Friday, January 20, 2012
Notes about an overheard conversation between a blogger and his lovely and talented copy editor
“I think you miscounted.”
“Here?”
“Yes. There are only two problems … cache invalidation … ”
“Uh huh.”
“Naming things … ”
“Yeah … ”
“and off-by-one errors … oh. Oh! D'oh!”
99 ways to program a hex, Part 12: C99, const and restrict correctness, assertive, GCC extenstions
And today's code is identical to part 10 save again for one line—it too uses a GCC extension per yesterday's code.
This also marks the end of the C versions for a couple of days.
/*************************************************************************
*
* 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, GCC extenstions */
#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) __attribute__((nonnull,nothrow));
/****************************************************************/
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);
}
}
}
/***************************************************************/
