Export/Import SharePoint farm solutions using PowerShell

In My environment we lost SharePoint updated code. We want migrate SharePoint from SP 2010 to SP2013. Simply I did Export all .WSP using following Script.

Steps:
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Export SharePoint 2010/2013 Farm Solutions:

1). Open SharePoint 2010/2013 Management Shell as administrator.

2).  Create new folder in any drive (In my case create new folder in D drive with ExportWSP name )

3). Type D: and type "cd ExportWSP"

4). Copy and run the following script.

        (Get-SPFarm).Solutions | ForEach-Object{$var = (Get-Location).Path + “\” + $_.Name; $_.SolutionFile.SaveAs($var)}

5). Go back to ExportWSP Folder, Here All SharePoint wsp export from SharePoint Farm.

Import SharePoint 2010/2013 Farm Solutions:

1). Open SharePoint 2010/2013 Management Shell as administrator.

3). Type D: and type "cd ExportWSP"

4). Copy and run the following script.

Get-ChildItem | ForEach-Object{Add-SPSolution -LiteralPath $_.Fullname}

5). Go to manage Farm Solutions under System Settings(Central Admin).Here Soltuions added. go  one by one to deploy using UI or Run following cmd "Install-SPSolution Sample.wsp -WebApplication "SharePointSite" -GacDeployment".