properly propogate errors

log.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include "log.h"
+
+void LOG(const char * tag, int num, const char * fmt, ...)
+{
+#ifdef ENABLE_FILE_LOGGING
+    printf("%s:%d: ", tag, num);
+#endif
+    va_list args;
+    va_start(args, fmt);
+    vprintf(fmt, args);
+    va_end(args);
+}