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From: Stephane Chazelas <stephane.chazelas@gmail.com>
Newsgroups: gnu.bash.bug
Subject: Re: SIGINT handling
Date: Tue, 22 Sep 2015 19:20:15 +0100
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Approved: bug-bash@gnu.org
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References: <55FDC8B4.4000505@case.edu> <20150919213101.GA4393@chaz.gmail.com> <55FE0BB8.8040500@case.edu> <20150920155219.GA8614@chaz.gmail.com> <20150920161245.GA14980@chaz.gmail.com> <20150920194542.GB14980@chaz.gmail.com> <560054CE.6000208@case.edu> <20150921210755.GC5598@chaz.gmail.com> <20150922121808.GK25574@eeg.ccf.org> <20150922115842587713157@bob.proulx.com>
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Xref: csiph.com gnu.bash.bug:11549

2015-09-22 12:04:45 -0600, Bob Proulx:
> Greg Wooledge wrote:
> > Just for the record, ping is the *classic* example of an incorrectly
> > written application that traps SIGINT but doesn't kill itself with
> > SIGINT afterward.  (This seems to be true on multiple systems -- at
> > the very least, HP-UX and Linux pings both suffer from it.)
> 
> The command I run into the problem most with is 'rsync' in a loop.
> 
>   EXIT VALUES
>        0      Success
>   ...
>        20     Received SIGUSR1 or SIGINT
> 
> Which forces me to write such things this way.
> 
>   rsync ...
>   rc=$?
>   if [ $rc -eq 20 ]; then
>     kill -INT $$
>   fi
>   if [ $rc -ne 0 ]; then
>     echo "Error: failed: ..." 1>&2
>     exit 1
>   fi
[...]

Another (generic) work-around as mentioned at
http://unix.stackexchange.com/a/230568
and here is to add:

trap '
  trap - INT
  kill -s INT "$$"
' INT

That doesn't work properly if there are subshells though.

That basically turns a WCE shell to WUE (for very simple scripts).

For SIGQUIT, you'd probably want to disable core dumps as well:
  
trap '
  trap - QUIT
  ulimit -c 0
  kill -s QUIT "$$"
' QUIT

-- 
Stephane