added datetime stamp to prefix

logger.cpp

@@ -8,6 +8,10 @@
 
 #include "logger.hpp"
 #include <unistd.h>
+#include <sys/time.h>
+#include <ctime>
+#include <cmath>
+#include <iomanip>
 
 using namespace sc;
 
@@ -26,6 +30,16 @@ void logger::msg(loglevel level, const char* file, int line, const char* func) {
 }
 
 void logger::write_prefix(loglevel level, const char* file, int line, const char* func) {
+    // retrieve accurate time for milliseconds display
+	struct timeval secs;
+	(void)::gettimeofday(&secs, nullptr);
+	int ms = static_cast<int>(std::roundf(secs.tv_usec / 1000.0)) % 1000;
+
+    // create a date/time stamp
+	char dtstamp[20];
+	std::strftime(dtstamp, 20, "%F %T", std::localtime(&secs.tv_sec));
+
+    std::cerr << dtstamp << "." << std::setw(3) << ms << " ";
     std::cerr << _name << "[" << ::getpid() << "] ";
     std::cerr << file << ":" << line << " " << func << "() ";
     std::cerr << '[' << loglevel_desc(level) << "] ";