Get the Bookmarks from a PDF

getBookmarks.php

<?php 
$sPdfContent   = file_get_contents("filename.pdf");
$sRegexPattern = "/R\/[A-Za-z0-9\s\/\[\.\]]*\/Title\(([A-Za-z0-9\.\s\:]*)\)[\/Prev|>>]/";

preg_match_all($sRegexPattern, $sPdfContent, $aBookmarkMatches);

$aBookmarkTitles = $aBookmarkMatches[1];

foreach($aBookmarkTitles as $sBookmarkTitle) {
  echo $sBookmarkTitle . '<br />';
}