dumps bytes to something readable

show_dump.c

#include "show_dump.h"

void show_dump(unsigned char *data, unsigned int len, FILE *stream) {
    const static char       hex[] = "0123456789abcdef";
    static unsigned char    buff[67];   /* HEX  CHAR\n */
    unsigned char           chr,
                            *bytes,
                            *p,
                            *limit,
                            *glimit = data + len;

    memset(buff + 2, ' ', 48);

    while(data < glimit) {
        limit = data + 16;
        if(limit > glimit) {
            limit = glimit;
            memset(buff, ' ', 48);
        }

        p     = buff;
        bytes = p + 50;
        while(data < limit) {
            chr = *data;
            *p++ = hex[chr >> 4];
            *p++ = hex[chr & 15];
            p++;
            *bytes++ = ((chr < ' ') || (chr >= 0x7f)) ? '.' : chr;
            data++;
        }
        *bytes++ = '\n';

        fwrite(buff, bytes - buff, 1, stream);
    }
}

// Copyright 2005,2006,2007,2008,2009,2010 Luigi Auriemma
//
// Patched for -Werror and GNU C99 standard. Copyright 2014 Andrew Udvare
//
// 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
//
// http://www.gnu.org/licenses/gpl-2.0.txt

show_dump.h

#ifndef SHOW_DUMP_H
#define SHOW_DUMP_H

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

void show_dump(unsigned char *data, unsigned int len, FILE *stream);
#endif // SHOW_DUMP_H

// Copyright 2005,2006,2007,2008,2009,2010 Luigi Auriemma
//
// Patched for -Werror and GNU C99 standard. Copyright 2014 Andrew Udvare
//
// 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
//
// http://www.gnu.org/licenses/gpl-2.0.txt