RE: [PATCH 3/4] lib/hexdump.c: Replace ascii bool in hex_dump_to_buffer with flags

From: David Laight <David.Laight@ACULAB.COM>
To: 'Alastair D'Silva' <alastair@d-silva.org>,
	'Petr Mladek' <pmladek@suse.com>
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	"'David S. Miller'" <davem@davemloft.net>,
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Subject: RE: [PATCH 3/4] lib/hexdump.c: Replace ascii bool in hex_dump_to_buffer with flags
Date: Mon, 15 Apr 2019 11:03:57 +0000	[thread overview]
Message-ID: <42fb90eb9c8f4ede8a56a09be90218e3@AcuMS.aculab.com> (raw)
In-Reply-To: <0db501d4f378$3bd50bb0$b37f2310$@d-silva.org>

From: Alastair D'Silva
> Sent: 15 April 2019 11:45
...
> > Although I think you'd want a 'no hex' flag to suppress the hex.
> >
> > Probably more useful flags are ones to suppress the address column.
> 
> This is already supported by the prefix_type parameter - are you proposing that we eliminate the
> parameter & combine it with flags?

I was looking at the flags on one of my hexdump() functions...

> > I've also used flags to enable (or disable) suppression of multiple lines of
> > zeros of constant bytes.
> > In that case you may want hexdump to return the flags for the next call when
> > a large buffer is being dumped in fragments.
> 
> I'm afraid I don't quite follow here, hex_dump_to_buffer doesn't alter the flags,
> so the caller already knows it.

If you are suppressing lines of zeros and dumping a buffer in several blocks
then subsequent calls need to know that the last line of the previous call
was suppressed zeros - and carry on with the same suppressed block.

I've not looked to see if it does support suppressing lines of zeros/0xff.

	David

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