///////   LowerIO.java   /////// 

import java.io.*;    // for file I/O

class LowerIO
{
    public static void doio(RandomAccessFile iofile)
    {   int i; char c;
        try
	{  while ( (i = iofile.read()) >= 0 )
           {  c = (char) i;
              if ( Character.isUpperCase( c) )
              {  iofile.seek(iofile.getFilePointer()-1);
                 iofile.write(Character.toLowerCase(c));
              }
           }
        } catch( IOException e )
          {  JavaSystem.error(e);
             System.exit(1);
          }
    }

    public static void main (String args[])
    {   if ( args.length != 1 )    // takes one arg
        { JavaSystem.err.println( "Usage: LowerIO file");
          System.exit(1);
        }
        File file = new File(args[0]);
        if ( file.isFile() && file.canRead()
                && file.canWrite() )
        {  try
	   { RandomAccessFile iofile =
                    new RandomAccessFile(file, "rw");
             doio(iofile);
             iofile.close();
           }  catch ( IOException e )
              {  JavaSystem.error(e);
                 System.exit(1);
              }
        }
        else
        {  JavaSystem.err.println(
               "Can't open file for I/O " + args[0]);
           System.exit(1);
        }
    }
}