Fast and simple binary concatenate files in Powershell

Question

What\'s the best way of concatenating binary files using Powershell? I\'d prefer a one-liner that simple to remember and fast to execute.

The best I\'ve come up with

Answer 1

I had a similar problem recently, where I wanted to append two large (2GB) files into a single file (4GB).

I tried to adjust the -ReadCount parameter for Get-Content, however I couldn't get it to improve my performance for the large files.

I went with the following solution:

function Join-File (
    [parameter(Position=0,Mandatory=$true,ValueFromPipeline=$true)]
    [string[]] $Path,
    [parameter(Position=1,Mandatory=$true)]
    [string] $Destination
)
{
    write-verbose "Join-File: Open Destination1 $Destination"
    $OutFile = [System.IO.File]::Create($Destination)
    foreach ( $File in $Path ) {
        write-verbose "   Join-File: Open Source $File"
        $InFile = [System.IO.File]::OpenRead($File)
        $InFile.CopyTo($OutFile)
        $InFile.Dispose()
    }
    $OutFile.Dispose()
    write-verbose "Join-File: finished"
} 

Performance:

• cmd.exe /c copy file1+file2 File3 around 5 seconds (Best)
• gc file1,file2 |sc file3 around 1100 seconds (yuck)
• join-file File1,File2 File3 around 16 seconds (OK)