python: Add convenience function for getting command line loadparm context

and default to using system smb.conf.

source/scripting/bin/winreg.py

@@ -12,7 +12,8 @@ import optparse
 import samba.getopt as options
 
 parser = optparse.OptionParser("%s <BINDING> [path]" % sys.argv[0])
-parser.add_option_group(options.SambaOptions(parser))
+sambaopts = options.SambaOptions(parser)
+parser.add_option_group(sambaopts)
 parser.add_option("--createkey", type="string", metavar="KEYNAME", 
         help="create a key")
 
@@ -25,7 +26,7 @@ if len(args) < 1:
 binding = args[0]
 
 print "Connecting to " + binding
-conn = winreg.winreg(binding, opts.configfile)
+conn = winreg.winreg(binding, sambaopts.get_loadparm())
 
 def list_values(key):
     (num_values, max_valnamelen, max_valbufsize) = conn.QueryInfoKey(key, winreg.String())[4:8]

source/scripting/python/samba/getopt.py

@@ -23,9 +23,25 @@ from credentials import Credentials
 class SambaOptions(optparse.OptionGroup):
     def __init__(self, parser):
         optparse.OptionGroup.__init__(self, parser, "Samba Common Options")
-        self.add_option("-s", "--configfile", type="string", metavar="FILE",
-                        help="Configuration file")
+        self.add_option("-s", "--configfile", action="callback",
+                        type=str, metavar="FILE", help="Configuration file", 
+                        callback=self._load_configfile)
+        self._configfile = None
 
+    def get_loadparm_path(self):
+        return self._configfile
+
+    def _load_configfile(self, option, opt_str, arg, parser):
+        self._configfile = arg
+
+    def get_loadparm(self):
+        import param
+        lp = param.LoadParm()
+        if self._configfile is None:
+            lp.load_default()
+        else:
+            lp.load(self._configfile)
+        return lp
 
 class VersionOptions(optparse.OptionGroup):
     def __init__(self, parser):