note 114154 modified in function.is-resource by googleguy

Try this to know behavior: <?php function resource_test($resource, $name) { echo '[' . $name. ']', PHP_EOL, '(bool)$resource => ', $resource ? 'TRUE' : 'FALSE', PHP_EOL, 'get_resource_type($resource) => ', get_resource_type($resource) ?: 'FALSE', PHP_EOL, 'is_resource($resource) => ', is_resource($resource) ? 'TRUE' : 'FALSE', PHP_EOL, PHP_EOL ; } $resource = tmpfile(); resource_test($resource, 'Check Valid Resource'); fclose($resource); resource_test($resource, 'Check Released Resource'); $resource = null; resource_test($resource, 'Check NULL'); ?> It will be shown as... [Check Valid Resource] (bool)$resource => TRUE get_resource_type($resource) => stream is_resource($resource) => TRUE [Check Released Resource] (bool)$resource => TRUE get_resource_type($resource) => Unknown is_resource($resource) => FALSE [Check NULL] (bool)$resource => FALSE get_resource_type($resource) => FALSE Warning: get_resource_type() expects parameter 1 to be resource, null given in ... on line 10 is_resource($resource) => FALSE --was-- Try this to know behavior: <?php function resource_test($resource, $name) { echo '[' . $name. ']', PHP_EOL, '(bool)$resource => ', $resource ? 'TRUE' : 'FALSE', PHP_EOL, 'get_resource_type($resource) => ', get_resource_type($resource) ?: 'FALSE', PHP_EOL, 'is_resoruce($resource) => ', is_resource($resource) ? 'TRUE' : 'FALSE', PHP_EOL, PHP_EOL ; } $resource = tmpfile(); resource_test($resource, 'Check Valid Resource'); fclose($resource); resource_test($resource, 'Check Released Resource'); $resource = null; resource_test($resource, 'Check NULL'); ?> It will be shown as... [Check Valid Resource] (bool)$resource => TRUE get_resource_type($resource) => stream is_resoruce($resource) => TRUE [Check Released Resource] (bool)$resource => TRUE get_resource_type($resource) => Unknown is_resoruce($resource) => FALSE [Check NULL] (bool)$resource => FALSE get_resource_type($resource) => FALSE Warning: get_resource_type() expects parameter 1 to be resource, null given in ... on line 10 is_resoruce($resource) => FALSE http://php.net/manual/en/function.is-resource.php