michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsISupports.idl"
michael@0: 
michael@0: /**
michael@0:  * Scriptable access to the current process environment.
michael@0:  *
michael@0:  */
michael@0: [scriptable, uuid(101d5941-d820-4e85-a266-9a3469940807)]
michael@0: interface nsIEnvironment : nsISupports
michael@0: {
michael@0:     /**
michael@0:      * Set the value of an environment variable.
michael@0:      *
michael@0:      * @param aName   the variable name to set.
michael@0:      * @param aValue  the value to set.
michael@0:      */
michael@0:     void set(in AString aName, in AString aValue);
michael@0: 
michael@0:     /**
michael@0:      * Get the value of an environment variable.
michael@0:      *
michael@0:      * @param aName   the variable name to retrieve.
michael@0:      * @return        returns the value of the env variable. An empty string
michael@0:      *                will be returned when the env variable does not exist or
michael@0:      *                when the value itself is an empty string - please use
michael@0:      *                |exists()| to probe whether the env variable exists
michael@0:      *                or not.
michael@0:      */
michael@0:     AString get(in AString aName);
michael@0: 
michael@0:     /**
michael@0:      * Check the existence of an environment variable.
michael@0:      * This method checks whether an environment variable is present in
michael@0:      * the environment or not.
michael@0:      *
michael@0:      * - For Unix/Linux platforms we follow the Unix definition:
michael@0:      * An environment variable exists when |getenv()| returns a non-NULL value.
michael@0:      * An environment variable does not exist when |getenv()| returns NULL.
michael@0:      * - For non-Unix/Linux platforms we have to fall back to a 
michael@0:      * "portable" definition (which is incorrect for Unix/Linux!!!!)
michael@0:      * which simply checks whether the string returned by |Get()| is empty
michael@0:      * or not.
michael@0:      *
michael@0:      * @param aName   the variable name to probe.
michael@0:      * @return        if the variable has been set, the value returned is
michael@0:      *                PR_TRUE. If the variable was not defined in the
michael@0:      *                environment PR_FALSE will be returned.
michael@0:      */
michael@0:     boolean exists(in AString aName);
michael@0: };
michael@0: