title: How to make all org-files under a folder added in agenda-list automatically?
body: <p>I am using org-mode to write notes and org-agenda to organize all notes, especially to search some info. by keyword or tag.</p>
  
  <p><strong>C-c a m</strong> can search some files by tag inputed, <strong>C-c a s</strong> by keyword ,those functions from org-agenda are well to utilize, however, I need to add org-file into the agenda-list by hand.</p>
  
  <p>I added some codes into <strong>.emacs</strong>, such as </p>
  
  <pre><code>(setq org-agenda-files (list "path/folder/*.org"))
  </code></pre>
  
  <p>or </p>
  
  <pre><code>(setq org-agenda-files (file-expand-wildcards "path/folder/*.org"))
  </code></pre>
  
  <p>but, both failed to add  files under the folder specified into agenda-list automatically, so I can't search keyword or tag among those org-files, unless that I open a org-file and type <strong>C-c [</strong> to add it into agenda-list.</p>
  
  <p>How can I make all org-files under a folder automatically added in agenda?</p>