| Message ID | tencent_0AEA8FB622DE1A740841643D5F36ABF8BD0A@qq.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] selftests: splice: Add usage() to splice_read.c | expand |
On 8/30/24 23:14, Rong Tao wrote: > From: Rong Tao <rongtao@cestc.cn> > > Give the programmer more help information to inform the program on how to > use it. > > Signed-off-by: Rong Tao <rongtao@cestc.cn> > --- > 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 <sys/types.h> > #include <sys/stat.h> > > +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
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 <sys/types.h> #include <sys/stat.h> +void usage(const char *prog) +{ + fprintf(stderr, "Usage: %s INPUT [BYTES]\n", prog); + fprintf(stderr, " %s /etc/os-release | cat\n", prog); +} + 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; }