Re: Idlde 5.4 under RedHat 6.2: Crashes and hanging procs

[Nigel Wade <nmw(at)ion.le.ac.uk>]

> Dear all,

> I have started using idlde under RedHat 6.2 on the gnome desktop.
> I am experiencing two quite annoying problems, which I hope that you
> can solve for me:

> 1) Sometimes idlde just dies on me. In particular, when I have changed 
the
> current program elsewhere, am prompted to reload, and click accept. This
> kills the session immediately.

That's the way of fancy GUIs. 
Crash and burn at the worst possible moment.


> 2) In my programs I frequently spawn a postscript viewer like
> spawn,unit=a,"/usr/bin/X11/gv "+outfile
> where a is some unit and outfile is the file I just wrote.
> This works fine, but when I close gv I am left with a "defunct" tcsh 
hanging
> around. If I spawn with /noshell, it is a defunct gv that is left. Not
> even "kill -9" works!! I need to exit IDL to get rid of them.

That's because you have specified unit=a on the spawn command.
IDL has not yet finished with the process, the command 'close,a'
should get rid of it.

You can't kill defunct, or zombie, processes. They don't really 
exist - they are a dead, gone away, extinct ex-processes.
All that's left is an entry in the kernel process table with
the process exit status so the parent can wait() and retrieve
it when it wishes. The only resources they use up is one entry
in the process table and a bit of kernel memory. They go away
when the parent wait()s or when the parent dies.

-- 
-----------------------------------------------------------
Nigel Wade, System Administrator, Space Plasma Physics Group,
            University of Leicester, Leicester, LE1 7RH, UK 
E-mail :    nmw@ion.le.ac.uk 
Phone :     +44 (0)116 2523568, Fax : +44 (0)116 2523555