Gnuplot commands embedded in Perl script

[uan_Blr]

Hi there,

could you please help me with the following script:

my $gnuplot = "/usr/local/bin/gnuplot";
my $sample = "foo";
open(GNUPLOT, "|$gnuplot");
print GNUPLOT <<gnuplot_Commands_Done;
	set grid
	set title "$sample"
	plot "$sample" u 1:6 w lines
	pause -1 
	gnuplot_Commands_Done
close(GNUPLOT);

I would like to be able to call gnuplot in a perl script in a loop (iterate the $sample-name) to plot a lot of graphs. I understand that it is possible to send gnuplot with the print-command the commands but above code does not work.
The error is: "Can't find string terminator "gnuplot_Commands_Done" anywhere before EOF".
What does it mean?
how do i correctly pipe and get perl to send commands to gnuplot?

thanks a lot in advance,
uan