unset.java

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/*
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: unset.java,v 1.1 2004/04/06 00:54:14 bondolo Exp $
 */

package net.jxta.impl.shell.bin.unset;

import net.jxta.impl.shell.ShellApp;
import net.jxta.impl.shell.ShellEnv;
import net.jxta.impl.shell.ShellObject;

/**
 * Set an environment variable
 */
public class unset extends ShellApp {
    
    /**
     *  {@inheritDoc}
     **/
    public int startApp(String[] args) {
        if ( args.length != 1 ) {
            consoleMessage( " error : unset <env>");
            return ShellApp.appParamError;
        }
        
        ShellEnv env = getEnv();

        if ( !env.contains(args[0]) ) {
            consoleMessage( "Cannot access '" + args[0] + "'" );
            return ShellApp.appMiscError;
        }
        
        env.remove( args[0] );
        
        return ShellApp.appNoError;
    }
    
    /**
     *  {@inheritDoc}
     **/
    public String getDescription() {
        return "Removes an environment variable";
    }
    
    /**
     *  {@inheritDoc}
     **/
    public void help() {
        println("NAME");
        println("    unset - " + getDescription() );
        println(" ");
        println("SYNOPSIS");
        println("    unset <env>");
        println(" ");
        println("DESCRIPTION");
        println(" ");
        println("    Removes an existing Shell environment variable.");
        println(" ");
        println("EXAMPLE");
        println(" ");
        println("    JXTA>unset var1");
        println(" ");
        println("    This example removes the enviroment variable 'var1' from " );
        println("    the Shell environment variables." );
        println(" ");
        println("SEE ALSO");
        println("    Shell env set");
    }
}