返回后非空字符串为空

Question

I'm writing a php script that deals with page processing via cURL, so I have a function to get and return pages by URL

function get_url($Url){
    if (!function_exists('curl_init')){
        die('Sorry cURL is not installed!');
    }
    set_time_limit (20);
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $Url);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array("Cookie: age_gate_birthday=19901101"));
    curl_setopt($ch, CURLOPT_REFERER, "http://www.facebook.com");
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2049.0 Safari/537.36");
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $output = curl_exec($ch);
    return $output;
}

echoing $output in this function always returns a string of HTML, however if I call on this function in another function

function get_vid ($sql, $url) {
    $data = get_url($url);
...

the returned value is an empty string, despite the fact that $output had value when get_url() was doing its thing.

Weirdly enough, the error only exists with specific URLs, but works fine with others.

Thank you for trying to help!

UPDATE: It seems CURL returns FALSE randomly on specific links, which seems to be a culprit of this issue, however curl_error is empty, so I'm unable to identify the cause of this.

Answer 1

I think it's because you get a http redirect.

Try to check http code like this :

  if (curl_getinfo($ch,CURLINFO_HTTP_CODE) == 302) {
    // Manage http redirect here
  }