From d87cad7328e43570ce17163244e5779458951c06 Mon Sep 17 00:00:00 2001
From: Benny Meisels <benny.meisels@gmail.com>
Date: Tue, 28 Jan 2020 15:03:51 +0200
Subject: [PATCH] Fixed Slcan fileno raising an exception on windows

---
 can/interfaces/slcan.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/can/interfaces/slcan.py b/can/interfaces/slcan.py
index 5d7450987..9ac38807b 100644
--- a/can/interfaces/slcan.py
+++ b/can/interfaces/slcan.py
@@ -7,6 +7,7 @@
 
 """
 
+import io
 import time
 import logging
 
@@ -244,9 +245,12 @@ def shutdown(self):
         self.serialPortOrig.close()
 
     def fileno(self):
-        if hasattr(self.serialPortOrig, "fileno"):
+        try:
             return self.serialPortOrig.fileno()
-        # Return an invalid file descriptor on Windows
+        except (io.UnsupportedOperation):
+            # Return an invalid file descriptor on a platform which doesn't implement fileno such as Windows
+            pass
+
         return -1
 
     def get_version(self, timeout):