python-plot

#!/usr/bin/python
import popen2
import sys

p=popen2.Popen3("gnuplot");
print p.pid;
p.tochild.write("plot sin(x)\n");
if p.poll()==-1:
i = 0;
p.tochild.flush();
print "plot over!\n";
p.wait();
else:
print "not over!\n"
exit(0);