Using Ruby & WMI to Get Win32 Process Information

In an earlier post, we looked at using Windows Management Instrumentation (WMI) to determine if a "USB Mass Storage Device" is inserted. Today we'll use WMI to get information about the Win32 processes being run.

WMI is installed and already running on all recent versions of Windows, so we'll connect to it using the win32ole library's connect method:

require 'win32ole'
wmi = WIN32OLE.connect("winmgmts://")

Next, we'll call WMI's ExecQuery method to query the Win32_Process table:

processes = wmi.ExecQuery("select * from win32_process")

This returns a collection of all WMI Win32_Process objects.

The Win32_Process class has dozens of properties. You can find a complete list of those properties here. You could also produce a list of these properties by calling the Properties_ method (note the underscore) on one of the Win32_Process objects. This returns a collection of Properties; then call the Name method/property for each of these Property objects. For example:

for process in processes do
    for property in process.Properties_ do
        puts property.Name
    end
    break
end

To obtain data about a process, call that Process object's relevant property/method. For example, the following code prints four properties for each process:

for process in processes do
    puts "Name: #{process.Name}"
    puts "CommandLine: #{process.CommandLine}"
    puts "CreationDate: #{process.CreationDate}"
    puts "WorkingSetSize: #{process.WorkingSetSize}"
    puts
end

That's all for now. Got a question or suggestion? Post a comment or send me email.

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