compare-directory.ps1

# Compare-Directory.ps1
# Compare files in one or more directories and return file difference results
# Victor Vogelpoel <[email protected]>
# Sept 2013
#
# Disclaimer
# This script is provided AS IS without warranty of any kind. I disclaim all implied warranties including, without limitation,
# any implied warranties of merchantability or of fitness for a particular purpose. The entire risk arising out of the use or
# performance of the sample scripts and documentation remains with you. In no event shall I be liable for any damages whatsoever
# (including, without limitation, damages for loss of business profits, business interruption, loss of business information,
# or other pecuniary loss) arising out of the use of or inability to use the script or documentation.


# Compare-Directory -ReferenceDirectory "C:\Compare-Directory\FrontEnd1-Site"  -DifferenceDirectory "C:\Compare-Directory\FrontEnd2-Site" 


function Compare-Directory
{
	[CmdletBinding()]
	param
	(
		[Parameter(Mandatory=$true, position=0, ValueFromPipelineByPropertyName=$true, HelpMessage="The reference directory to compare one or more difference directories to.")]
		[System.IO.DirectoryInfo]$ReferenceDirectory,

		[Parameter(Mandatory=$true, position=1, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, HelpMessage="One or more directories to compare to the reference directory.")]
		[System.IO.DirectoryInfo[]]$DifferenceDirectory,

		[Parameter(Mandatory=$false, ValueFromPipelineByPropertyName=$true, HelpMessage="Recurse the directories")]
		[switch]$Recurse,

		[Parameter(Mandatory=$false, ValueFromPipelineByPropertyName=$true, HelpMessage="Files to exclude from the comparison")]
		[String[]]$ExcludeFile,

		[Parameter(Mandatory=$false, ValueFromPipelineByPropertyName=$true, HelpMessage="Directories to exclude from the comparison")]
		[String[]]$ExcludeDirectory,

		[Parameter(Mandatory=$false, ValueFromPipelineByPropertyName=$true, HelpMessage="Displays only the characteristics of compared objects that are equal.")]
		[switch]$ExcludeDifferent,
		
		[Parameter(Mandatory=$false, ValueFromPipelineByPropertyName=$true, HelpMessage="Displays characteristics of files that are equal. By default, only characteristics that differ between the reference and difference files are displayed.")]
		[switch]$IncludeEqual,
		
		[Parameter(Mandatory=$false, ValueFromPipelineByPropertyName=$true, HelpMessage="Passes the objects that differed to the pipeline.")]
		[switch]$PassThru
	)


	begin
	{
		function Get-MD5
		{ 
			[CmdletBinding(SupportsShouldProcess=$false)]
			param
			(
				[Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, HelpMessage="file(s) to create hash for")]
				[Alias("File", "Path", "PSPath", "String")]
				[ValidateNotNull()]
				$InputObject
			)

			begin
			{
				$cryptoServiceProvider	= [System.Security.Cryptography.MD5CryptoServiceProvider]
				$hashAlgorithm 			= new-object $cryptoServiceProvider 
			}
			
			process
			{
				$hashByteArray = ""
				
				$item = Get-Item $InputObject -ErrorAction SilentlyContinue
				if ($item -is [System.IO.DirectoryInfo])	{ throw "Cannot create hash for directory" }
				if ($item) 									{ $InputObject = $item }
				
				if ($InputObject -is [System.IO.FileInfo])
				{
					$stream 		= $null; 
					$hashByteArray	= $null

					try
					{
						$stream 				= $InputObject.OpenRead(); 
						$hashByteArray 			= $hashAlgorithm.ComputeHash($stream); 
					}
					finally
					{
						if ($stream -ne $null)
						{
							$stream.Close(); 
						}
					}
				}
				else
				{
					$utf8 			= new-object -TypeName "System.Text.UTF8Encoding"
					$hashByteArray 	= $hashAlgorithm.ComputeHash($utf8.GetBytes($InputObject.ToString())); 
				}

				Write-Output ([BitConverter]::ToString($hashByteArray)).Replace("-","")
			}
		} 

		function Get-Files
		{
			[CmdletBinding(SupportsShouldProcess=$false)]
			param
			(
				[string]$DirectoryPath,
				[String[]]$ExcludeFile,
				[String[]]$ExcludeDirectory,
				[switch]$Recurse
			)
		
