sh bug?
Dan Nelson
dnelson at allantgroup.com
Fri Jan 28 08:19:33 PST 2005
In the last episode (Jan 28), Jilles Tjoelker said:
> On Fri, Jan 28, 2005 at 01:06:21AM -0800, Julian Elischer wrote:
> > Harti Brandt wrote:
> > >On Fri, 28 Jan 2005, Julian Elischer wrote:
> > >JE>however echo $$
> > >JE>and
> > >JE> ( echo $$ )
> > >JE>produce the same result.
> > >I think that the $$ is expanded in the old shell in any case.
>
> Although it seems similar, I prefer to say the value of $$ does not
> change when forking a subshell. man sh and POSIX also state that. Thus,
> all $ expandos work the same way.
>
> > hence my test of
> > ps -l vs (ps -l)
>
> > unfortunatly the shell short circuits that too if it's too simple.
>
> But unfortunately, it doesn't short circuit when you something like sh
> -c xterm, it keeps a useless shell waiting.
Try "sh -c exec xterm". The sh is not useless, since it must hang
around to print the signal name if the xterm gets killed.
--
Dan Nelson
dnelson at allantgroup.com
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