Terminal interruptions (Cntrl-C, Cntrl-Z) are not working in ROOT6 interactive session

ROOT
1

In my interactive ROOT6 session terminal interruption keys Cntrl-C and Cntr-Z are not working, while they are still working in the ROOT5 session with the same script. Any idea how to fix this annoying problem?

2

On which platform ? with which ROOT6 version ?

3 
** SYSTEM DEFINITIONS ***
  OS: Linux, Distribution: RedHat
  Info: 'Red Hat Enterprise Linux Server release 7.4 (Maipo)'
  System info (uname -a):
    Linux nu76-78.jinr.ru 3.10.0-693.5.2.el7.x86_64 #1 SMP Thu Oct 19 14:21:12 PDT 2017 x86_64 x86_64 x86_64 GNU/Linux

   ------------------------------------------------------------
  | Welcome to ROOT 6.10/08                http://root.cern.ch |
  |                               (c) 1995-2017, The ROOT Team |
  | Built for linuxx8664gcc                                    |
  | From tag v6-10-08, 16 October 2017                         |
  | Try '.help', '.demo', '.license', '.credits', '.quit'/'.q' |
   ------------------------------------------------------------
4

I cannot reproduce that, so I’ll need some extra info:

  • What happens when you press control-Z?
  • What happens when you press control-C? This is meant to cancel input, i.e. if you type “42” and then press control C you should get a new, empty input line, and the 42 should be ignored.
  • Which terminal do you use?
  • What does echo $TERM show?
  • Which display manager do you use?

Cheers, Axel.

5

It seems like problem occurs after some actions inside my script, which is quit complicated, if I run simple loop (the same stop code as in my big script):

{
int i=0;
while(true) {
Info(“Loop”,"Step %d: press [Enter] to continue… ",++i); cin.get();
}
}

Interruptions work for it.

I have also tried to run the script remotely from other terminal (putty under window computer connected by ssh), interruptions are also blocked. Some additional observations.

Before typing Cntrl-C scipt behaves in the same way like script above. Typed letters (not [Enter] or interruptions) are appeared in the input line, like here I have typed word ‘some’

ev 1: press [Enter] to continue… some

Pressing [Enter] leads to loop number of typed symbols +1 = 5 times, like it is expected from cin.get() functions:

ev 6: press [Enter] to continue…

After typing Cntrl-C symbol ^C appears on the screen

ev 6: press [Enter] to continue… ^C

but interruption doesn’t happen like in the simple script above:

Info in : Step 3: press [Enter] to continue…
^C
*** Break *** keyboard interrupt

But status is changing for the input. Now any character works like [Enter], typing of any character leads to one step loop cycle (work of cin.get() functions).

Cntrl-Z is actually works if Cntrl-C has not been yet pressed. After pressing Cntrl-C, Cntrl-Z is blocked and works like any other character.

It seems ok, I am using Cnrl-Z to stop&kill the script now, it is not clear how to catch the reason of this case in the main big script and whether it worth to spend time on it.

6

Thanks. Do you think you’ll be able to upload a reproducer? It’s impossible for me to guess what’s happening without, even based on the details you provided. (Terminals are complex beasts with lots of hidden state.)

7

Hi Axel,

I was thinking it is well known problem…

Just take hsimple.C and increase loop counts, that it runs for a while.
It cannot be stopped with Ctrl-C.
I observe it on my latest OpenSUSE since a while with all ROOT6 versions I tested.

Regards,
Sergey

8

Yes, I see the same effect with hsimple.C setting 25000000 events in the loop!

All is working well in ROOT5 (5.34/26).

9

That’s a bug; I have created https://sft.its.cern.ch/jira/browse/ROOT-9160

10

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.

11

Finally fixed in the future v6.12/08, 6.14/00 and 6.16/00. Thanks for reporting!
Axel.