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.

Wednesday, January 18, 2012

99 ways to program a hex, Part 10: C99, const and restrict correctness, assertive

It's pretty much the same as yesterday's version, only in 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
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* 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: sean@conman.org
*
*************************************************************************/

/* Style: C99, const and restrict correctness, assertive */

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

#define LINESIZE	  16

static void 	do_dump		(FILE *const restrict,FILE *const restrict);

/****************************************************************/

int main(const int argc,char *const restrict argv[])
{
  assert(argc    >= 1);
  assert(argv    != NULL);
  assert(argv[0] != NULL);
  
  if (argc == 1)
    do_dump(stdin,stdout);
  else
  {
    for (int i = 1 ; i < argc ; i++)
    {
      FILE *fp = fopen(argv[i],"rb");
      if (fp == NULL)
      {
        perror(argv[i]);
        continue;
      }

      printf("-----%s-----\n",argv[i]);
      do_dump(fp,stdout);
      fclose(fp);
    }
  }

  return EXIT_SUCCESS;
}

/******************************************************************/

static void do_dump(FILE *const restrict fpin,FILE *const restrict fpout)
{
  unsigned char  buffer[BUFSIZ];
  size_t         offset;
  size_t         bread;
  
  assert(fpin  != NULL);
  assert(fpout != NULL);
  
  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;

      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,"   ");

      fprintf(fpout,"%s\n",ascii);      
    }
    
    if (fflush(fpout) == EOF)
    {
      perror("output");
      exit(EXIT_FAILURE);
    }
  }
}

/***************************************************************/

Not much to say about today's version.

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