Re: FAQ: gnuplot vs. emacs' compile command

[Dan Jacobson]

The following message is a courtesy copy of an article
that has been posted to comp.graphics.apps.gnuplot as well.

cd /tmp && echo -e 1 1\\n2 2 >file && cat >Makefile<<!
gp:
        echo "plot 'file';pause -1"|gnuplot -persist
!
emacs -eval '(compile "make")' #doesn't plot anything.
emacs -eval '(shell-command "make&")' #doesn't plot anything
emacs -eval '(shell-command "make")'  #works wonderfully
make #works fine

H> Quite hard to tell, actually.  You've piled up three big programs
H> together (four, if you count in the shell), and somehow the combination
H> of all of them fails to do quite exactly what you want.
H> 
H> From the symptoms you quote, I'd put the blame at emacs, or the way
H> you're using it.  You're also over-doing things on the gnuplot end a
H> bit.  You should use either "pause -1", or "-persist". Doing both is
H> not generally useful. 
H> 
H> "Doesn't plot anything" is not the whole story, either.  What *else*
H> do you see?  I.e.: what _does_ it do?  What is displayed in your
H> *compile* buffer in emacs? Did you actually type a <Return> into the
H> compilation buffer to satisfy your "pause -1"?
No, it's all over before I have a chance.
Using emacs -eval '(compile "make")'
With: echo "plot 'file';pause -1"|gnuplot -persist
just flashes the graph for a split second.
With: 
        echo "plot 'file'"         |gnuplot
        echo "plot 'file'"         |gnuplot -persist
        echo "plot 'file';pause -1"|gnuplot
apparently gnuplot acts like a noop, no graph is seen; gnuplot's exit
value is 0.