Re: SIGINT handling

[Greg Wooledge]

On Mon, Sep 21, 2015 at 10:07:55PM +0100, Stephane Chazelas wrote:
> Maybe the test scenario was not clear:
> 
> bash -c 'cmd; echo hi'
> 
> is run from an interactive shell, cmd is a long running
> application (the problem that sparked this discussion was with
> ping and I showed examples with an inline-script calling sleep)

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.)

A loop like this works as expected:

while true; do
  sleep 1
done

A loop like this does not:

while true; do
  ping -c 1 some.host     # or on HP-UX, ping some.host -n 1
done

You might already have been aware of this; I'm not sure.  But in any case,
it makes a tremendous different what "cmd" is in your example.  You
can't generalize it.