#include <stdio.h>
#include <ctype.h>
 
#ifndef HEXDUMP_COLS
#define HEXDUMP_COLS 8
#endif
 
void hexdump(void *mem, unsigned int len)
{
	unsigned int i, j;
	
	for(i = 0; i < len + ((len % HEXDUMP_COLS) ? (HEXDUMP_COLS - len % HEXDUMP_COLS) : 0); i++)
	{
		/* print offset */
		if(i % HEXDUMP_COLS == 0)
		{
			printf("0x%06x: ", i);
		}
		/* print hex data */
		if(i < len)
		{
			printf("%02x ", 0xFF & ((char*)mem)[i]);
		}
		else /* end of block, just aligning for ASCII dump */
		{
			printf("   ");
		}
		
		/* print ASCII dump */
		if(i % HEXDUMP_COLS == (HEXDUMP_COLS - 1))
		{
			for(j = i - (HEXDUMP_COLS - 1); j <= i; j++)
			{
				if(j >= len) /* end of block, not really printing */
				{
					putchar(' ');
				}
				else if(isprint(((unsigned char*)mem)[j])) /* printable char */
				{
					putchar(0xFF & ((unsigned char*)mem)[j]);		
				}
				else /* other char */
				{
					putchar('.');
				}
			}
			putchar('\n');
		}
	}
}