$FileCreated = New-Object -TypeName psobject -Property $properties
        $AllCreatedFilles += $FileCreated
        Write-verbose "$($AllCreatedFilles) created $($FileCreated)"
        Write-Progress @Progress -CurrentOperation "Creating file $FileNumber of $NumberofFiles : $FileName is $FileSize bytes.  Done." -PercentComplete ($FileNumber/$NumberOfFiles*100)

   		$FileSize = ([Math]::Round($FileSize, 0)) + $FileSizeOffset
    }
}
end{
    Write-Output $AllCreatedFilles
    Write-Output "Start     time: $StartTime"
    Write-Output "Execution time: $(New-TimeSpan -Start $StartTime -end $(Get-Date))" #http://blogs.technet.com/b/heyscriptingguy/archive/2013/03/15/use-powershell-and-conditional-formatting-to-format-time-spans.aspx
}
#}