Differences

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--- tools:logger:start [2017/02/06 08:52] – changed "LogLevel::WARN" to "LogLevel::TRACE" to show all messages gehrig
+++ tools:logger:start [2020/11/26 13:06] (current) – [Default LogWriter] ursgraf
@@ Line 3: / Line 3: @@
 <code cpp>
-  StreamLogWriter w(std::cout);
+  Logger::setDefaultStreamLogger(std::cout);
-  Logger log();
+  Logger log = Logger::getLogger();
-  log.set(w);
   log.info() << "Logger Test";
@@ Line 16: / Line 15: @@
 While declaring a logger you can choose a category for it which is a single capital letter, see below:
 <code cpp>
-  Logger log1();      // no category
+  Logger log1 = Logger::getLogger();      // no category
-  Logger log2('A');   // category 'A', log messages will show an 'A'
+  Logger log2 = Logger::getLogger('A');   // category 'A', log messages will show an 'A'
 </code>
@@ Line 27: / Line 26: @@
   * ERROR
   * FATAL: highest level
-Every ''LogWriter'' can be configured to pass only log messages which have a minimum severity level. This is accomplished with
+Every ''Logger'' can be configured to pass only log messages which have a minimum severity level. This is accomplished with
 <code cpp>
-  StreamLogWriter w(std::cout);
+  log.show(LogLevel::WARN);
-  w.show(LogLevel::WARN);
 </code>
 This would enable levels WARN, ERROR and FATAL. \\
-If you do not specify a certain level the default level is INFO. If you want to see all messages you have to use ''show(LogLevel::TRACE)''.
+If you do not specify a certain level the default level is INFO. If you want to see all messages you have to use ''show(LogLevel::TRACE)'' or use the default ''show()'' which is also ''LogLevel::TRACE''.
 ===== Default LogWriter =====
@@ Line 39: / Line 37: @@
 <code cpp>
-  StreamLogWriter w(std::cout);
+  Logger::setDefaultStreamLogger(std::cout);
-  Logger::setDefaultWriter(&w);
+  Logger log = Logger::getLogger();  // this logger will output onto the default ''LogWriter''.
-  Logger log;  // this logger will output onto the default ''LogWriter''.
 </code>
 If you forget to assign a default logger, you will not get logging information from components of the library such as the safety system or the executor.
+===== Logging into the Console and into a File  =====
+Sometimes it can be desirable to have a logger write to the console and write the same content into a file. This is especially helpful on a embedded system where you start an application remotely (e.g. through //ssh//). In such a case you can define a ''StreamLogWriter'' as follows:
+<code cpp>
+  Logger::setDefaultStreamLogger(std::cout, "/tmp/log");
+</code>
+A log file will be created at the given location. Its file name will be appended with the current date and time of the creation of the file.