Have icon overlays persist after machine restart in Python - python

So, thanks to the Tim Golden guide and other questions here I have a script that will show overlays on files and folders based on their "state" similar to Tortoise SVN or Dropbox.
My problem is that once I restart the explorer.exe process or the OS itself and open explorer there are no longer any overlays.
My first thought:
Have the service that actually manages file state detect that no requests have come in and just re-register the overlay handler
The problem here is that registration requires elevated permissions which is acceptable on initial install of the application by the end user but not every time they restart their machine.
Can anyone suggest what I might be missing here?
I have the class BaseOverlay and its children in a single .py file and register from my main app by calling this script using subprocess.
subprocess.check_call(script_path, shell=True)
Is Explorer not able to re-load the script as it is Python? Do I need to compile into a DLL or EXE? Would that change the registration process?
Here's the registration call:
win32com.server.register.UseCommandLine(BaseOverlay)
Here's the class(simplified):
class BaseOverlay:
_reg_clsid_ = '{8D4B1C5D-F8AC-4FDA-961F-A0143CD97C41}'
_reg_progid_ = 'someoverlays'
_reg_desc_ = 'Icon Overlay Handler'
_public_methods_ = ['GetOverlayInfo', 'GetPriority', 'IsMemberOf']
_com_interfaces_ = [shell.IID_IShellIconOverlayIdentifier]
def GetOverlayInfo(self):
return icon_path, 0, shellcon.ISIOI_ICONFILE
def GetPriority(self):
return 50
def IsMemberOf(self, fname, attributes):
return winerror.S_OK

Related

Subprocess.Popen only runs second time

I have a boot controller which runs a boot.py file contained in each folder of each tool i am trying to deploy. I want my boot controller to run all of these boot files simultaneously. The config file has the tool names and the versions desired, which help to generate the path to the boot.py.
def run_boot():
config_file = get_config_file()
parse_config_file.init(config_file)
tools = parse_config_file.get_tools_to_deploy()
#tools is now a list of tool names
top_dir = os.getcwd()
for tool in tools:
ver = parse_config_file.get_tool_version(tool).strip()
boot_file_path = "{0}\\Deploy\\{1}\\{2}".format(os.getcwd(),tool,ver)
try:
subprocess.Popen('boot.py', shell=True, cwd=boot_file_path)
except:
print ("{0} failed to open".format(tool))
print(tool, boot_file_path)
os.chdir(top_dir)
The first time i run this, the print(tool, boot_file_path) executes but the processes do not. the second time it is run the processes do open. I cannot find a reason for this.

