// File: useful_io_subunit.java
//
// Author: Rahul Simha
// Created: Aug 18, 1998
//
// Illustrates packages

package useful_io_pack;

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

public class useful_io_subunit {

  // Read a string from the screen.

  public static String read_string (String prompt)
  {
    System.out.print (prompt);
    InputStreamReader isr = new InputStreamReader (System.in);
    LineNumberReader lr = new LineNumberReader (isr);
    try {
      String s = lr.readLine ();
      return s;
    }
    catch (IOException e) {
      System.out.println ("gwu_io::read_string: cannot read\n");
      System.exit (0);
      return "";
    }
  }


  // Parse a string for a property.

  public static double read_property (String in_string, String property)
  {
    StringTokenizer st = new StringTokenizer (in_string);

    String first_part = st.nextToken ("=");
    first_part = first_part.trim ();

    if (!first_part.equals (property)){
      System.out.println ("Improper string: " + in_string);
      System.exit (0);
    }
    String second_part = st.nextToken (" =\t\n\r");
    second_part = second_part.trim();

    try {
      Double d = Double.valueOf (second_part);
      return d.doubleValue();
    }
    catch (NumberFormatException e) {
      System.out.println ("Second part not a number: " + second_part);
      System.exit (0);
    }
    return 0;
  }


} // End of class useful_io_subunit