Tim Golden - python WMI

Description

Windows Management Instrumentation

Presents a consistent view across system administration functions on a Windows workstation.

Very good for finding out information about the system e.g. what is the serial number…

Notes

wmiweb.py is a nice browser which will show all the objects and methods (currently only available on trunk).

WMI is wrapping MOF files, which can easily be created for different sub-systems.

WMI always returns a set (or a list in python terminology).

Available on Windows 2000 onwards.

Is easy to query properties on other servers (have to satisfy security requirements).

Can use WMI to start and stop programs, list processes, list process attributes.

Can create watchers which call events.

Disadvantages

WMI is not fast.

Sometimes it can be too simplistic.

CIM data files… will try and grab every file on your machine and take down the service.

Not really designed to write properties back, but in some cases, there are change methods for some of the properties e.g. changing the name of a service.

Future

Microsoft are adding features to WMI, so we think it is a growing technology.

Event handling could be improved.

Asynchronous

Try and build a slimline version.

Might use com types rather than the win32 module… or might use a hand rolled library (to get a bit extra performance).

Sample

import wmi
c = wmi.WMI ()
for s in c.Win32_Service ():
  if s.State == 'Stopped':
    print s.Caption, s.State

import wmi
c = wmi.WMI()
c.Win32_

# Will speed up startup.
c = wmi.WMI (find_classes=False)

c.classes()
c.Win32_Processor
c.Win32_Processor.methods()
c.Win32_Processor.properties()
# To see the method and it's parameters.
c.Win32_Processor.SetPowerState()

for i in c.Win32_Service(State="Stopped")
c.Win32_Service.Change(

watcher = c.watch_for("creation"...

Associates of objects:

dd.associators