Using XPath starts-with or contains functions to search Windows event logs

问题

By editing the XML filter query manually in Windows event viewer, I can find events where the data matches a string exactly:

<QueryList>
  <Query Id="0" Path="Application">
    <Select Path="Application">*[EventData[Data and (Data="Session end: imzcjflrrsq1sfdk3okc4jpf")]]</Select>
  </Query>
</QueryList>

Now, I want to do a partial match:

<QueryList>
  <Query Id="0" Path="Application">
    <Select Path="Application">*[EventData[Data and (Data[starts-with(.,"Session")])]]</Select>
  </Query>
</QueryList>

Event log gives me the error:

The specified query is invalid

Do I have the syntax wrong?

回答1:

Windows Event Log supports a subset of XPath 1.0. It contains only 3 functions: position, Band, timediff.

Reference: https://docs.microsoft.com/en-us/windows/desktop/WES/consuming-events#xpath-10-limitations

回答2:

If you don't mind two passes, you can always use a powershell script to re-filter the data as its -where operator supports -like, -match, and -contains:

nv.ps1

$Query = @"
  <QueryList>
    <Query Id="0" Path="System">
      <Select Path="System">
        *[System[(EventID=20001)]]
      </Select>
    </Query>
  </QueryList>
"@

$events = Get-WinEvent -FilterXml $Query
ForEach ($Event in $Events) {
    # Convert the event to XML
    $eventXML = [xml]$Event.ToXml()
    Add-Member -InputObject $Event -MemberType NoteProperty -Force -Name  DriverVersion -Value $eventXML.Event.UserData.InstallDeviceID.DriverVersion
    Add-Member -InputObject $Event -MemberType NoteProperty -Force -Name  DriverDescription -Value $eventXML.Event.UserData.InstallDeviceID.DriverDescription
    Add-Member -InputObject $Event -MemberType NoteProperty -Force -Name  Data -Value $eventXML.Event.EventData.Data
}
$Events | Select TimeCreated, Id, DriverDescription, DriverVersion, ProviderName, @{Name="MessageData";Expression={$_.Message + $_.Data}} | Where {$_.DriverDescription -match "NVIDIA GeForce GTX*"} | Out-GridView
pause

A cmd to launch it (nv.cmd):

powershell.exe -executionpolicy bypass "& '.\nv.ps1'"

来源：https://stackoverflow.com/questions/8671194/using-xpath-starts-with-or-contains-functions-to-search-windows-event-logs

标签

xml

windows

xslt

xpath

event-log