Re: [Help-bash] backgrounding a process sends it into a tailspin

[Chet Ramey]

On 9/7/12 8:46 PM, Cook, Rich wrote:
> Hello, 
> I have built and installed gnuplot and wrapped it in a bash script.  The 
> script simply makes a usage entry in a database, calls gnuplot, then notes 
> that it exits.  I'm including the script below.  
> 
> When the user runs this script and puts it into the background, gnuplot 
> immediately starts taking up 100% of a CPU, spinning in readline.  This only 
> happens when gnuplot is wrapped in this way, not when it's called directly.  
> I would like to avoid this behavior, obviously, but I would also like to 
> continue using a wrapper script.  What is it about being called from a script 
> that is causing this odd behavior on gnuplot's part?  

I can't reproduce this on Mac OS X, using bash-3.2 to bash-4.2 and
gnuplot-4.whatever-fink-gives-you, or on Fedora 15, using bash-4.2 and
gnuplot-4.4.  I used the orignal script without the imgtrack stuff.
It doesn't matter whether I start the script in the background using `&'
or in the foreground and use ^Z.  Even ^Z/bg doesn't cause any weird
behavior.

Maybe we could get back to basics: system type, OS version, bash version,
gnuplot version.

Chet

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    address@hidden    http://cnswww.cns.cwru.edu/~chet/