Free "tail -f" Tool for all Platforms: Tail for Windows, Tail for Linux and Tail for Mac

/******************************************************************************
 
Copyright (C) 2005  MakeLogic

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA


Date		: 14th December 2005
Authors		: MakeLogic

Design		: Ujjwal
Developer	: Dharma

********************************************************************************/


package com.makeLogic;

import java.io.LineNumberReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintStream;

import javax.swing.*;
import java.net.InetAddress;

import javax.swing.JFrame;

//import com.makeLogic.messaging.Hub;


public class Tail implements Runnable{


	//...Fields
	String fileName;
	LineNumberReader in;
	File file;
	TailInternalFrame frame;
	long lastModifiedLength;
	long currentModifiedLength;
	long refreshRate;
	long bytesToSkip;
	boolean initialLineNoObtained;

	private ClassLoader cl;

	//..Static TailMDI object
	public static TailMDI tailMDI = null;

	//...Constructors
	public Tail(String fileName){
		this(fileName,500);
	}

	public Tail(String fileName,long refreshRate){

		this.refreshRate = refreshRate;
		this.fileName = fileName;

		initialLineNoObtained = false;

		file = new File(fileName);
		cl = this.getClass().getClassLoader();
		
		//..If the file is very long, skip the initial lines
		long fileLength = file.length();
		//..Assume to read the last 10 lines
		//..Each line may have about 80 chars => 800 chars
		//..Say each char takes 2 bytes ie 1600 bytes 
		//..As a better assumtion - read the last 3 kb if the file is bigger than 3 kb

		long minSize = 3*1024;

		if(fileLength > minSize)
		{
			bytesToSkip = fileLength - minSize;
			//System.outprintln("ML... Bytes Skipped : "+bytesToSkip);
		}
		else
		{
			bytesToSkip = 0;
		}

		try
		{
			in = new LineNumberReader(new FileReader(fileName));
			in.skip(bytesToSkip);
		}
		catch(FileNotFoundException fnfe)
		{
			//fnfe.printStackTrace();
			//System.exit(1);
		}
		catch(Exception excp)
		{
			//excp.printStackTrace();
		}

		frame=new TailInternalFrame("Tail - "+fileName,fileName);
		frame.setFrameIcon(new ImageIcon(cl.getResource("green-ball-static.gif")));

	}

	//...methods
	//...show
	public void show(){
		new Thread(this).start();
		
		//..Show the InternalFrame
		frame.show();
		frame.pack();
		frame.setSize(700,300);
	}

	//...getFrame
	public TailInternalFrame getInternalFrame(){
	    return frame;
	}


	//...run from Runnable interface
	public void run()
	{

		String temp=null;

		while(true)
		{
			frame.setFrameIcon(new ImageIcon(cl.getResource("green-ball-static.gif")));

			try
			{
				Thread.sleep(refreshRate);
			}
			catch(InterruptedException ie)
			{
				//System.outprintln("Refresh cycle skipped" );
			}

			currentModifiedLength=file.length();

			//..Debug
			////System.outprintln("File sizes "+ lastModifiedLength + ":"+currentModifiedLength);

			if(lastModifiedLength!=currentModifiedLength)
			//if(true)
			{
				frame.setFrameIcon(new ImageIcon(cl.getResource("green-ball.gif")));

				lastModifiedLength = currentModifiedLength;
				
				//..Show the contents in the frame
				while(true)
				{
					try
					{
						temp=in.readLine();
						////System.outprintln("ML... LineNo. : "+ in.getLineNumber()+" >>>> Temp : "+temp);
						if(!initialLineNoObtained)
						{
							frame.setInitialLineNo(in.getLineNumber());
							initialLineNoObtained = true;
						}
						//temp = temp.trim();
					}
					catch(IOException ie)
					{
						//ie.printStackTrace();
						//System.exit(1);
					}

					if(temp==null)
					{
						//frame.setEOFReached();
						break;
					}

					frame.append(temp+"\r\n");
				}
			}
		}
	}

public static void main(String args[]){

    try{
		MakeLogicTailSplashScreen splashScreen = new MakeLogicTailSplashScreen();

		//..Put the Look and feel if OS is windows

		String osName = System.getProperty("os.name");

		if(osName.startsWith("Windows"))
		{

			try 
			{
				//..Set the windowsClassName
				String windowsClassName = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";

				//..Set the look and feel to windows
				UIManager.setLookAndFeel(windowsClassName);
			} 
			catch (UnsupportedLookAndFeelException exc) 
			{
				//System.outprintln("Error loading Look & Feel");
			}
		}

    	tailMDI = new TailMDI();
	    tailMDI.show();

		new CheckForNewUpdates(tailMDI);

		splashScreen.setVisible(false);

	    //Hub hub = new Hub(InetAddress.getByName("localhost"),80);

	}
	catch(Exception e){
	    //System.outprintln("Exception : " + e);
		//e.printStackTrace();
	}

}

}