use File::Temp ();

sub showgraph {
        my($cmdfile, $cmdfilename);
        my $cmds = qq[set key off\nplot "] . quote($outname) . qq[" with lines\n! echo "Press return to continue"
; read\n];
        ($cmdfile, $cmdfilename) = File::Temp::tempfile undef, "UNLINK", 1;
        $out or die "error creating temporary commands file";
        print "Writing gnuplot command to temporary file $cmdfilename\n";
        print $cmdfile $cmds or
                die "error writing command file: $!";
        flush $cmdfile or die
                "error flushing comand file";
        print "Launching gnuplot\n";
        system "gnuplot", $cmdfilename;
        close $cmdfile;
}