blackbox, bbkeys, and .xinit... (solved) --> UNIX behind the scenes

[Mike Hauber]

On Wednesday 03 November 2004 09:25 pm, Parv proclaimed:
> in message <200411031739.23987.m.hauber at mchsi.com>, wrote
> Mike Hauber thusly...
>
> > I discovered that with the line "blackbox & bbkeys" in
> > the script, the bbscript remains when I exit blackbox,
> > and I have to close bbscript to return to KDM.
>
> ...
>
> > However, when I login and close bbkeys, then blackbox
> > abruptly closes (apparently a clean kill), and I return
> > to KDM.
>
> That's what you had asked for.  Using '&' after a
> command, a shell executes the command in the background. 
> Lack of '&' causes the command to be executed in the
> foreground.  Try these two commands in a bourne-like
> shell (such as ash (FreeBSD sh), ksh93, bash2, bash3) ...
>
>  sleep 15 && date &
>
>  sleep 15 && date
>

First of all, I get the syntax.  However, I do _not_ 
understand the apparent dependence between the first and 
the second binary (if you don't know what I'm referring to, 
then please read the rest of my last email).

>
> In your situation, blackbox runs in the background &
> bbkeys in foreground.  If you wanted to run bbkeys only
> if blackbox runs, then do AND operation ...
>
>   blackbox && bbkeys
>

Actually, no.  If I were to put 'blackbox && bbkeys' in the 
script, then blackbox would appear, and then _after_ I exit 
blackbox bbkeys shows up on the KDM "root" background.  
Then when I close bbkeys, the KDM login window is restored.  
Vice-versa the other way around.  Obviously, this is not 
what I'm after.

I've found the solution (as indicated in my last email), but 
again, I don't understand the dependency that the second 
binary seems to have on the first (ie. close the second and 
the first disappears, but _not_ vice-versa).  I haven't 
found the dependency documented anywhere, and therefore I 
don't understand _why_ it's the solution.

>
> ... optionally send the both commands in the background
> (say, if there are more commands to be run after the two
> commands)...
>
>   blackbox && bbkeys &
>
>
> See also...
>
>   - Get a good introductory Unix book
>
>   - Man page for the shell which will execute your .xinit
>
>   - Search "Google Groups" at http://groups.google.com/
> ...
>
>       + comp.unix.* newsgroups for "foreground background
> process OR command shell" search term
>
>       + comp.unix.* & comp.windows.x newsgroups for
> "shell xinitrc OR xsession background"
>
>
>   - Parv
>
> --

You're probably right.  This is more a NIX question in 
general rather than a FreeBSD-specific question.  I'll post 
it to another board.  Thanks.

Mike