[python-win32] Re: How to determine whether program running as service?

[Roger Upole]

You could list running services using wmi,
then check to see if your current process is amongst them.
This is kind of roundabout but appears to work:

import win32com.client, win32api
wmi=win32com.client.Dispatch('wbemscripting.swbemlocator')
ls=wmi.ConnectServer()
plist=[]
svcs=ls.InstancesOf('win32_service')
for svc in svcs:
    plist.append(svc.Properties_('ProcessId').Value)
if win32api.GetCurrentProcessId() in plist:
    print 'I am a service'

      Roger


----- Original Message ----- 
From: "David Rushby" <davidrushby at yahoo.com>
To: <python-win32 at python.org>
Sent: Wednesday, September 08, 2004 6:49 PM
Subject: [python-win32] How to determine whether program running as service?


> What's the canonical way to programmatically determine whether a
> pywin32-based Python program is running as a Windows service or as a
> regular process?
>
> This issue arises because Windows services don't have [functional]
> standard output streams, so even simple print statements will
> eventually cause the service to raise an unhandled exception.  This
> typically causes the thread on which the exception arose to die,
> leaving the SCM-listener thread still running, but the service useless
> from the perspective of its clients.
>
> So, when running as a service, it's necessary to replace sys.stdout and
> sys.stderr with streams that redirect to somewhere other than the
> [dysfunctional] console--but there are some complications.  For
> example, when the program is hosted by PythonService.exe but running in
> debug mode (via 'pythonservice -debug the_service_program.py'), the
> normal output streams are available, and because the program is being
> debugged, it should produce verbose output.
>
> In pre-200 builds of pywin32, one could simply:
> ------------------------------------------------
> try:
>     import servicemanager
>     needToReplaceStdStreams = not servicemanager.Debugging()
> except ImportError:
>     needToReplaceStdStreams = True
> else:
>     needToReplaceStdStreams = False
> ------------------------------------------------
>
> With build 200 and later, servicemanager can be imported by non-service
> processes, so the code above no longer works.
>
> Examining the name of the executable (sys.executable) won't work,
> because Python services don't require that PythonService.exe host them
> (a py2exe-fied service is a good example of a situation in which one
> might not want to use PythonService.exe).
>
> I noticed in the spambayes codebase that Mark Hammond appears to be
> implementing a test somewhat similar to this one with code like this:
> ------------------------------------------------
> try:
>     win32api.GetConsoleTitle()
> except win32api.error:
>     # Not a regular process.
> else:
>     # A regular process.
> ------------------------------------------------
> That test is not suitable for service-or-regular-process detection
> purposes because there are many non-service execution contexts that
> lack a proper win32 console.  win32api.GetConsoleTitle() fails in all
> of the graphical Python shells I've tried--including PythonWin--yet
> it's still desirable to print to the standard streams while running in
> a graphical shell.
>
> Can anyone advise me?
>
> Thanks.
>
>
>
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