/*
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
class Replace {

    public static void Usage() {
	System.out.println("\nUsage:  java Replace char1 char2 inFile outFile");
    }

    public static void main(String args[]) {
	InputFile	in = null;
        OutputFile	out = null;
    	char		former = 'A';
    	char		latter = 'A';
   	byte		buf[];

	try {
   	    former = args[0].charAt(0);
	} catch (ArrayIndexOutOfBoundsException e) {
	    Usage();
	    System.err.println("you must supply the character to replace\n");
	    System.exit(-1);
	}

	try {
   	    latter = args[1].charAt(0);
	} catch (ArrayIndexOutOfBoundsException e) {
	    Usage();
	    System.err.println("you must supply the new character\n");
	    System.exit(-1);
	}

	try {
	    in = new InputFile(args[2]);
	} catch (ArrayIndexOutOfBoundsException e) {
	    Usage();
	    System.err.println("you must supply the input replacement file\n");
	    System.exit(-1);
	}

	try {
	    out = new OutputFile(args[3]);
	} catch (ArrayIndexOutOfBoundsException e) {
	    Usage();
	    System.err.println("you must supply the output replacement file\n");
	    System.exit(-1);
	}

	System.out.println("Replacing "+args[0]+" with "+args[1]+" from "+
			   args[2]+" to "+args[3]);

	if (in.open() == false) {
	    System.out.println("Unable to open input file "+in.getFileName());
	}

	if (out.open() == false) {
	    System.out.println("Unable to open output file "+out.getFileName());
	}

	buf = new byte[1];
	while (in.read(buf, 1) == 1) {
	    if (buf[0] == former)
		buf[0] = (byte)latter;
	    if (out.write(buf, 1) != 1) {
		System.out.println("Error writing to "+out.getFileName());
	    }
	}
 	in.close();
 	out.close();
    }
}