title: How can I allow a literal dot in a Perl regular expression?
body: <p>I use this condition to check if the value is alphanumeric values:</p>
  
  <pre><code>$value =~ /^[a-zA-Z0-9]+$/
  </code></pre>
  
  <p>How can I modify this regex to account for a possible dot <code>.</code> in the value without accepting any other special characters?</p>