The Boston Diaries

The ongoing saga of a programmer who doesn't live in Boston, nor does he even like Boston, but yet named his weblog/journal “The Boston Diaries.”

Go figure.

Friday, January 13, 2012

99 ways to program a hex, Part 5: C99 in K&R style

Like part 3, today's version is C99 in the K&R style:

* Copyright 2012 by Sean Conner.  All Rights Reserved.
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* 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
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
* Comments, questions and criticisms can be sent to:

/* Style: C99 in K&R style */

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>

#define LINESIZE	  16

static void 	do_dump		(FILE *,FILE *);


int main(int argc,char *argv[]) {
	if (argc == 1) {
	} else {
		for (int i = 1 ; i < argc ; i++) {
			FILE *fp = fopen(argv[i],"rb");
			if (fp == NULL) {




static void do_dump(FILE *fpin,FILE *fpout) {
	unsigned char buffer[BUFSIZ];
	size_t offset=0,bread;
	while((bread = fread(buffer,1,BUFSIZ,fpin)) > 0) {
		unsigned char *pbyte = buffer;

		while (bread > 0) {
			char ascii[LINESIZE + 1];
			fprintf(fpout,"%08lX: ",(unsigned long)offset);
			size_t j = 0;
			do {
				fprintf(fpout,"%02X ",*pbyte);
				if (isprint(*pbyte)) {
					ascii [j] = *pbyte;
				} else {
					ascii [j] = '.';
				pbyte  ++;
				offset ++;
				j      ++;
				bread  --;
			} while ((j < LINESIZE) && (bread > 0));

			ascii [j] = '\0';

			if (j < LINESIZE) {
				for (size_t i = j ; i < LINESIZE ; i++) {
					fprintf(fpout,"   ");


			if (fflush(fpout) == EOF) {


To the untrained eye, it probably looks like every other version I've presented here, yet there is is a difference, subtle as it may be. But even in the book that inspired this series there were plenty of examples that weren't all that much different.

At least, that's what I keep telling myself.

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