/*
 * Copyright (c) 2023 DTB <trinity@trinity.moe>
 * Copyright (c) 2023–2024 Emma Tebibyte <emma@tebibyte.media>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero 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 Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see https://www.gnu.org/licenses/.
 */
#include <stdio.h> /* fprintf(3), perror(3), stderr */
#include <sysexits.h> /* EX_OK, EX_OSERR, EX_USAGE */

#ifdef __OpenBSD__
#	include <unistd.h> /* pledge(2), unveil(2) */
#endif

char *program_name = "strcmp";

int main(int argc, char *argv[]) {
	unsigned int i;

#ifdef __OpenBSD__
	if (pledge("stdio unveil", "") == -1 || unveil(NULL, NULL) == -1) {
		perror(argv[0] == NULL ? program_name : argv[0]);

		return EX_OSERR;
	}
#endif

	if (argc < 3) {
		(void)fprintf(
			stderr,
			"Usage: %s string string...\n",
			argv[0] == NULL ? program_name : argv[0]
		);

		return EX_USAGE;
	}

	for (; *argv[1] != '\0'; ++argv[1]) {
		for (i = 2; i < argc; ++i) {
			/* a former string has a greater byte value */
			if (*argv[i-1] > *argv[i]) { 
				return 1;
			/* a latter string has a greater byte value */
			} else if (*argv[i-1] < *argv[i]++) {
				return -1; /* actually 255 */
			}
		}
	}

	return EX_OK;
}