initial upload

lib/logger.h

@@ -0,0 +1,166 @@
+/*
+Functions to set up logging.
+
+Examples
+--------
+
+Logging to stderr:
+
+    #include "logger.h"
+
+    void my_func(){
+        log_info("From my_func!\n");
+    }
+
+    int main(){
+        // Enable logging to stderr in debug level
+        // will only print messages of level DEBUG or higher
+        log_init(LOG_DEBUG);
+        log_debug("debug line. The code is %d", LOG_DEBUG);
+        log_info("info line. The code is %d", LOG_INFO);
+        log_warning("warning line. The code is %d", LOG_WARNING);
+        log_error("error line. The code is %d", LOG_ERROR);
+        my_func();
+        return 0;
+    }
+
+will print:
+
+    DEBUG: debug line. The code is 0
+    info line. The code is 1
+    WARNING: warning line. The code is 2
+    ERROR: error line. The code is 3
+    From my_func!
+
+If function log_init() is not called than logging to stderr is disabled and no
+messages will be printed.
+
+Logging to a file:
+
+    #include <stdio.h>
+    #include "logger.h"
+
+    void my_func(){
+        log_info("From my_func!\n");
+        log_debug("Should not appear in log file\n");
+    }
+
+    int main(){
+        // Enable logging to file "log.txt" in info level
+        // will not print DEBUG level messages
+        // since log_init was not called, there is no logging to stderr
+        FILE *logfile = fopen("log.txt", "w");
+        log_tofile(logfile, LOG_INFO);
+        log_debug("debug line. The code is %d", LOG_DEBUG);
+        log_info("info line. The code is %d", LOG_INFO);
+        log_warning("warning line. The code is %d", LOG_WARNING);
+        log_error("error line. The code is %d", LOG_ERROR);
+        my_func();
+        return 0;
+    }
+
+File log.txt will look like:
+
+    info line. The code is 1
+    WARNING: warning line. The code is 2
+    ERROR: error line. The code is 3
+    From my_func!
+
+Note that you can combine loggin to stderr and to a file with different
+levels in the same program.
+*/
+
+#ifndef _TESSEROIDS_LOGGER_H_
+#define _TESSEROIDS_LOGGER_H_
+
+/* Needed for definition of FILE */
+#include <stdio.h>
+
+
+/** Logging level for debug messages */
+#define LOG_DEBUG   1
+/** Logging level for general information */
+#define LOG_INFO    2
+/** Logging level for warning messages */
+#define LOG_WARNING 3
+/** Logging level for error messages */
+#define LOG_ERROR   4
+
+
+/** Keep the information on the global logger */
+typedef struct logger_struct
+{
+    int level; /**< level of logging */
+    int filelogging; /**< flag to know wether loggint to a file is enabled */
+    int file_level; /**< logging level for the file */
+    FILE *logfile; /**< file to log to */
+
+} LOGGER;
+
+
+/** Global logger struct. Only declare in the main program! */
+//LOGGER logger;
+
+
+/** Setup logging to stderr.
+
+@param level level of logging to be made. Can be one of:
+    - LOG_DEBUG
+    - LOG_INFO
+    - LOG_WARNING
+    - LOG_ERROR
+*/
+void log_init(int level);
+
+
+/** Set logging to a file.
+
+@param logfile FILE pointer to the already open file to log to.
+@param level level of logging to be made to the file. Can be one of:
+    - LOG_DEBUG
+    - LOG_INFO
+    - LOG_WARNING
+    - LOG_ERROR
+*/
+void log_tofile(FILE *logfile, int level);
+
+
+/** Log a message at debug level.
+
+Pass parameters in the same format as printf()
+
+Prints a newline at the end.
+*/
+void log_debug(const char *fmt, ...);
+
+
+/** Log a message at info level.
+
+Pass parameters in the same format as printf()
+
+Does not print "INFO: " in front of the message when logging
+
+Prints a newline at the end.
+*/
+void log_info(const char *fmt, ...);
+
+
+/** Log a message at warning level.
+
+Pass parameters in the same format as printf()
+
+Prints a newline at the end.
+*/
+void log_warning(const char *fmt, ...);
+
+
+/** Log a message at error level.
+
+Pass parameters in the same format as printf()
+
+Prints a newline at the end.
+*/
+void log_error(const char *fmt, ...);
+
+
+#endif