			$relativeBasenameIndex = $DirectoryPath.ToString().Length

			# Get the files from the first deploypath
			# and ADD the MD5 hash for the file as a property
			# and ADD a filepath relative to the deploypath as a property
			Get-ChildItem -Path $DirectoryPath -Exclude $ExcludeFile -Recurse:$Recurse | foreach { 
				$hash = ""
				if (!$_.PSIsContainer) { $hash = Get-MD5 $_	}

				# Added two new properties to the DirectoryInfo/FileInfo objects
				$item = $_ |
					Add-Member -Name "MD5Hash" -MemberType NoteProperty -Value $hash -PassThru |
					Add-Member -Name "RelativeBaseName" -MemberType NoteProperty -Value ($_.FullName.Substring($relativeBasenameIndex)) -PassThru
				
				# Test for directories and files that need to be excluded because of ExcludeDirectory
				if ($item.PSIsContainer) { $item.RelativeBaseName += "\" }
				if ($ExcludeDirectory | where { $item.RelativeBaseName -like "\$_\*" })
				{	
					Write-Verbose "Ignore item `"$($item.Fullname)`""
				}
				else
				{
					Write-Verbose "Adding `"$($item.Fullname)`" to result set"
					Write-Output $item 
				}
			}
		}

		$referenceDirectoryFiles = Get-Files -DirectoryPath $referenceDirectory -ExcludeFile $ExcludeFile -ExcludeDirectory $ExcludeDirectory -Recurse:$Recurse
	}

	process
	{
		if ($DifferenceDirectory -and $referenceDirectoryFiles)
		{
			foreach($nextPath in $DifferenceDirectory)
			{
				$nextDifferenceFiles = Get-Files -DirectoryPath $nextpath -ExcludeFile $ExcludeFile -ExcludeDirectory $ExcludeDirectory -Recurse:$Recurse
							
				###################################################
				# Compare the contents of the two file/directory arrays and return the results
				$results = @(Compare-Object -ReferenceObject $referenceDirectoryFiles -DifferenceObject $nextDifferenceFiles -ExcludeDifferent:$ExcludeDifferent -IncludeEqual:$IncludeEqual -PassThru:$PassThru -Property RelativeBaseName, MD5Hash)
				
				if (!$PassThru)
				{
					foreach ($result in $results)
					{
						$path 		= $ReferenceDirectory
						$pathFiles	= $referenceDirectoryFiles
						if ($result.SideIndicator -eq "=>")
						{
							$path 		= $nextPath
							$pathFiles	= $nextDifferenceFiles
						}
					
						# Find the original item in the files array
						$itemPath = (Join-Path $path $result.RelativeBaseName).ToString().TrimEnd('\')
						$item = $pathFiles | where { $_.fullName -eq $itemPath }

						$result | Add-Member -Name "Item" -MemberType NoteProperty -Value $item
					}
				}
				
				Write-Output $results
			}
		}
	}


	<#
		.SYNOPSIS
			Compares a reference directory with one or more difference directories.		

		.DESCRIPTION
			Compare-Directory compares a reference directory with one ore more difference
			directories. Files and directories are compared both on filename and contents
			using a MD5hash.
			
			Internally, Compare-Object is used to compare the directories. The behavior
			and results of Compare-Directory is similar to Compare-Object.

		.PARAMETER  ReferenceDirectory
			The reference directory to compare one or more difference directories to.

		.PARAMETER  DifferenceDirectory
			One or more directories to compare to the reference directory.

		.PARAMETER Recurse
			Include subdirectories in the comparison.
			
		.PARAMETER ExcludeFile
			File names to exclude from the comparison.

		.PARAMETER ExcludeDirectory
			Directory names to exclude from the comparison. Directory names are 
			relative to the Reference of Difference Directory path

		.PARAMETER ExcludeDifferent
			Displays only the characteristics of compared files that are equal.
			
		.PARAMETER IncludeEqual
			Displays characteristics of files that are equal. By default, only 
			characteristics that differ between the reference and difference files 
			are displayed.

		.PARAMETER PassThru
			Passes the objects that differed to the pipeline. By default, this 
			cmdlet does not generate any output.

