title: How do you append to an already existing string?
body: <p>I want append to a string so that every time I loop over it, it will add &quot;test&quot; to the string.</p>
  <p>Like in <code>PHP</code> you would do:</p>
  <pre><code>$teststr = &quot;test1\n&quot;
  $teststr .= &quot;test2\n&quot;
  echo = &quot;$teststr&quot;
  </code></pre>
  <p>Returns:</p>
  <pre><code>test1
  test2
  </code></pre>
  <p>But I need to do this in a shell script</p>