Re: [PATCH 2/5] dts: skip first line of send_command output

[Luca Vizzarro <Luca.Vizzarro@arm.com>]

On 16/04/2024 09:48, Juraj Linkeš wrote:
> Oh, the first commit message was confusing. It said leading prompt
> which I understood to be the first prompt (the one with the command).
> I see that this commit actually addresses what I thought the first
> commit was trying to do.

Yes, my bad!

>> -    def send_command(self, command: str, prompt: str | None = None) -> str:
>> +    def send_command(
>> +        self, command: str, prompt: str | None = None, skip_first_line: bool = False
> 
> Do we generally want or don't want to include the first line? When do
> we absolutely not want to include it?

In the case of `show port info/stats {x}` if the provided port is 
invalid, then the first message starts with `Invalid port`. By providing 
an output that skips the command prompt, this is easily checked with 
output.startswith("Invalid port") as you may have noticed in the next 
commit. Otherwise it'd be a bit more complicated. Personally, I am not 
sure whether we care about the first line. With my limited knowledge I 
don't see a reason to include it (just as much as the trailing prompt).

>> +    ) -> str:
>>           """Send `command` and get all output before the expected ending string.
>>
>>           Lines that expect input are not included in the stdout buffer, so they cannot
>> @@ -121,6 +123,7 @@ def send_command(self, command: str, prompt: str | None = None) -> str:
>>               command: The command to send.
>>               prompt: After sending the command, `send_command` will be expecting this string.
>>                   If :data:`None`, will use the class's default prompt.
>> +            skip_first_line: Skip the first line when capturing the output.
>>
>>           Returns:
>>               All output in the buffer before expected string.
>> @@ -132,6 +135,9 @@ def send_command(self, command: str, prompt: str | None = None) -> str:
>>           self._stdin.flush()
>>           out: str = ""
>>           for line in self._stdout:
>> +            if skip_first_line:
>> +                skip_first_line = False
>> +                continue
> 
> Is there ever a reason to distinguish between the first line and the
> line with the command on it?

As above, not really sure. Would this always be a command prompt? The 
doubt arises only because I don't understand why we'd need the command 
prompt fed back.

> 
>>               if prompt in line and not line.rstrip().endswith(
>>                   command.rstrip()
>>               ):  # ignore line that sent command
>> --
>> 2.34.1
>>