TCC script to generate random numbers.

rand.c

#!/usr/bin/env -S tcc -run

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <time.h>

/*
 * Copyright (C) 2023  Gabriel de Brito
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/*
 * Quick way of generating random numbers ;)
 */

void generate_numbers(long min, long max, long n)
{
	long mod = max - min + 1;
	long r;
	for (; n > 0; n--) {
		r = (random() % mod) + min;
		printf("%ld\n", r);
	}
}

void init_pool()
{
	long seed = (long) time(NULL);
	FILE *urandom = fopen("/dev/urandom", "r");
	if (urandom != NULL) {
		long r;
		fread(&r, 1, 8, urandom);
		seed *= (long) r;
		fclose(urandom);
	}

	srand(seed);
}

void safely_parse_long(char *str, long *n)
{
	long tmp;
	errno = 0;
	int i = sscanf(str, "%ld", &tmp);
	if (i)
		*n = tmp;
}

int main(int argc, char *argv[])
{
	long min = 0;
	long max = 100;
	long n   = 1;

	if (argc >= 2) {
		errno = 0;
		safely_parse_long(argv[1], &min);
		if (argc >= 3) {
			errno = 0;
			safely_parse_long(argv[2], &max);
			if (argc >= 4) {
				errno = 0;
				safely_parse_long(argv[3], &n);
			}
		}
	}

	init_pool();

	generate_numbers(min, max, n);

	return 0;
}