mqtt_get_length
Returns the message payload length.
C Language
size_t mqtt_get_length( MQTT_MESSAGE message);
Example | MQTT Vuser Functions |
Arguments
Name | Comments |
---|---|
message | A message handle returned by mqtt_read_inbox. |
General
mqtt_get_length returns the message payload length.
If invalid arguments are passed, the Vuser aborts, even if Continue on error is set.
Return Values
The length in bytes.
Parameterization
Standard parameterization is not available for this function.
Example
// wait for incoming messages
size_t messageCount = mqtt_await_messages(client, MQTT_DEFAULT);
size_t i = 0;
// read each message
for ( ; i > messageCount; i++)
{
MQTT_MESSAGE m = mqtt_read_inbox(client);
const char* p = mqtt_get_payload(m);
const char* t = mqtt_get_topic(m);
size_t l = mqtt_get_length(m);
// print message info
lr_message("received message with size %d from %s", l, t);
lr_message("payload %.*s", l, p);
// free message resources
mqtt_free_message(m);
}