functions/Export-DbaLinkedServer.ps1

function Export-DbaLinkedServer {
    <#
        .SYNOPSIS
            Exports linked servers INCLUDING PASSWORDS, unless specified otherwise, to sql file.
 
        .DESCRIPTION
            Exports linked servers INCLUDING PASSWORDS, unless specified otherwise, to sql file.
     
            Requires remote Windows access if exporting the password.
 
        .PARAMETER SqlInstance
            Source SQL Server. You must have sysadmin access and server version must be SQL Server version 2005 or higher.
 
        .PARAMETER SqlCredential
            Login to the target instance using alternative linked servers. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
 
        .PARAMETER Credential
            Login to the target OS using alternative linked servers. Accepts credential objects (Get-Credential)
    
        .PARAMETER Path
            The path to the exported sql file.
     
        .PARAMETER LinkedServer
            The linked server(s) to export. If unspecified, all linked servers will be processed.
     
        .PARAMETER InputObject
            Allow credentials to be piped in from Get-DbaLinkedServer
     
        .PARAMETER ExcludePassword
            Exports the linked server without any sensitive information.
 
        .PARAMETER Append
            Append to Path
     
        .PARAMETER EnableException
            By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
            This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
            Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
     
        .NOTES
            Tags: LinkedServer
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: MIT https://opensource.org/licenses/MIT
 
        .EXAMPLE
            Export-DbaLinkedServer -SqlInstance sql2017 -Path C:\temp\ls.sql
 
            Exports the linked servers, including passwords, from sql2017 to the file C:\temp\ls.sql
 
        .EXAMPLE
            Export-DbaLinkedServer -SqlInstance sql2017 -Path C:\temp\ls.sql -ExcludePassword
 
            Exports the linked servers, without passwords, from sql2017 to the file C:\temp\ls.sql
     
    #>

    [CmdletBinding()]
    param (
        [Parameter(Mandatory, ValueFromPipeline)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [string[]]$LinkedServer,
        [PSCredential]$SqlCredential,
        [PSCredential]$Credential,
        [string]$Path,
        [switch]$ExcludePassword,
        [switch]$Append,
        [Microsoft.SqlServer.Management.Smo.LinkedServer[]]$InputObject,
        [switch]$EnableException
    )
    process {
        foreach ($instance in $SqlInstance) {
            try {
                Write-Message -Level Verbose -Message "Connecting to $instance."
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $sqlcredential -MinimumVersion 9
                $InputObject += $server.LinkedServers
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }
            
            if ($LinkedServer) {
                $InputObject = $InputObject | Where-Object Name -in $LinkedServer
            }
            
            if (-not $InputObject) {
                Write-Message -Level Verbose -Message "Nothing to export"
                continue
            }
            
            if (!(Test-SqlSa -SqlInstance $instance -SqlCredential $sqlcredential)) {
                Stop-Function -Message "Not a sysadmin on $instance. Quitting." -Target $instance -Continue
            }
            
            Write-Message -Level Verbose -Message "Getting NetBios name for $instance."
            $sourceNetBios = Resolve-NetBiosName $server
            
            Write-Message -Level Verbose -Message "Checking if Remote Registry is enabled on $instance."
            try {
                Invoke-Command2 -Raw -Credential $Credential -ComputerName $sourceNetBios -ScriptBlock { Get-ItemProperty -Path "HKLM:\SOFTWARE\" } -ErrorAction Stop
            }
            catch {
                Stop-Function -Message "Can't connect to registry on $instance." -Target $sourceNetBios -ErrorRecord $_
                return
            }
            
            if (-not (Test-Bound -ParameterName Path)) {
                $timenow = (Get-Date -uformat "%m%d%Y%H%M%S")
                $mydocs = [Environment]::GetFolderPath('MyDocuments')
                $path = "$mydocs\$($server.name.replace('\', '$'))-$timenow-linkedserver.sql"
            }
            
            $sql = @()
            
            if ($ExcludePassword) {
                $sql += $InputObject.Script()
            }
            else {
                try {
                    $decrypted = Get-DecryptedObject -SqlInstance $server -Type LinkedServer
                }
                catch {
                    Stop-Function -Continue -Message "Failure" -ErrorRecord $_
                }
                
                foreach ($ls in $InputObject) {
                    $currentls = $decrypted | Where-Object Name -eq $ls.Name
                    
                    if ($currentls.Password) {
                        $password = $currentls.Password.Replace("'", "''")
                        
                        $tempsql = $ls.Script()
                        $tempsql = $tempsql.Replace(' /* For security reasons the linked server remote logins password is changed with ######## */', '')
                        $tempsql = $tempsql.Replace("rmtpassword='########'", "rmtpassword='$password'")
                        $sql += $tempsql
                    }
                    else {
                        $sql += $ls.Script()
                    }
                }
            }
            
            try {
                if ($Append) {
                    Add-Content -Path $path -Value $sql
                }
                else {
                    Set-Content -Path $path -Value $sql
                }
                Get-ChildItem -Path $path
            }
            catch {
                Stop-Function -Message "Can't write to $path" -ErrorRecord $_ -Continue
            }
        }
    }
}