perf stat: Add --log-fd <N> option to redirect stderr elsewhere (56f3bae7) · Commits · 戴 / test

tools/perf/Documentation/perf-stat.txt

+10 −1

Original line number	Diff line number	Diff line
		@@ -95,12 +95,21 @@ corresponding events, i.e., they always refer to events defined earlier on the c
		line.

		-o file::
		-output file::
		--output file::
		Print the output into the designated file.

		--append::
		Append to the output file designated with the -o option. Ignored if -o is not specified.

		--log-fd::

		Log output to fd, instead of stderr. Complementary to --output, and mutually exclusive
		with it. --append may be used here. Examples:
		3>results perf stat --log-fd 3 -- $cmd
		3>>results perf stat --log-fd 3 --append -- $cmd



		EXAMPLES
		--------

+14 −0

Original line number	Diff line number	Diff line
		@@ -196,6 +196,7 @@ static bool csv_output = false;
		static bool group = false;
		static const char *output_name = NULL;
		static FILE *output = NULL;
		static int output_fd;

		static volatile int done = 0;

		@@ -1080,6 +1081,8 @@ static const struct option options[] = {
		OPT_STRING('o', "output", &output_name, "file",
		"output file name"),
		OPT_BOOLEAN(0, "append", &append_file, "append to the output file"),
		OPT_INTEGER(0, "log-fd", &output_fd,
		"log output to fd, instead of stderr"),
		OPT_END()
		};

		@@ -1166,6 +1169,10 @@ int cmd_stat(int argc, const char *argv, const char prefix __used)
		if (output_name && strcmp(output_name, "-"))
		output = NULL;

		if (output_name && output_fd) {
		fprintf(stderr, "cannot use both --output and --log-fd\n");
		usage_with_options(stat_usage, options);
		}
		if (!output) {
		struct timespec tm;
		mode = append_file ? "a" : "w";
		@@ -1177,6 +1184,13 @@ int cmd_stat(int argc, const char *argv, const char prefix __used)
		}
		clock_gettime(CLOCK_REALTIME, &tm);
		fprintf(output, "# started on %s\n", ctime(&tm.tv_sec));
		} else if (output_fd != 2) {
		mode = append_file ? "a" : "w";
		output = fdopen(output_fd, mode);
		if (!output) {
		perror("Failed opening logfd");
		return -errno;
		}
		}

		if (csv_sep)