perf list: Remove blank lines, headers when piping output
So that one can, for instance, use it with wc -l:
# perf list *:*write* | wc -l
60
Or to look for the "bio" tracepoints, without 'perf list' headers:
# perf list *:*bio* | head
block:block_bio_backmerge [Tracepoint event]
block:block_bio_bounce [Tracepoint event]
block:block_bio_complete [Tracepoint event]
block:block_bio_frontmerge [Tracepoint event]
block:block_bio_queue [Tracepoint event]
block:block_bio_remap [Tracepoint event]
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ts7sc0x8u4io4cifzkup4j44@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index ac42c97..41a356b 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1026,7 +1026,7 @@
printf(" %-50s [Kernel PMU event]\n", aliases[j]);
printed++;
}
- if (printed)
+ if (printed && pager_in_use())
printf("\n");
out_free:
for (j = 0; j < len; j++)