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@xxxxxxxxxxxxx>
Signed-off-by: Paul Chaignon <paul@xxxxxxxxxxxxx>
---
Changes in v3:
- Title changed from "bpftool: Flush tracelog output".
- Enable line buffering for all of bpftool, as suggested by Andrii.
- Rebased on bpf.
Changes in v2:
- Resending to fix a format error.
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 28237d7cef67..8fbcff9d557d 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -400,6 +400,8 @@ int main(int argc, char **argv)
};
int opt, ret;
+ setlinebuf(stdout);
+
last_do_help = do_help;
pretty_output = false;
json_output = false;
--
2.25.1
