#include <sys/sysmacros.h>
#include <sys/stat.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>

unsigned int parse_int(const char *str) {
	char *ptr = NULL;
	unsigned int value = (unsigned int)strtol(str, &ptr, 10);

	if (*ptr) {
		fprintf(stderr, "mknod: not a number: %s\n", str);
		exit(1);
	}

	else if (value < 1) {
		fprintf(stderr, "mknod: number is negative: %s\n", str);
		exit(1);
	}

	return value;
}

int main(const int argc, const char **argv) {
	mode_t mode = 0666;

	int i;
	for (i = 1; i < argc; i++) {
		if (argv[i][0] != '-')
			break;

		else if (!strncmp("-m=", argv[i], 3)) {
			char *ptr = NULL;
			mode = (mode_t)strtol(argv[i] + 3, &ptr, 8);
			if (*ptr) {
				fprintf(stderr, "mknod: invalid mode %s\n", argv[i] + 3);
				return 1;
			}
		}
	}

	unsigned int major = 0;
	unsigned int minor = 0;
	dev_t dev = 0;

	if (argc - i >= 2 && argc - i != 3) {
		if (argc - i == 4) {
			major = parse_int(argv[i + 2]);
			minor = parse_int(argv[i + 3]);
			dev = makedev(major, minor);
		}


		if (!strncmp("b", argv[i + 1], 1))
			mode |= S_IFBLK;

		else if (!strncmp("c", argv[i + 1], 1) || !strncmp("u", argv[i + 1], 1))
			mode |= S_IFCHR;

		else if (!strncmp("p", argv[i + 1], 1))
			mode |= S_IFIFO;

		else if (!strncmp("s", argv[i + 1], 1))
			mode |= S_IFSOCK;

		if (mknod(argv[i], mode, dev) < 0) {
			fprintf(stderr, "mknod: %s\n", strerror(errno));
			return 1;
		}

	}

	else {
		printf("mknod [-m=mode] [NAME] [TYPE] [MAJOR MINOR]\n");
		printf("Types:\n b - block deviece\n c or u - character device\n p - named pipe (MAJOR MINOR must be omitted)\n s - socket\n");
		return 0;
	}

	return 0;
}