Off-the-Shelf C++ Hex Dump Code

Question

I work a lot with network and serial communications software, so it is often necessary for me to have code to display or log hex dumps of data packets.

Every time I

Answer 1

Could you write your own dissector for Wireshark?

Edit: written before the precision in the question

Answer 2

I have seen PSPad used as a hex editor, but I usually do the same thing you do. I'm surprised there's not an "instant answer" for this question. It's a very common need.

Answer 3

The unix tool xxd is distributed as part of vim, and according to http://www.vmunix.com/vim/util.html#xxd, the source for xxd is ftp://ftp.uni-erlangen.de:21/pub/utilities/etc/xxd-1.10.tar.gz. It was written in C and is about 721 lines. The only licensing information given for it is this:

* Distribute freely and credit me,
* make money and share with me,
* lose money and don't ask me.

The unix tool hexdump is available from http://gd.tuwien.ac.at/softeng/Aegis/hexdump.html. It was written in C and can be compiled from source. It's quite a bit bigger than xxd, and is distributed under the GPL.

Answer 4

xxd is the 'standard' hex dump util and looks like it should solve your problems

Answer 5

I often use this little snippet I've written long time ago. It's short and easy to add anywhere when debugging etc...

#include <ctype.h>
#include <stdio.h>

void hexdump(void *ptr, int buflen) {
  unsigned char *buf = (unsigned char*)ptr;
  int i, j;
  for (i=0; i<buflen; i+=16) {
    printf("%06x: ", i);
    for (j=0; j<16; j++) 
      if (i+j < buflen)
        printf("%02x ", buf[i+j]);
      else
        printf("   ");
    printf(" ");
    for (j=0; j<16; j++) 
      if (i+j < buflen)
        printf("%c", isprint(buf[i+j]) ? buf[i+j] : '.');
    printf("\n");
  }
}

Answer 6

Just in case someone finds it useful...

I've found single function implementation for ascii/hex dumper in this answer.

A C++ version based on the same answer with ANSI terminal colours can be found here.

More lightweight than xxd.