perf record: auto detect when stdout is a pipe (d7065adb) · Commits · 戴 / test

This patch gives the ability to 'perf record' to detect when its stdout has been redirected to a pipe. There's now no more need to add '-o -' switch in this case. However '-o <path>' option has always precedence, that is if specified and stdout has been connected via a pipe then the output will go into the specified output. LKML-Reference: <m3ipxo966i.fsf@gmail.com> Signed-off-by:

Franck Bui-Huu <fbuihuu@gmail.com> Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

+20 −12

Original line number	Diff line number	Diff line
		@@ -48,7 +48,7 @@ static unsigned int user_freq = UINT_MAX;
		static int freq = 1000;
		static int output;
		static int pipe_output = 0;
		static const char *output_name = "perf.data";
		static const char *output_name = NULL;
		static int group = 0;
		static int realtime_prio = 0;
		static bool nodelay = false;
		@@ -497,6 +497,13 @@ static int __cmd_record(int argc, const char **argv)
		exit(-1);
		}

		if (!output_name) {
		if (!fstat(STDOUT_FILENO, &st) && S_ISFIFO(st.st_mode))
		pipe_output = 1;
		else
		output_name = "perf.data";
		}
		if (output_name) {
		if (!strcmp(output_name, "-"))
		pipe_output = 1;
		else if (!stat(output_name, &st) && st.st_size) {
		@@ -510,6 +517,7 @@ static int __cmd_record(int argc, const char **argv)
		} else if (write_mode == WRITE_APPEND) {
		write_mode = WRITE_FORCE;
		}
		}

		flags = O_CREAT\|O_RDWR;
		if (write_mode == WRITE_APPEND)

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