Support external writer

.vscode/settings.json

@@ -5,6 +5,8 @@
         "fstream": "cpp",
         "*.tcc": "cpp",
         "ostream": "cpp",
-        "mutex": "cpp"
+        "mutex": "cpp",
+        "functional": "cpp",
+        "iomanip": "cpp"
     }
 }

README.md

@@ -34,6 +34,12 @@ using namespace marcelb;
 */
 log mylog("../log", Level::INFO);
 
+// or use external writer callback (for occasional writing)
+
+log mylog("../example", [](string log, string path) {
+    cout << log << " " << path << endl;
+}, Level::INFO)
+
 /**
 * Put log in file
 */

lib/log.hpp

@@ -9,6 +9,7 @@
 #include <time.h>
 #include <sys/stat.h>
 #include <mutex>
+#include <functional>
 
 #if _WIN32
 typedef unsigned int uint;
@@ -39,6 +40,7 @@ class log {
     uint day;
     string path;
     mutex io;
+    function<void(string, string)> extWriter;
 
     /**
      * Checking if the path is in the string dir directory
@@ -83,8 +85,10 @@ class log {
      * optional: a bool variable if it keeps the file open, 
      * and a bool variable if it prints log lines to the console
     */
-    log (string _dir, Level loglevel = WARNING, bool _isKeepOpen = true, bool _printInConsole = false);
+    log (string _dir, Level _loglevel = WARNING, bool _isKeepOpen = true, bool _printInConsole = false);
 
+    
+    log (string _dir, function<void(string, string)> _extWriter, Level _loglevel = WARNING, bool _printInConsole = false);
 
     /**
      * Debug log line

src/log.cpp

@@ -25,19 +25,35 @@ log::log(string _dir, Level _loglevel, bool _isKeepOpen, bool _printInConsole) {
 
 }
 
+log::log (string _dir, function<void(string, string)> _extWriter, Level _loglevel, bool _printInConsole) {
+   dir = _dir;
+   loglevel = _loglevel;
+   extWriter = _extWriter;
+   printInConsole = _printInConsole;
+   setMoment();
+   day = moment->tm_mday;
+   setPath();
+}
+
+
 bool log::isdir() {
    struct stat sb;
    return stat(dir.c_str(), &sb) == 0;
 }
 
 bool log::open() {
+   if (extWriter) {
+      return false;
+   }
    logfile = ofstream (path, ios_base::app);
    return logfile.is_open();
 }
 
 
 void log::loose() {
-   logfile.close();
+   if (!extWriter) {
+      logfile.close();
+   }
 }
 
 void log::setMoment() {
@@ -59,27 +75,31 @@ void log::put(string logline, Level _level) {
    setPrefix(logline, _level);
 
    if (day != moment->tm_mday) {
-      if (isKeepOpen && logfile.is_open()) {
+      if (!extWriter && isKeepOpen && logfile.is_open()) {
          loose();
       }
       day = moment->tm_mday;
       setPath();
-      if (isKeepOpen) {
+      if (!extWriter && isKeepOpen) {
          if (!open()) {
             throw string("[ERROR] Opening log file! ");
          }
       }
    }
 
-   if (!isKeepOpen || !logfile.is_open()) {      
+   if (!extWriter && (!isKeepOpen || !logfile.is_open())) {      
       if (!open()) {
          throw string("[ERROR] Opening log file! ");
       }
    }
 
-   logfile << logline << endl;
+   if (!extWriter) {
+      logfile << logline << endl;
+   } else {
+      extWriter(logline, path);
+   }
 
-   if (!isKeepOpen && logfile.is_open()) {
+   if (!extWriter && !isKeepOpen && logfile.is_open()) {
       loose();
    }
    io.unlock();

test/test.cpp

@@ -6,6 +6,9 @@ using namespace std;
 using namespace marcelb::logging;
 
 log mylog("../example", Level::INFO, false);
+// log mylog("../example", [](string log, string path) {
+//     cout << log << " " << path << endl;
+// }, Level::INFO);
 
 int main() {
     mylog.debug("Start debug loging");