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.

Thursday, January 12, 2012

99 ways to program a hex, Part 4: C99

Today's variation: C99.

* 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.
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* 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 */

#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)
    for (int i = 1 ; i < argc ; i++)
      FILE *fp = fopen(argv[i],"rb");
      if (fp == NULL)


  return EXIT_SUCCESS;


static void do_dump(FILE *fpin,FILE *fpout)
  unsigned char  buffer[BUFSIZ];
  size_t         offset;
  size_t         bread;
  offset = 0;

  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;

        fprintf(fpout,"%02X ",*pbyte);
        if (isprint(*pbyte))
          ascii [j] = *pbyte;
          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)


It's not much different than the C89 version. The main difference is the ability to declare variables when needed instead of the beginning of a block of code. I don't particularly care for that feature, but I do like the ability to declare variables inside the for() statement, like I've done here.

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