[PATCH 1/3] vsprintf: add support for printing raw buffers as hex (%*ph)

[Ahmad Fatoum]

On 13.12.21 23:28, Sascha Hauer wrote:
> On Thu, Dec 09, 2021 at 11:57:06AM +0100, Ahmad Fatoum wrote:
>> Import from Linux support for printing buffers as a hex string
>> with a certain separator. For larger buffers consider using
>> print_hex_dump(). Examples:
>>
>>   %*ph	00 01 02  ...  3f
>>   %*phC	00:01:02: ... :3f
>>   %*phD	00-01-02- ... -3f
>>   %*phN	000102 ... 3f
>>
>> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
>> ---
>>  lib/Kconfig    |  3 +++
>>  lib/vsprintf.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 53 insertions(+)
>>
>> diff --git a/lib/Kconfig b/lib/Kconfig
>> index 718033e56e64..27e7bea6852f 100644
>> --- a/lib/Kconfig
>> +++ b/lib/Kconfig
>> @@ -166,6 +166,9 @@ config PRINTF_UUID
>>  config PRINTF_WCHAR
>>  	bool
>>  
>> +config PRINTF_HEXSTR
>> +	bool
> 
> So hexdumps are silently ignored when this option is disabled. Not sure
> if this should really be configurable, but I think when it is
> configurable it should be default y to avoid surprises.

It will be printed as a raw pointer when the option is disabled.
There's no code in-tree that uses this format specifier yet,
so I prefer to not make this the default and increase binary size.

Cheers,
Ahmad

> 
> Sascha
> 
> 


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