title: Merge all files in a directory into one using bash
body: <p>I have a directory with several *.js files. Quantity and file names are unknown. Something like this:</p>
  
  <pre><code>js/
   |- 1.js
   |- 2.js
   |- blabla.js
  </code></pre>
  
  <p>I need to merge all the files in this directory into one <code>merged_dmYHis.js</code>. For example, if files contents are:</p>
  
  <p><strong>1.js</strong></p>
  
  <pre><code>aaa
  bbb
  </code></pre>
  
  <p><strong>2.js</strong></p>
  
  <pre><code>ccc
  ddd
  eee
  </code></pre>
  
  <p><strong>blabla.js</strong></p>
  
  <pre><code>fff
  </code></pre>
  
  <p>The <code>merged_280120111257.js</code> would contain:</p>
  
  <pre><code>aaa
  bbb
  ccc
  ddd
  eee
  fff
  </code></pre>
  
  <p>Is there a way to do it using bash, or such task requires higher level programming language, like python or similar?</p>