absolutely haram

binary.c

/* 
 * binary.c
 * by yuuko
 *
 * This file is intended to never exceed 200 LOC.
 *
 * DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
 * Version 2, December 2004 
 *
 * Copyright (C) 2004 Sam Hocevar <[email protected]> 
 *
 * Everyone is permitted to copy and distribute verbatim or modified 
 * copies of this license document, and changing it is allowed as long 
 * as the name is changed. 
 *
 * DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
 * TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 
 *
 * 0. You just DO WHAT THE FUCK YOU WANT TO.
 */

#include <stdio.h>	// Basic I/O
#include <stdlib.h>	// strtoul, malloc, free
#include <stdarg.h>	// vfprintf for variadic die
#include <getopt.h>	// I'll give you 3 guesses
#include <errno.h>	// check if input is over length
#include <string.h>	// strlen
#include <math.h>	// log2

#define BINLEN(T) (sizeof(T) * 8 + 1) // Not inline for typelessness

typedef enum {
	OK = EXIT_SUCCESS,
	NOARGS = 1,
	EMPTYARG = 2,
	BADINTARG = 3
} die_code;

static const char *die_strings[] = {
	[OK] = "",
	[NOARGS] = "You must provide at least one character, string, or "
	           "octal, decimal, or hexadecimal integer.\n",
	[EMPTYARG] = "Argument %d (after %s) is an empty string.\n",
	[BADINTARG] = "Argument to option -%c (%s) is not an integer.\n"
};

int die(die_code dc, ...)
{
	if(dc) {
		fputs("", stderr);
		va_list args;

		va_start(args, dc);
		vfprintf(stderr, die_strings[dc], args);
		va_end(args);
	}
	exit(dc);
}

char *ultonba(size_t ul, size_t n, char *ba)
{	
	ba[n] = '\0';
	while(n) {
		ba[--n] = '0' + ul % 2;
		ul /= 2;
	}
	return ba;
}

int main(int argc, char *argv[])
{	
	size_t pad = 0;

	for (int opt; (opt = getopt(argc, argv, "0:h")) != -1;) {
		switch(opt) {
		case '0': 
			pad = strtoul(optarg, NULL, 0) + 1;
			if(pad || *optarg == '0')
				break;
			else
				die(BADINTARG, opt, optarg);
		case 'h':
			//help code
		case ':':
		case '?':
		default:
			break;
		}
	}
	
	if(optind == argc) die(NOARGS);

	unsigned long in;
	size_t len, pos = 0;
	char *buf = calloc(len = BINLEN(in), sizeof(*buf));
	
	for (int i = optind; i < argc; i++) {
		if ((in = strtoul(argv[i], NULL, 0)) || *argv[i] == '0')
			puts(ultonba(in, pad > (pos = (size_t)log2(in) + 1) ? pad : pos, buf));
		else if (strlen(argv[i])) {
			for (size_t max = strlen(argv[i]); pos < max && argv[i][pos]; pos++) {
				printf("%s%c", ultonba(argv[i][pos], 8, buf), argv[i][pos + 1] ? ' ' : '\n');
			}
			pos = 0;
		} else {
			free(buf);
			die(EMPTYARG, i, argv[i - 1]);
		}
	}
	
	free(buf);
	die(OK);
}