[PATCH v2 3/7] lib/hexdump.c: Optionally suppress lines of repeated bytes

Alastair D'Silva alastair at d-silva.org
Mon May 13 07:35:47 UTC 2019

> -----Original Message-----
> From: Geert Uytterhoeven <geert at linux-m68k.org>
> Sent: Monday, 13 May 2019 5:01 PM
> To: Alastair D'Silva <alastair at au1.ibm.com>
> Cc: alastair at d-silva.org; Jani Nikula <jani.nikula at linux.intel.com>; Joonas
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> Subject: Re: [PATCH v2 3/7] lib/hexdump.c: Optionally suppress lines of
> repeated bytes
> Hi Alastair,
> Thanks for your patch!

And thanks for your politeness :)

> On Wed, May 8, 2019 at 9:04 AM Alastair D'Silva <alastair at au1.ibm.com>
> wrote:
> > From: Alastair D'Silva <alastair at d-silva.org>
> >
> > Some buffers may only be partially filled with useful data, while the
> > rest is padded (typically with 0x00 or 0xff).
> >
> > This patch introduces a flag to allow the supression of lines of
> > repeated bytes,
> Given print_hex_dump() operates on entities of groupsize (1, 2, 4, or 8)
> bytes, wouldn't it make more sense to consider repeated groups instead of
> repeated bytes?

Maybe, it would mean that subsequent addresses may not be a multiple of rowsize though, which is useful.

> > which are replaced with '** Skipped %u bytes of value 0x%x **'
> Using a custom message instead of just "*", like "hexdump" uses, will require
> preprocessing the output when recovering the original binary data by
> feeding it to e.g. "xxd".
> This may sound worse than it is, though, as I never got "xxd" to work without
> preprocessing anyway ;-)

I think showing the details of the skipped values is useful when reading the output directly. In situations where binary extracts are desired, the feature can always be disabled.

Alastair D'Silva           mob: 0423 762 819
skype: alastair_dsilva     msn: alastair at d-silva.org
blog: http://alastair.d-silva.org    Twitter: @EvilDeece

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