Public/Copy-FileHash.ps1
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function Copy-FileHash { <# .SYNOPSIS Copies an item from one location to another based on determining change via computed hash value. .DESCRIPTION The Copy-FileHash cmdlet uses the Get-FileHash cmdlet to compute the hash value of one or more files and then copies any changed and new files to the specified destination path. If you use the -Recurse parameter the cmdlet will synchronise a full directory tree, preserving the structure and creating any missing directories in the destination path as required. The purpose of this cmdlet is to copy specific file changes between two paths in situations where you cannot rely on the modified date of the files to determine if a file has changed. This can occur in situations where file modified dates have been changed, such as when cloning a set of files from a source control system. .PARAMETER Path The Source file or folder to copy any new or changed files from. .PARAMETER Destination The Destination file or folder to compare to source and overwrite with any changed or new files. .PARAMETER Recurse Indicates that this cmdlet performs a recursive copy. .PARAMETER Force Indicates that this cmdlet will copy items that cannot otherwise be changed, such as copying over a read-only file or alias. .EXAMPLE Copy-FileHash -Source C:\Some\Files -Destination D:\Some\Other\Files -Recurse #> [cmdletbinding(SupportsShouldProcess)] param( [Parameter(Mandatory)] [ValidateScript( {if (Test-Path $_) {$True} Else {Throw '-Source must be a valid path.'} })] [String] $Path, [Parameter(Mandatory)] [String] $Destination, #Recurse sub-folders [switch] $Recurse, #Enable -Force on Copy-Item [switch] $Force ) $Source = (Get-Item $Path).FullName $Destination = (Get-Item $Destination).FullName $SourceFiles = (Get-ChildItem -Path $Source -Recurse:$Recurse -File).FullName ForEach ($SourceFile in $SourceFiles) { $DestFile = $SourceFile -Replace "^$([Regex]::Escape($Source))", $Destination If ((-Not (Test-Path $DestFile)) -and $PSCmdlet.ShouldProcess($DestFile, 'New-Item')) { #Using New-Item -Force creates an initial destination file along with any folders missing from its path. New-Item -Path $DestFile -Force | Out-Null } $SourceHash = (Get-FileHash $SourceFile).hash $DestHash = (Get-FileHash $DestFile).hash If (($SourceHash -ne $DestHash) -and $PSCmdlet.ShouldProcess($SourceFile, 'Copy-Item')) { Copy-Item -Path $SourceFile -Destination $DestFile -Force:$Force } } } |