Extract session ID from psexec / PowerShell query user command

问题

I'm writing a PowerShell script to find out the session ID of the active user at a remote machine, to then launch a program using that session ID. Here is what I have so far.

$queryusers = $psexecdirectory + ' \\' +  $remotepc + ' -u ' + $domain + '\' + $username + ' -p ' + $password + ' query user'
$results = iex $queryusers

The above works fine, with the example results below being stored on the variable $results

 USERNAME              SESSIONNAME        ID  STATE   IDLE TIME  LOGON TIME
 usr1                              3  Disc         1:12  9/5/2013 11:59
AM
>usr2          rdp-tcp#1           4  Active          .  9/5/2013 11:59
AM

I've used the below to get the ID, but the number on session name 'rdp-ctp#0' changes when another user logs in, like in the output above, rendering it useless:

$id = $results | Select-String "$rdp-tcp#0\s+(\w+)" |
                 Foreach {$_.Matches[0].Groups[1].Value}

I am unfamiliar with the PowerShell syntax, and have been unable to find a site where formatting options are explained. Can someone help me out? And if you know of a website where I can learn more about extracting snippets from strings? Thanks in advance.

回答1:

Try this:

$id = $results | ? { $_ -match '(\d+)\s+Active' } | % { $matches[1] }

The regular expression (\d+)\s+Active will match the keyword "Active" preceeded by a number and the subsequent loop returns the first submatch (i.e. the number).

来源：https://stackoverflow.com/questions/18642355/extract-session-id-from-psexec-powershell-query-user-command