Re: FAQ: gnuplot vs. emacs' compile command

[Kim F. Storm]

Stefan Monnier <address@hidden> writes:

> > Did anyone actually look at this bug back in May ?
> > FYI, I have included the text at the referenced link here.
> 
> What is the bug exactly?

I don't know.  Dan, can you elaborate?

> My understanding is of the problem:
> when Emacs exits, gnuplot is killed because its stdout is connected to
> Emacs (i.e. it receives a SIGPIPE or SIGHUP or somesuch).

.. which emacs cannot do anything about.

> 
> 
>         Stefan
> 
> 
> > Dan Jacobson <address@hidden> writes:
> 
> >> Fellas, the gnuplot team may have found ugly emacs process bugs, see
> >> <...>
> >> 
> 
> > : Dan Jacobson <address@hidden> wrote:
> > : 
> > : > Using emacs -eval '(compile "make")'
> > : > With: echo "plot 'file';pause -1"|gnuplot -persist
> > : > just flashes the graph for a split second.
> > : 
> > : So let's get into dissecting this further.  The first candidate to
> > : remove is 'make'.  It doesn't really do anything useful in this whole
> > : setup, so we might as well get rid of it.  Let's replace it by a shell
> > : script doing the same things.  And while at it, let's get rid of the
> > : separate data file, too:
> > : 
> > : --- gpaction ---
> > : gnuplot -persist <<EOS
> > :  plot '-'
> > :    1 1
> > :    2 2
> > :   e
> > : EOS
> > : ---- end ---
> > : 
> > : sh gpaction                                 # does the plot and returns
> > : emacs -eval '(compile "sh gpaction")'       # doesn't plot, but returns
> > : emacs -eval '(shell-command "sh gpaction")' # plot, but no return
> > : 
> > : For the latter, emacs is unresponsive --- it's obviously waiting for
> > : something to happen, which doesn't.  Only after you terminate the
> > : gnuplot graph window (key 'q' into it), or press Ctrl-G in emacs to
> > : forcibly break out of the wait loop, it will continue.
> > : 
> > : During that pause, look at the output from 'ps jx' and you'll find
> > : that gnuplot_x11 is an orphan --- i.e. it's the only surviving process
> > : in its process group.  In "shell-command", emacs apparently doesn't
> > : kill it, whereas in "compile", it probably does.
> > : -- 
> > : Hans-Bernhard Broeker (address@hidden)
> > : Even if all the snow were burnt, ashes would remain.
> 
> > -- 
> > Kim F. Storm  http://www.cua.dk
> 
> 
> 
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> > Emacs-devel mailing list
> > address@hidden
> > http://mail.gnu.org/mailman/listinfo/emacs-devel
> 
> 

-- 
Kim F. Storm <address@hidden> http://www.cua.dk