Thread: Can anyone help to change java program into c program? thanks

Code:

import java.io.*;
import java.net.*;
import java.util.*;

public class JavaDNS {
    private final int TIMEOUT = 5000;
    boolean isRunning = true;
    DatagramSocket socket = null;
    MonitorThread monitorThread = null;
    long startTime = 0;
    long enquiryCount = 0;
    int downCount = 0;
    boolean silentMode = false;
    HashMap <String, String> lookupHash = new HashMap<String, String>();
    
    public static void main(String [] argc) {
        boolean silent = false;
        if (argc.length == 1 && argc[0].equals("silent"));
            silent = true;
            
        JavaDNS dns = new JavaDNS(silent);
        dns.start();
    }

    public JavaDNS(boolean silentMode) {
        startTime = System.currentTimeMillis();
        buildHash();
    }
    
    private void buildHash() {
        log("Build HashMap");
        
        int seg1, seg2, seg3, seg4;
        for (int i=1; i<=1000000; i++) {
            seg1 = 1;
            seg2 = (int) (i / 65535);
            seg3 = (int) (i / 255); 
            seg4 = i % 255;
            lookupHash.put(i + "abc.pepddns.com", seg1 + "." + seg2 + "." + seg3 + "." + seg4);
            if (i % 10000 == 0) {
                log(i + " records hashed");
            }
        }
    }
    
    public void stop() {
        isRunning = false;
        try {
            if (socket != null && socket.isConnected()) {
                socket.close();
            }
        } catch (Exception e) {
        }
    }
    
    private void bindSocket() throws SocketException {
        try {
            byte [] baddr = {0x0000, 0x0000, 0x0000, 0x0000};
            InetAddress addr = InetAddress.getByAddress(baddr);
            socket = new DatagramSocket(53, addr);
            
            log("-- Bind socket on port 53");
        } catch (Exception e) {
            e.printStackTrace();
            throw new SocketException(e.getMessage());
        }
    }
    
    public void start() {
        try {
            if (monitorThread == null || !monitorThread.isAlive() || !monitorThread.isRunning()) {
                monitorThread = null;
                monitorThread = new MonitorThread();
                monitorThread.start();
            }
            
            if (socket == null) {
                bindSocket();
            }
            
            byte[] buf = new byte[512];
            while (isRunning) {
                DatagramPacket packet = new DatagramPacket(buf, buf.length);    
                socket.receive(packet);
                
                ProcessThread processThread = new ProcessThread(socket, packet);
                processThread.start();
                
                enquiryCount++;
            }
        } catch (Exception e) {    
            e.printStackTrace();
            downCount++;
            
            if (isRunning) {
                start();
            }
        }
    }
    
    private class MonitorThread extends Thread {
        private boolean running = true;
        
        public MonitorThread() {
        }
        
        public void run() {
            try {
                while (running) {
                    if (!silentMode) {
                        log("Health Check " + new java.util.Date());
                        log("-- Enquiry Count: " + enquiryCount);
                        log("-- Processing Thread: " + Thread.currentThread().getThreadGroup().activeCount());
                        log("-- Up Time: " + ((System.currentTimeMillis() - startTime) / 1000) + " seconds");
                        log("-- Down Count: " + downCount);
                    }

                    Thread.sleep(60000);
                }
            } catch (Exception e){
                running = false;
            }
        }
        
        public boolean isRunning() {
            return running;
        }
    }
    
    private class ProcessThread extends Thread {
        DatagramSocket socket;
        DatagramPacket packet;
        
        public ProcessThread(DatagramSocket socket, DatagramPacket packet) {
            this.socket = socket;
            this.packet = packet;
        }
        
        public void run() {
            try {
                int offset = 12;  // Ignore first 12 bytes
        
                StringBuffer sb = new StringBuffer();
                byte[] queryData = packet.getData();
                
                int len = (int) queryData[offset];
                while (len > 0) {
                    if (sb.length() > 0) {
                        sb.append(".");
                    }
                    sb.append(new String(queryData, offset+1, len));
                    offset += len + 1;
                    len = queryData[offset];
                }
            
                offset = packet.getLength();    
                //log("Receive Query from " + packet.getAddress() + " for : " + sb.toString());
                
                queryData[2] = (byte) 0x0081; // Response Flag #1
                queryData[3] = (byte) 0x0080; // Response Flag #2
                queryData[7] = (byte) 0x0001; // It's a response
                queryData[offset++] = (byte) 0x00c0;  // Name is a pointer
                queryData[offset++] = (byte) 0x000c;  // Pointer is to the name at offset 0x000c
                queryData[offset++] = (byte) 0x0000;  
                queryData[offset++] = (byte) 0x0001;  // Answer is a type A query
                queryData[offset++] = (byte) 0x0000;  
                queryData[offset++] = (byte) 0x0001;  // Answer is clas IN
                queryData[offset++] = (byte) 0x0000;
                queryData[offset++] = (byte) 0x0000;
                queryData[offset++] = (byte) 0x0002;  // Response is valid for 0x0258 (600 sec)
                queryData[offset++] = (byte) 0x0058;
                queryData[offset++] = (byte) 0x0000;
                queryData[offset++] = (byte) 0x0004;  // Address is 4 bytes long
                
                // Return IP on below 

                String ip = lookupHash.get(sb.toString());
                if (ip == null)
                    ip = "1.2.3.4";
                
                String [] ipSec = ip.split("[.]");
                queryData[offset++] = (byte) Integer.parseInt(ipSec[0]);  // Ip Sec 1
                queryData[offset++] = (byte) Integer.parseInt(ipSec[1]);  // Ip Sec 2
                queryData[offset++] = (byte) Integer.parseInt(ipSec[2]);  // Ip Sec 3
                queryData[offset++] = (byte) Integer.parseInt(ipSec[3]);  // Ip Sec 4 
                
                packet.setData(queryData, 0, offset);
                
                socket.send(packet);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    
    private void log(String msg) {
        if (!silentMode)
            System.out.println(msg);
    }
}

Regards,
Man Pak Hong, Dave
[email protected]

This isn't how it is done here. You do the work and post specific questions when you run into trouble.