civetweb/docs/api/mg_websocket_client_write.md

Civetweb API Reference

mg_websocket_client_write( conn, opcode, data, data_len );

Parameters

Parameter	Type	Description
conn	struct mg_connection *	Connection on which to send data
opcode	int	Opcode
data const	char *	The data to be written
data_len	size_t	Length of the data buffer

Return Value

Type	Description
int	Number of bytes written or an error code

Description

The function mg_websocket_client_write() sends data to a websocket server wrapped in a masked websocket frame. The function issues calls to mg_lock_connection() and mg_unlock_connection() to ensure that the transmission is not interrupted. Interruption can happen the the application is proactively communicating and responding to a request simultaneously. This function is available only, if Civetweb is compiled with the option -DUSE_WEBSOCKET.

The return value is the number of bytes written on success, 0 when the connection has been closed and -1 if an error occurred.

See Also

• mg_lock_connection();
• mg_printf();
• mg_unlock_connection();
• mg_websocket_write();
• mg_write();