Re: [PATCH mptcp-net v2 4/5] selftests: mptcp: print trailing bytes with od

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 06/09/2025 01:42, Geliang Tang wrote:
> On Fri, 2025-09-05 at 20:18 +0200, Matthieu Baerts (NGI0) wrote:
>> This is better than printing random bytes in the terminal.
>>
>> Note Jakub suggested 'hexdump', but Mat found out that this tool is
>> not
>> often installed by default. 'od' can do a similar job, and it is in
>> the
>> POSIX specs and available in coreutils, so it should be on more
>> systems.
>>
>> Suggested-by: Jakub Kicinski <kuba@kernel.org>
>> Suggested-by: Mat Martineau <martineau@kernel.org>
>> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
>> ---
>> v2: switch to 'od', and no more check for its presence (Mat)
>> ---
>>  tools/testing/selftests/net/mptcp/mptcp_lib.sh | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
>> b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
>> index
>> 09cd24b2ae466205dacbdf8289eb86c08534c475..d62e653d48b0f2ef7a01e289fa0
>> be8907825667d 100644
>> --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
>> +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
>> @@ -384,7 +384,7 @@ mptcp_lib_make_file() {
>>  mptcp_lib_print_file_err() {
>>  	ls -l "${1}" 1>&2
>>  	echo "Trailing bytes are: "
>> -	tail -c 27 "${1}"
>> +	tail -c 32 "${1}" | od -x | head -n2
> 
> nit:
> 
> It shows more bytes (32) here, but it wasn't mentioned in the commit
> log.

Good point, I can add this when applying the patches:

  Show a few more bytes, just to fill in the two lines.

Would that be OK?

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.