title: How to search the tags file and load it automatically when vim start up
body: <p>Vim is my favorite editor, when I open a php or python file in vim, the first command is:</p>
  <pre><code>set tags=../../../tags
  </code></pre>
  <p>or</p>
  <pre><code>set tags=../../tags
  </code></pre>
  <p>I think vim can do this automatically:</p>
  <blockquote>
  <p>first search ./tags, if it is exists, set it, if not exists</p>
  <p>search ../tags,if it is exists, set it, if not exists</p>
  <p>search ../../tags,if it is exists, set it, if not exists</p>
  <p>until it reaches the / or D: directory</p>
  </blockquote>
  <p>However, I am not so familiar with the vim scripts.
  Any of your help will be appreciated!_</p>