fix double write on shutdown

1 files changed, 1 insertions, 1 deletions

diff --git a/imon.h b/imon.h
index 6e38217..513eef2 100644
--- a/imon.h
+++ b/imon.h
@@ -122,7 +122,7 @@ public:
   virtual int open(const char* szDevice, eProtocol pro);
   virtual void close ();
 
-
+  bool isopen() const { return imon_fd >= 0; }
   void clear ();
   int DrawText(int x, int y, const char* string);
   bool flush ();