import java.io.*;

/**
 * used for console (terminal) input which
 * is exceedingly ugly unless encapsulated in
 * a class.  This is a beginning, allows reading String,
 * int, and double values from "standard input".  Currently
 * each function reads an entire line, and parses according
 * to the memberfunction called, e.g., <em>readInt</em>
 *
 * In this, preliminary version bad I/O is caught, but
 * converted to a default value (e.g., 0 for int)
 *
 * This is a singleton class: one, per-program instance
 * is retunred by using <em>getInstance()</em>
 *
 * @version 2.0, revised 10/22/2000
 * @author Owen Astrachan
 *
 */
 
public class ConsoleInput
{
    /**
     * reads a line from standard input, returns string
     * @return the string read from the terminal/keyboard/stdin
     */
    
    public static String readString()
    {
	String line=null;
	try {
	    line = ourReader.readLine();	    
	}
	catch (IOException ioe)	{
	    System.out.println("error in readString");
	}
	
	return line;
    }

    /**
     * reads a line from standard input, returns first int on line
     * catches NumberFormatException, returns 0 if caught
     * @return the int read from the terminal/keyboard/stdin
     * 
     */

    public static int readInt()
    {
	String line = null;
	int local = 0;
	try
	{
	    line = ourReader.readLine();	    
	}
	catch (IOException ioe)	{ }

	try {
	    local = Integer.parseInt(line);
	}
	catch (NumberFormatException nfe) {
	    System.out.println("illegal numeric entry "+line);
	}
	return local;    
    }

    /**
     * reads a line from standard input, returns first double on line
     * catches NumberFormatException, returns 0 if caught
     * @return the double read from the terminal/keyboard/stdin
     */
    
    public static double readDouble()
    {
	String line = null;
	double local = 0.0;
	try {
	    line = ourReader.readLine();	    
	}
	catch (IOException ioe)	{ }

	try {
	    local = Double.valueOf(line).doubleValue();
	}
	catch (NumberFormatException nfe) {
	    System.out.println("illegal numeric entry "+line);
	}
	return local;    
    }
    
    private static BufferedReader ourReader =
    new BufferedReader(
	new InputStreamReader(System.in));
    
}