bash scripting try something, but quit if it's taking too long

[Chris F.A. Johnson]

On Tue, 22 Jun 2010, Matt Price wrote:

> On Tue, Jun 22, 2010 at 8:47 PM, Chris F.A. Johnson <chris-E7bvbYbpR6jSUeElwK9/Pw at public.gmane.org>wrote:
> 
> >
> >
> > wait=5       ## seconds before timing out
> > suspend_wl &   ## put function into the background
> >
> > while ps $! > /dev/null 2>&1 && [ $wait -gt 0 ]
> > do
> >  sleep 1
> >  wait=$(( $wait - 1 ))
> > done
> > ps $! > /dev/null 2>&1 && kill $!
> >
> > ah, that's super!  trying to understand it, does this mean:
> 
> while (ps $! gives a nonzero result)

while ps returns a zero exit code (0 == successful)

> and ($wait is greaterthan 0)
> sleep, reduce wait by 1
> and afterwards
> check if $1 is still running, and kill it
> 
> looks great, thanks much.  i didn't really know that ps returned an exit
> value!
> 
> matt
> 

-- 
   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)
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