Re: BASH_SUBSHELL documentation misleading

[Sam Liddicott]

On 23/03/11 18:52, Chris F.A. Johnson wrote:
> On Wed, 23 Mar 2011, Sam Liddicott wrote:
>
> > Configuration Information [Automatically generated, do not change]:
> > Machine: i686
> > OS: linux-gnu
> > Compiler: gcc
> > Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
> > -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
> > -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DP$ uname output: 
> > Linux sojo 2.6.35-28-generic-pae #49-Ubuntu SMP Tue Mar 1 14:58:06 
> > UTC 2011 i686 GNU/Linux
> > Machine Type: i686-pc-linux-gnu
> >
> > Bash Version: 4.1
> > Patch Level: 5
> > Release Status: release
> >
> > Description:
> >        man page says:
> >
> >        BASH_SUBSHELL
> >              Incremented by one each time a subshell or subshell 
> > environment
> >              is spawned.  The initial value is 0.
> >
> >        This suggests that:
> >
> >        echo $BASH_SUBSHELL ; ( echo ) ; echo $BASH_SUBSHELL
> >
> >        would not give the same answer for BASH_SUBSHELL
>
>    No, it suggests that:
>
> echo $BASH_SUBSHELL ; ( echo $BASH_SUBSHELL )
>
>    would not give the same answer for BASH_SUBSHELL

It should suggest that, because that is how it actually works.

But the man page is misleading and does not actually suggest this.

>    In your example, the second "echo $BASH_SUBSHELL" is at the same
>    depth as the first.

Yes. But a new subshell environment has been spawned. Each time that 
happens BASH_SUBSHELL should increase.

Of course I know how it does work, but the man page isn't clear. It 
doesn't say that the increase is only visible within the subshell and 
therefore it is a measurement of subshell depth.

Sam