title: How to open a serial port with read/write lines reversed?
body: <p>I know how to open a serial port using 'open' function:</p>
  
  <pre><code>open("/dev/portname", flags)
  </code></pre>
  
  <p>But I want two programs to open this port but with reversed read/write lines. For example when program 2 writes something to the port, program 1 can read it. </p>