System.IO.FileSystemWatcher仅在编辑的文件上通知一次

Question

该脚本使用文件系统观察程序监视蜜罐文件夹，并报告任何更改（编辑，重命名，删除或创建），然后执行某些操作。

创建，重命名和删除时，操作可以正常工作。

但是在编辑时，我只能让脚本触发一次动作。 因此，例如，如果测试设备尝试编辑honeypot文件夹上的文件，则会触发操作。 但是同一设备尝试再次编辑同一个文件或不同的文件，编辑的观察者似乎无法工作，因为没有触发操作。

所以我尝试通过任务调度程序每5分钟重置一次脚本（每5分钟启动一次脚本），但结果仍然相同。

这是代码：

### SET FOLDER TO WATCH + FILES TO WATCH + SUBFOLDERS YES/NO
$watcher = New-Object System.IO.FileSystemWatcher
$watcher.Path = "\\vmserver2\_Do_Not_Delete_Or_Rename"
$watcher.Filter = "*.*"
$watcher.IncludeSubdirectories = $true
$watcher.EnableRaisingEvents = $true

### DEFINE ACTIONS AFTER AN EVENT IS DETECTED
$action = {
    $path = $Event.SourceEventArgs.FullPath
    $changeType = $Event.SourceEventArgs.ChangeType

    $logline = "$(Get-Date), $changeType, $path"
    #Add-content "D:\log.txt" -value $logline
    #write-host $logline

    $targetdevice = Get-SmbOpenFile |
        select clientusername, clientcomputername, path |
        where {$_.Path -like  'E:\Data\Archive\_Do_Not_Delete_Or_Rename' }

    $targetIP = $targetdevice.clientcomputername
    $targetUser = $targetdevice.clientusername

    Send-ToEmail -email "edu.bit.es@gmail.com" $targetIP
    $targetUser
}

### DECIDE WHICH EVENTS SHOULD BE WATCHED
Register-ObjectEvent $watcher "Created" -Action $action
Register-ObjectEvent $watcher "Changed" -Action $action
Register-ObjectEvent $watcher "Deleted" -Action $action
Register-ObjectEvent $watcher "Renamed" -Action $action
while ($true) {sleep 5}

我对powershell很新，所以我不明白，其余事件的观察者工作，只有编辑不起作用。

Answer 1

你的核心逻辑是合理的。

如果将操作块简化为仅执行Write-host部分，则应始终有效。 我相信你的问题是，在第二次调用时，你得到一个你没有捕获的终止错误，作为回报，它会阻止事件触发。

尝试使用以下内容替换您的操作脚本块

$action = {
  try {
    $path = $Event.SourceEventArgs.FullPath
    $changeType = $Event.SourceEventArgs.ChangeType

    $logline = "$(Get-Date), $changeType, $path"
    #Add-content "D:\log.txt" -value $logline
    #write-host $logline

    $targetdevice = Get-SmbOpenFile |
        select clientusername, clientcomputername, path |
        where {$_.Path -like  'E:\Data\Archive\_Do_Not_Delete_Or_Rename' }

    $targetIP = $targetdevice.clientcomputername
    $targetUser = $targetdevice.clientusername

    Send-ToEmail -email "edu.bit.es@gmail.com" $targetIP
    $targetUser
  }
  catch {
      Write-Host 'an error was thrown :(... Fortunately, it was caught.'
  }
}

这应该可以解决仅触发一次的已更改事件的问题。

这是一个使用3个观察者的例子，它检查同一目录下的文件更改。 您会注意到，在计数器达到5后，3名观察者中只有2名继续正常工作。 没有产生任何错误的watcherNoError和一个产生终止错误但是在Try catch watcherErrorsTryCatch捕获的watcherErrorsTryCatch 。

### SET FOLDER TO WATCH + FILES TO WATCH + SUBFOLDERS YES/NO
$PathToWatch = "\\127.0.0.1\c$\_"

$watcherNoError = New-Object System.IO.FileSystemWatcher -Property @{Path = $PathToWatch;Filter = '*.*';IncludeSubdirectories=$true;EnableRaisingEvents = $true}
$watcherWithErrors = New-Object System.IO.FileSystemWatcher -Property @{Path = $PathToWatch;Filter = '*.*';IncludeSubdirectories=$true;EnableRaisingEvents = $true}
$watcherErrorsTryCatch = New-Object System.IO.FileSystemWatcher -Property @{Path = $PathToWatch;Filter = '*.*';IncludeSubdirectories=$true;EnableRaisingEvents = $true}

$Global:Counter = @{
    watcherNoError = 0 
    watcherWithErrors = 0 
    watcherErrorsTryCatch = 0
}
### DEFINE ACTIONS AFTER AN EVENT IS DETECTED
$action = {

    $path = $Event.SourceEventArgs.FullPath
    $changeType = $Event.SourceEventArgs.ChangeType



    Switch ($Event.MessageData.Name) {
        "NoErrors" {
            $Global:Counter.watcherNoError +=1
            $count = $Global:Counter.watcherNoError
        }
        "WithErrors" {
            $Global:Counter.watcherWithErrors +=1
            $count = $Global:Counter.watcherWithErrors
            if ($count -eq 5) {
                Write-Host 'A terminated errow will be thrown...' -ForegroundColor DarkMagenta
                Throw 'oh no !'
            }

        }
         "WithErrorsTryCatch"  {
            $Global:Counter.watcherErrorsTryCatch +=1
            $count = $Global:Counter.watcherErrorsTryCatch
            if ($count -eq 5) {
                try {
                    Throw 'oh no !'
                }
                catch {
                    Write-Host 'error was caught... You are safe ;)' -ForegroundColor Green
                }
            }

        }
    }

    $logline = "Count: $Count - $($event.MessageData.Name): $changeType, $path" 
    write-host $logline -ForegroundColor $Event.MessageData.ForegroundColor


} 

### DECIDE WHICH EVENTS SHOULD BE WATCHED
Register-ObjectEvent $watcherNoError "Changed" -Action $action -MessageData @{Name='NoErrors';ForegroundColor='Yellow'}
Register-ObjectEvent $watcherWithErrors "Changed" -Action $action -MessageData @{Name='WithErrors';ForegroundColor='DarkMagenta'}
Register-ObjectEvent $watcherErrorsTryCatch "Changed" -Action $action -MessageData @{Name='WithErrorsTryCatch';ForegroundColor='Green'}

while ($true) {sleep 5}




$action = {
  try {
    $path = $Event.SourceEventArgs.FullPath
    $changeType = $Event.SourceEventArgs.ChangeType

    $logline = "$(Get-Date), $changeType, $path"
    #Add-content "D:\log.txt" -value $logline
    #write-host $logline

    $targetdevice = Get-SmbOpenFile |
        select clientusername, clientcomputername, path |
        where {$_.Path -like  'E:\Data\Archive\_Do_Not_Delete_Or_Rename' }

    $targetIP = $targetdevice.clientcomputername
    $targetUser = $targetdevice.clientusername

    Send-ToEmail -email "edu.bit.es@gmail.com" $targetIP
    $targetUser
  }
  catch {
      Write-Host 'an error was thrown :(... Fortunately, it was caught.'
  }
}

附加说明：即使它不是您的问题的解决方案，您仍应该在该Action脚本块中放置一个try / catch，因为终止错误将停止对下一个更改的进一步处理。

Answer 2

要么你需要使用

Remove-Event $watcher "Changed"

在$ Action脚本块的末尾或者使用

Unregister-Event $watcher "Changed"
Register-ObjectEvent $watcher "Changed -Action $action

在$ Action脚本块的末尾。