hexdump.c

/** hexdump.h */
/*
  Hexdump functions
  polprog 2021. Released on 3-clause BSD
 */


#ifndef _HEXDUMP_H
#define _HEXDUMP_H

void hexdump(char *data, size_t len);
void hexdump8(char *data, size_t len);


#endif // _HEXDUMP_H
/** hexdump.c */
/*
  Hexdump functions
  polprog 2021. Released on 3-clause BSD
 */

#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
void hexdump(char *data, size_t len){
  size_t i = 0;
  putchar('\n');
  printf("addr   +0 +1 +2 +3 +4 +5 +6 +7 +8 +9 +a +b +c +d +e +f 0123456789abcdef\n"); 
  for(i = 0; i < len;){
    if(i % 16 == 0) printf("0x%04x ", i);
    printf("%02x ", data[i]);
    i++;
    if(i % 16 == 0){
      for(size_t j = 16; j >= 1; j--){
	putchar((data[i-j] < 32 || data[i-j] > 127) ? '.' : data[i-j]);
      }
      putchar('\n');
    }
  }
  for(size_t j = 0; j < 16-i%16; j++) printf("   ");
  for(size_t j = i%16; j >= 1; j--){
    putchar((data[i-j] < 32 || data[i-j] > 127) ? '.' : data[i-j]);
  }
  
  putchar('\n');

}

void hexdump8(char *data, size_t len){
  size_t i = 0;
  putchar('\n');
  printf("addr   +0 +1 +2 +3 +4 +5 +6 +7 01234567\n"); 
  for(i = 0; i < len;){
    if(i % 8 == 0) printf("0x%04x ", i);
    printf("%02x ", data[i]);
    i++;
    if(i % 8 == 0){
      for(size_t j = 8; j >= 1; j--){
	putchar((data[i-j] < 32 || data[i-j] > 127) ? '.' : data[i-j]);
      }
      putchar('\n');
    }
  }
  for(size_t j = 0; j < 8-i%8; j++) printf("   ");
  for(size_t j = i%8; j >= 1; j--){
    putchar((data[i-j] < 32 || data[i-j] > 127) ? '.' : data[i-j]);
  }
  
  putchar('\n');

}