diff -r 0125e4089f88 -r 86a23238d8a1 ucx/logging.h
--- a/ucx/logging.h	Wed Feb 06 14:35:15 2013 +0100
+++ b/ucx/logging.h	Fri Feb 08 10:37:24 2013 +0100
@@ -22,6 +22,7 @@
 
 typedef struct {
     FILE *stream;
+    size_t(*writer)(const void*, size_t, size_t, FILE*);
     unsigned int level;
     unsigned int mask;
     UcxMap* levels;
@@ -30,16 +31,30 @@
 UcxLogger *ucx_logger_new(FILE *stream, unsigned int level, unsigned int mask);
 void ucx_logger_free(UcxLogger* logger);
 
-void ucx_logger_log(UcxLogger *logger, unsigned int level,
-        const sstr_t message, const char* file, const unsigned int line);
-#define ucx_logger_error(l,m) \
-    ucx_logger_log(l, UCX_LOGGER_ERROR, m, __FILE__, __LINE__)
-#define ucx_logger_info(l,m) \
-    ucx_logger_log(l, UCX_LOGGER_INFO, m, __FILE__, __LINE__)
-#define ucx_logger_warn(l,m) \
-    ucx_logger_log(l, UCX_LOGGER_WARN, m, __FILE__, __LINE__)
-#define ucx_logger_trace(l,m) \
-    ucx_logger_log(l, UCX_LOGGER_TRACE, m, __FILE__, __LINE__)
+/**
+ * Sets the output stream and writer for this logger.
+ * The parameters stream and writer may be NULL, if they shall remain unchanged
+ * in the logger.
+ * l
+ * @param logger The logger
+ * @param stream The stream the logger shall log to
+ * @param writer A pointer to the write function
+ */
+void ucx_logger_setoutput(UcxLogger *logger, FILE *stream,
+        size_t(*writer)(const void*,size_t,size_t,FILE*));
+
+void ucx_logger_logf(UcxLogger *logger, unsigned int level, const char* file,
+        const unsigned int line, const char* format, ...);
+#define ucx_logger_log(logger, level, format...) \
+    ucx_logger_logf(logger, level, __FILE__, __LINE__, format)
+#define ucx_logger_error(logger,format...) \
+    ucx_logger_log(logger, UCX_LOGGER_ERROR, format)
+#define ucx_logger_info(logger,format...) \
+    ucx_logger_log(logger, UCX_LOGGER_INFO, format)
+#define ucx_logger_warn(logger,format...) \
+    ucx_logger_log(logger, UCX_LOGGER_WARN, format)
+#define ucx_logger_trace(logger,format...) \
+    ucx_logger_log(logger, UCX_LOGGER_TRACE, format)
 
 #ifdef __cplusplus
 }