FreeBSD/showbits/showbits.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

/*
 * cc showbits.c -O3 -o sb
 */

static void showbits(const uint32_t data)
{
	uint32_t mask = 1<<31;
	size_t i = 31;

	for(; i;)
		printf("%02zu\u00B7", i--);

	puts("00");

	for(; mask; mask >>= 1 ) {
		printf("%s", (uint32_t)(data & mask) ? "\u2731\u2731" : "__");
		if (mask != 1)
			printf("\u205E");
	}

	puts("");
}

int main(int argc, char *argv[])
{
	if (argc < 2)
		exit(EXIT_FAILURE);

	showbits(strtol(argv[1], NULL, 16));
	puts("");

	return EXIT_SUCCESS;
}