使用 PowerShell 中的 WinSCP .NET 程序集和电子邮件结果从 FTP/SFTP 服务器上的一组文件夹下载文件

Question

我正在处理这个 PowerShell 脚本。导入 CSV 文件以获取源路径和目标路径。目标是将文件从 SFTP/FTP 服务器移动到目的地并发送电子邮件报告。

任务计划程序将每小时运行此代码。如果有新文件，将发送电子邮件。

快完成了，但是缺少两件事：

检查文件是否已经存在，正文电子邮件是否为空：出现以下错误：无法验证参数 'Body' 上的参数。参数为 null 或空。提供一个不是的论点 null 或为空，然后重试该命令。
我需要一些帮助，了解如何检查文件是否存在以及如果新文件被删除并复制到目标列表时如何获取此电子邮件

$SMTPBody = ""

$SMTPMessage  = @{
  "SMTPServer" = ""
  "From" = ""
  "To" = ""
  "Subject" = "New File"
}
try {
  # Load WinSCP .NET assembly
  Add-Type -Path "C:\Program Files (x86)\WinSCP\WinSCPnet.dll"

  # Setup session options
  $sessionOptions = New-Object WinSCP.SessionOptions -Property @{
    Protocol = [WinSCP.Protocol]::sftp
    HostName = ""
    UserName = ""
    Password = ""
    PortNumber = "22"
    FTPMode = ""
    GiveUpSecurityAndAcceptAnySshHostKey = $true
  }
  $session = New-Object WinSCP.Session
  try
  {
    # Connect
    $session.Open($sessionOptions)
    # Download files
    $transferOptions = New-Object WinSCP.TransferOptions
    $transferOptions.TransferMode = [WinSCP.TransferMode]::Binary

    Import-Csv -Path "D:\FILESOURCE.csv" -ErrorAction Stop |  foreach {

      $synchronizationResult = $session.SynchronizeDirectories(
        [WinSCP.SynchronizationMode]::Local, $_.Destination, $_.Source, $False)
      $synchronizationResult.Check()

      foreach ($download in $synchronizationResult.Downloads ) {
        Write-Host "File $($download.FileName) downloaded" -ForegroundColor Green
        $SMTPBody +=
          "`n Files: $($download.FileName -join ',    ') `n" +
          "Current Location: $($_.Destination)`n"
        Send-MailMessage @SMTPMessage  -Body $SMTPBody
      }

      $transferResult =
        $session.GetFiles($_.Source, $_.Destination, $False, $transferOptions)
      #Find the latest downloaded file
      $latestTransfer =
        $transferResult.Transfers |
        Sort-Object -Property @{ Expression = { (Get-Item $_.Destination).LastWriteTime }
        } -Descending |Select-Object -First 1
    }

    if ($latestTransfer -eq $Null) {
      Write-Host "No files found."
      $SMTPBody += "There are no new files at the moment"
    }
    else
    {
      $lastTimestamp = (Get-Item $latestTransfer.Destination).LastWriteTime
      Write-Host (
        "Downloaded $($transferResult.Transfers.Count) files, " +
        "latest being $($latestTransfer.FileName) with timestamp $lastTimestamp.")
      $SMTPBody += "file : $($latestTransfer)"
    }

    Write-Host "Waiting..."
    Start-Sleep -Seconds 5
  }  
  finally
  {
    Send-MailMessage @SMTPMessage  -Body  $SMTPBody
    # Disconnect, clean up
    $session.Dispose()
  }
}
catch
{
  Write-Host "Error: $($_.Exception.Message)"
}

Answer 1

要在处理整个文件之前检查并确保 csv 文件存在，您可以使用测试路径，

    ...
    if (!(Test-Path D:\FileSource.csv)) {
        Write-Output "No File Found"
        $SMTPBody += "There are no new files at the moment"
        return; # Dont run. file not found. Exit out.
    }

    Import-Csv -Path "D:\FILESOURCE.csv" -ErrorAction Stop |  foreach {
    ...

