001 /*
002 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003 *
004 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
005 *
006 * The contents of this file are subject to the terms of either the GNU
007 * General Public License Version 2 only ("GPL") or the Common Development
008 * and Distribution License("CDDL") (collectively, the "License"). You
009 * may not use this file except in compliance with the License. You can
010 * obtain a copy of the License at
011 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
012 * or packager/legal/LICENSE.txt. See the License for the specific
013 * language governing permissions and limitations under the License.
014 *
015 * When distributing the software, include this License Header Notice in each
016 * file and include the License file at packager/legal/LICENSE.txt.
017 *
018 * GPL Classpath Exception:
019 * Oracle designates this particular file as subject to the "Classpath"
020 * exception as provided by Oracle in the GPL Version 2 section of the License
021 * file that accompanied this code.
022 *
023 * Modifications:
024 * If applicable, add the following below the License Header, with the fields
025 * enclosed by brackets [] replaced by your own identifying information:
026 * "Portions Copyright [year] [name of copyright owner]"
027 *
028 * Contributor(s):
029 * If you wish your version of this file to be governed by only the CDDL or
030 * only the GPL Version 2, indicate your decision by adding "[Contributor]
031 * elects to include this software in this distribution under the [CDDL or GPL
032 * Version 2] license." If you don't indicate a single choice of license, a
033 * recipient has the option to distribute your version of this file under
034 * either the CDDL, the GPL Version 2 or to extend the choice of license to
035 * its licensees as provided above. However, if you add GPL Version 2 code
036 * and therefore, elected the GPL Version 2 license, then the option applies
037 * only if the new code is made subject to such option by the copyright
038 * holder.
039 */
040
041 package com.sun.enterprise.admin.cli;
042
043 import java.io.Writer;
044 import java.io.Reader;
045 import java.io.OutputStreamWriter;
046 import java.io.InputStreamReader;
047 import java.io.IOException;
048 import java.io.FileReader;
049 import java.io.FileNotFoundException;
050 import java.io.BufferedWriter;
051 import java.io.BufferedReader;
052
053
054 /**
055 * More.java
056 *
057 * @author <a href="mailto:toby.h.ferguson@sun.com">Toby H Ferguson</a>
058 *
059 * This class provides a primitive more(1) functionality, paging
060 * through the given file, with an optional pagelength.
061 */
062
063 public class More {
064 private BufferedReader in;
065 private BufferedWriter out;
066 private String quit;
067 private String prompt;
068
069 public More(int linesPerPage, Reader src, Writer dest,
070 Reader fromUser, Writer toUser, String quitPrefix, String prompt)
071 throws IOException {
072 in = new BufferedReader(fromUser);
073 out = new BufferedWriter(toUser);
074 quit = quitPrefix;
075 this.prompt = prompt;
076
077 Pager pager = new Pager(linesPerPage, src, dest);
078 do {
079 pager.nextPage();
080 } while (pager.hasNext() && wantsToContinue());
081 }
082
083 /**
084 * Return false iff the line read from the user starts with the
085 * quit character. This is a blocking call, waiting on input
086 * from the user
087 */
088 boolean wantsToContinue() throws IOException {
089 out.write(prompt);
090 out.newLine();
091 out.flush();
092 String line = in.readLine();
093 return line != null && !line.startsWith(quit);
094 }
095 }