PowerShell System.Net.WebClient never closes ftp connection-CodePudding

I'm trying to use PowerShell to upload a (long) list of queued files, using System.Net.WebClient and the UploadFile function. This works fine, but after a file us uploaded, the ftp-connection never closes, either when the WebClient object instance goes out of scope or even after the script has finished. The function looks as follows:

function Upload-File() {
    Param (
        [string] $user,
        [string] $password,
        [string] $srceFileName,
        [string] $destFileName
    )
    # Set up FTP-client
    $client = New-Object System.Net.WebClient
    $client.Credentials = New-Object System.Net.NetworkCredential($user, $password)
    $client.UploadFile($destFileName, ".\$srceFileName")
    $client.Dispose()
}

All the information I can find states that the connection should close automatically when $client goes out of scope but this is clearly not happening.

Any idea on how to force the connection to close?

(This is part of a legacy system and for now I am stuck with ftp, so switching to another protocol is not an option.)

CodePudding user response：

For anyone else running into this problem, the solution is to use FtpWebRequest instead of WebClient and to set KeepAlive = $false. The function below will upload and then terminate the connection immediately afterwards.

function Upload-File() {
    Param (
        [string] $user,
        [string] $password,
        [string] $srceFileName,
        [string] $destFileName
    )
    $request = [Net.WebRequest]::Create($destFileName)
    $request.KeepAlive = $false
    $request.Credentials =
        New-Object System.Net.NetworkCredential($user, $password)
    $request.Method = [System.Net.WebRequestMethods Ftp]::UploadFile 
    
    $fileStream = [System.IO.File]::OpenRead(".\$srceFileName")
    $ftpStream = $request.GetRequestStream()
    $fileStream.CopyTo($ftpStream)
    
    $ftpStream.Dispose()
    $fileStream.Dispose()
}

This post pointed me in the right direction.