Print HEX in C

print_hex.c

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

#define MAX_DATA_LEN 1024

static unsigned char hex_string[MAX_DATA_LEN];
 
static inline char convert_to_printable(char c)
{
    return c < 32 || c > 126 ? '.' : c;
}
 
static void print_hex(const unsigned char *buf,
                            int   length,
                            int   width,
                            int   error /* void (*printf)(const char *) */)
{
    int remainder      = length % width;
    int whole          = length - remainder;
    int i              = 0;
    int j              = 0;
    int offset         = 0;
 
    memset(hex_string, 0, sizeof(hex_string));
 
    if (!error)
        fprintf(stdout, "(%p, %d bytes)\n", buf, length);
    else
        fprintf(stderr, "(%p, %d bytes)\n", buf, length);
 
    for (i = 0; i < whole; i += width)
    {
        offset  = 0;
        offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "| 0x%08X | ", i);
 
        for (j = 0; j < width; j++)
            offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "%02X ", buf[i + j]);
        
	offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "| ");
 
        for (j = 0; j < width; j++)
            offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "%c", convert_to_printable(buf[i + j]));

        offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, " |");
 
        if (!error)
            fprintf(stdout, "%s\n", hex_string);
        else
            fprintf(stderr, "%s\n", hex_string);
    }
 
    if (remainder)
    {
        offset  = 0;
        offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "| 0x%08X | ", i);
 
        for (j = 0; j < remainder; j++)
            offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "%02X ", buf[whole + j]);
 
        for (j = 0; j < width - remainder; j++)
            offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "   ");

        offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "| ");
 
        for (j = 0; j < remainder; j++)
            offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, "%c", convert_to_printable(buf[i + j]));
 
        for (j = 0; j < width - remainder; j++)
            offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, " ");

        offset += snprintf((char *)(hex_string + offset), sizeof(hex_string) - offset, " |");
 
        if (!error)
            fprintf(stdout, "%s\n", hex_string);
        else
            fprintf(stderr, "%s\n", hex_string);
    }

    memset(hex_string, 0, sizeof(hex_string));
}

int main(int argc, char **argv) 
{
    const char *str = "What is the key to life on Earth?";
    print_hex(str, strlen(str), 16, 0);
    
    return 0;
}