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 do this, I write yet another hex-dump routine from scratch. I'm about to do so again, but figured I'd ask here: Is there any good free hex dump code for C++ out there somewhere?
Features I'd like:
- N bytes per line (where N is somehow configurable)
- optional ASCII/UTF8 dump alongside the hex
- configurable indentation, per-line prefixes, per-line suffixes, etc.
- minimal dependencies (ideally, I'd like the code to all be in a header file, or be a snippet I can just paste in)
Edit: Clarification: I am looking for code that I can easily drop in to my own programs to write to stderr, stdout, log files, or other such output streams. I'm not looking for a command-line hex dump utility.
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.
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");
}
}
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.
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.
I used this in one of my internal tools at work.
Could you write your own dissector for Wireshark?
Edit: written before the precision in the question
xxd is the 'standard' hex dump util and looks like it should solve your problems