001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.examples.unix;
019
020import java.io.IOException;
021import java.net.InetAddress;
022import java.net.UnknownHostException;
023
024import org.apache.commons.net.finger.FingerClient;
025
026/**
027 * This is an example of how you would implement the finger command in Java using NetComponents. The Java version is much shorter. But keep in mind that the
028 * Unix finger command reads all sorts of local files to output local finger information. This program only queries the finger daemon.
029 * <p>
030 * The -l flag is used to request long output from the server.
031 */
032public final class finger {
033
034    public static void main(final String[] args) {
035        boolean longOutput = false;
036        int arg = 0, index;
037        String handle, host;
038        final FingerClient finger;
039        InetAddress address = null;
040
041        // Get flags. If an invalid flag is present, exit with usage message.
042        while (arg < args.length && args[arg].startsWith("-")) {
043            if (args[arg].equals("-l")) {
044                longOutput = true;
045            } else {
046                System.err.println("usage: finger [-l] [[[handle][@<server>]] ...]");
047                System.exit(1);
048            }
049            ++arg;
050        }
051
052        finger = new FingerClient();
053        // We want to timeout if a response takes longer than 60 seconds
054        finger.setDefaultTimeout(60000);
055
056        if (arg >= args.length) {
057            // Finger local host
058
059            try {
060                address = InetAddress.getLocalHost();
061            } catch (final UnknownHostException e) {
062                System.err.println("Error unknown host: " + e.getMessage());
063                System.exit(1);
064            }
065
066            try {
067                finger.connect(address);
068                System.out.print(finger.query(longOutput));
069                finger.disconnect();
070            } catch (final IOException e) {
071                System.err.println("Error I/O exception: " + e.getMessage());
072                System.exit(1);
073            }
074
075            return;
076        }
077
078        // Finger each argument
079        while (arg < args.length) {
080
081            index = args[arg].lastIndexOf('@');
082
083            if (index == -1) {
084                handle = args[arg];
085                try {
086                    address = InetAddress.getLocalHost();
087                } catch (final UnknownHostException e) {
088                    System.err.println("Error unknown host: " + e.getMessage());
089                    System.exit(1);
090                }
091            } else {
092                handle = args[arg].substring(0, index);
093                host = args[arg].substring(index + 1);
094
095                try {
096                    address = InetAddress.getByName(host);
097                    System.out.println("[" + address.getHostName() + "]");
098                } catch (final UnknownHostException e) {
099                    System.err.println("Error unknown host: " + e.getMessage());
100                    System.exit(1);
101                }
102            }
103
104            try {
105                finger.connect(address);
106                System.out.print(finger.query(longOutput, handle));
107                finger.disconnect();
108            } catch (final IOException e) {
109                System.err.println("Error I/O exception: " + e.getMessage());
110                System.exit(1);
111            }
112
113            ++arg;
114            if (arg != args.length) {
115                System.out.print("\n");
116            }
117        }
118    }
119}