added shell service and fixed service

lib/service/service.py

@@ -1,7 +1,6 @@
-
 class Service:
-    def __init__(self):
-        pass
+    def __init__(self, parser):
+        self.parser = parser
 
     def _execute(self):
         self.pre_execute()
@@ -16,7 +15,7 @@ class Service:
         pass
 
     def parse_result(self):
-        pass
+        self.parser._parse()
 
     def handle_result(self):
         pass

lib/service/shell.py

@@ -1,4 +1,18 @@
 """
-The shell service. This is for executing services as shell commands and don't use a builtin function. This is useful to
-be free to do what you want.
+The shell service. This is for executing services as shell commands
+and don't use a builtin function. This is useful to be free to do what you want.
 """
+
+from service import Service
+
+
+class ShellService(Service):
+    def __init__(self, parser, log, **kwargs):
+        super(Service, self).__init__(parser)
+        if "command" in kwargs:
+            self.command = kwargs["command"]
+        else:
+            log.w("There is no command")
+
+    def execute(self):
+        self.command.call()