import java.io.File;
import java.util.Scanner;
import java.io.FileNotFoundException;

/**
 * CommandLine.java
 * Jeff Ondich, Carleton College, 2014-01-05
 * Modified: Anna Rafferty, Carleton College, 2016-08-24
 * Modified: Jed Yang, Carleton College, 2017-01-07
 *
 * A copy of LineReader.java that takes the input file path from the command
 * line rather than from a hard-coded string.  For example, I might run this
 * like:
 *   java CommandLine somelines.txt
 * "somelines.txt" is a command line argument (an argument entered in the
 * terminal) and the program will read this and use it as the filename to read
 * from.  Note that you've seen command line arguments in other contexts--for
 * example, you've probably typed something like "cd Desktop" to change into
 * the directory named Desktop.
 * 
 * Once you've tried running this program, try modifying it to so that if there
 * is more than one command line argument, it prints out the second one.
 * 
 * This is the Java half of a pair of parallel examples in Python and Java.
 * See commandline.py.
 */
public class CommandLine
{
   public static void main(String[] args)
   {
      // START CHANGES
      // This is the only part that's different from LineReader.java
      if (args.length == 0)
      {
         System.err.println("Usage: java CommandLine inputFilePath");
         System.exit(1);
      }
      String inputFilePath = args[0];
      // END CHANGES

      File inputFile = new File(inputFilePath);

      Scanner scanner = null;
      try
      {
         scanner = new Scanner(inputFile);
      }
      catch (FileNotFoundException e)
      {
         System.err.println(e);
         System.exit(1);
      }

      int numberOfLines = 0;
      while (scanner.hasNextLine())
      {
         String line = scanner.nextLine();
         System.out.println(line.toUpperCase());
         numberOfLines++;
      }
      scanner.close();
      System.out.println("\nNumber of lines: " + numberOfLines);
   }
}