NAME¶

curl_ws_send - send WebSocket data

SYNOPSIS¶

#include <curl/easy.h>
CURLcode curl_ws_send(CURL *curl, const void *buffer, size_t buflen,


                      size_t *sent, curl_off_t fragsize,


                      unsigned int flags);

DESCRIPTION¶

This function call is EXPERIMENTAL.

Send the specific message fragment over an established WebSocket connection. The buffer holds the data to send and it is buflen number of payload bytes in that memory area.

sent is returned as the number of payload bytes actually sent.

To send a (huge) fragment using multiple calls with partial content per invoke, set the CURLWS_OFFSET bit and the fragsize argument as the total expected size for the first part, then set the CURLWS_OFFSET with a zero fragsize for the following parts.

If not sending a partial fragment or if this is raw mode, fragsize should be set to zero.

If CURLWS_RAW_MODE is enabled in CURLOPT_WS_OPTIONS(3), the flags argument should be set to 0.

FLAGS¶

CURLWS_TEXT

The buffer contains text data. Note that this makes a difference to WebSocket but libcurl itself will not make any verification of the content or precautions that you actually send valid UTF-8 content.

CURLWS_BINARY

This is binary data.

CURLWS_CONT

This is not the final fragment of the message, which implies that there will be another fragment coming as part of the same message where this bit is not set.

CURLWS_CLOSE

Close this transfer.

CURLWS_PING

This is a ping.

CURLWS_PONG

This is a pong.

CURLWS_OFFSET

The provided data is only a partial fragment and there will be more in a following call to curl_ws_send(). When sending only a piece of the fragment like this, the fragsize must be provided with the total expected fragment size in the first call and it needs to be zero in subsequent calls.

EXAMPLE¶

AVAILABILITY¶

Added in 7.86.0.

RETURN VALUE¶

SEE ALSO¶

curl_easy_setopt(3), curl_easy_perform(3), curl_easy_getinfo(3), curl_ws_recv(3)