fix: cast ctype_digit() arguments to string to resolve PHP 8.1+ deprecation notice. Fix #41.

Author: pocketarc

system/database/DB_driver.php

@@ -1349,7 +1349,7 @@ public function escape_identifiers($item, $split = TRUE)
 			return $item;
 		}
 		// Avoid breaking functions and literal values inside queries
-		elseif (ctype_digit($item) OR $item[0] === "'" OR ($this->_escape_char !== '"' && $item[0] === '"') OR strpos($item, '(') !== FALSE)
+		elseif (ctype_digit((string) $item) OR $item[0] === "'" OR ($this->_escape_char !== '"' && $item[0] === '"') OR strpos($item, '(') !== FALSE)
 		{
 			return $item;
 		}

system/database/drivers/oci8/oci8_driver.php

@@ -177,7 +177,7 @@ public function __construct($params)
 			return;
 		}
 		elseif ($this->hostname !== '' && strpos($this->hostname, '/') === FALSE && strpos($this->hostname, ':') === FALSE
-			&& (( ! empty($this->port) && ctype_digit($this->port)) OR $this->database !== ''))
+			&& (( ! empty($this->port) && ctype_digit((string) $this->port)) OR $this->database !== ''))
 		{
 			/* If the hostname field isn't empty, doesn't contain
 			 * ':' and/or '/' and if port and/or database aren't
@@ -187,7 +187,7 @@ public function __construct($params)
 			 * that the database field is a service name.
 			 */
 			$this->dsn = $this->hostname
-				.(( ! empty($this->port) && ctype_digit($this->port)) ? ':'.$this->port : '')
+				.(( ! empty($this->port) && ctype_digit((string) $this->port)) ? ':'.$this->port : '')
 				.($this->database !== '' ? '/'.ltrim($this->database, '/') : '');
 
 			if (preg_match($valid_dsns['ec'], $this->dsn))

system/database/drivers/postgre/postgre_driver.php

@@ -95,7 +95,7 @@ protected function _build_dsn()
 
 		$this->hostname === '' OR $this->dsn = 'host='.$this->hostname.' ';
 
-		if ( ! empty($this->port) && ctype_digit($this->port))
+		if ( ! empty($this->port) && ctype_digit((string) $this->port))
 		{
 			$this->dsn .= 'port='.$this->port.' ';
 		}