Vehicle_Road_Counter/external/paho.mqtt.c/docs/MQTTClient/man/man3/pubsync.3

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.TH "pubsync" 3 "Sat Aug 16 2025 14:15:23" "Paho MQTT C Client Library" \" -*- nroff -*-
.ad l
.nh
.SH NAME
pubsync \- Synchronous publication example
.PP
.PP
.nf
#include <stdio\&.h>
#include <stdlib\&.h>
#include <string\&.h>
#include "MQTTClient\&.h"
#define ADDRESS "tcp://test\&.mosquitto\&.org:1883"
#define CLIENTID "ExampleClientPub"
#define TOPIC "MQTT Examples"
#define PAYLOAD "Hello World!"
#define QOS 1
#define TIMEOUT 10000L
int main(int argc, char* argv[])
{
MQTTClient client;
MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
MQTTClient_message pubmsg = MQTTClient_message_initializer;
MQTTClient_deliveryToken token;
int rc;
if ((rc = MQTTClient_create(&client, ADDRESS, CLIENTID,
MQTTCLIENT_PERSISTENCE_NONE, NULL)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to create client, return code %d\\n", rc);
exit(EXIT_FAILURE);
}
conn_opts\&.keepAliveInterval = 20;
conn_opts\&.cleansession = 1;
if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to connect, return code %d\\n", rc);
exit(EXIT_FAILURE);
}
pubmsg\&.payload = PAYLOAD;
pubmsg\&.payloadlen = (int)strlen(PAYLOAD);
pubmsg\&.qos = QOS;
pubmsg\&.retained = 0;
if ((rc = MQTTClient_publishMessage(client, TOPIC, &pubmsg, &token)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to publish message, return code %d\\n", rc);
exit(EXIT_FAILURE);
}
printf("Waiting for up to %d seconds for publication of %s\\n"
"on topic %s for client with ClientID: %s\\n",
(int)(TIMEOUT/1000), PAYLOAD, TOPIC, CLIENTID);
rc = MQTTClient_waitForCompletion(client, token, TIMEOUT);
printf("Message with delivery token %d delivered\\n", token);
if ((rc = MQTTClient_disconnect(client, 10000)) != MQTTCLIENT_SUCCESS)
printf("Failed to disconnect, return code %d\\n", rc);
MQTTClient_destroy(&client);
return rc;
}
.fi
.PP