Syslog appender/formatter

include/plog/Appenders/SyslogAppender.h

@@ -0,0 +1,39 @@
+#pragma once
+#include <plog/Appenders/IAppender.h>
+#include <syslog.h>
+
+namespace plog
+{
+    template<class Formatter>
+    class PLOG_LINKAGE_HIDDEN SyslogAppender : public IAppender
+    {
+    public:
+        virtual void write(const Record& record) PLOG_OVERRIDE
+        {
+            std::string str = Formatter::format(record);
+
+            syslog(toPriority(record.getSeverity()), "%s", str.c_str());
+        }
+
+    private:
+        static int toPriority(Severity severity)
+        {
+            switch (severity)
+            {
+            case fatal:
+                return LOG_EMERG;
+            case error:
+                return LOG_ERR;
+            case warning:
+                return LOG_WARNING;
+            case info:
+                return LOG_NOTICE;
+            case debug:
+                return LOG_INFO;
+            case verbose:
+            default:
+                return LOG_DEBUG;
+            }
+        }
+    };
+}

include/plog/Formatters/SyslogFormatter.h

@@ -0,0 +1,30 @@
+#pragma once
+#include <plog/Record.h>
+#include <plog/Util.h>
+#include <utility>
+
+namespace plog
+{
+    class SyslogFormatter
+    {
+    public:
+        static util::nstring header()
+        {
+            return util::nstring();
+        }
+
+        static util::nstring format(const Record& record)
+        {
+            util::nostringstream ss;
+            ss << PLOG_NSTR("[") << record.getTid() << PLOG_NSTR("] ")
+               << record.getFunc() << PLOG_NSTR("@") << record.getLine()
+               << PLOG_NSTR(" ") << record.getMessage() /* no line feed */;
+
+#if __cplusplus > 201703L
+            return std::move(ss).str();
+#else
+            return ss.str();
+#endif
+        }
+    };
+}

samples/CMakeLists.txt

@@ -78,5 +78,6 @@ add_subdirectory(PrintVar)
 add_subdirectory(SetFileName)
 add_subdirectory(Shared)
 add_subdirectory(SkipNativeEOL)
+add_subdirectory(Syslog)
 add_subdirectory(UtcTime)
 add_subdirectory(Utf8Everywhere)

samples/Syslog/CMakeLists.txt

@@ -0,0 +1,7 @@
+if(UNIX)
+    add_executable(Syslog Main.cpp)
+    target_link_libraries(Syslog plog)
+    target_compile_options(Syslog PRIVATE -pthread)
+    target_link_options(Syslog PRIVATE -pthread)
+    set_target_properties(Syslog PROPERTIES FOLDER Samples)
+endif()

samples/Syslog/Main.cpp

@@ -0,0 +1,53 @@
+//
+// Syslog - shows how to use the syslog appender/formatter.
+// For the mappings between plog and syslog severities, refer to SyslogAppender
+//
+
+#include <plog/Log.h>
+#include <plog/Init.h>
+#include <plog/Formatters/SyslogFormatter.h>
+#include <plog/Appenders/SyslogAppender.h>
+#if __cplusplus >= 201103L
+#include <thread>
+#endif
+
+static void log_messages()
+{
+    PLOG_VERBOSE << "This is a VERBOSE message";
+    PLOG_DEBUG << "This is a DEBUG message";
+    PLOG_INFO << "This is an INFO message";
+    PLOG_WARNING << "This is a WARNING message";
+    PLOG_ERROR << "This is an ERROR message";
+    PLOG_FATAL << "This is a FATAL message";
+}
+
+int main()
+{
+    static plog::SyslogAppender<plog::SyslogFormatter> syslogAppender;
+    plog::init(plog::verbose, &syslogAppender);
+
+    // Calling openlog() is optional. If omitted, the application name is
+    // used (depends on the used C library) and the PID is not included.
+    openlog("MyApp", LOG_PID, LOG_USER);
+
+    // optional: log only messages up to PLOG_INFO (maps to LOG_NOTICE)
+    setlogmask(LOG_UPTO(LOG_NOTICE));
+
+#if __cplusplus >= 201103L
+    // optional: start a 2nd thread which also generates log messages
+    // you'll get the same PID but different TID values in the syslog file
+    std::thread myThread(log_messages);
+#endif
+
+    log_messages();
+
+#if __cplusplus >= 201103L
+    // wait until the 2nd thread has finished
+    myThread.join();
+#endif
+
+    // Calling closelog() is optional
+    closelog();
+
+    return 0;
+}