/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.osgi.service.command;

import java.io.*;

/**
 * A command shell can create and maintain a number of command sessions.
 * 
 * @author aqute
 * 
 */
public interface CommandProcessor {
	/**
	 * The scope of commands provided by this service. This name can be used to distinguish
	 * between different command providers with the same function names.
	 */
	final static String	COMMAND_SCOPE		= "osgi.command.scope";

	/**
	 * A list of method names that may be called for this command provider. A
	 * name may end with a *, this will then be calculated from all declared public
	 * methods in this service.
	 * 
	 * Help information for the command may be supplied with a space as
	 * separation.
	 */
	final static String	COMMAND_FUNCTION	= "osgi.command.function";

	/**
	 * Create a new command session associated with IO streams.
	 * 
	 * The session is bound to the life cycle of the bundle getting this
	 * service. The session will be automatically closed when this bundle is
	 * stopped or the service is returned.
	 * 
	 * The shell will provide any available commands to this session and
	 * can set additional variables.
	 * 
	 * @param in
	 *            The value used for System.in
	 * @param out
	 *            The stream used for System.out
	 * @param err
	 *            The stream used for System.err
	 * @return A new session.
	 */
	CommandSession createSession(InputStream in, PrintStream out,
			PrintStream err);
}