This function prints hex dump of memory specified as a pointer

hexDump.c

/*
 *   This function prints hex dump of memory specified as a pointer.
 *   Reference: http://stackoverflow.com/questions/7775991/how-to-get-hexdump-of-a-structure-data
 */ 
#include <stdio.h>

void hexdump(void *addr, int len)
{
  int i;
  unsigned char buff[17];
  unsigned char *pc = (unsigned char*)addr;

  for (i = 0; i < len; i++) {
    if ((i % 16) == 0) {
      if (i != 0)
        printf ("  %s\n", buff);
      printf (" %04x ", i);
    }

    printf (" %02x", pc[i]);

    if ((pc[i] < 0x20) || (pc[i] > 0x7e))
      buff[i % 16] = '.';
    else
      buff[i % 16] = pc[i];
    buff[(i % 16) + 1] = '\0';
  }

  while ((i % 16) != 0) {
    printf ("   ");
    i++;
  }

  printf ("  %s\n", buff);
}

int main (int argc, char *argv[]) {
  char my_str[] = "a char string greater than 16 chars";
  hexdump (&my_str, sizeof (my_str));
  return 0;
}

/*
  0000  61 20 63 68 61 72 20 73 74 72 69 6e 67 20 67 72  a char string gr
  0010  65 61 74 65 72 20 74 68 61 6e 20 31 36 20 63 68  eater than 16 ch
  0020  61 72 73 00                                      ars.
*/