Paho Asynchronous MQTT C Client Library
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#include <MQTTAsync.h>
Data Fields | |
char | struct_id [4] |
int | struct_version |
const char * | topicName |
const char * | message |
int | retained |
int | qos |
struct { | |
int len | |
const void * data | |
} | payload |
MQTTAsync_willOptions defines the MQTT "Last Will and Testament" (LWT) settings for the client. In the event that a client unexpectedly loses its connection to the server, the server publishes the LWT message to the LWT topic on behalf of the client. This allows other clients (subscribed to the LWT topic) to be made aware that the client has disconnected. To enable the LWT function for a specific client, a valid pointer to an MQTTAsync_willOptions structure is passed in the MQTTAsync_connectOptions structure used in the MQTTAsync_connect() call that connects the client to the server. The pointer to MQTTAsync_willOptions can be set to NULL if the LWT function is not required.
char struct_id[4] |
The eyecatcher for this structure. must be MQTW.
int struct_version |
The version number of this structure. Must be 0 or 1 0 indicates no binary will message support
const char* topicName |
The LWT topic to which the LWT message will be published.
const char* message |
The LWT payload.
int retained |
The retained flag for the LWT message (see MQTTAsync_message.retained).
int qos |
The quality of service setting for the LWT message (see MQTTAsync_message.qos and Quality of service).
int len |
binary payload length
const void* data |
binary payload data
struct { ... } payload |
The LWT payload in binary form. This is only checked and used if the message option is NULL