diff -r 1c2241dde942 -r 6eea85d8b91d VirtualMailManager/common.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/VirtualMailManager/common.py	Sat Apr 24 02:49:45 2010 +0000
@@ -0,0 +1,72 @@
+# -*- coding: UTF-8 -*-
+# Copyright (c) 2010, Pascal Volk
+# See COPYING for distribution information.
+
+"""
+    VirtualMailManager.common
+
+    Some common functions
+"""
+
+import os
+
+from VirtualMailManager import ENCODING
+from VirtualMailManager.constants.ERROR import \
+     NOT_EXECUTABLE, NO_SUCH_BINARY, NO_SUCH_DIRECTORY
+from VirtualMailManager.errors import VMMError
+
+_ = lambda msg: msg
+
+
+def expand_path(path):
+    """Expands paths, starting with ``.`` or ``~``, to an absolute path."""
+    if path.startswith('.'):
+        return os.path.abspath(path)
+    if path.startswith('~'):
+        return os.path.expanduser(path)
+    return path
+
+
+def get_unicode(string):
+    """Converts `string` to `unicode`, if necessary."""
+    if isinstance(string, unicode):
+        return string
+    return unicode(string, ENCODING, 'replace')
+
+
+def is_dir(path):
+    """Checks if `path` is a directory.
+
+    Throws a `VMMError` if `path` is not a directory.
+    """
+    path = expand_path(path)
+    if not os.path.isdir(path):
+        raise VMMError(_(u"'%s' is not a directory") % get_unicode(path),
+                       NO_SUCH_DIRECTORY)
+    return path
+
+
+def exec_ok(binary):
+    """Checks if the `binary` exists and if it is executable.
+
+    Throws a `VMMError` if the `binary` isn't a file or is not
+    executable.
+    """
+    binary = expand_path(binary)
+    if not os.path.isfile(binary):
+        raise VMMError(_(u"'%s' is not a file") % get_unicode(binary),
+                       NO_SUCH_BINARY)
+    if not os.access(binary, os.X_OK):
+        raise VMMError(_(u"File is not executable: '%s'") %
+                       get_unicode(binary), NOT_EXECUTABLE)
+    return binary
+
+
+def version_hex(version_string):
+    """Convert the version string '1.2.3' to an int.
+    hex(version_hex('1.2.3')) -> '0x10203'
+    """
+    major, minor, patch = map(int, version_string.split('.'))
+    return (major << 16) + (minor << 8) + patch
+
+del _