CURLOPT_WS_OPTIONS(3) Introduction to Library Functions

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(3) and
curl_ws_recv(3) functions after the HTTP upgrade procedure, set the
CURLOPT_CONNECT_ONLY(3) option to 2L.

Available bits in the bitmask

CURLWS_RAW_MODE (1)
Deliver "raw" WebSocket traffic to the
CURLOPT_WRITEFUNCTION(3) callback. Read "raw" WebSocket
traffic from the CURLOPT_READFUNCTION(3) 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(3). This feature is
added with version 8.14.0.

DEFAULT

0

PROTOCOLS

This functionality affects ws only

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode result;
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);
result = 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(3).

AVAILABILITY

Added in curl 7.86.0

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).

SEE ALSO

CURLOPT_CONNECT_ONLY(3), curl_ws_recv(3), curl_ws_send(3)

libcurl 2026-01-08 CURLOPT_WS_OPTIONS(3)