/**
 * ParseLines.java
 * @author Jeff Ondich, 29 October 2010
 *
 * A demonstration of the use of a Scanner to read an input
 * file one line at a time, and another Scanner to parse data
 * from the line.
 *
 * The data file read by this program is expected to have lines
 * of the form:
 *
 *    Lovelace 1815 1852
 *    Babbage 1791 1871
 *    Turing 1912 1954
 * 
 * etc. That is, a string (containing no spaces) and two integers
 * separated by spaces.
 */
import java.io.*;
import java.util.*;

public class ParseLines
{
    public static void main(String args[])
    {
        if (args.length != 1) {
            System.err.println("Usage: java ReadLines fileName");
            System.exit(1);
        }

        Scanner fileScanner = null;
        try {
            fileScanner = new Scanner(new File(args[0]));
        } catch (Exception e) {
            System.err.println(e.toString());
            System.exit(1);
        }

        int lineNumber = 0;
        while (fileScanner.hasNextLine()) {
            String line = fileScanner.nextLine();
            lineNumber++;

            // Now that you have the line, there are lots
            // of ways to get the string and two integers
            // out of it. Here's one ugly approach.
            String name;
            int birthYear, deathYear;
            Scanner lineScanner = new Scanner(line);
            if (lineScanner.hasNext()) {
                name = lineScanner.next();
                if (lineScanner.hasNextInt()) {
                    birthYear = lineScanner.nextInt();
                    if (lineScanner.hasNextInt()) {
                        deathYear = lineScanner.nextInt();
                        System.out.println(name + "'s age at death: " + (deathYear - birthYear));
                        continue;
                    }
                }
            }

            System.out.println("Malformed input line #" + lineNumber + ": " + line);
        }
    }
}