curl / libcurl / API / curl_easy_setopt / CURLOPT_WS_OPTIONS

CURLOPT_WS_OPTIONS explained

Name

CURLOPT_WS_OPTIONS - WebSocket behavior options

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_WS_OPTIONS, long bitmask);

Description

Pass a long with a bitmask to tell libcurl about specific WebSocket behaviors.

To detach a WebSocket connection and use the curl_ws_send and curl_ws_recv functions after the HTTP upgrade procedure, set the CURLOPT_CONNECT_ONLY option to 2L.

Available bits in the bitmask

CURLWS_RAW_MODE (1)

Deliver "raw" WebSocket traffic to the CURLOPT_WRITEFUNCTION callback. Read "raw" WebSocket traffic from the CURLOPT_READFUNCTION callback.

In raw mode, libcurl does not handle pings or any other frame for the application.

CURLWS_NOAUTOPONG (2)

Disable the automatic reply to PING messages. This means users must send a PONG message with curl_ws_send. This feature is added with version 8.14.0.

Default

Protocols

This functionality affects ws only

Example

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "ws://example.com/");
    /* tell curl we deal with all the WebSocket magic ourselves */
    curl_easy_setopt(curl, CURLOPT_WS_OPTIONS, CURLWS_RAW_MODE);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

History

CURLWS_RAW_MODE and CURLWS_NOAUTOPONG macros became long types in 8.16.0, prior to this version a long cast was necessary when passed to curl_easy_setopt.

Availability

Added in curl 7.86.0

Return value

curl_easy_setopt returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors.