title: ubuntu add c++ libraries
body: <p>I would like to install boost.iostreams library. I read on their <a href="http://www.boost.org/doc/libs/1_57_0/libs/iostreams/doc/index.html" rel="nofollow">website</a>, i may not do good things because this is not working.
  So i try to install <a href="http://biopp.univ-montp2.fr/wiki/index.php/Installation" rel="nofollow">bio++ package</a>.</p>
  
  <p>I add to my software manager the new sources. In command line I do this : </p>
  
  <pre><code>wget http://biopp.univ-montp2.fr/repos/apt/conf/biopp.gpg.key
  sudo apt-key add biopp.gpg.key
  </code></pre>
  
  <p>But I am not sure to be in the good directory to do this. Where do I have to go ? </p>
  
  <p>In general, how can i install a package or a library ?</p>