What are some alternative methods, besides calling the PHP executable, for validating PHP syntax at runtime?

One alternative method for validating PHP syntax at runtime is to use the `php -l` command in the shell to check the syntax of a PHP file without actually executing it. This command will return any syntax errors found in the file. Another method is to use an online syntax checker tool that allows you to paste your PHP code and check for syntax errors.

// Example using the `php -l` command in the shell to validate PHP syntax
$output = shell_exec('php -l your_php_file.php');
echo $output;