Duping stdin fd before using fdopen

py65/monitor.py

@@ -54,17 +54,17 @@ class Monitor(cmd.Cmd):
         self.prompt = "."
         self._add_shortcuts()
 
+        # Save the current system input mode so it can be restored after
+        # after processing commands and before exiting.
+        console.save_mode(sys.stdin)
+
         # Attempt to get a copy of stdin that is unbuffered on systems
         # that support it.  This allows for immediate response to
         # typed input as well as pasted input.  If unable to get an
         # unbuffered version of stdin, the original version is returned.
-        stdin = console.get_unbuffered_stdin(stdin)
+        self.unbuffered_stdin = console.get_unbuffered_stdin(stdin)
 
-        cmd.Cmd.__init__(self, stdin=stdin, stdout=stdout)
-
-        # Save the current input mode so it can be restored after
-        # after processing commands and before exiting.
-        console.save_mode(self.stdin)
+        cmd.Cmd.__init__(self, stdin=self.unbuffered_stdin, stdout=stdout)
 
         # Check for any exceptions thrown during __init__ while
         # processing the arguments.
@@ -93,9 +93,21 @@ class Monitor(cmd.Cmd):
         except:
             # Restore input mode on any exception and then rethrow the
             # exception.
-            console.restore_mode(self.stdin)
+            console.restore_mode()
             raise
 
+    def __del__(self):
+        try:
+            # Restore the input mode.
+            console.restore_mode()
+            # Close the unbuffered input file handle, if it exists.
+            if self.unbuffered_stdin != None:
+                if self.unbuffered_stdin != sys.stdin:
+                    self.unbuffered_stdin.close()
+        except:
+            pass
+
+
     def _parse_args(self, argv):
         try:
             shortopts = 'hi:o:m:l:r:g:'
@@ -160,7 +172,7 @@ class Monitor(cmd.Cmd):
             self._output_mpu_status()
 
         # Switch back to the previous input mode.
-        console.restore_mode(self.stdin)    
+        console.restore_mode()
 
         return result
 
@@ -511,7 +523,7 @@ class Monitor(cmd.Cmd):
                     break
 
         # Switch back to the previous input mode.
-        console.restore_mode(self.stdin)    
+        console.restore_mode()
 
     def help_radix(self):
         self._output("radix [H|D|O|B]")
@@ -907,7 +919,7 @@ def main(args=None):
         c.cmdloop()
     except KeyboardInterrupt:
         c._output('')
-        console.restore_mode(c.stdin)
+        console.restore_mode()
 
 if __name__ == "__main__":
     main()

py65/utils/console.py

@@ -45,6 +45,7 @@ else:
     from select import select
 
     oldattr = None
+    oldstdin = None
 
     def get_unbuffered_stdin(stdin):
         """ Attempt to get and return a copy of stdin that is 
@@ -55,21 +56,20 @@ else:
         if stdin != None:
             try:
                 # Reopen stdin with no buffer.
-                return os.fdopen(stdin.fileno(), 'rb', 0)
+                return os.fdopen(os.dup(stdin.fileno()), 'rb', 0)
             except Exception as e:
                 print(e)
                 # Unable to reopen this file handle with no buffer.
                 # Just use the original file handle.
-                print("Error opening unbuffered stdin - using buffered version")
                 return stdin
         else:
             # If stdin is None, try using sys.stdin for input.
             try:
                 # Reopen the system's stdin with no buffer.
-                return os.fdopen(sys.stdin.fileno(), 'rb', 0)
-            except Exception as e:
-                print(e)
-                print("Error opening default unbuffered stdin - using buffered version")
+                return os.fdopen(os.dup(sys.stdin.fileno()), 'rb', 0)
+            except:
+                # If unable to get an unbuffered stdin, just return
+                # None, which is what we started with if we got here.
                 return None
 
     def save_mode(stdin):
@@ -82,11 +82,13 @@ else:
         # For non-Windows systems, save the original input settings,
         # which will typically be blocking reads with echo.
         global oldattr
+        global oldstdin
 
         # When the input is not a pty/tty, this will fail.
         # In that case, it's ok to ignore the failure.
         try:
             # Save the current terminal setup.
+            oldstdin = stdin
             fd = stdin.fileno()
             oldattr = termios.tcgetattr(fd)
         except:
@@ -120,19 +122,22 @@ else:
             # a tty.
             pass
         
-    def restore_mode(stdin):
+    def restore_mode():
         """For operating systems that support it, restore the previous 
         input mode.
         """
 
         # Restore the previous input setup.
         global oldattr
+        global oldstdin
 
         try:
-            fd = stdin.fileno()
+            # Restore the original system stdin.
+            oldfd = oldstdin.fileno()
             # If there is a previous setting, restore it.
             if oldattr != None:
-                termios.tcsetattr(fd, termios.TCSANOW, oldattr)
+                # Restore it on the original system stdin.
+                termios.tcsetattr(oldfd, termios.TCSANOW, oldattr)
         except:
             # Quietly ignore termios errors, such as stdin not being a tty.
             pass