framework/requirements/YiiRequirementChecker.php
function checkPhpIniOn($name)
    {
        $value = ini_get($name);
        if (empty($value)) {
            return false;
        }

        return ((int) $value === 1 || strtolower($value) === 'on');
    }
function checkPhpIniOn($name)
    {
        $value = ini_get($name);
        if (empty($value)) {
            return false;
        }

        return ((int) $value === 1 || strtolower($value) === 'on');
    }
Checks if PHP configuration option (from php.ini) is on.
@param string $name configuration option name.
@return bool option is on.