Python 3 Windows Service starts only in debug mode

I first posted an answer in this post, but it didn't conform to the forum standards. I hope this time te answer fits the forum standards. This code should be more clear and easy to read.
In Python 3+ I have the following class that I use to build a Windows Service (it does nothing, just writes a log file):
#MyWindowsService.py
import win32serviceutil
import servicemanager
import win32service
import win32event
import sys
import logging
import win32api
class MyWindowsService(win32serviceutil.ServiceFramework):
_svc_name_ = 'ServiceName'
_svc_display_name_ = 'Service Display Name'
_svc_description_ = 'Service Full Description'
logging.basicConfig(
filename = 'c:\\Temp\\{}.log'.format(_svc_name_),
level = logging.DEBUG,
format = '%(levelname)-7.7s # %(asctime)s: %(message)s'
)
def __init__(self, *args):
self.log('Initializing service {}'.format(self._svc_name_))
win32serviceutil.ServiceFramework.__init__(self, *args)
self.stop_event = win32event.CreateEvent(None, 0, 0, None)
def SvcDoRun(self):
self.ReportServiceStatus(win32service.SERVICE_START_PENDING)
try:
self.log('START: Service start')
self.ReportServiceStatus(win32service.SERVICE_RUNNING)
self.start()
win32event.WaitForSingleObject(self.stop_event, win32event.INFINITE)
except Exception as e:
self.log('Exception: {}'.format(e))
self.SvcStop()
def SvcStop(self):
self.log('STOP: Service stopping...')
self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
self.stop()
win32event.SetEvent(self.stop_event)
self.ReportServiceStatus(win32service.SERVICE_STOPPED)
def log(self, msg):
servicemanager.LogInfoMsg(str(msg)) #system log
logging.info(str(msg)) #text log
def start(self):
self.runflag = True
while self.runflag:
win32api.Sleep((2*1000), True)
self.log('Service alive')
def stop(self):
self.runflag = False
self.log('Stop received')
if __name__ == '__main__':
win32serviceutil.HandleCommandLine(MyWindowsService)
In the script I use a log file to check if it's working properly. I'm running python3.6 (also tried with python3.4) on Windows 7 and I'm experiencing the following problem. When I run python MyWindowsService.py install the prompt says that the service has been installed (but nothing is written in the log file). If I try to start the service, I get Service Error: 1 - More info NET HELPMSG 3547 which doesn't say much about the error. If I run python MyWindowsService.py debug, the program runs just fine (the log file is written), but still I don't have any control over the service: if I open another prompt and try to stop/start the service I still got the same results as stated above.
I also tryed to insert some debug code inside the init function, and when I run python MyWindowsService.py install it seems it doesn't get called. Is it possible?
I've checked for multiple solution and workarounds around the net, but I didn't find anything suitable. What am I missing?
As pointed out by eriksun in the comment to the first post, the problem came from the location of the python script, that was in a drive mapped with an UNC path - I'm working with a virtual machine. Moving the python script in the same drive as the python installation did the job.
To sum it up for future uses, if the service fails to start and you're pretty sure about your code, these are helpful actions to try and solve your issues:
use sc start ServiceName, sc query ServiceName and sc stop ServiceName to get info about the service.
check if your file is in a physical drive or in a UNC-mapped drive. If the latter try to run the script using the UNC path (for example python \\Server\share\python\your-folder\script.py) or move your script in the same drive as the python installation
make sure that "python36.dll", "vcruntime140.dll", and "pywintypes36.dll" are either symlink'd to the directory that has PythonService.exe; or symlink'd to the System32 directory; or that the directories with these DLLs are in the system (not user) Path
Check the system register with command reg query HKLM\System\CurrentControlSet\Services\your_service_name /s to get more information about the script
PLease, feel free to complete, change, modify the last so that it can be usefull for anyone that like me encounder this issue.
EDIT: One more thing... My project was thought to work actually with network folders (and UNC-mapped drive) and it failed when I tried to make it run as service. One very useful (day-saving) resource that I used to make it work is the SysinternalsSuite by Mark Russinovich that I found in this post. Hope this helps.

How to get linux screen title from command line

How can I fetch the title of a screen session from the command line?
I came up with a very small and simple python script with pexpect to do it.
It is handy in multiuser environments where some host is reserved and status is written to screen title by user.
It works for me, feel free to make it better.
In order to fetch specific session title, you need to modify the script and call for correct session.
If you run this through remote connection as local script (through SSH for example), remember to set export TERM=xterm before execution.
try:
import pexpect
import sys
child=pexpect.spawn('screen -x')
child.sendcontrol('a');
child.send('A');
i = child.expect('Set window.*')
child.sendcontrol('c');
child.sendcontrol('a');
child.send('d');
TITLE=str(child.after)
TITLE_P=TITLE.split('7m')
if str(TITLE_P[-1]) == '':
print 'Title not found'
else:
print str(TITLE_P[-1])
except:
print 'Could not check screen Title'

