title: gnuplot stdin, how to plot two lines?
body: <p>I'm trying to produce a plot with two lines using data taken from stdin.  I have a file "test.csv":</p>
  
  <pre><code>0,1.1,2
  1,2,3
  2,6,4
  4,4.6,5
  5,5,6
  </code></pre>
  
  <p>I've been trying to plot this with commands like,</p>
  
  <pre><code>$ cat test | gnuplot -p -e "set datafile separator \",\"; plot '-' using 1:2 with lines, '' using 1:3 with lines;"
  </code></pre>
  
  <p>But no matter what I try I get,</p>
  
  <pre><code>line 5: warning: Skipping data file with no valid points
  </code></pre>
  
  <p>I assume this is because for the second line, stdin has already been exhausted.  Is there a way to get gnuplot to take data from each column of stdin for different plots?</p>
  
  <p>Thanks.</p>