+/**
+ * Auto-link hashtags.
+ *
+ * @param string $description Given description.
+ * @param string $indexUrl Root URL.
+ *
+ * @return string Description with auto-linked hashtags.
+ */
+function hashtag_autolink($description, $indexUrl = '')
+{
+ /*
+ * To support unicode: http://stackoverflow.com/a/35498078/1484919
+ * \p{Pc} - to match underscore
+ * \p{N} - numeric character in any script
+ * \p{L} - letter from any language
+ * \p{Mn} - any non marking space (accents, umlauts, etc)
+ */
+ $regex = '/(^|\s)#([\p{Pc}\p{N}\p{L}\p{Mn}]+)/mui';
+ $replacement = '$1<a href="'. $indexUrl .'?addtag=$2" title="Hashtag $2">#$2</a>';
+ return preg_replace($regex, $replacement, $description);
+}
+
+/**
+ * This function inserts where relevant so that multiple spaces are properly displayed in HTML
+ * even in the absence of <pre> (This is used in description to keep text formatting).
+ *
+ * @param string $text input text.
+ *
+ * @return string formatted text.
+ */
+function space2nbsp($text)
+{
+ return preg_replace('/(^| ) /m', '$1 ', $text);
+}
+
+/**
+ * Format Shaarli's description
+ *
+ * @param string $description shaare's description.
+ * @param string $redirector if a redirector is set, use it to gerenate links.
+ * @param bool $urlEncode Use `urlencode()` on the URL after the redirector or not.
+ * @param string $indexUrl URL to Shaarli's index.
+
+ * @return string formatted description.
+ */
+function format_description($description, $redirector = '', $urlEncode = true, $indexUrl = '') {
+ return nl2br(space2nbsp(hashtag_autolink(text2clickable($description, $redirector, $urlEncode), $indexUrl)));
+}
+
+/**
+ * Generate a small hash for a link.
+ *
+ * @param DateTime $date Link creation date.
+ * @param int $id Link ID.
+ *
+ * @return string the small hash generated from link data.
+ */
+function link_small_hash($date, $id)
+{
+ return smallHash($date->format(LinkDB::LINK_DATE_FORMAT) . $id);