[PATCH v7 4/5] eal: allow user to set default log stream before init

[Stephen Hemminger <stephen@networkplumber.org>]

It is useful for application to be able to set the default log
stream before call rte_eal_init(). This makes all messages go
to the new default.

For example, to skip using syslog; just doing
	rte_openlog_stream(stderr);

There is no reason for helper command line applications to clutter
syslog with messages.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 app/dumpcap/main.c              | 3 +++
 app/pdump/main.c                | 3 +++
 app/proc-info/main.c            | 3 +++
 lib/eal/common/eal_common_log.c | 6 ++++++
 lib/eal/common/eal_log.h        | 1 +
 lib/eal/unix/eal_log.c          | 4 ++++
 6 files changed, 20 insertions(+)

diff --git a/app/dumpcap/main.c b/app/dumpcap/main.c
index 64294bbfb3e6..bf31eef13cf4 100644
--- a/app/dumpcap/main.c
+++ b/app/dumpcap/main.c
@@ -639,6 +639,9 @@ static void dpdk_init(void)
 		eal_argv[i++] = strdup(file_prefix);
 	}
 
+	/* keep any logging away from syslog. */
+	rte_openlog_stream(stderr);
+
 	if (rte_eal_init(eal_argc, eal_argv) < 0)
 		rte_exit(EXIT_FAILURE, "EAL init failed: is primary process running?\n");
 }
diff --git a/app/pdump/main.c b/app/pdump/main.c
index c94606275b28..82c67350e4ab 100644
--- a/app/pdump/main.c
+++ b/app/pdump/main.c
@@ -989,6 +989,9 @@ main(int argc, char **argv)
 
 	argc += 2;
 
+	/* keep any logging away from syslog. */
+	rte_openlog_stream(stderr);
+
 	diag = rte_eal_init(argc, argp);
 	if (diag < 0)
 		rte_panic("Cannot init EAL\n");
diff --git a/app/proc-info/main.c b/app/proc-info/main.c
index 53e852a07c14..371b1f382d66 100644
--- a/app/proc-info/main.c
+++ b/app/proc-info/main.c
@@ -1774,6 +1774,9 @@ main(int argc, char **argv)
 
 	argc += 4;
 
+	/* keep any logging away from syslog. */
+	rte_openlog_stream(stderr);
+
 	ret = rte_eal_init(argc, argp);
 	if (ret < 0)
 		rte_panic("Cannot init EAL\n");
diff --git a/lib/eal/common/eal_common_log.c b/lib/eal/common/eal_common_log.c
index 1b2080e8ef04..1533ee871f47 100644
--- a/lib/eal/common/eal_common_log.c
+++ b/lib/eal/common/eal_common_log.c
@@ -584,6 +584,12 @@ eal_log_set_default(FILE *default_log)
 #endif
 }
 
+FILE *
+eal_log_get_default(void)
+{
+	return default_log_stream;
+}
+
 /*
  * Called by eal_cleanup
  */
diff --git a/lib/eal/common/eal_log.h b/lib/eal/common/eal_log.h
index 31dc489350f6..268c2a264382 100644
--- a/lib/eal/common/eal_log.h
+++ b/lib/eal/common/eal_log.h
@@ -22,6 +22,7 @@ int eal_log_level_parse(int argc, char * const argv[]);
  * Determine where log data is written when no call to rte_openlog_stream.
  */
 void eal_log_set_default(FILE *default_log);
+FILE *eal_log_get_default(void);
 
 /*
  * Save a log option for later.
diff --git a/lib/eal/unix/eal_log.c b/lib/eal/unix/eal_log.c
index 85d817c2d31e..e66bcc68d07f 100644
--- a/lib/eal/unix/eal_log.c
+++ b/lib/eal/unix/eal_log.c
@@ -60,6 +60,10 @@ eal_log_init(const char *id, int facility)
 {
 	FILE *log_stream;
 
+	/* has user has already setup a log stream */
+	if (eal_log_get_default())
+		return 0;
+
 	log_stream = fopencookie(NULL, "w+", console_log_func);
 	if (log_stream == NULL)
 		return -1;
-- 
2.39.2