/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002. All rights
 * reserved. Software written by Ian F. Darwin and others. $Id: LICENSE,v 1.8
 * 2004/02/09 03:33:38 ian Exp $
 * 
 * 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.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS 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 THE AUTHOR OR 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.
 * 
 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee cup"
 * logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java
 * language and environment is gratefully acknowledged.
 * 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;


/**
 * Strings -- extract printable strings from binary file
 * 
 * @author Ian F. Darwin, http://www.darwinsys.com/
 * @version $Id: Strings.java,v 1.3 2004/02/08 23:57:29 ian Exp $
 */

public class Strings
{
	
	protected int	minLength	= 4;
	
	/**
	 * Return true if the character is printable IN ASCII. Not using
	 * Character.isLetterOrDigit(); applies to all unicode ranges
	 */
	protected boolean isStringChar( char ch )
	{
		if( ch >= 'a' && ch <= 'z' )
			return true;
		if( ch >= 'A' && ch <= 'Z' )
			return true;
		if( ch >= '0' && ch <= '9' )
			return true;
		switch( ch )
		{
			case '/':
			case '-':
			case ':':
			case '.':
			case ',':
			case '_':
			case '$':
			case '%':
			case '\'':
			case '(':
			case ')':
			case '[':
			case ']':
			case '<':
			case '>':
				return true;
		}
		return false;
	}
	
	/** Process one file */
	protected void process( String fileName, InputStream inStream )
	{
		try
		{
			int i;
			char ch;
			
			// This line alone cuts the runtime by about 66% on large files.
			BufferedInputStream is = new BufferedInputStream( inStream );
			
			StringBuffer sb = new StringBuffer();
			
			// Read a byte, cast it to char, check if part of printable string.
			while( (i = is.read()) != -1 )
			{
				ch = (char)i;
				if( isStringChar( ch ) || (sb.length() > 0 && ch == ' ') )
					// If so, build up string.
					sb.append( ch );
				else
				{
					// if not, see if anything to output.
					if( sb.length() == 0 )
						continue;
					if( sb.length() >= minLength )
					{
						report( fileName, sb );
					}
					sb.setLength( 0 );
				}
			}
			is.close();
		}
		catch( IOException e )
		{
			System.out.println( "IOException: " + e );
		}
	}
	
	/**
	 * This simple main program looks after filenames and opening files and such
	 * like for you.
	 */
	public static void main( String[] av )
	{
		Strings o = new Strings();
		if( av.length == 0 )
		{
			o.process( "standard input", System.in );
		}
		else
		{
			for( int i = 0; i < av.length; i++ )
				try
				{
					o.process( av[i], new FileInputStream( av[i] ) );
				}
				catch( FileNotFoundException e )
				{
					System.err.println( e );
				}
		}
	}
	
	/** Output a match. Made a separate method for use by subclassers. */
	protected void report( String fName, StringBuffer theString )
	{
		System.out.println( /* fName + ": " + */ theString );
	}
}