title: php regex finding a string between two strings
body: <p>I wanted to perform a regex in php. From the $str variable I want to select out common_name = Bangladesh . I wore my regex. The regex is not finding any match here. How can I fix this?</p>
  
  <pre><code>$str = "| conventional_long_name = People's Republic of Bangladesh | common_name = Bangladesh | image_flag = Flag of Bangladesh.svg";
      $pat = "/(?=\common_name\s=).*?(?=\s\|)/";
  
      if(preg_match($pat, $str, $matches)){
          echo "Matches found";
          echo $matches[0];
      } else {
          echo "No match found";
      }
  </code></pre>
  
  <p>the result shows</p>
  
  <pre><code>No match found
  </code></pre>