99 ways to program a hex, Part 3: C89 in K&R style

To separate the style from the version, here's the program, written in C89 [1], using the K&R style [2].

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

• 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: C89 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) {

do_dump(stdin,stdout);

} else {

int i;

for (i = 1 ; i < argc ; i++) {

FILE *fp;

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 *fpin,FILE *fpout) {

unsigned char buffer[BUFSIZ],*pbyte;

size_t offset=0,bread,j;

char ascii[LINESIZE + 1];

while((bread = fread(buffer,1,BUFSIZ,fpin)) > 0) {

pbyte = buffer;

while (bread > 0) {

fprintf(fpout,"%08lX: ",(unsigned long)offset);

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) {

size_t i;

for (i = j ; i < LINESIZE ; i++) {

fprintf(fpout," ");

}

}

fprintf(fpout,"%s\n",ascii);

}

if (fflush(fpout) == EOF) {

perror("output");

exit(EXIT_FAILURE);

}

}

}

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

We have function prototypes, and more appropriate typedefs for some of the variables, but in the K&R style (ick). Lots of software is still written using this style, like Linux [3], on the grounds that if it was Good Enough™ for Kernighan and Ritchie [4], then it's Good Enough™ for the rest of us, never mind that Kernighan [5] and Ritchie [6] wrote their software on teletypes [7], which is near enough to a manual typewriter hooked up to a computer that if I used one, I would try to type as little as possible myself. But personally, I don't use a teletype; I use a real keyboard [8] and a huge monitor with a small font, so I find little use for the K&R style.

• Part 2: K&R C [9]
• Part 4: C99 [10]

=> [1] http://en.wikipedia.org/wiki/ANSI_C | [2] http://en.wikipedia.org/wiki/1_true_brace_style | [3] http://www.kernel.org/doc/Documentation/CodingStyle | [4] https://www.amazon.com/exec/obidos/ASIN/0131103628/conmanlaborat-20 | [5] http://en.wikipedia.org/wiki/Brian_Kernighan | [6] http://en.wikipedia.org/wiki/Dennis_Ritchie | [7] http://en.wikipedia.org/wiki/Teleprinter | [8] http://en.wikipedia.org/wiki/Model_M_keyboard | [9] /boston/2012/01/10.1 | [10] /boston/2012/01/12.3

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