		.EXAMPLE
			Compare-Directory -reference "D:\TEMP\CompareTest\path1" -difference "D:\TEMP\CompareTest\path2" -ExcludeFile "web.config" -recurse
			
			Compares directories "D:\TEMP\CompareTest\path1" and "D:\TEMP\CompareTest\path2" recursively, excluding "web.config"
			Only differences are shown. Results:
			
			RelativeBaseName  MD5Hash                          SideIndicator Item                                                                     
			----------------  -------                          ------------- ----                                                                     
			bin\site.dll      87A1E6006C2655252042F16CBD7FB41B =>            D:\TEMP\CompareTest\path2\bin\site.dll
			index.html        02BB8A33E1094E547CA41B9E171A267B =>            D:\TEMP\CompareTest\path2\index.html                                     
			index.html        20EE266D1B23BCA649FEC8385E5DA09D <=            D:\TEMP\CompareTest\path1\index.html                                     
			web_2.config      5E6B13B107ED7A921AEBF17F4F8FE7AF <=            D:\TEMP\CompareTest\path1\web_2.config                                   
			bin\site.dll      87A1E6006C2655252042F16CBD7FB41B =>            D:\TEMP\CompareTest\path2\bin\site.dll
			index.html        02BB8A33E1094E547CA41B9E171A267B =>            D:\TEMP\CompareTest\path2\index.html                                     
			index.html        20EE266D1B23BCA649FEC8385E5DA09D <=            D:\TEMP\CompareTest\path1\index.html                                     
			web_2.config      5E6B13B107ED7A921AEBF17F4F8FE7AF <=            D:\TEMP\CompareTest\path1\web_2.config                                   

		.EXAMPLE
			Compare-Directory -reference "D:\TEMP\CompareTest\path1" -difference "D:\TEMP\CompareTest\path2" -ExcludeFile "web.config" -recurse -IncludeEqual
			
			Compares directories "D:\TEMP\CompareTest\path1" and "D:\TEMP\CompareTest\path2" recursively, excluding "web.config".
			Results include the items that are equal:
			
			RelativeBaseName    MD5Hash                          SideIndicator Item                                                 
			----------------    -------                          ------------- ----                                                 
			bin 	                                             ==            D:\TEMP\CompareTest\path1\bin                        
			bin\site2.dll       98B68D681A8D40FA943D90588E94D1A9 ==            D:\TEMP\CompareTest\path1\bin\site2.dll
			bin\site3.dll       9408C4B29F82260CBBA528342CBAA80F ==            D:\TEMP\CompareTest\path1\bin\site3.dll
			bin\site4.dll       0616E1FBE12D468F611F07768D70C2EE ==            D:\TEMP\CompareTest\path1\bin\site4.dll
			...
			bin\site8.dll       87A1E6006C2655252042F16CBD7FB41B =>            D:\TEMP\CompareTest\path2\bin\site8.dll
			index.html          02BB8A33E1094E547CA41B9E171A267B =>            D:\TEMP\CompareTest\path2\index.html                 
			index.html          20EE266D1B23BCA649FEC8385E5DA09D <=            D:\TEMP\CompareTest\path1\index.html                 
			web_2.config        5E6B13B107ED7A921AEBF17F4F8FE7AF <=            D:\TEMP\CompareTest\path1\web_2.config               

		.EXAMPLE
			Compare-Directory -reference "D:\TEMP\CompareTest\path1" -difference "D:\TEMP\CompareTest\path2" -ExcludeFile "web.config" -recurse -ExcludeDifference
			
			Compares directories "D:\TEMP\CompareTest\path1" and "D:\TEMP\CompareTest\path2" recursively, excluding "web.config".
			Results only include the files that are equal; different files are excluded from the results.
			
		.EXAMPLE
			Compare-Directory -reference "D:\TEMP\CompareTest\path1" -difference "D:\TEMP\CompareTest\path2" -ExcludeFile "web.config" -recurse -Passthru
			
			Compares directories "D:\TEMP\CompareTest\path1" and "D:\TEMP\CompareTest\path2" recursively, excluding "web.config" and returns NO comparison
			results, but the different files themselves!
			
			FullName                                                                                                                                                                  
			--------                                                                                                                                                                  
			D:\TEMP\CompareTest\path2\bin\site3.dll
			D:\TEMP\CompareTest\path2\index.html
			D:\TEMP\CompareTest\path1\index.html
			D:\TEMP\CompareTest\path1\web_2.config

		.LINK
			Compare-Object
	#>
}