Hexdump in Binpac

hexdump.pac

%extern{
	#include <stdio.h>
	#include <iostream>
	#include <iomanip>
	#include <sstream>
%}

function dump_message(msg: const_bytestring): bool
    %{
        int i;
        int len = msg.length();
        unsigned char buff[17];
        const unsigned char *pc = (const unsigned char*)reinterpret_cast<const unsigned char*>(msg.begin());
    
        memset(buff, 0, sizeof(buff));
        if (len == 0) {
            printf("  ZERO LENGTH\n");
            return true;
        }
        if (len < 0) {
            printf("  NEGATIVE LENGTH: %i\n",len);
            return true;
        }
    
        // Process every byte in the data.
        for (i = 0; i < len; i++) {
            // Multiple of 16 means new line (with line offset).
    
            if ((i % 16) == 0) {
                // Just don't print ASCII for the zeroth line.
                if (i != 0)
                    printf ("  %s\n", buff);
    
                // Output the offset.
                printf ("  %04x ", i);
            }
    
            // Now the hex code for the specific character.
            printf (" %02x", pc[i]);
    
            // And store a printable ASCII character for later.
            if ((pc[i] < 0x20) || (pc[i] > 0x7e))
                buff[i % 16] = '.';
            else
                buff[i % 16] = pc[i];
            buff[(i % 16) + 1] = '\0';
        }
    
        // Pad out last line if not exactly 16 characters.
        while ((i % 16) != 0) {
            printf ("   ");
            i++;
        }
    
        // And print the final ASCII bit.
        printf ("  %s\n", buff);

        return true;
    %}