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Tue, 03 Sep 2024 15:07:54 -0700 (PDT) Received: from [192.168.1.128] ([38.175.170.29]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-82a1a2f0d9fsm328832439f.7.2024.09.03.15.07.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 03 Sep 2024 15:07:54 -0700 (PDT) Message-ID: <52a6d4ab-99a4-46b3-bd43-58054602d86b@linuxfoundation.org> Date: Tue, 3 Sep 2024 16:07:53 -0600 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] selftests: splice: Add usage() to splice_read.c To: Rong Tao , shuah@kernel.org Cc: rongtao@cestc.cn, "open list:KERNEL SELFTEST FRAMEWORK" , open list , Shuah Khan References: Content-Language: en-US From: Shuah Khan In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/30/24 23:14, Rong Tao wrote: > From: Rong Tao > > Give the programmer more help information to inform the program on how to > use it. > > Signed-off-by: Rong Tao > --- > tools/testing/selftests/splice/splice_read.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/splice/splice_read.c b/tools/testing/selftests/splice/splice_read.c > index 46dae6a25cfb..73a8bc146f97 100644 > --- a/tools/testing/selftests/splice/splice_read.c > +++ b/tools/testing/selftests/splice/splice_read.c > @@ -9,6 +9,12 @@ > #include > #include > > +void usage(const char *prog) > +{ > + fprintf(stderr, "Usage: %s INPUT [BYTES]\n", prog); > + fprintf(stderr, " %s /etc/os-release | cat\n", prog); How does replacing %s INPUT [BYTES]\n", prog with /etc/os-release | cat\n" do? Also what happens on distros that don't have os-release file? > +} > + > int main(int argc, char *argv[]) > { > int fd; > @@ -16,7 +22,7 @@ int main(int argc, char *argv[]) > ssize_t spliced; > > if (argc < 2) { > - fprintf(stderr, "Usage: %s INPUT [BYTES]\n", argv[0]); > + usage(argv[0]); > return EXIT_FAILURE; > } > > @@ -49,6 +55,7 @@ int main(int argc, char *argv[]) > size, SPLICE_F_MOVE); > if (spliced < 0) { > perror("splice"); > + usage(argv[0]); > return EXIT_FAILURE; > } > I don't understand how this change helps user. thanks, -- Shuah