NTEventLogHandler from a Python executable

import logging, logging.handlers
def main():
ntl = logging.handlers.NTEventLogHandler("Python Logging Test")
logger = logging.getLogger("")
logger.setLevel(logging.DEBUG)
logger.addHandler(ntl)
logger.error("This is a '%s' message", "Error")
if __name__ == "__main__":
main()
The Python (2.7.x) script above writes "This is a 'Error' message" to the Windows Event Viewer. When I run it as a script, I get the expected output. If I convert the script to an executable via PyInstaller, I get an entry in the event log but it says something completely different.
The description for Event ID ( 1 ) in Source ( Python Logging Test ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: This is a 'Error' message.
This is the command I use to convert the script into an executable: pyinstaller.py --onefile --noconsole my_script.py though the command line parameters do not appear to have any impact on this behaviour and it will suffice to just call pyinstaller.py my_script.py.
I would appreciate any help in understanding what is going on and how I go about fixing this.
Final solution
I didn't want to go down the resource hacker route, as that is going to be a difficult step to automate. Instead, the approach I took was to grab the win32service.pyd file from c:\Python27\Lib\site-packages\win32 and place it next to my executable. The script was then modified pass the full path to the copy of the win32service.pyd file and this works in both script and exe form. The final script is included below:
import logging, logging.handlers
import os
import sys
def main():
base_dir = os.path.dirname(sys.argv[0])
dllname = os.path.join(base_dir, "win32service.pyd")
ntl = logging.handlers.NTEventLogHandler("Python Logging Test", dllname=dllname)
logger = logging.getLogger("")
logger.setLevel(logging.DEBUG)
logger.addHandler(ntl)
logger.error("This is a '%s' message", "Error")
if __name__ == "__main__":
main()
Usually, the Windows Event Log doesn't store error messages in plain text, but rather message ID references and insertion strings.
Instead of storing a message like Service foo crashed unexpectedly, it stores a message ID which points to a resource string stored in a DLL. In this case, the resource would be something like Service %s crashed unexpectedly and foo would be stored as insertion string. The program which writes the message registers the resource DLL.
The reason for this is localization. DLLs can store lots of different resources (dialog layout, strings, icons…), and one DLL can contain the same resource in many different languages. The operating system automatically chooses the right resources depending on the system locale. Resource DLLs are used by virtually all Microsoft utilities and core utilities.
Side note: Nowadays, the preferred (and cross-platform) way for localization is gettext.
This is used for the message log as well – ideally, you could open a log from an German Windows installation on an English one with all messages in English.
I suspect that the pywin32 implementation skips that mechanism by only having one single message ID (1) which is just something like "%s". It is stored in win32service.pyd and registered by pywin32. This works fine as long as this file exists on the file system, but breaks as soon as it's hidden inside a PyInstaller executable. I guess you have to embed the message ID into your executable directly.
Edit: suspicion confirmed, the message table is indeed stored inside win32service.pyd
Resource Hacker showing the message table http://media.leoluk.de/evlog_rh.png
Try to copy the message table resource from win32service.pyd to your PyInstaller executable (for example using Resource Hacker).
Looking at the logging handler implementation, this might work:
def __init__(self, appname, dllname=None, logtype="Application"):
logging.Handler.__init__(self)
try:
import win32evtlogutil, win32evtlog
self.appname = appname
self._welu = win32evtlogutil
if not dllname:
dllname = os.path.split(self._welu.__file__)
dllname = os.path.split(dllname[0])
dllname = os.path.join(dllname[0], r'win32service.pyd')
You'd have to set dllname to os.path.dirname(__file__). Use something like this if you want it to continue working for the unfrozen script:
if getattr(sys, 'frozen', False):
dllname = None
elif __file__:
dllname = os.path.dirname(__file__)
ntl = logging.handlers.NTEventLogHandler("Python Logging Test", dllname=dllname)

