From 5d4ec1ab9ed65015e70a6ddf7027a310f4ad66ac Mon Sep 17 00:00:00 2001
From: lantz <rlantz@cs.stanford.edu>
Date: Sun, 7 Feb 2021 19:12:38 -0800
Subject: [PATCH] catch IOError when writing .mininet_history (#1031)

write_history seems to raise a spurious IOError,
so we catch it.
---
 mininet/cli.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/mininet/cli.py b/mininet/cli.py
index 82e2ac5..ce5bcdc 100644
--- a/mininet/cli.py
+++ b/mininet/cli.py
@@ -89,7 +89,15 @@ class CLI( Cmd ):
             if os.path.isfile( history_path ):
                 read_history_file( history_path )
                 set_history_length( 1000 )
-            atexit.register( lambda: write_history_file( history_path ) )
+
+            def writeHistory():
+                "Write out history file"
+                try:
+                    write_history_file( history_path )
+                except IOError:
+                    # Ignore probably spurious IOError
+                    pass
+            atexit.register( writeHistory )
 
     def run( self ):
         "Run our cmdloop(), catching KeyboardInterrupt"