Re: Bash cannot kill itself?

[Clark J. Wang]

On Wed, Jun 30, 2010 at 12:38 PM, Chris F.A. Johnson
<chris@cfajohnson.com>wrote:

> On Wed, 30 Jun 2010, Clark J. Wang wrote:
>
> > I have a bash script like this:
> >
> > #!/bin/bash
> >
> > trap 'echo killed by SIGALRM; exit 1' ALRM
> >
> > function wait_kill()
> > {
> >     sleep 5
> >     kill -ALRM $$
> > }
> >
> > wait_kill &
> >
> > sleep 3600
> >
> > ### END OF THE SCRIPT ###
> >
> > It does not work as I expected. The running script was not terminated
> after
> > 5 seconds. So what's wrong here?
>
>   $$ refers to the subshell.


There's no subshell here, I think.


> Try:
>
> trap 'echo killed by SIGALRM; exit 1' ALRM
>
> function wait_kill()
> {
>    sleep 5
>     kill -ALRM $pid
> }
>
> pid=$$
> wait_kill &
>
> sleep 3600
>
> --
>   Chris F.A. Johnson, <http://cfajohnson.com>
>   Author:
>   Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)
>   Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
>