title: Concatenate strings in elisp
body: <p>I need to concatenate path string as follows, so I added the following lines to my <code>.emacs</code> file:</p>
  <pre><code>(setq org_base_path &quot;~/smcho/time/&quot;)
  (setq org-default-notes-file-path (concatenate 'string org_base_path &quot;notes.org&quot;))
  (setq todo-file-path (concatenate 'string org_base_path &quot;gtd.org&quot;))
  (setq journal-file-path (concatenate 'string org_base_path &quot;journal.org&quot;))
  (setq today-file-path (concatenate 'string org_base_path &quot;2010.org&quot;))
  </code></pre>
  <p>When I do <kbd>C-h v</kbd> <code>today-file-path</code> <kbd>RET</kbd> to check, it has no variable assigned.</p>
  <p>What's wrong with my code? Is there any other way to concatenate the path string?</p>
  <h2>EDIT</h2>
  <p>I found that the problem was caused by the wrong setup, the code actually works. Thanks for the answers which are better than my code.</p>