--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/VirtualMailManager/ext/Postconf.py	Tue Sep 16 05:55:54 2008 +0000
@@ -0,0 +1,92 @@
+# -*- coding: UTF-8 -*-
+# Copyright 2007-2008 VEB IT
+# See COPYING for distribution information.
+# $Id$
+
+"""A small - r/o - wrapper class for Postfix' postconf."""
+
+from VirtualMailManager.constants.VERSION import VERSION
+
+__author__ = 'Pascal Volk <p.volk@veb-it.de>'
+__version__ = VERSION
+__revision__ = 'rev '+'$Rev$'.split()[1]
+__date__ = '$Date$'.split()[1]
+
+import re
+from subprocess import Popen, PIPE
+
+import VirtualMailManager.constants.ERROR as ERR
+from VirtualMailManager.Exceptions import VMMException
+
+RE_PC_PARAMS = """^\w+$"""
+RE_PC_VARIABLES = r"""\$\b\w+\b"""
+
+class Postconf:
+    def __init__(self, postconf_bin):
+        """Creates a new Postconf instance.
+        
+        Keyword arguments:
+        postconf_bin -- absolute path to Postfix' postconf binary (str)
+        """
+        self.__bin = postconf_bin
+        self.__val = ''
+        re.compile(RE_PC_PARAMS)
+        re.compile(RE_PC_VARIABLES)
+
+    def read(self, parameter, expand_vars=True):
+        """Returns the parameters value.
+
+        If expand_vars is True (default), all variables in the value will be 
+        expanded:
+        e.g. mydestination -> mail.example.com, localhost.example.com, localhost
+        Otherwise the value may contain one or more variables.
+        e.g. mydestination -> $myhostname, localhost.$mydomain, localhost
+
+        Keyword arguments:
+        parameter -- the name of a Postfix configuration parameter (str)
+        expand_vars -- default True (bool)
+        """
+        if not re.match(RE_PC_PARAMS, parameter):
+            raise VMMException(_(u'The value »%s« looks not like a valid\
+ postfix configuration parameter name.'), ERR.INVALID_AGUMENT)
+        self.__val = self.__read(parameter)
+        if expand_vars:
+            self.__expandVars()
+        return self.__val
+
+    def __expandVars(self):
+        while True:
+            pvars = set(re.findall(RE_PC_VARIABLES, self.__val))
+            pvars_len = len(pvars)
+            if pvars_len < 1:
+                break
+            if pvars_len > 1:
+                self.__expandMultiVars(self.__readMulti(pvars))
+                continue
+            for var in pvars:
+                self.__val = self.__val.replace(var, self.__read(var[1:]))
+
+    def __expandMultiVars(self, old_new):
+        for old, new in old_new.items():
+            self.__val = self.__val.replace('$'+old, new)
+
+    def __read(self, parameter):
+        out, err = Popen([self.__bin, '-h', parameter], stdout=PIPE,
+                stderr=PIPE).communicate()
+        if len(err):
+            raise Exception, err.strip()
+        return out.strip()
+
+    def __readMulti(self, parameters):
+        cmd = [self.__bin]
+        for parameter in parameters:
+            cmd.append(parameter[1:])
+        out, err = Popen(cmd, stdout=PIPE, stderr=PIPE).communicate()
+        if len(err):
+            raise Exception, err.strip()
+        par_val = {}
+        for line in out.splitlines():
+            par, val = line.split(' = ')
+            par_val[par] = val
+        return par_val
+