a class that gets available, running, and stopped services (Ubuntu/Debian)

[rootVIII]

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#! /usr/bin/python3 import os     class ServiceReport:     def __init__(self):         self.services = []         self.all_services = []         self.stopped_services = []         self.running_services = []         self.srvc_cmd = "service --status-all &> /dev/null"         self.set_services()         self.extract_services()       def set_services(self):         self.services = os.popen(self.srvc_cmd)       def get_all_services(self):         return self.all_services       def get_running_services(self):         return self.running_services       def get_stopped_services(self):         return self.stopped_services       def running_services_count(self):         return len(self.running_services)       def stopped_services_count(self):         return len(self.stopped_services)       def all_services_count(self):         return len(self.all_services)       def extract_services(self):         for service in sorted(self.services):             self.all_services.append(service[8:-1])             if "+" in service:                 self.running_services.append(service[8:-1])             else:                 self.stopped_services.append(service[8:-1])     if __name__ == "__main__":     sr = ServiceReport()     print("\n" + str(sr.all_services_count()) + " services are available")     for x in sr.get_all_services():         print(x)     print("\n" + str(sr.running_services_count()) + " services are running")     for y in sr.get_running_services():         print(y)     print("\n" + str(sr.stopped_services_count()) + " services are stopped")     for z in sr.get_stopped_services(): print(z)

[Gribouillis]

I would rather return a sequence of small Service objects for such a program, because Python is very strong at manipulating collections and I think it opens more flexible possibilities. Here is a proposal

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from collections import namedtuple import os   class Service(namedtuple('Service', 'name status')):     __slots__ = ()     def is_running(self):         return self.status == '+'     def is_stopped(self):         return self.status == '-'     def has_no_status(self):         return self.status == '?'   def service_status_all():     for line in os.popen("service --status-all &> /dev/null"):         _, status, _, name = line.strip().split()         yield Service(name, status)           if __name__ == '__main__':     services = list(service_status_all())     print("{} services are available".format(len(services)))     for x in services:         print(x.name)     running = [s for s in services if s.is_running()]     print()     print("{} services are running".format(len(running)))     for y in running:         print(y.name)     stopped = [s for s in services if s.is_stopped()]     print()     print("{} services are stopped".format(len(stopped)))     for y in stopped:         print(y.name)

[rootVIII]

Ah I like the yield keyword. I actually attempted to use that as the service command seems to gradually output the services. I couldn’t get it to work. I’m glad you posted that to see how to return an iterator correctly

[rootVIII]

Just out of curiosity... I noticed that you used the "?" in case of no status... does the output of service --status-all on your machine give a service/status that does not have a [+] or a [-]?

[Gribouillis]

does the output of service --status-all on your machine give a service/status that does not have a [+] or a [-]?

They all have [ + ] or [ - ], however man service indicates

service --status-all runs all init scripts, in alphabetical order, with the status
command. The status is [ + ] for running services, [ - ] for stopped services and
[ ? ] for services without a 'status' command. This option only calls status for
sysvinit jobs; upstart jobs can be queried in a similar manner with initctl list.

It could be a good idea to parse more seriously the lines of output in case the syntax of service --status-all changes. The re module can be used for this. Also the command can be made a classmethod of the Service class, which would allow further code to subclass the Service class

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from collections import namedtuple import os import re   class Service(namedtuple('Service', 'name status')):     __slots__ = ()     def is_running(self):         return self.status == '+'     def is_stopped(self):         return self.status == '-'     def has_no_status(self):         return self.status == '?'       @classmethod     def iterate_all(cls):         for line in os.popen("service --status-all &> /dev/null"):             match = re.match(                 r"\[\s*(?P<status>[-+?])\s*\]\s*(?P<name>[^\s].+)", line.strip())             if not match:                 raise ValueError(('Unknown service status syntax:', line))             yield cls(match.group('name'), match.group('status'))   if __name__ == '__main__':     for service in Service.iterate_all():         print(service)

[rootVIII]

Yes thank you:)