并且对于 Body 错误，它来自 finally 循环，因为在某些情况下 $SMTPBody 将为空。这将不再是一个问题，因为如果在开头找不到文件，$SMTPBody 将有一些文本。

即使您在 if 语句中使用 return 来检查文件是否存在，finally 也会始终被执行。由于我们更新了 $smtpbody，您的 Send-MailMessage 将不再出错。

更新

如果你想检查你正在下载的文件是否已经存在，你可以像这样使用if语句，

foreach ($download in $synchronizationResult.Downloads ) {
    if (!(Test-Path Join-Path D: $download.FileName) {
        $SMTPBody += "File $($download.Filename) already exists, skipping."
        continue # will go to the next download...
    }
    Write-Host "File $($download.FileName) downloaded" -ForegroundColor Green
    ...

如果您确实收到有关正文的错误，那主要是因为您的脚本遇到异常并直接发送到 finally 语句。 Finally 语句发送带有空正文的电子邮件，因为它从未被设置（由于异常）。我建议使用调试器（单步执行）并查看是哪一步导致了异常，并考虑添加步骤以确保脚本不会失败。

Answer 2

我相信您的代码存在的问题比您想象的要多。

您的 SynchronizeDirectories 和 GetFiles 组合很可疑。您首先通过 SynchronizeDirectories 下载新文件，然后通过 GetFiles 下载所有文件。我不认为你想要那样。
如果出现任何错误，.Check 调用将抛出并且您不会将错误收集到您的报告中。
您在 foreach 循环中 Send-MailMessage 继续发送部分报告

这是我对你的问题的看法，希望我已经正确理解你想要实施的内容：

$SMTPBody = ""

Import-Csv -Path "FILESOURCE.csv" -ErrorAction Stop |  foreach {

    Write-Host "$($_.Source) => $($_.Destination)"
    $SMTPBody += "$($_.Source) => $($_.Destination)`n"

    $synchronizationResult =
        $session.SynchronizeDirectories(
            [WinSCP.SynchronizationMode]::Local, $_.Destination, $_.Source, $False)

    $downloaded = @()
    $failed = @()
    $latestName = $Null
    $latest = $Null
    foreach ($download in $synchronizationResult.Downloads)
    {
        if ($download.Error -eq $Null)
        {
            Write-Host "File $($download.FileName) downloaded" -ForegroundColor Green
            $downloaded += $download.FileName
            $ts = (Get-Item $download.Destination).LastWriteTime
            if ($ts -gt $latest)
            {
                $latestName = $download.FileName;
                $latest = $ts
            }
        }
        else
        {
            Write-Host "File $($download.FileName) download failed" -ForegroundColor Red
            $failed += $download.FileName
        }
    }

    if ($downloaded.Count -eq 0)
    {
        $SMTPBody += "No new files were downloaded`n"
    }
    else
    {
        $SMTPBody += 
            "Downloaded $($downloaded.Count) files:`n" +
            ($downloaded -join ", ") + "`n" +
            "latest being $($latestName) with timestamp $latest.`n"
    }

    if ($failed.Count -gt 0)
    {
        $SMTPBody += 
            "Failed to download $($failed.Count) files:`n" +
            ($failed -join ", ") + "`n"
    }

    $SMTPBody += "`n"
}

它会给你这样的报告：

/source1 => C:\dest1`
Downloaded 3 files:
/source1/aaa.txt, /source1/bbb.txt, /source1/ccc.txt
latest being /source1/ccc.txt with timestamp 01/29/2020 07:49:07.

/source2 => C:\dest2
Downloaded 1 files:
/source2/aaa.txt
latest being /source2/aaa.txt with timestamp 01/29/2020 07:22:37.
Failed to download 1 files:
/source2/bbb.txt

使用 PowerShell 中的 WinSCP .NET 程序集和电子邮件结果从 FTP/SFTP 服务器上的一组文件夹下载文件

Download files from set of folders on FTP/SFTP server with WinSCP .NET assembly in PowerShell and email results

ftp

powershell

sftp

winscp

winscp-net