title: Format 11 digit numbers with sed and RegEx
body: <p>I'm writing a script that can convert numbers (with 11 digits) like this:</p>
  <p>Example input:</p>
  <pre><code>11111111111
  12345678900
  </code></pre>
  <p>Example output:</p>
  <pre><code>(11) 1 1111-1111
  (12) 3 4567-8900
  </code></pre>
  <p>And here's the command I'm using:</p>
  <pre><code>echo &quot;$(sed 's/\(..\)\(.\{5\}\)/(\1)\2-/g' $file)&quot;
  </code></pre>
  <p>But the output is:</p>
  <pre><code>(11)11111-1111
  (12)34567-8900
  </code></pre>
  <p>Anyone can help me on how to isolate the third number with spaces as the example output? All I can use is sed and RegEx. Thank you!</p>