From c51ecde8966b8b94502264af84db7c2e8b07b2ef Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sat, 21 Feb 2009 22:22:49 +0100
Subject: [PATCH] Logging: Following streams by stderr is now configurable.

---
 cf/libucw            |  3 +++
 ucw/log-conf-test.cf |  1 +
 ucw/log-conf.c       | 22 +++++++++++++++-------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/cf/libucw b/cf/libucw
index 4f0f81b1..b92efad6 100644
--- a/cf/libucw
+++ b/cf/libucw
@@ -219,6 +219,9 @@ Logging {
 #	# guaranteed to be complete. (default: 0)
 #	ErrorsFatal	1
 #
+#	# Let stderr of the program point to this file-based log_stream (default: 0)
+#	StdErrFollows	1
+#
 #	# Some events are logworthy, but they could happen too frequently and flood the log.
 #	# You can avoid the flooding by setting up a rate limiter for a specific subset of
 #	# message types. If more limiters match the type of a message, only the last one applies.
diff --git a/ucw/log-conf-test.cf b/ucw/log-conf-test.cf
index 3ceaaf34..f1d2b20a 100644
--- a/ucw/log-conf-test.cf
+++ b/ucw/log-conf-test.cf
@@ -5,6 +5,7 @@ Logging {
 Stream {
 	Name		logfile
 	FileName	log/test
+	StdErrFollows	1
 	Limit { Rate 100 }
 }
 
diff --git a/ucw/log-conf.c b/ucw/log-conf.c
index 15be98e8..d0afece0 100644
--- a/ucw/log-conf.c
+++ b/ucw/log-conf.c
@@ -35,6 +35,7 @@ struct stream_config {
   int show_types;
   int syslog_pids;
   int errors_fatal;
+  int stderr_follows;
   struct log_stream *ls;
   int mark;				// Used temporarily in log_config_commit()
 };
@@ -60,12 +61,17 @@ stream_commit(void *ptr)
 {
   struct stream_config *c = ptr;
 
-  if (c->file_name && c->syslog_facility)
-    return "Both FileName and SyslogFacility selected";
-  if (c->syslog_facility && !log_syslog_facility_exists(c->syslog_facility))
-    return cf_printf("SyslogFacility `%s' is not recognized", c->syslog_facility);
-  if (c->syslog_facility && c->microseconds)
-    return "Syslog streams do not support microsecond precision";
+  if (c->syslog_facility)
+    {
+      if (!log_syslog_facility_exists(c->syslog_facility))
+	return cf_printf("SyslogFacility `%s' is not recognized", c->syslog_facility);
+      if (c->file_name)
+	return "Both FileName and SyslogFacility selected";
+      if (c->microseconds)
+	return "Syslog streams do not support microsecond precision";
+    }
+  if (c->stderr_follows && !c->file_name)
+    return "StdErrFollows requires a file-based stream";
   return NULL;
 }
 
@@ -105,6 +111,7 @@ static struct cf_section stream_config = {
     CF_INT("ShowTypes", P(show_types)),
     CF_INT("SyslogPID", P(syslog_pids)),
     CF_INT("ErrorsFatal", P(errors_fatal)),
+    CF_INT("StdErrFollows", P(stderr_follows)),
 #undef P
     CF_END
   }
@@ -285,7 +292,7 @@ do_new_configured(struct stream_config *c)
     return c->ls;
 
   if (c->file_name)
-    ls = log_new_file(c->file_name, 0);
+    ls = log_new_file(c->file_name, (c->stderr_follows ? FF_FD2_FOLLOWS : 0));
   else if (c->syslog_facility)
     ls = log_new_syslog(c->syslog_facility, (c->syslog_pids ? LOG_PID : 0));
   else
@@ -350,6 +357,7 @@ int main(int argc, char **argv)
       msg(L_INFO | ls->regnum | type, "Hello, universe!");
       usleep(200000);
     }
+  fprintf(stderr, "Alas, this was printed to stderr.\n");
 
   log_close_all();
   return 0;
-- 
2.39.2