/* Copyright (C) 2016 Ben Wolsieffer
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <stdio.h>
#include <stdbool.h>

int main(int argc, char *argv[]) {
	bool decrypt = false;
	if(argc > 1 && !strcmp(argv[1], "-d")){
		decrypt = true;
	}

	setvbuf(stdout, NULL, _IONBF, 0);

	unsigned char i;
	while (true) {
		int ret = getc(stdin);
		if (ret != EOF) {
			i = ret;
			if (decrypt) {
				i--;
			} else {
				i++;
			}
			putc(i, stdout);
		} else {
			break;
		}
	}
}