[Toybox] RFC: od toy

[Rob Landley]

On 06/26/2012 04:06 PM, Andre Renaud wrote:
> Hi,
> I've started to do an implementation of 'od' - it is most of the way
> there, but I'm not particularly happy with the method I've used for
> determining which 'printf' format string and which data alignment to
> use. At the moment I'm essentially reparsing the -t XX parameters each
> time you want to print a new character, which has pretty hideous
> performance (and currently doesn't support the -to2o4 syntax).

The performance doesn't have to be that hideous if it fits in l1 cache.

> I'm debating about pre-parsing these, and then a list of function
> pointers. This would also require me to have ~20 tiny stub functions,
> which basically just do a printf with a different format string & data
> type, and return the length of data that they've consumed (or possibly
> iterate over an entire line, I haven't decided).

You can take advantage of the data all being the same sizes (char is
promoted to int, long and pointer are the same size), and set up a more
generic call to printf.  Lemme see what I can do...

> Does anyone have any comments about an alternative method to do this?

Well, "toybox od -t a filename" doesn't work. And the number in the
front has one more digit of zero padding than the ubuntu one. I'll have
to read the spec to see what's expected...

Rob
-- 
GNU/Linux isn't: Linux=GPLv2, GNU=GPLv3+, they can't share code.
Either it's "mere aggregation", or a license violation.  Pick one.

 1340763178.0