# WMI calls for virtualization - not returning values

**URL:** <https://www.ruby-forum.com/t/wmi-calls-for-virtualization-not-returning-values/172001>\
**Category:** Ruby\
**Created:** [July 13, 2009, 10:20am UTC](https://www.ruby-forum.com/t/wmi-calls-for-virtualization-not-returning-values/172001 "2009-07-13T10:20:30Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![shreya](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@shreya](https://www.ruby-forum.com/u/shreya)\
**Post date:** [July 13, 2009, 10:20am UTC](https://www.ruby-forum.com/t/wmi-calls-for-virtualization-not-returning-values/172001/1 "2009-07-13T10:20:30Z")

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Hi,  
I am using WMI calls to ge the Virtual system information of a VM on  
Hyper-V using Ruby.  
Below is my code:

require ‘pp’  
require ‘win32ole’  
wmi = WIN32OLE.connect(“winmgmts://./root/virtualization”)

processes = wmi.ExecQuery(“select \* from  
MsVM\_virtualSystemManagementService”)  
temp = nil  
result = Array.new  
input = nil

for process in processes do  
pp process.Caption  
pp process.Name  
pp ret = process.GetSummaryInformation(input,  
[0,1,2,3,4,100,101,102,103,104,105,106,107,108],  
result)  
end  
pp result

ret is 0. which is for success. But ‘result’ is empty. Iam know that Iam  
missing out something. Please do let me know how to make this work. Iam  
stuck here.

Thanks in Advance,  
Shreya

---

<div class="post-metadata">

**Author:** ![shreya](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@shreya](https://www.ruby-forum.com/u/shreya)\
**Post date:** [July 13, 2009, 3:23pm UTC](https://www.ruby-forum.com/t/wmi-calls-for-virtualization-not-returning-values/172001/2 "2009-07-13T15:23:24Z")

</div>

On Mon, Jul 13, 2009 at 3:20 AM, Shreya Govind \<  
removed\_email\_address@domain.invalid\> wrote:

> processes = wmi.ExecQuery("select \* from  
> result)  
> end  
> pp result
> 
> ret is 0. which is for success. But ‘result’ is empty. Iam know that Iam  
> missing out something. Please do let me know how to make this work. Iam  
> stuck here.

Check WIN32OLE::ARGV for the result. This is explained here:

[http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/169830](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/169830)