Issue1270

CTRL+C in Jython 2.5b2 does not exit the console properly: the shell
behaves strangely afterwards, with NEWLINE not working anymore for example.

Well, to be fair:

  1. CTRL+D exits properly,

  2. an exit on CTRL+C (clean or not) is not the CPython behavior. 
Instead it displays 'KeyboardInterrupt' and does not exit.

This will likely be fixable on Unix by registering a SIGINT handler. Not 
sure about Windows.

This may be a function of the underlying readline support. Now that we
have JLine installed by default, on OS X at the very least it exhibits
the same behavior as CPython. No signal handling required!

boisgera, is this still a problem?

I removed my registry file so that GnuReadline does not kick in. The
registry file was:

   python.console=org.python.util.ReadlineConsole
   python.console.readlinelib=GnuReadline

That change alone did cause the beta 3 version to exit properly on a
CTRL+C. The RC3 version exhibits the same behavior (and the rev. 6450 as
well): clean exit on CTRL+C when the Readline console is not selected,
ugly exit when the registry file is present, and never the
'KeyboardInterrupt' behavior.

this is a dupe of #1746106

I just tested this with 2.5 rc 3 and could still reproduce the problem.
Is this a regression?

Ctrl-c killing the console isn't that big problem, but the fact that
ctrl-c cannot be caught as KeyboardInterrupt (issue 1313) means that I
cannot implement graceful shutdown from the CLI to my app easily. I
assume these problems have the same root cause.

Ooops, the version I used in testing was 2.5.1 RC 3 i.e. the latest
available release.

This is still outstanding; there has been no regression.

I thought this was closed as the resolution says 'fixed'.

I think that this is to do with the JLineConsole.

If you change the "python.console" property in the registry file to "org.python.util.InteractiveConsole", i.e

python.console=org.python.util.InteractiveConsole

The ctrl-c starts working fine.

If you leave it at the default JLine console (http://jline.sourceforge.net/) then ctrl-c seems to get treated as a normal character (shows up as a heart symbol on my windows command line).

I suggest you try a different console class until this is fixed.

I'll look into how we can address this.

In the meantime, I would be interested in reports to see if changing the console class fixes the issue on various platforms.

Isn't this only an issue on Windows? As Jim pointed out, it's ok on OS X at least (I can't reproduce it on there as of today w/ 2.5.x)

Nobody specified a platform.

I did use windows and experienced an issue, but a different one to what this bug report is about. And still do.

X:\xhaus\jython\jython_27_2016\dist>java -jar jython.jar
Jython 2.7b1+ (default:e80a189574d0+, Feb 28 2013, 22:54:17)
[Java HotSpot(TM) Client VM (Sun Microsystems Inc.)] on java1.6.0_41
Type "help", "copyright", "credits" or "license" for more information.
>>> ♥♥♥♥♥♥♥♥
  File "<stdin>", line 1
    ♥♥♥♥♥♥♥♥
    ^
SyntaxError: no viable alternative at character '♥'
>>>

With each heart symbol representing a Ctrl-C.

The fact that boisgera and pekka.klarck experience different behaviour (i.e. console killed, no KeyboardInterrupt generated) indicates that they are not using windows, since they did not see heart symbols, as I do.

If it is windows only (requires evidence), then we *could* fix it by specializing the installer to default to a different console on windows.

But I don't like that solution. I'd rather the same console everywhere.

Doesn't jruby use jline as well? They must have had similar problems.

Well we don't generate a KeyboardInterrupt under any circumstances (which is really a separate issue #1313)

Indeed, it looks like #1270 and #1313 are the same issue.

On #1313, pekka.klarck declares that he uses OSX.

"""
This problem can be tested with the attached script. When I execute it
with Jython (tested both with 2.2 and 2.5b3) on my OS X and press ctrl-c
it simply quits without even a traceback. With CPython it prints both
'KeyboardInterrupt' and 'Bye!' before exiting cleanly.
"""

#1313 should be closed as a duplicate of #1270, or vice versa.

I also get hearts on Windows 7 and on Linux the console is killed. Tested with 2.5.3 on both. Don't anymore have OSX for testing.

Useful content in #1313, which is a duplicate. There is no easy solution for Jython, although partial solutions certainly exist. Perhaps we can document them?