[PATCH bpf] bpftool: Flush tracelog output

[Paul Chaignon <paul@xxxxxxxxxxxxx>]

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 flushing the tracelog output after each line from the trace_pipe file.

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>
---
 tools/bpf/bpftool/tracelog.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/bpf/bpftool/tracelog.c b/tools/bpf/bpftool/tracelog.c
index e80a5c79b38f..b310229abb07 100644
--- a/tools/bpf/bpftool/tracelog.c
+++ b/tools/bpf/bpftool/tracelog.c
@@ -158,6 +158,7 @@ int do_tracelog(int argc, char **argv)
                        jsonw_string(json_wtr, buff);
                else
                        printf("%s", buff);
+               fflush(stdout);
        }

        fclose(trace_pipe_fd);
--
2.25.1