On Wed, 30 Jun 2010, Clark J. Wang wrote:
> On Wed, Jun 30, 2010 at 1:40 PM, Jan Schampera <jan.schamp...@web.de> wrote:
>
> > Clark J. Wang wrote:
> >
> > Running a cmd in background (by &) would not create subshell. Simple
> >> testing:
> >>
> >> #!/bin/bash
> >>
> >> function foo()
> >> {
> >> echo $$
> >> }
> >>
> >> echo $$
> >> foo &
> >>
> >> ### END OF SCRIPT ###
> >>
> >> The 2 $$s output the same.
> >>
> >
> > This doesn't mean that it doesn't create a subshell. It creates one, since
> > it can't replace your foreground process.
> >
> > This makes sense.
>
> It just shows that $$ does what it should do, it reports the relevant PID of
> > the parent ("main") shell you use.
>
>
> Then what's the problem with my script in my original mail? Seems like Bash
> does not handle the signal in a real-time way.
The special variable $$ refers to the current process, even if it
has the same numeric value as the parent script.
--
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)
