Re: [tlug] binary search of binary data

[Edward Wright <edw@example.com>]

On Wed, Dec 29, 2004 at 07:52:48AM -0800, Dave Brown wrote:
> On Thu, Dec 30, 2004 at 12:43:08AM +0900, Edward Wright wrote:
> > On Wed, Dec 29, 2004 at 07:12:05AM -0800, Dave Brown wrote:
> 
> echo is a shell builtin and printf is an external program.  Save
> the PIDs!  (Shell builtins will run faster, if you have lots of
> them.)

Good point - although bash has a builtin printf 
(which wouldn't work anyway....)

> 
> > > :) [~] echo -n $'\x26\x9d\x00\x00\x28\x9d\x00\x00' | od -t x1
> > > 0000000 26 9d 00 00 28 9d 00 00
> > > 0000010
> > > :) [~] 
> > > 
> > 
> > 1) again, I need the byte values, not the hex representation, so I'm
> > not sure what this gets me...
> 
> The "od -t x1" is just to demonstrate that the raw byte-value
> output is, indeed, what I claim it is.  Instead of piping it to
> od, you can (say) dump it into a file.
> 

Oh.... missed the point... my bad :)
It seems that would work (and elegantly, if I were using zsh)

> > 2) interestingly, when I used the exact command you used, I got
> > different output:
> > 
> > echo -n $'\x26\x9d\x00\x00\x28\x9d\x00\x00' | od -t x1
> > 0000000 26 9d
> > 0000002
> > 
> > truncated at the null byte. Hmm...
> 
> Oh, hrm, that's interesting.  I'm using zsh, which preserves the
> entire output.  
> 
> I just verified it with my bash-3.00 and it does, indeed,
> truncate.  I just sent in a bug report to the bash folks about
> this--I think that's incorrect behaviour.

I'll second that.

Thanks,
Ed