CURLOPT_SUPPRESS_CONNECT_HEADERS(3)                   Library Functions Manual

NAME
       CURLOPT_SUPPRESS_CONNECT_HEADERS - suppress proxy CONNECT response
       headers

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SUPPRESS_CONNECT_HEADERS, long onoff);

DESCRIPTION
       When CURLOPT_HTTPPROXYTUNNEL(3) is used and a CONNECT request is made,
       suppress proxy CONNECT response headers from the user callback
       functions CURLOPT_HEADERFUNCTION(3) and CURLOPT_WRITEFUNCTION(3).

       Proxy CONNECT response headers can complicate header processing since
       it is essentially a separate set of headers. You can enable this option
       to suppress those headers.

       For example let's assume an HTTPS URL is to be retrieved via CONNECT.
       On success there would normally be two sets of headers, and each header
       line sent to the header function and/or the write function. The data
       given to the callbacks would look like this:

       HTTP/1.1 200 Connection established
       {headers}
       ...

       HTTP/1.1 200 OK
       Content-Type: application/json
       {headers}
       ...

       {body}
       ...

       However by enabling this option the CONNECT response headers are
       suppressed, so the data given to the callbacks would look like this:

       HTTP/1.1 200 OK
       Content-Type: application/json
       {headers}
       ...

       {body}
       ...

DEFAULT
       0

PROTOCOLS
       All

EXAMPLE
       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

           curl_easy_setopt(curl, CURLOPT_HEADER, 1L);
           curl_easy_setopt(curl, CURLOPT_PROXY, "http://foo:3128");
           curl_easy_setopt(curl, CURLOPT_HTTPPROXYTUNNEL, 1L);
           curl_easy_setopt(curl, CURLOPT_SUPPRESS_CONNECT_HEADERS, 1L);

           curl_easy_perform(curl);

           /* always cleanup */
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY
       Added in 7.54.0

RETURN VALUE
       CURLE_OK or an error such as CURLE_UNKNOWN_OPTION.

SEE ALSO
       CURLOPT_HEADER(3), CURLOPT_HTTPPROXYTUNNEL(3), CURLOPT_PROXY(3)

libcurl                          April 26 2024
                                           CURLOPT_SUPPRESS_CONNECT_HEADERS(3)