1 files changed, 42 insertions, 0 deletions
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 04bb81db7..b7bd280ee 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1084,6 +1084,48 @@ class CI_Form_validation {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Valid URL
+	 *
+	 * @param	string	$str
+	 * @return	bool
+	 */
+	public function valid_url($str)
+	{
+		if (empty($str))
+		{
+			return FALSE;
+		}
+		elseif (preg_match('/^(?:([^:]*)\:)?\/\/(.+)$/', $str, $matches))
+		{
+			if (empty($matches[2]))
+			{
+				return FALSE;
+			}
+			elseif ( ! in_array($matches[1], array('http', 'https'), TRUE))
+			{
+				return FALSE;
+			}
+
+			$str = $matches[2];
+		}
+
+		$str = 'http://'.$str;
+
+		// There's a bug affecting PHP 5.2.13, 5.3.2 that considers the
+		// underscore to be a valid hostname character instead of a dash.
+		// Reference: https://bugs.php.net/bug.php?id=51192
+		if (version_compare(PHP_VERSION, '5.2.13', '==') === 0 OR version_compare(PHP_VERSION, '5.3.2', '==') === 0)
+		{
+			sscanf($str, 'http://%[^/]', $host);
+			$str = substr_replace($str, strtr($host, array('_' => '-', '-' => '_')), 7, strlen($host));
+		}
+
+		return (filter_var($str, FILTER_VALIDATE_URL) !== FALSE);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Valid Email
 	 *
 	 * @param	string