使用PowerShell从FTP服务器删除文件

Question

我编写了一个PowerShell脚本，使用FTP将文件下载到我的本地机器上。

下载文件后，我想从FTP服务器中删除它。我也写了这段代码。但不幸的是，它不起作用。

谁能帮我指出我的代码有什么问题？任何线索都会有所帮助...

这是我的代码

function Delete-File($Source,$Target,$UserName,$Password)
{
$ftprequest = [System.Net.FtpWebRequest]::create($Source)
$ftprequest.Credentials =  New-Object System.Net.NetworkCredential($UserName,$Password)
if(Test-Path $Source)
{
"ABCDEF File exists on ftp server."
$ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::DeleteFile
$ftprequest.GetResponse()
"ABCDEF File deleted."
}
}
function Get-FTPFile ($Source,$Target,$UserName,$Password)  
{  
# Create a FTPWebRequest object to handle the connection to the ftp server  
$ftprequest = [System.Net.FtpWebRequest]::create($Source)  
# set the request's network credentials for an authenticated connection  
$ftprequest.Credentials =  
New-Object System.Net.NetworkCredential($username,$password)  
if(Test-Path $targetpath)
{
"ABCDEF File exists"
}
else 
{ 
"ABCDEF File downloaded"
$ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::DownloadFile  
$ftprequest.UseBinary = $true  
$ftprequest.KeepAlive = $false  
Delete-File $sourceuri $targetpath $user $pass
}
# send the ftp request to the server  
$ftpresponse = $ftprequest.GetResponse()  
# get a download stream from the server response  
$responsestream = $ftpresponse.GetResponseStream()  
# create the target file on the local system and the download buffer  
$targetfile = New-Object IO.FileStream ($Target,[IO.FileMode]::Create)  
[byte[]]$readbuffer = New-Object byte[] 1024  
# loop through the download stream and send the data to the target 
file  
do{  
$readlength = $responsestream.Read($readbuffer,0,1024)  
$targetfile.Write($readbuffer,0,$readlength)  
}  
while ($readlength -ne 0)  
$targetfile.close()  
}  
$sourceuri = "ftp://ftpxyz.com/vit/ABCDEF.XML"  
$targetpath = "C:TempMNEWFOLDERABCDEF.XML"  
$user = "*******"  
$pass = "*******"  
Get-FTPFile $sourceuri $targetpath $user $pass 
Delete-File $sourceuri $targetpath $user $pass

每次我执行这个脚本时，我得到的唯一语句

ABCDEF 文件已下载

或

ABCDEF 文件存在

我想Delete-File根本没有执行...任何类型的线索都会有所帮助。

Answer 1

不能将Test-Path与 FTP URL 一起使用。因此，用于删除文件的代码将永远不会执行。

只需删除Test-Path条件并尝试无条件删除文件即可。然后检查错误并根据需要处理"文件不存在">错误。

$ftprequest = [System.Net.FtpWebRequest]::create($Source)
$ftprequest.Credentials =
New-Object System.Net.NetworkCredential($UserName, $Password)
try
{
$ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::DeleteFile
$ftprequest.GetResponse() | Out-Null
Write-Host ("File {0} deleted." -f $Source)
}
catch
{
if ($_.Exception.InnerException.Response.StatusCode -eq 550)
{
Write-Host ("File {0} does not exist." -f $Source)
}
else
{
Write-Host $_.Exception.Message
}
}

---

尽管您仅在成功下载文件后才尝试删除该文件，因此该文件实际上不太可能不存在。

因此，您可以考虑放弃任何特定的错误处理。

Answer 2

我在本地运行您的脚本进行尝试，发现了一些问题。我还重构了一些东西，只是为了让它更具可读性(至少在我看来:))。

问题

• 第 13 行。$Source参数中，有一个ftp://...路径。Test-Path将始终在此处返回$false，并且永远不会执行删除请求。
• 在Get-FTPFile中，您引用的不是函数的输入参数，而是在函数外部定义的变量。我不知道这只是一个复制和粘贴错误还是故意的。在我看来，您应该使用发送给函数的参数。至少在下面的代码中，第 38、39 和 50 行。

法典

function Delete-File
{  
param(
[string]$Source,
[string]$Target,
[string]$UserName,
[string]$Password
) 
$ftprequest = [System.Net.FtpWebRequest]::create($Source)
$ftprequest.Credentials =  New-Object System.Net.NetworkCredential($UserName,$Password)
if(Test-Path $Source)
{
"ABCDEF File exists on ftp server."
$ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::DeleteFile
$ftprequest.GetResponse()
"ABCDEF File deleted."
}
}
function Get-FTPFile
{  
param(
[string]$Source,
[string]$Target,
[string]$UserName,
[string]$Password
) 
# Create a FTPWebRequest object to handle the connection to the ftp server  
$ftprequest = [System.Net.FtpWebRequest]::create($Source)  
# set the request's network credentials for an authenticated connection  
$ftprequest.Credentials =  
New-Object System.Net.NetworkCredential($UserName,$Password)  
if(Test-Path $Target)
{
"ABCDEF File exists"
}
else 
{ 
"ABCDEF File downloaded"
$ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::DownloadFile  
$ftprequest.UseBinary = $true  
$ftprequest.KeepAlive = $false  
Delete-File $Source $Target $UserName $Password
}
# send the ftp request to the server  
$ftpresponse = $ftprequest.GetResponse()  
# get a download stream from the server response  
$responsestream = $ftpresponse.GetResponseStream()  
# create the target file on the local system and the download buffer  
$targetfile = New-Object IO.FileStream ($Target,[IO.FileMode]::Create)  
[byte[]]$readbuffer = New-Object byte[] 1024  
# loop through the download stream and send the data to the target 
file  
do{  
$readlength = $responsestream.Read($readbuffer,0,1024)  
$targetfile.Write($readbuffer,0,$readlength)  
}  
while ($readlength -ne 0)  
$targetfile.close()  
}  
$sourceuri = "ftp://ftpxyz.com/vit/ABCDEF.XML"  
$targetpath = "C:TempMNEWFOLDERABCDEF.XML"  
$user = "*******"  
$pass = "*******"   
Get-FTPFile $sourceuri $targetpath $user $pass 
#Delete-File $sourceuri $targetpath $user $pass

还有现成的PowerShell cmdlet，用于与FTP/SFTP通信，除非需要，否则无需从头开始创建所有内容。

无论如何，作为参考，请查看

例如

• https://www.powershellgallery.com/packages/PSFTP
• https://www.powershellgallery.com/packages/WinSCP