[PATCH] cmd: Remove default prompt from output

[Heiko Schocher]

Hi Daniel,

On 15.08.25 18:12, Tom Rini wrote:
> On Fri, Aug 15, 2025 at 09:06:35AM -0700, Daniel Schultz wrote:
> 
>> Some commands include the U-Boot prompt (=>) in their output,
>> which can interfere with tools like labgrid that rely on prompt
>> detection to determine when a command has completed. This may cause
>> such tools to misinterpret partial output.
>>
>> To avoid this issue, it's better to update the command output itself
>> rather than modifying the actual U-Boot prompt. Changing the prompt
>> is not acceptable in many cases, as some boards have used the default
>> prompt (=>) for years, and altering it - especially just for testing -
>> could lead to inconsistencies or unintended side effects.
>> Instead, replace instances of the prompt that appear within command
>> output (not the real prompt) with an alternative like -> to ensure
>> correct parsing by tools that rely on prompt recognition.
>>
>> Signed-off-by: Daniel Schultz <d.schultz at phytec.de>
>> ---
>>   cmd/i2c.c      |  2 +-
>>   cmd/mtdparts.c | 12 ++++++------
>>   common/hash.c  |  6 +++---
>>   3 files changed, 10 insertions(+), 10 deletions(-)
> 
> This is two cases, and I'm not sure I like the proposal here, sorry. For
> cmd/mtdparts.c, it's debug statements. We can change them, but are they
> also enabled by default in anything? The other cases, we're changing
> output along the lines of:
> 
>> -	printf ("CRC32 for %08lx ... %08lx ==> ", addr, addr + count - 1);
>> +	printf("CRC32 for %08lx ... %08lx --> ", addr, addr + count - 1);
> 
> In each case, and I'm surprised there's not testing that globs on that
> today. I see the wget case that uses "==>" and we do have a test that
> checks it, today. Is your testing framework not able to handle "=>" in
> the middle of a line? Thanks.

That would be exactly also my question ... fix the tool instead?

Changing this output may breaks automated tests with other tools...

for example tbot handles this case:

https://tbot.tools/modules/machine_channel.html#tbot.machine.channel.Channel.read_until_prompt

bye,
Heiko
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