From: Paul Chaignon paul@isovalent.com
[ Upstream commit 1a1a0b0364ad291bd8e509da104ac8b5b1afec5d ]
The output of bpftool prog tracelog is currently buffered, which is inconvenient when piping the output into other commands. A simple tracelog | grep will typically not display anything. This patch fixes it by enabling line buffering on stdout for the whole bpftool binary.
Fixes: 30da46b5dc3a ("tools: bpftool: add a command to dump the trace pipe") Signed-off-by: Quentin Monnet quentin@isovalent.com Signed-off-by: Paul Chaignon paul@isovalent.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: Yonghong Song yhs@fb.com Link: https://lore.kernel.org/bpf/20211220214528.GA11706@Mem Signed-off-by: Sasha Levin sashal@kernel.org --- tools/bpf/bpftool/main.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index c58a135dc355e..1854d6b978604 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -396,6 +396,8 @@ int main(int argc, char **argv) }; int opt, ret;
+ setlinebuf(stdout); + last_do_help = do_help; pretty_output = false; json_output = false;