title: How to prepare a regex that will escape partial digits while matching?
body: <p>I'm using <code>pcre_exec()</code> to compile regular expressions.</p>
  
  <p>I want to match the string having number with 3 digits followed by "-", but it should not match if the number is prefixed with one or more digits.
  e.g.</p>
  
  <pre><code>345- =&gt; match and matches text =&gt; (345-)
  :546- = match and matches text =&gt; (546-)
   123- = match and matches text =&gt; (123-)
  2355- = Should not match as 355- is prefixed with "2" digit.
  </code></pre>
  
  <p>I tried <code>^([\\s|:]*)([0-7]\\d{2})-</code> but it is not working.</p>