From 7f7077f5566e11ee5ac98818d190c4a119ea9a17 Mon Sep 17 00:00:00 2001
From: Perry Werneck <perry.werneck@gmail.com>
Date: Tue, 23 Jul 2019 13:40:44 -0300
Subject: [PATCH] Adding option to use syslog (when available).

---
 configure.ac              |  1 +
 src/include/config.h.in   |  1 +
 src/include/lib3270/log.h | 10 ++++++++++
 src/lib3270/init.c        | 11 +++++++++++
 src/lib3270/linux/log.c   | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/lib3270/log.c         |  2 ++
 src/lib3270/private.h     |  6 ++++++
 src/lib3270/windows/log.c |  5 +++++
 8 files changed, 82 insertions(+), 0 deletions(-)

diff --git a/configure.ac b/configure.ac
index 799e2fc..3f61c8f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -463,6 +463,7 @@ dnl Check for headers
 dnl ---------------------------------------------------------------------------
 
 AC_CHECK_HEADER(malloc.h, AC_DEFINE(HAVE_MALLOC_H,,[do we have malloc.h?]))
+AC_CHECK_HEADER(syslog.h, AC_DEFINE(HAVE_SYSLOG,,[do we have malloc.h?]))
 
 AC_CHECK_FUNCS(getaddrinfo, AC_DEFINE(HAVE_GETADDRINFO) )
 AC_CHECK_FUNC(vasprintf, AC_DEFINE(HAVE_VASPRINTF) )
diff --git a/src/include/config.h.in b/src/include/config.h.in
index 3bf894e..77c1e8c 100644
--- a/src/include/config.h.in
+++ b/src/include/config.h.in
@@ -55,6 +55,7 @@
 	#undef HAVE_INET_NTOP
 	#undef HAVE_DBUS
 	#undef HAVE_LIBCURL
+	#undef HAVE_SYSLOG
 
 	#undef HAVE_ICONV
 	#undef ICONV_CONST
diff --git a/src/include/lib3270/log.h b/src/include/lib3270/log.h
index 7a69ea2..a838c72 100644
--- a/src/include/lib3270/log.h
+++ b/src/include/lib3270/log.h
@@ -57,6 +57,16 @@
 		LIB3270_EXPORT int	  lib3270_write_rc(H3270 *session, const char *module, int rc, const char *fmt, ...) LIB3270_GNUC_FORMAT(4,5);
 		LIB3270_EXPORT void	  lib3270_write_va_log(H3270 *session, const char *module, const char *fmt, va_list arg);
 
+		/**
+		 * @brief Send logs to system log (if available)
+		 *
+		 * @param flag	Non-zero to use syslog.
+		 *
+		 * @return 0 if ok, non zero if not.
+		 *
+		 */
+		LIB3270_EXPORT int	  lib3270_set_syslog(int flag);
+
 		#ifdef DEBUG
 			#include <stdio.h>
 			#undef trace
diff --git a/src/lib3270/init.c b/src/lib3270/init.c
index b7856f9..d4a3116 100644
--- a/src/lib3270/init.c
+++ b/src/lib3270/init.c
@@ -54,6 +54,10 @@
 #include <lib3270/log.h>
 #include "private.h"
 
+#ifdef HAVE_SYSLOG
+	#include <syslog.h>
+#endif // HAVE_SYSLOG
+
 #if defined WIN32
 	BOOL WINAPI DllMain(HANDLE hinst, DWORD dwcallpurpose, LPVOID lpvResvd);
 #else
@@ -118,6 +122,13 @@ int lib3270_unloaded(void)
 	curl_global_cleanup();
 #endif // HAVE_LIBCURL
 
+#ifdef HAVE_SYSLOG
+	if(use_syslog)
+	{
+		closelog();
+	}
+#endif // HAVE_SYSLOG
+
     return 0;
 }
 
diff --git a/src/lib3270/linux/log.c b/src/lib3270/linux/log.c
index 32a944d..9f73a99 100644
--- a/src/lib3270/linux/log.c
+++ b/src/lib3270/linux/log.c
@@ -34,13 +34,59 @@
 #include <lib3270.h>
 #include <lib3270/log.h>
 
+#ifdef HAVE_SYSLOG
+	#include <syslog.h>
+#endif // HAVE_SYSLOG
+
 /*---[ Implementacao ]--------------------------------------------------------------------------------------*/
 
+ int use_syslog = 0;
+
  void default_log_writer(H3270 GNUC_UNUSED(*session), const char *module, int GNUC_UNUSED(rc), const char *fmt, va_list arg_ptr)
  {
+#ifdef HAVE_SYSLOG
+	if(use_syslog)
+	{
+		vsyslog(LOG_USER, fmt, arg_ptr);
+	}
+	else
+	{
+		printf("%s:\t",module);
+		vprintf(fmt,arg_ptr);
+		printf("\n");
+		fflush(stdout);
+	}
+#else
  	printf("%s:\t",module);
 	vprintf(fmt,arg_ptr);
 	printf("\n");
 	fflush(stdout);
+#endif
  }
 
+ LIB3270_EXPORT int lib3270_set_syslog(int flag)
+ {
+#ifdef HAVE_SYSLOG
+	if(flag)
+	{
+		if(!use_syslog)
+		{
+			openlog(LIB3270_STRINGIZE_VALUE_OF(LIB3270_NAME), LOG_NDELAY, LOG_USER);
+			use_syslog = 1;
+		}
+	}
+	else
+	{
+		if(use_syslog)
+		{
+			closelog();
+			use_syslog = 0;
+		}
+	}
+
+	return 0;
+
+#else
+ 	return errno  = ENOENT;
+#endif // HAVE_SYSLOG
+ }
diff --git a/src/lib3270/log.c b/src/lib3270/log.c
index a3215fd..e03ccc3 100644
--- a/src/lib3270/log.c
+++ b/src/lib3270/log.c
@@ -41,6 +41,7 @@
 #include <config.h>
 #include <lib3270.h>
 #include <lib3270/log.h>
+#include <errno.h>
 
 /*---[ Constants ]------------------------------------------------------------------------------------------*/
 
@@ -75,3 +76,4 @@
  {
 	loghandler(session,module,0,fmt,arg);
  }
+
diff --git a/src/lib3270/private.h b/src/lib3270/private.h
index 929fcf7..eeaefda 100644
--- a/src/lib3270/private.h
+++ b/src/lib3270/private.h
@@ -691,6 +691,12 @@ struct _h3270
 LIB3270_INTERNAL HANDLE hEventLog;
 #endif // _WIN32
 
+#ifdef HAVE_SYSLOG
+/// @brief Windows Event Log Handler.
+LIB3270_INTERNAL int use_syslog;
+#endif // HAVE_SYSLOG
+
+
 /* Library internal calls */
 LIB3270_INTERNAL int	key_ACharacter(H3270 *hSession, unsigned char c, enum keytype keytype, enum iaction cause,Boolean *skipped);
 LIB3270_INTERNAL int	cursor_move(H3270 *session, int baddr);
diff --git a/src/lib3270/windows/log.c b/src/lib3270/windows/log.c
index d5d94cd..dedc075 100644
--- a/src/lib3270/windows/log.c
+++ b/src/lib3270/windows/log.c
@@ -74,3 +74,8 @@
 
  }
 
+ LIB3270_EXPORT int lib3270_set_syslog(int flag)
+ {
+ 	return errno  = ENOENT;
+ }
+
--
libgit2 0.21.2