PHP的file_get_contents设置超时

1.

ini_set('default_socket_timeout', '5');
file_get_contents("http://lyxint.com/");

2.

$context = stream_context_create(
    array(
        'http' => array(
            'timeout' => 5,
        )
    )
);
file_get_contents("http://lyxint.com/", 0, $context);