xpcom/threads/nsIEnvironment.idl

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla embedding code.
  16  *
  17  * The Initial Developers of the Original Code are
  18  * Benjamin Smedberg <bsmedberg@covad.net> and
  19  * Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>.
  20  *
  21  * Portions created by the Initial Developer are Copyright (C) 2003/2004
  22  * the Initial Developer. All Rights Reserved.
  23  *
  24  * Contributor(s):
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either the GNU General Public License Version 2 or later (the "GPL"), or
  28  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
  31  * under the terms of either the GPL or the LGPL, and not to allow others to
  32  * use your version of this file under the terms of the MPL, indicate your
  33  * decision by deleting the provisions above and replace them with the notice
  34  * and other provisions required by the GPL or the LGPL. If you do not delete
  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #include "nsISupports.idl"
  41
  42 /**
  43  * Scriptable access to the current process environment.
  44  *
  45  */
  46 [scriptable, uuid(101d5941-d820-4e85-a266-9a3469940807)]
  47 interface nsIEnvironment : nsISupports
  48 {
  49     /**
  50      * Set the value of an environment variable.
  51      *
  52      * @param aName   the variable name to set.
  53      * @param aValue  the value to set.
  54      */
  55     void set(in AString aName, in AString aValue);
  56
  57     /**
  58      * Get the value of an environment variable.
  59      *
  60      * @param aName   the variable name to retrieve.
  61      * @return        returns the value of the env variable. An empty string
  62      *                will be returned when the env variable does not exist or
  63      *                when the value itself is an empty string - please use
  64      *                |exists()| to probe whether the env variable exists
  65      *                or not.
  66      */
  67     AString get(in AString aName);
  68
  69     /**
  70      * Check the existence of an environment variable.
  71      * This method checks whether an environment variable is present in
  72      * the environment or not.
  73      *
  74      * - For Unix/Linux platforms we follow the Unix definition:
  75      * An environment variable exists when |getenv()| returns a non-NULL value.
  76      * An environment variable does not exist when |getenv()| returns NULL.
  77      * - For non-Unix/Linux platforms we have to fall back to a
  78      * "portable" definition (which is incorrect for Unix/Linux!!!!)
  79      * which simply checks whether the string returned by |Get()| is empty
  80      * or not.
  81      *
  82      * @param aName   the variable name to probe.
  83      * @return        if the variable has been set, the value returned is
  84      *                PR_TRUE. If the variable was not defined in the
  85      *                environment PR_FALSE will be returned.
  86      */
  87     boolean exists(in AString aName);
  88 };
  89