Curl returns blank or null without output. Solve the problem

curl No output returns blank or null Problem solving

If you find a problem similar to the title , It's probably because of ssl Certificate problems cause that you only need to curl Method by adding the following code ：

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);// prohibit  cURL  Verify peer certificate 
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);// Check whether the domain name of the server is consistent with that on the certificate 

• Give a complete gift curl Code

/** * CURL Request function : Support POST And basic header Header definition  * @param [api_url: The goal is url | post_data:post Parameters  | header: Header information array  | referer_url: source url] * @return [code: Status code (200 Successful implementation 、400 Perform abnormal ) | data: data ] */
function curl_request($api_url, $post_data = [], $header = [], $referer_url = ''){
        
    $ch = curl_init();// initialization CURL Handle 
    curl_setopt( $ch, CURLOPT_URL, $api_url);

    /** Configuration return information **/
    curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1);// The information is returned as a file stream , No direct output 
    curl_setopt( $ch, CURLOPT_HEADER, 0);// No return header part 

    /** Configuration timeout **/
    curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, 10);// Wait time before connecting ,0 Don't wait for 
    curl_setopt( $ch, CURLOPT_TIMEOUT, 5);// Wait time after connection ,0 Don't wait for . Such as download mp3

    /** Configure page redirection **/
    curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1);// Track crawl redirect page 
    curl_setopt( $ch, CURLOPT_MAXREDIRS, 10);// Specify the most HTTP Number of redirections 
    curl_setopt( $ch, CURLOPT_AUTOREFERER, 1); //  Automatic setting Referer

    /** To configure Header、 Request header 、 Agreement information **/
    curl_setopt( $ch, CURLOPT_HTTPHEADER, $header);
    curl_setopt( $ch, CURLOPT_ENCODING, "");//Accept-Encoding code , Support "identity"/"deflate"/"gzip", Null supports all codes 
    curl_setopt( $ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)" );// Simulate browser header information 
    $referer_url && curl_setopt( $ch, CURLOPT_REFERER, $referer_url);// Forge the source address 
    //curl_setopt( $ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1 ); // Set up curl The use of HTTP agreement 

    /** To configure POST request **/
    if($post_data && is_array($post_data)){
    
        curl_setopt( $ch, CURLOPT_POST, 1 );// Support post Submit data 
        curl_setopt( $ch, CURLOPT_POSTFIELDS, http_build_query($post_data));//
    }    

    /** Prohibit certificate validation to prevent curl Output blank **/
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);// prohibit  cURL  Verify peer certificate 
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);// Check whether the domain name of the server is consistent with that on the certificate 

    $code = 200; // Successful implementation 
    $data = curl_exec( $ch );
    // Abnormal capture 
    if (curl_errno($ch)) {
    
        $code = 400; // Perform abnormal 
        $data = curl_error($ch);
    }
    curl_close( $ch );    

    return ['code' => $code, 'data' => $data];
}