$timeout = array(
'http'=> array(
'timeout'=>5//设置一个超时时间，单位为秒
)
);
$ctx = stream_context_create($timeout);
$text = file_get_contents("https://www.jb51.net/",0, $ctx);

$timeout = array(
'http' => array(
'timeout' => 5 //设置一个超时时间，单位为秒
)
);
$ctx = stream_context_create($timeout);
if ($fp = fopen("https://www.jb51.net/", "r", false, $ctx)) {
while( $c = fread($fp, 8192)) {
echo $c;
}
fclose($fp);
}

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_TIMEOUT,60);  //只需要设置一个秒的数量就可以
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_USERAGENT, $defined_vars['HTTP_USER_AGENT']);