/**
 * Args.java
 *
 * @author Jeff Ondich
 * @version 4/2/05
 *
 * Based on a C++ program written during class in 2004 to
 * illustrate one approach to parsing command-line arguments.  The
 * basic approach is: (1) set your default behaviors, (2) scan
 * through the arguments to set non-default behaviors, and
 * (3) execute the specified behaviors.
 *
 * The program's job, such as it is, is to change its input to
 * upper case, sending the output to standard out.  The input
 * can come from either a file or standard input, and there are
 * usage and version flags that override the input->output
 * and just print suitable messages.
 */

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

public class Args
{
    public static void main( String[] args )
    {
        // Set default behaviors.
        String fileName = null;
        boolean printUsage = false;
        boolean printVersion = false;

        for( int k=0; k < args.length; k++ )
        {
            if( args[k].equals( "-u" ) )
                printUsage = true;

            else if( args[k].equals( "-v" ) )
                printVersion = true;

            else if( k < args.length - 1 )
            {
                // A file for input can only be the last argument.
                // Thus, if we find something that isn't a valid
                // option before the last argument, we have an
                // invalid command line.
                printUsage = true;
            }

            else // There's a single file specified.
                fileName = args[k];
        }

        if( printUsage  ||  printVersion )
        {
            if( printVersion )
                printVersionStatement();

            if( printUsage )
                printUsageStatement();

            System.exit( 1 );
        }

        else
        {
            Scanner in = null;

            if( fileName == null )
                in = new Scanner( System.in );
            else
            {
                try
                {
                    File inputFile = new File( fileName );
                    in = new Scanner( inputFile );
                }
                catch( IOException e )
                {
                    System.err.println( "Can't open " + fileName );
                    System.exit( 1 );
                }
            }

            capitalize( in );
        }
    }


    public static void printUsageStatement()
    {
        System.err.println( "Usage: java Args [-u] [-v] [file]" );
    }


    public static void printVersionStatement()
    {
        System.err.println( "Args, version 0.00001" );
    }

    public static void capitalize( Scanner in )
    {
        while( in.hasNextLine() )
        {
            String line = in.nextLine();
            System.out.println( line.toUpperCase() );
        }
    }
}