///////   lowercase.java   /////// 
// example for text-file i/o

import java.io.*;

class lowercase
{   public static void doio(inputstream i, outputstream o)
    {   int c;
        inputstreamreader in = new inputstreamreader(i);
        outputstreamwriter out = new outputstreamwriter(o);
        try
        {  while ( (c = in.read()) >= 0 )
           {  c = character.tolowercase( (char) c);
              out.write(c);
            }
            out.flush();
        } catch( ioexception e )
          {  system.err.println("doio: i/o problem");
             system.err.println(e.getmessage());
             system.exit(1);
          }
    }

    public static void main (string args[])
    {   int argn = args.length;
        if ( argn == 0 )      // use standard i/o
            doio(system.in, system.out);
        else if ( argn == 2 ) // use files given
        { try 
          {  fileinputstream infile = 
                   new fileinputstream(args[0]);
             fileoutputstream ofile =
                   new fileoutputstream(args[1]);
             doio(infile, ofile);
             infile.close(); ofile.close();
          } catch ( filenotfoundexception e )
            {  system.err.println(
                  "can't open input file " + args[0]);
               system.err.println(e.getmessage());
               system.exit(1);
            }
            catch ( ioexception e )
            {  system.err.println(
                  "can't open output file " + args[1]);
               system.err.println(e.getmessage());
               system.exit(1);
            }
        }
        else   // error
        { system.err.println("usage: lowercase infile outfile");
          system.exit(1);
        }
    }
}