CherryPy3 and IIS 6.0

I have a small Python web application using the Cherrypy framework. I am by no means an expert in web servers.
I got Cherrypy working with Apache using mod_python on our Ubuntu server. This time, however, I have to use Windows 2003 and IIS 6.0 to host my site.
The site runs perfectly as a stand alone server - I am just so lost when it comes to getting IIS running. I have spent the past day Googling and blindly trying any and everything to get this running.
I have all the various tools installed that websites have told me to (Python 2.6, CherrpyPy 3, ISAPI-WSGI, PyWin32) and have read all the documentation I can. This blog was the most helpful:
http://whatschrisdoing.com/blog/2008/07/10/turbogears-isapi-wsgi-iis/
But I am still lost as to what I need to run my site. I can't find any thorough examples or how-to's to even start with. I hope someone here can help!
Cheers.
I run CherryPy behind my IIS sites. There are several tricks to get it to work.
When running as the IIS Worker Process identity, you won't have the same permissions as you do when you run the site from your user process. Things will break. In particular, anything that wants to write to the file system will probably not work without some tweaking.
If you're using setuptools, you probably want to install your components with the -Z option (unzips all eggs).
Use win32traceutil to track down problems. Be sure that in your hook script that you're importing win32traceutil. Then, when you're attempting to access the web site, if anything goes wrong, make sure it gets printed to standard out, it'll get logged to the trace utility. Use 'python -m win32traceutil' to see the output from the trace.
It's important to understand the basic process to get an ISAPI application running. I suggest first getting a hello-world WSGI application running under ISAPI_WSGI. Here's an early version of a hook script I used to validate that I was getting CherryPy to work with my web server.
#!python
"""
Things to remember:
easy_install munges permissions on zip eggs.
anything that's installed in a user folder (i.e. setup develop) will probably not work.
There may still exist an issue with static files.
"""
import sys
import os
import isapi_wsgi
# change this to '/myapp' to have the site installed to only a virtual
# directory of the site.
site_root = '/'
if hasattr(sys, "isapidllhandle"):
import win32traceutil
appdir = os.path.dirname(__file__)
egg_cache = os.path.join(appdir, 'egg-tmp')
if not os.path.exists(egg_cache):
os.makedirs(egg_cache)
os.environ['PYTHON_EGG_CACHE'] = egg_cache
os.chdir(appdir)
import cherrypy
import traceback
class Root(object):
#cherrypy.expose
def index(self):
return 'Hai Werld'
def setup_application():
print "starting cherrypy application server"
#app_root = os.path.dirname(__file__)
#sys.path.append(app_root)
app = cherrypy.tree.mount(Root(), site_root)
print "successfully set up the application"
return app
def __ExtensionFactory__():
"The entry point for when the ISAPIDLL is triggered"
try:
# import the wsgi app creator
app = setup_application()
return isapi_wsgi.ISAPISimpleHandler(app)
except:
import traceback
traceback.print_exc()
f = open(os.path.join(appdir, 'critical error.txt'), 'w')
traceback.print_exc(file=f)
f.close()
def install_virtual_dir():
import isapi.install
params = isapi.install.ISAPIParameters()
# Setup the virtual directories - this is a list of directories our
# extension uses - in this case only 1.
# Each extension has a "script map" - this is the mapping of ISAPI
# extensions.
sm = [
isapi.install.ScriptMapParams(Extension="*", Flags=0)
]
vd = isapi.install.VirtualDirParameters(
Server="CherryPy Web Server",
Name=site_root,
Description = "CherryPy Application",
ScriptMaps = sm,
ScriptMapUpdate = "end",
)
params.VirtualDirs = [vd]
isapi.install.HandleCommandLine(params)
if __name__=='__main__':
# If run from the command-line, install ourselves.
install_virtual_dir()
This script does several things. It (a) acts as the installer, installing itself into IIS [install_virtual_dir], (b) contains the entry point when IIS loads the DLL [__ExtensionFactory__], and (c) it creates the CherryPy WSGI instance consumed by the ISAPI handler [setup_application].
If you place this in your \inetpub\cherrypy directory and run it, it will attempt to install itself to the root of your IIS web site named "CherryPy Web Server".
You're also welcome to take a look at my production web site code, which has refactored all of this into different modules.
OK, I got it working. Thanks to Jason and all his help. I needed to call
cherrypy.config.update({
'tools.sessions.on': True
})
return cherrypy.tree.mount(Root(), '/', config=path_to_config)
I had this in the config file under [/] but for some reason it did not like that. Now I can get my web app up and running - then I think I will try and work out why it needs that config update and doesn't like the config file I have...

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